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Ballistic Injuries In The
Emergency Department
Abstract
According to 2007 data, gunshot wounds from homicides, suicides, and accidents caused 31,000 deaths in the United States,
with even higher numbers of serious, nonfatal injuries. In recent
years, new evidence on effective treatment of patients with gunshot wounds has come from military settings and is being adapted
for civilian emergency departments (EDs). Effective, evidencebased management of ballistic injuries in the ED is vital. This
issue reviews the physics of ballistics as it relates to the tracts and
patterns of tissue injury caused by different types of firearms and
missiles, and it takes a regional approach to reviewing the current
evidence for managing gunshot wounds to the head, neck, thorax,
abdomen, genitourinary (GU) system, extremities, and soft tissues.
Current guidelines as well as new research and evidence regarding fluid resuscitation, airway management, evaluation strategies,
drug therapies, and documentation are discussed.
Case Presentations
A 25-year-old man presents to the ED via ambulance after sustaining a
single gunshot wound to the upper abdomen. There is no apparent exit
wound. He is awake, in obvious pain and distress, with labored spontaneEditor-in-Chief
School of Medicine, Boston, MA
Charles V. Pollack, Jr., MA, MD,
FACEP
Andy Jagoda, MD, FACEP
Steven A. Godwin, MD, FACEP
Chairman, Department of Emergency
Professor and Chair, Department of
Associate Professor, Associate Chair
Medicine, Pennsylvania Hospital,
Emergency Medicine, Mount Sinai
and Chief of Service, Department
University of Pennsylvania Health
School of Medicine; Medical Director,
of Emergency Medicine, Assistant
System, Philadelphia, PA
Mount Sinai Hospital, New York, NY
Dean, Simulation Education,
University of Florida COMMichael S. Radeos, MD, MPH
Editorial Board
Jacksonville, Jacksonville, FL
Assistant Professor of Emergency
William J. Brady, MD
Medicine, Weill Medical College
Gregory L. Henry, MD, FACEP
Professor of Emergency Medicine,
of Cornell University, New York;
CEO, Medical Practice Risk
Chair, Resuscitation Committee,
Research Director, Department of
Assessment, Inc.; Clinical Professor
University of Virginia Health System,
Emergency Medicine, New York
of Emergency Medicine, University of
Charlottesville, VA
Hospital Queens, Flushing, New York
Michigan, Ann Arbor, MI
Peter DeBlieux, MD Robert L. Rogers, MD, FACEP,
John M. Howell, MD, FACEP
Louisiana State University Health
FAAEM, FACP
Science Center Professor of Clinical Clinical Professor of Emergency
Assistant Professor of Emergency
Medicine, George Washington
Medicine, LSUHSC Interim Public
Medicine, The University of
University, Washington, DC; Director
Hospital Director of Emergency
Maryland School of Medicine,
of Academic Affairs, Best Practices,
Medicine Services, LSUHSC
Baltimore, MD
Inc, Inova Fairfax Hospital, Falls
Emergency Medicine Director of
Church, VA
Alfred Sacchetti, MD, FACEP
Faculty and Resident Development
Assistant Clinical Professor,
Shkelzen Hoxhaj, MD, MPH, MBA
Francis M. Fesmire, MD, FACEP
Department of Emergency Medicine,
Chief of Emergency Medicine, Baylor
Director, Heart-Stroke Center,
Thomas Jefferson University,
College of Medicine, Houston, TX
Erlanger Medical Center; Assistant
Philadelphia, PA
Professor, UT College of Medicine,
Eric Legome, MD
Scott Silvers, MD, FACEP
Chattanooga, TN
Chief of Emergency Medicine, King’s
Chair, Department of Emergency
County Hospital; Associate Professor
Nicholas Genes, MD, PhD
Medicine, Mayo Clinic, Jacksonville, FL
(Visiting),
SUNY
Downstate
College
of
Assistant Professor, Department of
Medicine, Brooklyn, NY
Corey M. Slovis, MD, FACP, FACEP
Emergency Medicine, Mount Sinai
Professor and Chair, Department
School of Medicine, New York, NY
Keith A. Marill, MD
of Emergency Medicine, Vanderbilt
Assistant Professor, Department of
Michael A. Gibbs, MD, FACEP
University Medical Center; Medical
Emergency Medicine, Massachusetts
Professor and Chief, Department of
Director, Nashville Fire Department and
General Hospital, Harvard Medical
Emergency Medicine, Maine Medical
International Airport, Nashville, TN
School, Boston, MA
Center, Portland, ME; Tufts University
December 2011
Volume 13, Number 12
Authors
David Bruner, MD, FAAEM
Assistant Program Director, Emergency Medicine
Department, Naval Medical Research Center, Portsmouth, VA
Corey G. Gustafson, DO
Staff Emergency Physician, Naval Hospital Camp Pendleton,
Camp Pendleton, CA
Catherine Visintainer, MD, FACEP
Academic Faculty, Naval Medical Center Portsmouth,
Portsmouth, VA
Peer Reviewers
Keith A. Marill, MD
Assistant Professor, Department of Emergency Medicine,
Massachusetts General Hospital, Harvard Medical School,
Boston, MA
Matthew J. Walsh, MD
Associate Professor, Department of Emergency Medicine,
University of New Mexico, Albuquerque, NM
CME Objectives
Upon completion of this article, you should be able to:
1.
2.
3.
4.
Understand the physics of ballistic weapons and their
projectiles.
Understand the difference between high-velocity, lowvelocity, and shotgun weapons.
Perform a thorough history and physical examination of
a patient with a gunshot wound.
Recognize life- and limb-threatening injuries that require
immediate intervention and provide stabilizing treatment
in the ED.
Prior to beginning this activity, see “Physician CME
Information” on page 32.
Stephen H. Thomas, MD, MPH
George Kaiser Family Foundation
Professor & Chair, Department of
Emergency Medicine, University of
Oklahoma School of Community
Medicine, Tulsa, OK
Jenny Walker, MD, MPH, MSW
Assistant Professor, Departments of
Preventive Medicine, Pediatrics, and
Medicine Course Director, Mount
Sinai Medical Center, New York, NY
Monash University, Melbourne,
Australia
Giorgio Carbone, MD
Chief, Department of Emergency
Medicine Ospedale Gradenigo,
Torino, Italy
Amin Antoine Kazzi, MD, FAAEM
Associate Professor and Vice Chair,
Department of Emergency Medicine,
University of California, Irvine;
American University, Beirut, Lebanon
Ron M. Walls, MD
Professor and Chair, Department of Hugo Peralta, MD
Chair of Emergency Services,
Emergency Medicine, Brigham and
Hospital Italiano, Buenos Aires,
Women’s Hospital, Harvard Medical
Argentina
School, Boston, MA
Dhanadol Rojanasarntikul, MD
Scott Weingart, MD, FACEP
Associate Professor of Emergency Attending Physician, Emergency
Medicine, King Chulalongkorn
Medicine, Mount Sinai School of
Memorial Hospital, Thai Red Cross,
Medicine; Director of Emergency
Thailand; Faculty of Medicine,
Critical Care, Elmhurst Hospital
Chulalongkorn University, Thailand
Center, New York, NY
Senior Research Editor
Joseph D. Toscano, MD
Emergency Physician, Department
of Emergency Medicine, San Ramon
Regional Medical Center, San
Ramon, CA
International Editors
Peter Cameron, MD
Academic Director, The Alfred
Emergency and Trauma Centre,
Maarten Simons, MD, PhD
Emergency Medicine Residency
Director, OLVG Hospital, Amsterdam,
The Netherlands
Research Editor
Matt Friedman, MD
Emergency Medicine Residency,
Mount Sinai School of Medicine,
New York, NY
Accreditation: EB Medicine is accredited by the ACCME to provide continuing medical education for physicians. Faculty Disclosure: Dr. Bruner, Dr. Gustafson, Dr. Visintainer, Dr.
Marill, Dr. Walsh, Dr. Jagoda and their related parties report no significant financial interest or other relationship with the manufacturer(s) of any commercial product(s) discussed in this
educational presentation. Commercial Support: This issue of Emergency Medicine Practice did not receive any commercial support.
ous breathing. He was reportedly shot with a handgun
at close range, and there was significant blood loss at the
scene. He has decreased breath sounds on the left side and
a mildly tender abdomen with a small wound over the
left anterior lower chest. A FAST examination shows no
free fluid in the abdomen and no pericardial effusion. A
left-sided chest tube is placed, with 200 mL of blood out
immediately, and subsequent chest x-ray shows a right
hemothorax with a bullet lodged in the left lower lobe.
You contact the trauma surgeon, who asks if you think the
bullet traversed the diaphragm and if additional tests are
needed before he arrives for surgery.
An 18-year-old man presents after being accidentally
shot in the left leg with a shotgun while hunting with his
family. He has multiple small- and medium-size wounds
Table Of Contents
Abstract........................................................................ 1
Case Presentations..................................................... 1
Introduction................................................................ 2
Critical Appraisal Of The Literature....................... 3
Weapons, Ammunition, And Basic Terminology..... 3
Prehospital Care......................................................... 6
Emergency Department Evaluation........................ 6
Management Of Gunshot Wounds To The Head..... 8
Clinical Pathway For Gunshot Wounds
To The Head......................................................... 9
Management Of Gunshot Wounds
To The Neck.........................................................11
Clinical Pathway For Gunshot Wounds
To The Neck........................................................ 12
Management Of Thoracic Gunshot Wounds....... 13
Clinical Pathway For Gunshot Wounds
To The Thorax..................................................... 15
Management Of Abdominal Gunshot Wounds.......16
Clinical Pathway For Gunshot Wounds
To The Abdomen................................................ 18
Management Of Genitourinary
Gunshot Wounds............................................... 19
Management Of Gunshot Wounds To
The Extremities.................................................. 20
Clinical Pathway For Gunshot Wounds
To The Extremities............................................. 21
Risk Management Pitfalls For
Gunshot Wounds............................................... 22
Management Of Soft Tissue Injuries..................... 24
Documentation Of Gunshot Wounds................... 24
Controversies And Cutting Edge........................... 25
Summary................................................................... 26
Case Conclusions..................................................... 26
References.................................................................. 27
CME Questions......................................................... 31
Available Online At No Charge To Subscribers
in his left thigh and lower leg. He is in excruciating pain,
but he has good distal pulses, has an intact neurologic
examination of that extremity, and is otherwise hemodynamically stable. An x-ray shows multiple metal fragments within the leg and midshaft fractures of the tibia
and fibula. As you treat his pain and address the wounds,
you wonder about the need for further vascular studies.
A 38-year-old man who was shot in the head is
brought in by EMS with a laryngotracheal airway in
place. He has a GCS score of 5 on arrival. His vital signs
are normal except for a pulse of 115 beat per minute; his
oxygen saturation is 94% via the airway. There appears
to be only 1 wound and no other injuries elsewhere on his
body. Before you send him to the CT scanner, you prepare
to establish a definitive airway, but you wonder about
the right drugs and ventilator strategy to help control his
intracranial pressure.
Introduction
Ballistics is the scientific study of the characteristics
of projectiles (bullets or missiles), how they move
in flight, and how they impart damage to tissue.
Emergency clinicians play a critical role in the management of ballistic injuries. According to Centers
for Disease Control and Prevention statistics, in 2007
there were over 31,000 firearms-related deaths in the
United States, of which 40.5% were due to homicide
and over 55% were due to suicides. Firearms-related
injuries are much more common among men than
women, and blacks are more than twice as likely to
die from gun-related violence than whites.1
There has been much debate over the differences
in the method of management for wounds from lowand high-velocity weapons. Based on the available
literature, the traditional teachings may be flawed.
Understanding of terminal ballistics (a projectile’s
action on tissue) has been revolutionized in the last
40 years due to high-speed photography and the
development of ballistic gelatin.2 High-speed photography allows scientists to evaluate an object with
great clarity, frame by frame, as it strikes another
object. Ballistic gelatin was developed in the 1940s,
and has subsequently undergone studies validating
its use as a tissue surrogate.3,4 Nonetheless, ballistic
gelatin does not account for the effects of skin or the
varying densities of different tissues within a given
anatomic location (bone, vessels, etc), and it has
been found to overestimate the size of the temporary
cavity.5,6 The goal of this issue of Emergency Medicine
Practice is to discuss the physics of ballistic injuries
with respect to the differences between low-velocity
weapons and high-velocity weapons and to discuss
the emergency department (ED) management of
gunshot wounds to various areas of the body.
EM Practice Guidelines Update: “MRSA In The ED:
IDSA Guideline” www.ebmedicine.net/MRSA
Emergency Medicine Practice © 20112
www.ebmedicine.net • December 2011
Shotguns are similar to rifles in their basic appearance, but differ significantly in their engineering. Shotgun projectiles generate less pressure in the
breech, but their barrels are thin-walled and usually
contain no rifling because their ammunition is made
up of numerous spherical projectiles that are propelled simultaneously.
Ammunition is a term for complete cartridges
containing the projectile of a firearm, commonly
referred to as a bullet. For rifles and handguns,
ammunition is more accurately called a cartridge
or round, which includes the casing, primer, and
propellant (gunpowder), as well as the bullet.9 The
bullet is the actual projectile and is typically composed primarily of lead with a rounded or pointed
tip, in various sizes, or calibers. The caliber denotes
the width of the bullet itself in proportion of an inch
or millimeter. Bullets come in a variety of designs
that affect their energy transference, such as pointed
tips, and round tips, hollow points, as well as full
metal jackets (FMJ), partial metal jackets, and scored
or “expanding” bullets.
A useful distinction among bullets subdivides
them into 2 types: expanding bullets and nonexpanding solid bullets. Expanding types are designed
to maximize tissue damage; nonexpanding solid
bullets are designed to have greater penetration.10
The nonexpanding solid bullet has a pointed tip
and is coated with a thin metal covering, or jacket
(usually copper), and is referred to as an FMJ bullet. These are the bullets used by the United States
military forces. There are 3 reasons for the design
of FMJ bullets. First, for a given caliber, solid and
expanding bullets commonly have the same weight.
Military rifles have evolved over the last 150 years
to smaller calibers, with lighter, faster bullets that
have better stability in flight, allowing soldiers to
carry more rounds and be more accurate marksmen.
Second, jacketing limits the lead residue left behind
on the bore of the rifle, which can cause dangerous
mechanical malfunctions. Third, the jacketing allows
the bullet to maintain its shape when it hits a target
rather than expanding and fragmenting. Historically,
this was felt to be more “humane,” by wounding
rather than killing an enemy combatant. In addition,
a wounded combatant requires more resources to
care for than a dead combatant.8
Expanding bullets are designed for hunting
nondangerous animals and for self-defense and thus
to kill or incapacitate at a lower velocity. They are
typically soft-tipped (ie, lead only), which allows for
nearly immediate deformation when hitting tissue
and thus imparting most of their energy with less
penetration of the victim. Expanding rounds vary
greatly in design. They may have metal jacketing in
some form; typically, the jacket covers most of the
bullet except the tip, allowing for a combination of
rapid expansion and increased overall integrity of
Critical Appraisal Of The Literature
A literature search was performed using the following databases: PubMed, Web of Science, Ovid
MEDLINE®, and The Defense Technical Information Center, as well as the Cochrane Database of
Systematic Reviews. Searches were limited to those
published in English. Search terms included, but
were not limited to, the following: ballistics, penetrating injury, gunshot, firearms, emergency, emergency
department, trauma, physics, biophysics, forensics, and
forensic documentation. The search was further refined
by defining the specific area of injury. The search
returned 4200 abstracts, which were reviewed by
the authors for relevance. The bibliographies of the
relevant articles were also reviewed for additional
publications. Various trauma-related guidelines
were identified through www.guidelines.gov. The
American College of Radiology (ACR) Appropriateness Criteria® of imaging modalities used in trauma
were also reviewed.
Prospective randomized trials of treatment for
gunshot wounds are inherently difficult to perform.
Many of the studies with large patient numbers are
observational or retrospective. Much of the trauma
literature is based on case reports and case series.
The Advanced Trauma Life Support® (ATLS®)
protocols were also reviewed. The 8th (and most
recent) revision of ATLS® included extensive literature review as well as expert opinion, and much
of the evidence for recent changes comes from the
emergency medicine literature.7
Weapons, Ammunition, And Basic Terminology
A firearm is a weapon designed to expel a projectile
by the action of highly combustible, gas-generating
gunpowder. This includes rifles, handguns, and
shotguns, which are collectively referred to as small
arms.8 Small arms are relatively simple mechanical
devices that share the same basic anatomy, which
consists of the handling portion (stock), the breech
(the chamber where the bullet is seated and from
which the combustive reaction is triggered), and the
barrel, which acts as the projectile’s guide. The differences between small arms are largely delineated
by the amount of pressure the breech can withstand
and the length of the barrel.
Rifles are shoulder-fired weapons engineered
to withstand the very high pressures (50,000-60,000
psi) generated from combustion of the gunpowder.
They have long barrels (usually > 16 inches) with
a spiraled groove cut into the inner lumen that
imparts a spin on the bullet, enhancing inflight stability and accuracy. Handguns are basically small
rifles with the same engineering features, but with
smaller pressure tolerances (20,000-30,000 psi) and
shorter barrels.9
December 2011 • www.ebmedicine.net
3
Emergency Medicine Practice © 2011
the bullet. The same distinction between solid and
expanding bullets applies to handguns. Handguns
are limited in their velocity and range due to barrel
length and pressure tolerance of the breech, but this
is partly compensated for by an expanding bullet design (such as hollow point). Hollow point tip bullets
have an inward depression at the tip that deforms
instantly upon striking any solid object. The bullet
enlarges up to 3 times its initial diameter, creating a
larger permanent cavity.11
Shotgun ammunition comes in 4 basic categories: birdshot, buckshot, slugs, and sabot rounds.12
Birdshot and buckshot shells contain numerous
spherical projectiles (shot) that are housed within the
shotshell. They are propelled and released simultaneously when fired. The difference between birdshot
and buckshot is the size and metal composition;
birdshot is typically made of smaller, softer lead or
similar metal shot, whereas buckshot shells contain
only a few tightly packed balls of a much larger
diameter, and may be made of lead or steel.
Slugs are composed of a single, large, solid
projectile that may or may not have rifling built
into the lead itself (thus imparting a spiral path in
flight, which increases accuracy). Slugs are used
primarily for hunting large game in populated
areas where a heavy, relatively low-velocity projectile will have limited range. Slugs also are used
by police and military personnel because of their
ample stopping power.9
Weapons and their corresponding projectiles are
generally categorized based on their velocity, ie, lowvelocity (usually shotgun and pistol bullets,
< 2000 f/s) and high-velocity (usually rifle bullets or
explosive fragment missiles > 2000 f/s).13 (See Table
1.) Although conceptually useful, these categories
have some important limits. First, these values are
not universally applied; for instance, the British use
values of 1200 f/s for “high-velocity.” This lack of
agreement has the unfortunate effect of less-rigorous
scientific study. Second, these terms imply the weapons’ wounding capacity. Using this logic, it would be
easy to infer that low-velocity wounds are less severe,
yet they can be devastating wounds. Because of the
frequency of use, low-velocity weapons cause nearly
twice the number of deaths of high-velocity weapons.
Ballistic Physics
Ballistic physics is divided into 3 components:
internal, external, and terminal (wound).9 Of
these, terminal ballistics is the primary concern of
emergency clinicians, but knowledge of the other
components can prove to be a valuable resource for
understanding the injury pattern. Conceptually, the
science of ballistics is relatively simple, but oversimplification can lead to erroneous conclusions
(such as mistakenly thinking bullets are sterile due
to being heated).14,15
Emergency Medicine Practice © 20114
Internal ballistics describes the path of the
projectile from the breech to the muzzle (the end of
the weapon barrel). Technological advances have
revolutionized modern firearms into the devastating
weapons they are today (smokeless powder, rifling,
automated cartridge feeding, high-stress metallurgy). The differing range of pressures generated from
the combustion of gunpowder is what distinguishes
the various weapons.8 Rifles can withstand more
pressure than a handgun, and a handgun can withstand more pressure than a shotgun. Rifling, which
is a helical groove carved into the inner lumen of the
barrel, imparts a spin on the bullet to prevent yawing (the deviation of a projectile’s path). Clinically
speaking, internal ballistics have little relevance to
treating tissue damage other than noting that the
technological advances have led to faster, more
accurate projectiles that can enable the projectile to
impart more energy onto its target.
External ballistics describes the projectile from
the point when it leaves the barrel until it hits its
target (muzzle to target) or the study of the projectile
in flight. While this aspect of ballistics lends itself to
more traditional aspects of physics, it can be divided
into the 2 components that have the most effect on a
projectile - gravity and drag.
The effects of gravity can be visualized by the
trajectory of any object in flight (parabolic curve).
Even though all objects will drop to the ground at the
same rate, faster rounds have a flatter trajectory, making them easier to aim and thus, more accurate. Drag
(the resistance to a traveling object’s passage through
air) affects a projectile’s velocity downrange. Drag
can be limited by making a bullet more aerodynamic,
Table 1. Gun Velocity Categories
Velocity
Effects
Low velocity
• < 2000 f/s (usually handguns)
• Smaller zones of injury
• Wounding potential significant despite “low
velocity”
• Associated fractures often behave similarly to
closed fractures
• Soft tissue/superficial injury often amenable to
ED wound care
High velocity
• > 2000 f/s (rifles)
• Larger zones of injury; cavitation, deeper
penetration
• Ammunition used and distance from target
plays significant role in wounding
• Associated fractures are common, devastating;
consider infected
Shotguns
•
•
•
•
•
< 2000 f/s (low velocity)
Highest kinetic energy transference
Highest rate of compartment syndrome
Highest infectivity rate
Double mortality rate versus rifle, handgun
www.ebmedicine.net • December 2011
with an elongated, narrow, pointed configuration.8,16
For example, birdshot and buckshot are composed of
spherical projectiles and therefore have poor aerodynamic profiles with rapid loss of velocity as well as
dispersion of the shot; hence, much of their energy is
dissipated after about 25-50 yards.17
Terminal (or wound) ballistics is the component
of ballistics that studies the interaction of penetrating projectiles with living tissue and is therefore
an emergency clinician’s primary interest. Ballistic
missile wounding occurs by 2 primary mechanisms,
described by the cavities created by the missile:
the permanent cavity and temporary cavity.3,6
(See Figure 1.) As a missile penetrates the skin, it
crushes and destroys the tissue in its path (creating
a permanent cavity) while simultaneously imparting a shock wave that radiates outward from this
path. This shock wave causes tissue to stretch and
shear outward, followed by subsequent collapse
and reverberation. The size of the permanent cavity
is determined by the caliber of the bullet and its
corresponding fragments. The temporary cavity is
transitory, lasting only milliseconds, and its size is
determined by the velocity of the missile. Higher
velocities create larger temporary cavities, ranging
up to 10-30 times the size of the missile’s permanent
cavity.8,9 There is also a measurable pressure wave
that travels in front of the missile, but it has not
been found to impart any significance towards the
wounding mechanism.10
There are 3 relevant principles in appreciating the extent of the wounding mechanism: energy
transference, zones of injury, and secondary wounding.18 When a bullet strikes skin, the process of energy transference starts. The ability of the missile to
transfer its kinetic energy is the primary determinant
of tissue damage.5,19 (See Table 2.) Although clearly
important, the projectile’s velocity is neither the only
nor the dominant factor in energy transference, as
seen with the effectiveness of low-velocity shotgun
wounds and handguns using hollow-point rounds.
The zones of injury were first described by
Wang and are conceptually linked to the mechanisms of ballistic wounding.20 (See Table 3.) The first
zone is the permanent cavity, which is the primary
wound cavity consisting of dead, crushed tissue.
The second zone is the contusion zone, consisting
of tissue adjacent to and encircling the permanent
cavity. The tissue here is in an inflammatory state. It
is swollen and bathed in a milieu of inflammatory
mediators and cellular debris. The third zone is the
concussion zone, or temporary cavity. Damage here
occurs by stretching, shearing, or compression and is
dependent on the cavity in which the missile travels and the tissue contents. Inelastic tissues such as
bone, liver, and brain are highly susceptible to injury
because they have little intrinsic ability to dissipate
the energy transferred even if they are remote to the
primary injury path.21
Secondary wounding is caused by missiles as
well as wound infections. Secondary missile wounding occurs when the projectile strikes and breaks an
object and accelerates some portion of that object
through adjacent tissue. Examples of secondary
missiles are bone fragments or objects such as clothing or buttons. Secondary missiles tend to move at
much slower velocities, but can be equally destructive if they damage vital adjacent tissues (such as
an artery). Contrary to popular belief, missiles are
not sterile due to the heat they retain.15 As a bullet
Table 2. Variables Of Missile Energy
Transference
•
•
•
•
•
Figure 1. Mechanism Of Ballistic Missile
Wounding
•
Temporary cavity
Table 3. Zones Of Injury Of Ballistic
Wounding20
Projectile
Permanent cavity
©2010 Lichte et al; licensee BioMed Central Ltd. Used with permission
under Creative Commons Attribution License 2.0.
December 2011 • www.ebmedicine.net
Projectile velocity
Entrance profile
Caliber
Projectile design
Distance traveled within the body and anatomic structures
impacted
Tissue elasticity
5
Zone of Injury
Description
Primary wound tract
Permanent cavity; dead, crushed tissue
Contusion zone
Tissue adjacent to primary wound tract; in
inflammatory state with cellular debris
Concussion zone
Temporary cavity; tissue damage occurs
by stretching, shearing, and compression. Inelastic tissues (liver, bone, brain)
are most susceptible due to little intrinsic
ability to dissipate transferred energy
even if remote to the path of injury
Emergency Medicine Practice © 2011
travels through tissue, a vacuum is created when the
permanent and temporary cavities are formed. This
vacuum pulls in potential infective sources such as
clothing, dirt, and skin flora. Other potential inoculum include components of the cartridge or shotshell
and devitalized bone fragments.22
Prehospital Care
Prehospital management of gunshot wounds varies somewhat based on the location of the injury, but
almost all ballistic injury patients require immediate
transport to a trauma center. Two large retrospective
Canadian studies have suggested that direct transport to a Level I trauma center instead of a closer,
non-trauma center results in better outcomes.23,24
Emergency medical services (EMS) providers should
follow common ATLS® prehospital guidelines to
control the airway, provide oxygen as needed, and
control bleeding with direct pressure as well as obtain
vital signs and intravenous (IV) access as soon as possible. Although EMS protocols will vary from region
to region and each crew has varying capabilities, the
EMS crew should perform lifesaving procedures as
indicated but should primarily do their best to minimize transport time to the nearest trauma center.
Many patients with penetrating brain injury will
have a depressed mental status and difficulty maintaining an open airway. The EMS providers may be
authorized to provide advanced airway care in these
patients, but recent literature suggests that out-ofhospital intubation in traumatic brain injury (TBI)
may be associated with worse outcomes.25 Transport
times and the proficiency of EMS with intubation
will play a role in the decision to establish a prehospital airway. The wide array of supraglottic devices
available offer easy-to-use and viable alternatives to
prehospital intubation.
Because gunshot wounds to the chest can be
immediately life-threatening, EMS providers must
be able to rapidly treat and transport these patients
to the nearest center capable of managing thoracic
ballistic trauma with minimal on-scene time. Emergent life-saving interventions such as intubation and
needle decompression should be the only procedures performed that may delay transport.26
Abdominal gunshot wound patients should be
evaluated for hemodynamic stability, as they are at
risk for life-threatening bleeding and many other injuries. If there is concern for a pelvic bleeding injury,
pelvic compression may provide some prehospital
stabilization of bleeding, but this should not delay
prompt transportation.
Extremity gunshot wounds should be assessed
for arterial bleeding and ischemia, specifically. If
bleeding is found, attempt hemostasis by either
direct pressure or use of a tourniquet. Prehospital
tourniquet use had been discouraged for some time
Emergency Medicine Practice © 20116
because the prevailing logic was that the constriction
applied to control bleeding also led to occlusion of
collateral flow, thereby worsening distal ischemia.
However, recent evidence stemming from the conflicts in Afghanistan and Iraq supports the contrary:
tourniquet use may prevent exsanguination and
promote hemodynamic stabilization. A recent study
by Kragh et al found that prehospital tourniquet use,
when shock was not present, was strongly associated with survival compared to patients who did not
receive them.27
Emergency Department Evaluation
History
If the patient’s overall status permits, certain historical information may help the clinician in management. If the patient is unable to provide any historical information, EMS personnel or friends/family
present may be able to assist with providing information. Per ATLS® protocol, an “AMPLE” history
should be taken at a minimum (see Table 4) along
with the following questions.28
• What type of weapon was used? Handguns are
low-velocity weapons and typically involve less
kinetic energy transfer than high-velocity rifles
or the variable force and pattern of shotgun
injuries. If the patient or witness can tell you
the type of gun used, it may help you anticipate
unseen injuries.
• How far away were you from the weapon at the
time it was fired and at what angle were you
when it hit? This may help to anticipate the missile’s trajectory and possible pathway through the
body in order to determine which skin wound
is the likely entrance wound and to anticipate
potential injury patterns and locations.
• How many shots did you hear? There may
only be 2 visible surface injuries, which can
lead you to assume entry and exit wounds,
but if there were 2 shots fired, possibly neither
bullet found an exit track and both are still
inside the patient. This will also prompt you to
continue to look for more missile wounds that
may not initially be visible.
Curiosity will often lead the emergency clinician to ask about the circumstances of the ballistic
injury, but these details are rarely helpful except to
determine whether the wound was self-inflicted,
which will require later psychiatric evaluation
after the traumatic injuries are addressed and
the patient is stabilized. For more information on
assessing depressed and suicidal patients in the
ED, see the September 2011 issue of Emergency
Medicine Practice, “The Depressed Patient And
Suicidal Patient In The Emergency Department:
Evidence-Based Management And Treatment
www.ebmedicine.net • December 2011
Strategies.” Tetanus status should be obtained, and
prophylaxis is indicated for most gunshot wounds.
The patient presenting to the ED with penetrating injury to the neck from a gunshot wound can
have a variety of presentations. Airway involvement
may be indicated by dyspnea, crepitus, air bubbling
from a wound, dysphonia, or hemoptysis. Great
vessel involvement may be obvious, presenting
with “hard” signs of vascular injury such as active
hemorrhage, expanding hematoma, pulse deficit, or
a bruit or thrill. (See Table 5.) However, great vessel
involvement may be more insidious, presenting only
with “soft” signs of vascular injury such as a nonpulsatile hematoma, nervous system ischemia, or
proximity to a major vessel. Esophageal injury may
be asymptomatic initially but may also present with
dysphagia, hematemesis, drooling, or odynophagia.
Emergency clinicians often refer to the areas of
the body at risk for cardiac and mediastinal injuries
as “the box,” which is the area bounded superiorly by the clavicles and sternal notch, inferiorly
by the costal margins, and laterally by the nipple
line. However, injuries outside of the box, such as
posterior and lateral chest wounds, can traverse the
mediastinum as well.27 While a thorough physical
examination is always necessary, in many of these
cases, diagnostic tests are required to delineate the
extent of injuries.
Rapid reversal of hypoxia is often necessary,
with supplemental oxygen and airway control if
the patient is unable to protect his own airway or
respiratory distress is present. Immediately perform
an evaluation of the lungs to ascertain shortness of
breath, pleuritic chest pain, and decreased breath
sounds concerning for pneumothorax or hemothorax.
Obvious deformities of the chest wall, asymmetric
chest rise, and tracheal deviation can be initial signs
of a significant pneumothorax. Many of these findings on physical examination warrant placement of a
large (36 French) thoracostomy tube before proceeding with further management or while other members of the trauma team continue their evaluation.28
Listen for muffled heart sounds and assess for
jugular venous distension as indicators of a traumatic cardiac tamponade. Hypotension is an ominous
sign for hemorrhagic shock and ongoing internal
bleeding from cardiac or great vessel injuries. Diminished distal pulses can also be an indicator of
vascular or cardiac injury.
Physical Examination
Assessment of patients with ballistic trauma should
proceed according to the ATLS® protocol, with
stabilization of the airway and rapid attention
to immediately life-threatening injuries. Often,
history, examination, and treatment must occur
simultaneously. Certain initial impressions such as
agitation or combativeness, hypoxia or respiratory
distress, diaphoresis, and an unwillingness to lie
flat may suggest pending hemodynamic collapse.28
Full exposure of the patient – including the back
– is necessary to evaluate the number of wounds
present. Vital sign abnormalities (hypoxia, tachycardia, hypotension) suggest a serious underlying
injury. Initially, normal signs can be insensitive as
an indicator of significant injury and need to be
continually reassessed for deterioration.
The primary survey is performed immediately
upon arrival, with an orderly evaluation of immediately life-threatening injuries, starting with the
airway and progressing to assessment of breathing
and circulation. Often, a team approach is utilized
for the sake of efficiency. After addressing the ABCs,
further evaluation of neurologic disability and
complete exposure of the patient take precedence
before proceeding to the secondary survey. At any
point, note the life- or limb-threatening injuries and
address treatment of those specific injuries.28
Many vital structures are at particular risk from
ballistic trauma, including the lungs, heart, great
vessels, esophagus, and tracheobronchial tree; failure to address these immediately can lead to death.
The location of the external wounds may suggest a
track for the projectile, but physical examination is
generally inadequate to determine the direction and
extent of the penetrating projectiles due to the cavitation effects of the projectile through body tissues.
A small external wound may belie massive internal
injuries that are not immediately evident on history
and physical examination. Penetrating projectiles
are frequently known to ricochet on bony structures,
thus altering the trajectory of the permanent cavity
produced. High-velocity ballistic missiles create a
large temporary cavity that can lead to significant
tissue damage.
Table 5. Hard And Soft Signs Of Penetrating
Gunshot Injury
Table 4. “AMPLE” History
A – Allergies
M – Medications
P - Past medical history
L – Last meal (what time)
E – Events surrounding the time of injury
December 2011 • www.ebmedicine.net
7
Hard signs
•
•
•
•
Soft signs
• Nonpulsatile hematoma
• Nervous system ischemia
• Proximity to a major vessel
Active hemorrhage
Expanding hematoma
Pulse deficit
Bruit or thrill
Emergency Medicine Practice © 2011
Chest wall crepitus or the sensation of a foreign
body in the throat heightens the concern for esophageal or tracheobronchial injury. Because diaphragmatic injuries can occur in up to 19% of penetrating
thoracoabdominal trauma cases and in up to 59%
of patients with gunshot wounds to the left lower
chest, examination of the abdomen for peritonitis
is also warranted early in the primary survey.29,30
Undress the patient completely to evaluate for the
location of the wound(s) and other injuries. Log-roll
the patient to assess for entrance or exit wounds posteriorly, and consider a rectal examination to assess
for gross blood and rectal tone.
Documentation of the pulse strength and character as well as the skin temperature, color, and capillary refill in comparison to the unaffected limb is essential. Pay special attention to presence or absence
of these hard signs of vascular injury since they
generally warrant operative management.31,32 (See
Table 5, page 7.) Angiography in these patients may
lead to the complications associated with unnecessary testing and surgical exploration.33 Some authors
have suggested that soft signs do not correlate with
a vascular injury at all.34,35
Early realignment of a grossly deformed extremity is recommended to provide hemostasis and pain
relief. If a bleeding vessel is visualized, hemostasis
should be obtained by direct pressure or tourniquet.
Clamping of a vessel is not recommended due to the
risk of further injury to the vessel and unintentional
injury of adjacent nerves. Wounds should not be
explored digitally or with instruments unless gross
decontamination of clothing or debris is required.
Arterial pressure indices (APIs) can be used to
improve diagnostic accuracy for vascular injuries
and are readily performed at the bedside. The APIs
are calculated by dividing the systolic blood pressure (SBP) distal to the injury of the extremity in
question by the similarly located SBP of the uninjured extremity. An API is considered abnormal if
the result is < 0.9, and studies have suggested that
API is 95% sensitive and 97% specific for a major
arterial injury. An API of < 0.5 suggests a serious
single-segment or multisegment arterial injury.32
Management Of Gunshot Wounds
To The Head
The mortality associated with penetrating ballistic
brain injury is high. Zafonte et al performed a 7-year
prospective study and found that 36% of patients
with gunshot wounds to the head were dead on
arrival to the ED or expired in the ED. Of those who
survived to hospital admission, 41% expired in the
first 48 hours, an overall 77% mortality in the first
48 hours.36 Before 2001, no standardized guidelines
existed for the care of the patient with penetrating
head injury. In 2001, the Eastern Association for the
Emergency Medicine Practice © 20118
Surgery of Trauma (EAST) introduced a set of guidelines directed specifically to the care of the patient
with penetrating brain injury.37 These guidelines
provide some important direction for both initial
resuscitation and surgical care of these patients.
Early and appropriate resuscitation is imperative for the victim of penetrating head trauma. A
single episode of hypotension is associated with
worse outcomes for the severely brain-injured
patient. While early and aggressive resuscitation is
standard, the selection of the appropriate resuscitation fluid is a subject of much debate.
Albumin administration has been associated
with worse outcomes in severe TBI patients and is
not used in trauma resuscitation.38 However, the advent of modern synthetic colloid solutions may lead
to changes in the current resuscitation algorithms.
Although potentially promising experimental data
exist, no large randomized controlled trials show a
mortality benefit to synthetic colloid solutions.39
Hypertonic saline resuscitation continues to
be a subject of much research and interest. Prehospital studies using hypertonic saline in severe TBI
patients show no benefit over isotonic solutions.40
Potential benefits of hypertonic saline resuscitation
include lower fluid volumes, limited edema formation, and reduced inflammation.42 However, no
current large trials exist that show a survival benefit
of hypertonic saline over conventional trauma resuscitation. With the current literature not identifying
a clearly superior resuscitation fluid, it is prudent to
recommend using the fluid that the emergency clinician’s center is most comfortable with to ensure safe
and rapid resuscitation. For a more complete discussion of fluid management in traumatic hemorrhagic
shock, see the November 2011 issue of Emergency
Medicine Practice, “Traumatic Hemorrhagic Shock:
Advances In Fluid Management.”
Neuroimaging
Noncontrast computed tomography (CT) scan is
the imaging modality of choice for penetrating
brain injury.37 Cranial x-rays provide no additional
information and are not recommended as an initial
or additional study in penetrating brain injury. Due
to the metal content of many ballistics, magnetic
resonance imaging is currently not a prudent choice
for the initial evaluation of these patients.
Antibiotics
The early use of prophylactic antibiotics is recommended in the treatment of penetrating brain
injury.38 Although there are no randomized controlled studies comparing the use of antibiotics to
nonuse of antibiotics, comparison of infection rates
from the preantibiotics era suggest that antibiotics
are effective. From military literature, it appears that
antibiotics have been routinely used in penetrating
www.ebmedicine.net • December 2011
Clinical Pathway For The Management Of Gunshot Wounds To The Head
• Primary survey per ATLS® protocol
• Neurosurgery consultation
Need for airway protection?
YES
NO
Intubate
Continue to monitor for deterioration
Consider neuroprotective strategy
(Class III)
• Lidocaine, 1.5 mg/kg
• Fentanyl, 1-3 mcg/kg
• Elevate the head of the bed 30° postintubation
• Maintain end-tidal CO2 at a level of 35
• Give crystalloids and/or blood products as appropriate
• Avoid hypoxia at all times
Secondary survey for other injuries and
neurologic status
Obtain CT scan of the brain
Consider:
• Mannitol/hypertonic saline for increased ICP
• Seizure prophylaxis, dilantin 20 mg/kg
• Antibiotics: ceftriaxone 1 g IV +
metronidazole 500 mg IV +/- vancomycin 1 g IV
(See pages 8-10)
Abbreviations: ATLS®, Advanced Trauma Life Support®; CPP, cerebral perfusion pressure; CT, computed tomography; ICP, intracranial pressure; IV,
intravenous.
Class Of Evidence Definitions
Each action in the clinical pathways section of Emergency Medicine Practice receives a score based on the following definitions.
Class I
• Always acceptable, safe
• Definitely useful
• Proven in both efficacy and
effectiveness
Level of Evidence:
• One or more large prospective
studies are present (with rare
exceptions)
• High-quality meta-analyses
• Study results consistently positive and compelling
Class II
• Safe, acceptable
• Probably useful
Level of Evidence:
• Generally higher levels of
evidence
• Non-randomized or retrospective studies: historic, cohort, or
case control studies
• Less robust RCTs
• Results consistently positive
Class III
• May be acceptable
• Possibly useful
• Considered optional or alternative treatments
Level of Evidence:
• Generally lower or intermediate
levels of evidence
• Case series, animal studies, consensus panels
• Occasionally positive results
Indeterminate
• Continuing area of research
• No recommendations until
further research
Level of Evidence:
• Evidence not available
• Higher studies in progress
• Results inconsistent, contradictory
• Results not compelling
Significantly modified from: The
Emergency Cardiovascular Care
Committees of the American
Heart Association and represen-
tatives from the resuscitation
councils of ILCOR: How to Develop Evidence-Based Guidelines
for Emergency Cardiac Care:
Quality of Evidence and Classes
of Recommendations; also:
Anonymous. Guidelines for cardiopulmonary resuscitation and
emergency cardiac care. Emergency Cardiac Care Committee
and Subcommittees, American
Heart Association. Part IX. Ensuring effectiveness of communitywide emergency cardiac care.
JAMA. 1992;268(16):2289-2295.
This clinical pathway is intended to supplement, rather than substitute for, professional judgment and may be changed depending upon a patient’s individual
needs. Failure to comply with this pathway does not represent a breach of the standard of care.
Copyright © 2011 EB Medicine. 1-800-249-5770. No part of this publication may be reproduced in any format without written consent of EB Medicine.
December 2011 • www.ebmedicine.net
9
Emergency Medicine Practice © 2011
head injuries since 1946.43 Prophylactic antibiotics
are used by the majority of neurosurgeons during
even minor neurosurgical procedures.44 In addition,
prophylactic antibiotics have been shown to reduce
infection during clean neurosurgical procedures.45
It is therefore reasonable to conclude that antibiotics
are indicated in penetrating head injury.
No studies exist to demonstrate the best antibiotic choice in penetrating injury. In 1991, a survey of
neurosurgical care was performed, which indicated
that cephalosporins were the preferred antibiotics
for penetrating head injury.46 No current United
States guidelines exist to direct antibiotic choice in
penetrating brain injury. Current British guidelines
recommend IV cefuroxime plus IV metronidazole as
a first-line antibiotic regimen.47 Other experts recommend a combination of IV ceftriaxone, metronidazole, and vancomycin in penetrating brain injuries.47
Antibiotics should be chosen in conjunction with the
consulting neurosurgeon; however, early initiation
of a broad-spectrum antibiotic with good cerebral
penetration (such as ceftriaxone) is recommended.
Antiepileptic Drugs
The use of antiepileptic drugs (AEDs) to control
posttraumatic seizures remains controversial. Of
primary interest in the ED is the control of early
(< 1 week) posttraumatic seizures. Current recommendations from the American Academy of Neurology support the use of phenytoin for the prevention
of early posttraumatic seizures.48 This recommendation is supported by a large blinded randomized
trial showing successful reduction in seizures with
phenytoin in the first week after severe head trauma.49 However, a later study in children demonstrated a very low posttraumatic seizure rate in the first
48 hours and no reduction of seizures with the addition of phenytoin.50 More-recent studies have looked
at other AEDs, as compared to phenytoin, and show
varying results.51-54 There are no good studies that
provide recommendations for the new-generation
AEDs over the standard phenytoin therapy.
Elevated Intracranial Pressure Control
Patients with penetrating brain injury are at risk
for acute neurological deterioration due to elevated
intracranial pressure (ICP) from brain edema
resulting from the trauma. Though debated, use of
additional premedications during rapid sequence
intubation (RSI) — so-called “neuroprotective RSI”
— may help blunt a rise in ICP during intubation
and can be considered. (See Clinical Pathway For
The Management Of Gunshot Wounds To The
Head, page 9.) In addition, mannitol has traditionally been used to acutely reduce intracranial
edema through osmotic pressure. More recently,
hypertonic solutions of saline or crystalloids have
been investigated for ICP reduction. Vialet et al
Emergency Medicine Practice © 201110
studied 7.5% saline compared to 20% mannitol
in 20 patients with TBI and persistent coma. This
randomized trial showed fewer episodes of intracranial hypertension and a lower failure rate in
the hypertonic saline group as compared to the
mannitol group.55 Similarly, Ichai et al performed a
randomized trial comparing mannitol to a sodium
lactate solution of similar osmolarity in 34 patients
with severe TBI. They also found that the sodium
lactate solution was more effective in intracranial
pressure reduction than mannitol.56 Unfortunately,
no consistent recommendations exist for the concentration or dosage of hypertonic saline. Concentrations of hypertonic saline range from 3% to
23.4%.55,57 The current literature suggests, however,
that hypertonic saline is likely more effective than
mannitol for the reduction of intracranial pressure.58 For clinicians not experienced in administration of hypertonic saline, a reasonable initial dose
(as demonstrated by Vialet et al) is 2 mL/kg of 7.5%
saline solution.56
A simple, noninvasive method to help decrease
ICP is to raise the head of the bed 30° above parallel.
This maneuver has been demonstrated to lower ICP
without adversely affecting cerebral perfusion pressure or cerebral oxygenation, and it is recommended
to be started within the first 24 hours after injury.59
Hyperventilation is no longer recommended as an
ICP reduction strategy except in preherniation states.
Current Brain Trauma Foundation guidelines can
be found online at https://www.braintrauma.org/
coma-guidelines/. They are summarized in Table 6
Table 6. Brain Trauma Foundation
Recommendations For Traumatic Brain
Injury
Intervention
Recommendation
Blood pressure
Maintain SBP > 90
Oxygenation
Maintain PaO2 > 60; avoid hypoxia
Hyperventilation
Insufficient evidence to support
hyperventilation
Hyperosmolar therapy
Mannitol is recommended. Insufficient evidence to support hypertonic saline
Seizure prophylaxis
Phenytoin is recommended in the
ED for prevention of early posttraumatic seizures
Antibiotics
Insufficient evidence to support
prophylactic antibiotics
Steroids
No role for steroids
Therapeutic hypothermia
Level III recommendation for 48
hours of hypothermia
Abbreviations: ED, emergency department; PaO2, arterial oxygen
pressure; SBP, systolic blood pressure.
www.ebmedicine.net • December 2011
and are relevant for both blunt and penetrating head
trauma. These differ from some of the newest data
and earlier discussion, reflecting existing controversies and areas of needed research.
alone. This same study noted 3 unsuccessful fiberoptic intubations that were then successfully intubated
using RSI. No patients in this study required a surgical airway.64 In 2004, another retrospective review of
patient charts showed successful intubation with RSI
in the ED as well as a 90% success rate with prehospital blind nasotracheal intubation (BNTI). This
study calls into question the traditional teaching that
BNTI is contraindicated in patients with neck injury
for fear of worsening an airway injury.65
Although current literature indicates that RSI is a
safe and effective method of managing the airway in
patients with penetrating neck injury,64-66 these situations are highly variable and have the potential to be
difficult intubations. A clearly defined backup strategy
must be in place, including a variety of airway devices.
In addition, preparation for an emergent surgical
airway must be made, if possible, prior to inducing the
patient for RSI (double setup). If the patient appears
stable in the ED without signs of acute airway compromise or other indications for emergent intubations, it is
prudent to transport the patient to the operating room
for definitive airway management.
Extreme caution should be exercised in patients
with penetrating neck injuries likely to have caused
partial or total tracheal transection, as orotracheal or
nasotracheal intubation attempts could lead to separation and retraction of the distal tracheal segment.
If control of the distal segment can be maintained
with a tracheal hook or other device, then a patient
with an open tracheal injury may be directly intubated with an endotracheal or tracheostomy tube.
Management Of Gunshot Wounds
To The Neck
The high concentration of critical anatomy located in
the neck makes penetrating neck injuries potentially
life-threatening. Penetrating neck injury caused by
even a single bullet has the potential to cause multiple devastating injuries.
A rapid and thorough physical examination
is important in penetrating neck injury, as it may
provide important clues to the severity of injury.
Some authors suggest that physical examination
is a reliable indicator of injury in penetrating neck
wounds, and certain asymptomatic patients may
be evaluated with observation alone.60,61 In one
study, patients with penetrating neck injuries whose
physical examination did not show signs indicative of surgical injuries were also evaluated with CT
scans. The authors concluded that CT scan added
little information in patients determined by physical examination to be low-risk.62 The decision on
whether to proceed with imaging versus purely
observational management must be made in consultation with the surgeon. Typical practice patterns in
the United States include liberal use of CT imaging
in penetrating neck trauma, and the risk-to-benefit
ratio of CT scan to identify serious underlying neck
injury is low. If there is any question of a possible
serious neck injury, a CT with angiography should
be obtained to evaluate for vascular or aerodigestive
tract injuries.63 All patients with penetrating neck
injury violating the platysma should be observed for
a minimum of 24 hours.60
Evaluation Of Neck Injuries
Penetrating neck injuries are traditionally classified
into 3 zones, which are described in Table 7. The
zones provide a framework for discussing injuries
with consulting services as well as indicating poten-
Airway Management In Neck Injuries
Table 7. Zones Of Injury In Penetrating Neck
Injuries
Neck wounds have the potential to make intubation
extremely difficult by obscuring visualization due to
bleeding and/or altered anatomy. Rapid sequence
intubation is a commonly performed procedure
in the ED; however, traditional teaching cautions
against using paralytics in the patient with penetrating neck trauma. It is theorized that the addition
of a paralytic may turn a spontaneously breathing
patient into a patient that can neither be intubated
nor ventilated, and therefore, a crash airway.
There are very few studies evaluating the management of the airway in penetrating neck trauma.
More-recent literature indicates that RSI is likely
a safe and effective way of managing the airway
in penetrating neck injuries. One small study of
58 patients with penetrating neck injury requiring
emergency airway control showed a 100% success
rate in the 39 patients who were intubated using RSI
December 2011 • www.ebmedicine.net
11
Zone
Anatomy
Structures at Risk
Zone 1
Clavicle to cricoid cartilage
Great vessels (subclavian vessels,
brachiocephalic veins, common
carotid arteries, aortic arch, and
jugular veins), trachea, esophagus, lung apices, cervical spine,
spinal cord, cervical nerve roots
Zone 2
Cricoid cartilage
to angle of
mandible
Carotid and vertebral arteries,
jugular veins, pharynx, larynx, trachea, esophagus, cervical spine,
spinal cord
Zone 3
Angle of mandible to base of
skull
Salivary and parotid glands,
esophagus, trachea, vertebral
bodies, carotid arteries, jugular
veins, spinal cord, and other
major nerves
Emergency Medicine Practice © 2011
Clinical Pathway For The Management Of Gunshot Wounds To The Neck
• Primary survey per ATLS® protocol
• Maintain C-spine stabilization
Airway protection required?
YES
NO
Intubate or perform cricothyroidotomy
as indicated
Unstable +/- hard signs of
vascular injury?
NO
Secondary survey to include thorough
neurologic examination
YES
Operative intervention +/intraoperative arteriogram
Determine zone of injury
Zone 1
CT angiography
+/bronchoscopy, esophagography, and
esophagoscopy (Class III)
Zone 2
Operative exploration or CT angiography
+/bronchoscopy, esophagography, and
esophagoscopy (Class III)
Zone 3
Arteriography or CT angiography
+/bronchoscopy, esophagography, and
esophagoscopy (Class III)
Abbreviations: ATLS®, Advanced Trauma Life Support®; CT, computed tomography.
For class of evidence definitions, see page 9.
Emergency Medicine Practice © 201112
www.ebmedicine.net • December 2011
tially injured structures and ease of surgical exploration. Zones 1 and 3 are difficult areas to expose
surgically, and injuries to these areas are evaluated
by additional imaging in the stable patient. Zone 2
is fairly easy to expose surgically, and penetrating
injuries in this zone have traditionally been treated
with mandatory surgical exploration. Nonetheless,
advances in imaging technology and large numbers
of negative surgical explorations have called this
dogma into question.
As with all trauma patients, the unstable patient
with injury to any of the zones of the neck should be
taken immediately to the operating room. However,
the stable patient may undergo a series of imaging
studies to better evaluate the extent of injury. Recent
practice guidelines from EAST offer a Level I recommendation that selective operative management of
zone 2 neck injuries is recommended to minimize
unnecessary operations.67 Because it can be difficult
to determine the zone(s) of injury based on the external gunshot wound, diagnostic imaging or operative
management is required to visualize the zones that
are injured.
Imaging options for arterial injury in the neck
include angiography, CT angiography (CTA) and
duplex ultrasonography. Angiography is useful
because it can be both diagnostic and therapeutic;
however, it is also a time- and labor-intensive test.
Recent studies have shown that CTA is a reasonable
alternative to angiography for imaging the vasculature of the neck.68,69 In addition, CTA can provide information regarding the trajectory of the projectile as
well as visualizing other injuries. A CT scan showing
a trajectory remote from vital structures may obviate
the need for further imaging or unnecessary surgery
in a stable patient.70 The use of CTA has been shown
to significantly reduce the number of negative neck
explorations with no increase in mortality.71
Duplex ultrasound has also been proposed as
an imaging modality for vascular injury in penetrating neck trauma. Corr et al performed a prospective
study in 1999 on 25 patients with penetrating neck
injury, showing 100% sensitivity of duplex ultrasound
as compared to angiography.72 Demetriades et al
found similar results using ultrasound in 99 patients
who also underwent angiography. They found a sensitivity of 91.7% and specificity of 100%. When only
lesions requiring treatment were considered, both
the sensitivity and specificity were 100%.73 In recent
practice guidelines, EAST allows for use of CTA or
duplex ultrasound instead of arteriography to rule
out arterial injury (Level II recommendation).67
Evaluation of the aerodigestive tract is accomplished by contrast studies or by direct visualization. Computed tomography evaluation of
the trachea has been shown to reliably diagnose
injury.74 Esophageal and pharyngeal injuries, however, can be difficult to evaluate, and there are often
December 2011 • www.ebmedicine.net
no physical examination findings on presentation.
Delay of more than 24 hours in the diagnosis of
esophageal injuries can lead to increased morbidity
and mortality.75 Although CT scanning cannot reliably evaluate for esophageal trauma, some studies
suggest that a CT scan showing a bullet trajectory
remote to the esophagus can reliably risk stratify
patients to a very-low-risk category suitable for
24-hour observation.70 In most patients sustaining gunshot wounds to the neck, however, it is
likely that an esophagogram should be performed.
Esophagography has a sensitivity approaching
100%.76 A strategy of esophagography followed by
esophagoscopy was recommended by Weigelt et al
for the identification and evaluation of esophageal
injury.77 The clinical practice guidelines from EAST
recommend either contrast esophagography or
esophagoscopy to rule out an esophageal perforation that requires surgical repair.67
Management Of Thoracic Gunshot Wounds
Thoracic ballistic wounds often injure multiple
structures and require significant hospital resources
to manage emergently. (See Table 8.) Major vascular injuries occur in 4% of penetrating chest trauma
cases. If tracheobronchial injuries are present, the
proportion of patients with major vascular injuries
can be as high as 30% (not including cardiac injuries
that occur in 3% of cases).78 Many patients with penetrating thoracic injuries do not survive to the ED,
and those that do survive to the ED often require
immediate interventions such as tube thoracostomy,
intubation, and thoracotomy. Thus, the emergency
Table 8. Potential Thoracic Injuries
13
Thoracic Structure
Potential Injuries
Chest wall
• Rib fractures
• Flail chest
• Intercostal artery laceration
Heart
•
•
•
•
•
Cardiac tamponade
Hemorrhagic shock
Ventricular lacerations or punctures
Atrial lacerations or punctures
Valvular or conduction system injury
Lungs
•
•
•
•
Pneumothorax
Hemothorax
Pulmonary lacerations
Pulmonary contusions
Esophagus
• Esophageal perforation
Great vessels
• Lacerations leading to hemorrhagic shock
• Massive hemothorax
Tracheobronchial tree
•
•
•
•
Complete transection
Partial tears
Tracheoesophageal fistulas
Mediastinitis
Emergency Medicine Practice © 2011
clinician must be able to rapidly diagnose and treat
injuries that are immediately life-threatening.
Evaluation Of Thoracic Trauma
Focused assessment with sonography in trauma
(FAST) examination has become a mainstay of early
trauma management, as bedside ultrasound has
become readily available in many institutions. The
FAST examination should be performed early in the
initial assessment of penetrating thoracic trauma as
it can help accurately diagnose a pericardial effusion, hemoperitoneum, pneumothorax, and hemothorax and thus direct timely treatment to the most
appropriate location. Bedside ED ultrasound of the
pericardium has been shown in multiple studies to
have excellent sensitivity, specificity, and accuracy
(100%, 97%, and 97%, respectively).79,80 A false-negative examination is possible if the cardiac injury is
not contained within the pericardium and is causing
a massive hemothorax, but false-positive pericardial ultrasounds are rare. Case reports describing
false-positive pericardial ultrasounds have been
reported most frequently in the setting of a massive
hemothorax or mediastinal injury.81 Tube thoracostomy to relieve the hemothorax followed by a repeat
pericardial ultrasound may improve the diagnostic
accuracy in these cases.
Recent improvements in the performance of
bedside ultrasound have led to the expanded FAST
(E-FAST) examination to include sonographic
evaluation of the chest cavity to assess for pneumothorax and hemothorax. A positive ultrasound for
a pneumothorax in a symptomatic patient suggests
that decompression is warranted. The findings on
ultrasound include a lack of lung sliding and the
“seashore” or “bar code” sign.
Chest radiographs are necessary in all thoracic
ballistic injuries, regardless of presenting symptoms.
In many institutions, portable chest radiographs are
frequently ordered on trauma patients, but they are
notoriously less accurate than upright posteroanterior and lateral chest films. Nonetheless, portable
films are the practical choice for more severely
injured patients. Chest films can help determine the
presence of most thoracic injuries to the lungs, bony
chest wall, and vertebrae, and they can help locate
the projectile as well.
In hemodynamically stable patients, CT is warranted if there is still suspicion for intrathoracic injuries after physical examination, FAST examination,
and chest films. Computed tomography is highly
accurate for diagnosing injuries missed clinically and
on chest x-ray. With advances in CT technology and
its widespread availability, many clinically important
and occult diagnoses may be found only on CT. For
example, Ball et al detected an occult pneumothorax
on CT in 14.5% of 338 patients with a normal chest
radiograph, 47% of whom required drainage.82 SimiEmergency Medicine Practice © 201114
larly, Stafford found that 21% of 410 trauma patients
with a normal chest film had a hemothorax in CT, and
half of these patients required tube thoracostomy.83
As always, the emergency clinician should weigh the
risks and benefits of CT versus observation based
upon ED resources, the potential dangers of irradiation, and the likelihood of complications.
Treatment Of Thoracic Trauma
The management of penetrating thoracic trauma can
be complex because so many structures are at risk
for injury. Early involvement of a trauma surgeon is
recommended, since the final common pathway for
many of these patients is surgery or admission for
close observation and serial examinations.
When the patient presents in extremis or loses
vital signs in the ED, an emergency thoracotomy
should be performed, if possible. Indications for
emergency thoracotomy include loss of vital signs
in the ED (or immediately prior to arrival), evidence
of cardiac tamponade, and massive hemothorax.
Emergency thoracotomy should not be performed if
there are inadequate surgical resources available to
definitively manage the patient.
Emergent needle decompression and tube
thoracostomy are indicated in the presence of a
clinically significant pneumothorax or hemothorax,
respectively. Needle decompression should only be
performed as a stabilizing procedure while preparing to place a thoracostomy tube. Many needle decompressions fail to get into the pleural space when
placed in the classic anterior position of the second
intercostal space in the midclavicular line because
the chest wall in many adults may be too thick for
standard IV catheters.84 The lateral chest wall at the
fourth or fifth intercostal spaces in the midaxillary
line has been found to be just as thick as the anterior
chest wall.84-86 Angiocatheters are longer and stand
a greater chance of penetrating the pleural cavity,
but there are still many failures when this procedure
is attempted.86 Therefore, needle decompression
may be ineffective at temporarily relieving a tension
pneumothorax, and a thoracostomy tube should
be placed immediately if there is truly a concern
for a tension pneumothorax. Chest tubes should be
placed prior to imaging if there is any suggestion of
instability, tension pneumothorax, or hemothorax.28
Fluid resuscitation of the patient with hemorrhagic shock often starts with a crystalloid bolus,
but immediate release of blood products (at least 6
units of packed red blood cells [PRBCs] and fresh
frozen plasma [FFP]) should be obtained concurrently and started immediately, when available.
Literature supports the role of permissive hypotension in the penetrating trauma patient to reduce
the possibility of causing increased hemorrhage by
dislodging a clot or tamponade that has occurred
naturally.87,88 Blood products are recommended
www.ebmedicine.net • December 2011
Clinical Pathway For The Management Of
Gunshot Wounds To The Thorax
NO
Stable?
YES
Indications for thoracotomy?
• Primary survey per
ATLS® protocol
• Airway control as
indicated
• Damage control
resuscitation with
1:1:1 ratio of blood
products (Class II)
• Tranexamic acid, 1 g
IV over < 10 min, followed by 1 g IV over
8 hours (Class I)
NO
YES
Tension
pneumothorax
or possible
hemothorax?
Thoracotomy
and right-sided
thoracostomy
tube
YES
NO
Thoracostomy
tube
NO
Portable chest x-ray
and FAST examination
(Class II)
Massive
hemothorax?
YES
Pneumothorax
or hemothorax?
YES
Thoracostomy
tube
Intra-abdominal bleeding
Pericardial
tamponade
Normal,
negative
Thoracotomy
NO
Stable?
Stable?
YES
NO
Appropriate CT
scans
Surgical
consult and
intervention as
appropriate
NO
YES
Consider
pelvic injury or
other source of
instability
• Continue to secondary survey
• Observe and
evaluate
Abbreviations: ATLS®, Advanced Trauma Life Support®; CT, computed tomography; FAST, focused assessment with sonography in trauma; IV, intravenous.
For class of evidence definitions, see page 9.
December 2011 • www.ebmedicine.net
15
Emergency Medicine Practice © 2011
at a 1:1 ratio of PRBCs, FFP, and platelets to prevent coagulopathy from developing or worsening.
These patients should also be kept warm (> 34oC [>
93.2oF]) to prevent hypothermia from occurring and
worsening coagulopathy.89
The recent CRASH-2 trial of over 20,000 bleeding trauma patients from 40 countries worldwide
concluded that providing early use of tranexamic
acid decreased all-cause mortality and the risk of
death due to bleeding compared to placebo and
states that this medication may be a useful adjunct
in the bleeding trauma patient.90
Administration of prophylactic antibiotics in patients with penetrating chest trauma requiring tube
thoracostomy has been debated. Sanabria et al performed a meta-analysis of 5 randomized controlled
trials and found that patients given prophylactic
antibiotics had a decreased frequency of pneumonia
and posttraumatic empyema.91
Management Of Abdominal Gunshot Wounds
Firearms injuries to the abdomen can affect multiple
organs and can even traverse the diaphragm and
cause thoracic injuries. Abdominal gunshot wounds
may be isolated, but as in over one-quarter of these
patients, there may be more than 1 injury present.92
Hollow-organ injuries are the most common, with
the small bowel being the most commonly injured
organ. Solid-organ injuries and genitourinary
injuries are less common but must be considered
and evaluated. Historically, many of these wounds
mandated emergent exploratory laparotomy, but
recently, more-conservative management plans have
also been shown to have success.92,93
Table 9. Location Of Abdominal Zones
Abdominal Zone
Location
Anterior abdomen
Between the anterior axillary lines;
bound by the costal margin superiorly and the groin crease distally.
Thoracoabdominal area
From the nipple line superiorly to
the inferior costal margin distally
between the tips of the scapulae
and the posterior portion of the
inferior costal margin. Injuries in
the region increase the likelihood of
chest, mediastinal, and diaphragmatic injuries.
Flanks
Back
From the inferior costal margin
superiorly to the iliac crests; bound
anteriorly by the anterior axillary
line and posteriorly by the posterior
axillary line.
Between the posterior axillary lines
extending from the inferior scapular
tips to the iliac crests.
Emergency Medicine Practice © 201116
There are 4 anatomic zones of the abdominal
cavity, which can help suggest the type of injury
potentially present.92 (See Table 9.) Regardless of
the external site of injury and the initial tract of the
projectile, injuries can occur in remote sites due to
ricochet and cavitary effects of the projectile. Because of the many possible intra-abdominal injuries,
management of patients with abdominal gunshot
wounds is based initially on physical examination
and hemodynamic findings. Clearly, the unstable patient, the patient with an eviscerating injury, or the
patient with peritonitis on examination will likely
require operative intervention,94-96 but many of these
patients are initially hemodynamically stable or
unable to be assessed because they are sedated and
intubated. In these less clearcut cases, diagnostic
studies must be performed to help identify which
patients can be managed nonoperatively and which
patients require urgent exploratory surgery.
Serial physical examinations and frequent vital
sign re-evaluation are the most important diagnostic
tests to perform, as the development of instability or
peritonitis later in the course of the ED evaluation
can direct an immediate need for surgical exploration. (See Table 10.) In patients who remain stable,
laboratory and radiographic tests are required to
determine a location of injury or the presence of
intra-abdominal blood.
Typical laboratory studies that are obtained
include complete blood count, blood gas, renal
function, electrolytes, lactic acid, and urinalysis. A
type and crossmatch for blood products may also be
necessary, depending on the severity of the injury.
Results of these laboratory studies alone are rarely
indications to proceed to surgery, but significant
base deficits, highly elevated lactate levels, and
significant anemia may indicate the need for more
aggressive or operative management.
Radiographic studies should always be obtained
in the stable patient with an abdominal gunshot
wound. The FAST scan is useful in the unstable patient to determine the presence of blood in the peri-
Table 10. Specified Physical Examination
Findings To Suggest Injured Organ From
Abdominal Gunshot Wound
Finding
Possible Injury Location
Vomiting blood
Esophageal or gastric injury
Gross blood on digital rectal
examination
Colon or small bowel injury
Hematuria
Kidney, ureter, or bladder injury
Grey-Turner or Cullen sign
Retroperitoneal hemorrhage
Cool or pulseless extremities
Intra-abdominal or pelvic vascular
injury
www.ebmedicine.net • December 2011
cardium and/or peritoneum, but a negative study
does not rule out intra-abdominal organ injuries,
particularly hollow-organ injuries. A positive FAST
scan in the stable trauma patient does not necessarily warrant emergent operative intervention, but it
may help direct further testing and evaluation, as
intraperitoneal fluid found on FAST without other
ultrasound or clinical findings may suggest hollow
viscus or diaphragmatic injuries.92
Plain film radiography of the chest, abdomen,
and pelvis is typically employed to determine intrathoracic injuries, and it can help provide information
regarding the location of the projectile as well as the
number of missiles within the abdominal cavity. Both
anteroposterior and lateral films must be obtained to
determine whether the projectile is in the abdominal
cavity. (See Figures 2 and 3.) If the number of superficial wounds does not match the number or projectiles
present on plain films, further imaging or thorough
operative exploration is required.
Computed tomography scans have become standard in the evaluation of the stable trauma patient
with suspected intra-abdominal or pelvic injuries
from gunshot wounds. Not only do CT scans assist
in determining the location of penetrating injuries
and the amount of blood present in the peritoneum,
they also allow for evaluation of the missile path and
help with decision-making for operative versus nonoperative management. Velmahos et al performed a
prospective observational study of 100 patients with
abdominal gunshot wounds who were hemodynam-
ically stable and were initially planned to undergo
nonoperative management.98 The investigators used
CT scans with IV contrast only and found a 90.5%
sensitivity and 96% specificity for determining the
need for operative intervention. Twenty-six patients required exploratory laparotomy based on CT
findings, and only 5 of these had a nontherapeutic
laparotomy; none had postoperative complications.
Two patients had missed injuries on CT but had
clinical worsening and required surgical evaluation.
Neither had a bad outcome because of the delay to
surgery. Based on this study, many trauma centers
have opted to drop oral and/or rectal contrast from
their trauma CT protocols.
The availability and advances in CT and ultrasound have now largely relegated diagnostic peritoneal lavage (DPL) to an infrequently performed
procedure in many facilities. Diagnostic peritoneal
lavage is a highly sensitive, invasive test with a
reported sensitivity of 96% for identifying intraperitoneal injuries caused by gunshot wounds,99
and it may still have utility in certain situations,
particularly in unstable patients who cannot proceed
to CT scanning. For example, in the patient who is
intubated and cannot be clinically evaluated, a positive DPL can detect a possible hollow viscus injury.
Likewise, in a patient with penetrating trauma to the
lower thorax, flank, or back, a positive DPL can determine if there is an intraperitoneal injury. A grossly
positive DPL in the unstable patient indicates that
intra-abdominal bleeding may be the source of hemodynamic instability. A positive DPL in penetrating trauma is classically 5000 to 10,000 red blood
Figure 2. Kidney/Ureter/Bladder Radiograph
Of Abdominal Gunshot Wound With
Penetration Of Peritoneum
Figure 3. Computed Tomography Scan
Of Abdominal Gunshot Wound With No
Penetration Of Peritoneum
This patient suffered a penetrating wound to the abdomen; arrows
point to 2 projectile fragments that can be seen in the left upper
quadrant of this kidney/ureter/bladder image.
Image used with permission of David Bruner, MD.
December 2011 • www.ebmedicine.net
The above patient’s CT scan showed the projectile fragments to be
outside of the abdominal cavity (arrow); an exploratory laparotomy
showed no signs of violation of the peritoneum.
Image used with permission of David Bruner, MD.
17
Emergency Medicine Practice © 2011
Clinical Pathway For The Management Of
Gunshot Wounds To The Abdomen
• Primary survey per ATLS® protocol
• Airway control as indicated
Stable?
YES
NO
• Damage control resuscitation with
1:1:1 ratio of blood products (Class II)
• Tranexamic acid, 1 g IV over < 10
min, followed by 1 g IV over 8 hours
(Class I)
• Damage control resuscitation with
1:1:1 ratio of blood products (Class II)
• Tranexamic acid, 1 g IV over < 10
min, followed by 1 g IV over 8 hours
(Class I)
Portable chest x-ray and FAST exam
Intra-abdominal bleeding?
Remains unstable?
NO
YES
NO
Secondary survey
NO
DPL (Class III), serial FAST
examination, or operative intervention
• Operative intervention (Class III)
• Consider angiography if pelvic bleeding is the likely source (Class III)
Appropriate CT scans
YES
Stable?
NEGATIVE
YES
Appropriate CT scans
Secondary survey
POSITIVE
NEGATIVE
POSITIVE
NO
Peritonitis?
YES
Surgical consult and intervention
as appropriate
Re-evaluate, perform serial examinations,
consider admission and observation
Surgical consult and intervention
as appropriate
Abbreviations: ATLS®, Advanced Trauma Life Support®; CT, computed tomography; DPL, diagnostic peritoneal lavage; FAST, focused assessment with
sonography in trauma; IV, intravenous.
For class of evidence definitions, see page 9.
Emergency Medicine Practice © 201118
www.ebmedicine.net • December 2011
cells (RBCs)/mm3. A recent retrospective study by
Thacker suggests the criteria for a positive test can
be changed without missing clinically significant
injuries. This study identified the following criteria
as a positive DPL: 100,000 RBC/mm3 plus either >
500 white blood cells/mm3 or the presence of bile, or
the presence of amylase in the peritoneal fluid.99
an exploratory laparotomy is not deemed necessary.
Hemodynamically stable patients without peritonitis can be managed with a more selective approach,
as time may allow for CT imaging to assess for the
location of injury and to determine if the injuries present warrant exploratory laparotomy. Head, C-spine,
thoracic, and abdominal CT scanning (“pan scan”) is
occasionally warranted in the multiply injured patient
or those in whom a full clinical evaluation is not possible because of intubation, but many of these patients
will require surgical exploration.
Interventional Radiology
In circumstances where a vascular injury or isolated pelvic vascular injury is the primary source of
hemorrhage, interventional radiology may be the
diagnostic and therapeutic modality of choice. Interventional radiology can be therapeutic if the vessel
can be embolized to help control the bleeding.
Selective Nonoperative Management For
Abdominal Trauma
In recent years, more cases of penetrating abdominal
trauma have been managed successfully without
proceeding to exploratory laparotomy. This management strategy is the surgeon’s prerogative and
is clearly not the emergency clinician’s decision to
make. Velmahos et al retrospectively reviewed 792
patients who underwent selective nonoperative
management at 1 institution and found that only
4% required delayed laparotomy after worsening
clinical examination; none of the patients had a bad
long-term outcome. They noted that nonoperative
management is only appropriate at institutions
where there is always an on-call surgeon available,
rapid transfer to the operating room is feasible at all
hours of the day, and there are providers available
24 hours a day for serial examinations to assess for
acute worsening.101
Diagnostic Laparoscopy
Laparoscopy can also be performed as a diagnostic
procedure to gain direct visualization of the source
of intraperitoneal bleeding, possible bowel perforations, and diaphragmatic injuries before proceeding
to an open exploratory laparotomy in select patients.
Laparoscopy, however, is limited as a diagnostic test
because it can miss posterior diaphragmatic injuries,
retroperitoneal structure injuries, and subtle hollow
viscus injuries.100
Treatment For Abdominal Gunshot Wounds
After thorough evaluation for other injuries requiring more emergent treatment, initial resuscitation of
the abdominal gunshot wound victim begins with
fluid resuscitation. Classically, crystalloid (lactated
Ringer solution) is the initial resuscitative fluid
used, but prompt use of blood products is the mainstay of appropriate fluid resuscitation. Recent literature suggests a low RBC:FFP ratio (as discussed
on page 14) be instituted as soon as the need for
blood products is determined. Likewise, hypotensive resuscitation is recommended while awaiting
surgical intervention, when appropriate. With all
ballistic trauma to the abdomen, immediate trauma
surgery consultation or transfer is indicated. If the
patient is not at a trauma center, stabilization with
fluid and blood products is appropriate, but there
should be no delay in transfer to a higher level of
care. If the patient is unstable and requires transfer,
CT imaging can be deferred, but all transfers should
be discussed with the receiving surgeon.
Hemodynamically unstable patients or those
with peritonitis after abdominal gunshot wound
injuries should be appropriately resuscitated with
fluid and blood products and referred for emergent
exploratory laparotomy. Bleeding is controlled with
pressure, when possible, and potentially unstable
pelvic injuries are managed with compression of the
pelvis with a pelvic binder or a tightly wrapped sheet.
Patients with suspected pelvic bleeding may be selectively managed with angiography as noted above if
December 2011 • www.ebmedicine.net
Management Of Genitourinary
Gunshot Wounds
Only 10% of trauma patients have a GU injury,
and only 15% of this subset is from penetrating
trauma.102 Fortunately, there are few life-threatening
GU surgical emergencies other than a shattered
kidney or major lacerations of the renal vasculature.
The majority (up to two-thirds) of GU injuries are
to the external genitalia, and most patients have
other, more urgent, nongenitourinary injuries.103 In
up to 45% of trauma cases, bladder injuries are due
to gunshot wounds, but 90% of traumatic ureteral
injuries are due to penetrating trauma.104-106 Only a
small percentage (5%-10%) of direct kidney injuries
are from penetrating trauma, but many of these injuries require complete nephrectomy.107
The evaluation of GU trauma typically begins
with an evaluation of the distal structures and
proceeds more proximally to the kidneys. A thorough examination of the external genitalia for blood
at the urethral meatus and an evaluation for gross
hematuria may indicate the presence of an injury. A
lack of external signs and a lack of microscopic or
macroscopic hematuria do not rule out significant
GU injuries, as a normal urinalysis is present in 25%
19
Emergency Medicine Practice © 2011
of upper GU injuries.105,106 If there is concern for a
urethral injury, delay placement of a Foley catheter
until after further testing in order to avoid making a
partial urethral injury worse.
Upon examination, if there is concern for an
upper or lower GU injury (or from the potential
trajectory of the projectile), diagnostic imaging will
likely be necessary. Testing for a GU injury should
be delayed in patients who require further evaluation and treatment of more life-threatening injuries.
A retrograde urethrogram or cystogram can help
determine if there is a urethral or bladder injury and
suggest whether the bladder injury is intraperitoneal or extraperitoneal. Retrograde CT cystography
can also be performed to assess the extent of injury
to distal structures, and the CT can be extended
superiorly and should include IV contrast to evaluate for kidney involvement. To assess for contrast
leakage proximally at the kidneys, it is indicated to
delay abdominal CT scanning for 10 minutes after
the IV contrast is administered.107 When other intraabdominal or pelvic injuries that require surgical
exploration are present, the ureters and kidneys can
be directly visualized to assess for GU injuries.
When a GU injury is noted and other lifethreatening injuries have been treated or excluded,
consultation with a urologist for definitive management is indicated. Decompression of the bladder
with a catheter is the mainstay of early management
of bladder injuries in the ED, but most other injuries
to the GU system require surgical management by
a urologist. The bladder should be irrigated to help
evacuate blood clots. The most important ED management strategy is simply to recognize and test for
GU injuries and resuscitate appropriately.
Management Of Gunshot Wounds
To The Extremities
The most important factors to consider with a firearm injury to the extremities are the possibility of
vascular and nerve injuries, compartment syndrome,
fractures and knowledge of the type of weapon
used. Artery and nerve injuries are the major causes
of mortality and long-term morbidity in extremity
gunshot wounds.108
Although low-velocity injuries from handguns
account for the majority of extremity injures in the
civilian population, high-velocity wounds and shotgun wounds have the greatest potential for devastating injury, largely because they have a higher percentage of kinetic energy transference, have a higher
degree of wound contamination, have a higher risk
for compartment syndrome, and more often have
associated comminuted fractures with devitalized
bony fragments.109,119 Shotgun injuries, overall, have
been found to have twice the mortality rate of rifle
or handgun wounds.
Emergency Medicine Practice © 201120
Wounds to the shoulder have been found to
represent 9% of upper extremity gunshot wounds.
Approximately 15% of these wounds are associated
with a vascular injury and up to 25% involve injuries
to the subclavian and axillary arteries.111 Forearm
gunshot wounds have been found to account for up
to 20% of gunshot wounds overall, of which pulse
deficits of the radial and ulnar arteries have been
reported to be as high as 86% and 83%, respectively.111,112 Furthermore, penetrating forearm injuries
are the most common cause of upper-extremity
compartment syndrome, with a rate of 10%.30,113
Lower-extremity ballistic injuries have the
highest rate of fractures. The majority involve the
femur (22%-49%); the tibia accounts for 11% to 14%.5
Injuries to the hip and bony pelvis carry significantly higher morbidity and mortality due to related
injuries to the abdominal and pelvic organs.114 Thigh
wounds carry significant potential for vascular
injury with high risk of massive hemorrhage, especially when the injury involves the medial aspect of
the thigh or when a severe femur fracture occurs.
Injuries to the leg, especially the tibia, can be
especially devastating. Overall, the majority of
compartment syndromes are found in tibial trauma
from both blunt and penetrating injuries. Gonzalez
showed that 60% of patients who developed compartment syndrome in penetrating lower extremity
trauma had associated tibial fractures.115
Vascular Injuries Of Extremities
An extremity vascular injury can cause hemodynamic instability from significant exsanguination and
can affect the viability of the injured limb. Neurovascular structures in the extremities travel closely
together, from proximal to distal, while traversing
compartments that are well-demarcated by fascia
and muscle tissue. The fascial separations can play a
critical role in injury patterns because they may act
as a conduit for the transfer of kinetic energy from
the projectile and can impart immediate injuries
distal to the permanent cavity and late complications such as compartment syndrome. The timing of
presentation for treatment is critical, as studies have
shown that delays of greater than 6 to 8 hours have
infection and complication rates that are significantly higher than in patients who present early after
sustaining a firearm injury.112
A recent large review of the National Trauma
Data Bank® from 2002-2005 looked at isolated
lower-extremity trauma with an arterial component
and found that penetrating trauma accounted for
66% of these injuries. The most commonly injured
vessel is the superficial femoral artery, followed by
the popliteal artery and the common femoral artery.
The amputation rate from penetrating trauma is
5.1% and is most frequently associated with a popliteal artery injury.116
www.ebmedicine.net • December 2011
Clinical Pathway For The Management Of
Gunshot Wounds To The Extremities
Hard signs of vascular injury, ischemia,
or persistent, active hemorrhage?
YES
NO
Consult trauma/ vascular/orthopedic
surgeon and consider a tourniquet
Assess risk for neurovascular injury
LOW
Orthopedic fixation +/intraoperative angiography,
vascular repair
HIGH
•
•
•
•
• API ≥ 0.9 (Class III)
• No pulse deficit
• Angiography (Class II)
• CTA (Class II)
• Duplex ultrasound (Class III)
Observation/serial examinations
Consult trauma/ vascular surgery
API < 0.9 (Class III)
Pulse deficit Shotgun wound
Proximal thigh wound
NO
Normal results?
YES
• Operative repair
• Serial imaging
• Observation
Observation
Abbreviations: API, arterial pressure indices; CTA, computed tomography angiography.
For class of evidence definitions, see page 9.
December 2011 • www.ebmedicine.net
21
Emergency Medicine Practice © 2011
Gunshot wounds to the proximal aspect of the
upper extremity warrant evaluation for brachial
plexus injuries. One study noted that shotgun injuries to the shoulder carried a 50% chance of nerve
transection.19 The more proximal the vessel injury,
the higher the risk for significant injury. Additionally, patients with an underlying vascular disease are
susceptible to more problematic injuries and merit
a higher degree of clinical suspicion for associated
vascular injury.
Traditionally, after physical examination, the
gold standard for further assessment for a vascular injury has been conventional angiography.5,111
Historically, soft signs of vascular injury on physical
examination were an indication to obtain angiography. However, other methods such as computed
tomography angiography (CTA) have replaced
conventional angiography in many circumstances.
Conventional angiography’s advantage is that it has
been consistently shown to have 99% sensitivity and
97% specificity.33,117 However, up to 95% of arteriograms are negative, they have a false-positive rate of
2%, they carry a complication rate of 1% to 3% (fur-
ther arterial injury), and they often do not change
management decisions.33 Prospective studies of
CTA have shown sensitivities ranging from 99% to
100% and specificities of 87% to 100%.33,117,118 Duplex
ultrasound offers some significant advantages to
other study methods because it is readily available
in many EDs, can be done at the bedside, is noninvasive, requires no radiation exposure or contrast material, and has a high degree of diagnostic accuracy
in the experienced provider’s hands. Studies have
shown sensitivities of 95% to 100%, with specificities
of 97% to 98%.114,115
In the patient with equivocal signs of vascular
injury, choosing the best diagnostic imaging test can
be difficult. If no hard signs are found but there is
still a concern for vascular injury, many institutions
advocate admission and serial examinations along
with some form of diagnostic testing such as duplex
ultrasound or CTA.
Nerve Injuries In Extremity Trauma
Peripheral nerve injuries due to trauma are rare, accounting for only 2% to 3% of all traumatic injuries.121
Risk Management Pitfalls For Gunshot Wounds (Continued on page 23)
1. “The patient presented with a severe penetrating head injury. I’m aware that brain edema is
a big problem in these injuries, so I avoided
giving IV fluids to him.”
Under-resuscitation of head injury leads to
hypotension and results in increased morbidity
and mortality. Fluid resuscitation should not be
withheld for fear of brain edema. If edema is a
serious concern, resuscitation with hypertonic
saline can be instituted.
2. “EMS brought in a young male with a gunshot
wound to his neck and a GCS score of 6. It was
obvious that the patient was not protecting his
airway, but I was hesitant to secure the airway
due to the possible complications.”
Studies have shown that application of RSI
to patients with penetrating neck injuries is
safe and effective. The emergency clinician
should not avoid securing the airway in the
trauma patient if it is needed; however, backup
airway devices should be available in case of
complications.
3. “A young woman presented to the ED with a
small puncture wound on her neck between
her clavicle and her cricoid cartilage. The
wound looked small, so I decided to suture up
the wound and send her home.”
Emergency Medicine Practice © 201122
Be wary of the penetrating neck injury. Unless
you can definitively prove that the wound does
not penetrate the platysma, the patient with a
penetrating neck injury must undergo a series of
imaging studies and/or a period of observation
to ensure that no serious injury has occurred.
4. “The patient had a through-and-through
gunshot wound to his arm. The wound on the
front of the arm was smaller than on the back
of the arm, so I documented in the chart that
the entrance wound was located on the front of
the arm.”
Be careful with your documentation of
gunshot wounds. Your chart should contain
only descriptions of the wound and factual
information about the case. You do not know
which wound is the entrance wound, as not all
entrance wounds are smaller than exit wounds.
5. “I didn’t give the patient antibiotics because
bullets are sterile, due to the high heat
associated with missile injuries.” Numerous studies have proven that bullets are
not sterile, and even if they were, the vacuum
created by cavitation facilitates inoculating the
patient with infectious material such as clothing
or other debris.
www.ebmedicine.net • December 2011
Noble et al found that gunshot wounds accounted for
7.4% of peripheral nerve injuries overall (and as high
as 84% in developing countries).122 Neurologic injuries are associated with a concomitant vascular injury
in approximately 10% to 16% of cases.116,123
Nerve injuries are notoriously difficult to assess
in the immediate setting, and there is considerable
controversy as to the best management of these injuries. If the injury is neuropraxic (the nerve remains
intact but is transiently nonfunctional) or axonometric (axon alone is severed), these patients will usually regain function. Nearly 70% of individuals with
a documented peripheral nerve injury go on to make
complete recovery.123 Focal neurologic findings have
been suggested as risk factors for unrecognized
vascular injury because of their proximity. Frequent
reassessments of neurologic status are important
because changes can also indicate development of
compartment syndrome.
sible. Realignment can provide hemostasis, reduce
pain, and prevent further injury, such as compartment
syndrome. Initial stabilization includes fracture reduction with the best possible anatomic realignment,
soft tissue wound care, and appropriate splinting,
with care to avoid constrictive dressings. Always
reassess neurovascular status after these measures. If
wounds are large, obviously contaminated, or involve
the joints, IV antibiotics are indicated. Imaging of the
injured area as well as the anatomic area above or
below the wound should be performed.
A simple way to describe the fracture to an
orthopedic consultant is to use the mnemonic
NOLARD: Neurovascular status, Open versus
closed, Location, Angulation/Alignment/Articular
involvement, Rotation, and Displacement.119 Always
include the mechanism of injury and estimate the
level of contamination as well. Definitive treatment
of joint and bone injures often requires operative
treatment, and bone injuries may need to be repaired
to facilitate a vascular repair.
A study by Brown et al found that firearms-related injuries accounted for 15% of all fractures requir-
Management Of Bone And Joint Injuries
Bone and joint injuries are often grossly visible on
examination and should be stabilized as soon as pos-
Risk Management Pitfalls For Gunshot Wounds (Continued from page 22)
6. “Shotguns are low-velocity weapons, so I
didn’t think it could be so serious.”
Shotguns are devastatingly effective at closer
ranges, despite their “low” velocity and lessaerodynamic projectiles. Avoid making judgments solely on velocity classifications and
adhere to the maxim “treat the wound, not the
weapon.”
9. “The entrance wound appears on the anterior
chest wall and the exit wound can be found in
the lower back . . .” When describing ballistic wounds, do not try to
be a forensic pathologist or a detective. Simply
describe the wound’s size and appearance, but
do not describe it as an entrance or exit wound.
10, “He is awake and pain is under control, but
his blood pressure is only 95/55 mm Hg. Do we
need to give him another bolus of crystalloid to
get his blood pressure back to normal?” There are 2 pitfalls in this question. First, the primary resuscitative fluid in penetrating trauma
should be blood products in an equal ratio
rather than crystalloid or colloid. The second
pitfall is attempting to maintain a “normal”
blood pressure. Multiple studies have demonstrated that permissive hypotension is a useful
prehospital and ED strategy that complements
the idea of damage control resuscitation. If a
patient is awake and alert and tolerating permissive hypotension, it is best to try to maintain the
mean arterial pressure around 65 mm Hg or the
SBP around 90 mm Hg to decrease bleeding. For
more information about damage control resuscitation, see the November 2011 issue of Emergency Medicine Practice, “Traumatic Hemorrhagic
Shock: Advances In Fluid Management.”
7. “He had a through-and-through wound in his
leg, so I didn’t think he could get compartment
syndrome.” Compartment syndrome is a clinical diagnosis, and intracompartment pressures should be
measured to verify the diagnosis. Just because
the patient has a big hole in his leg doesn’t mean
that swelling doesn’t occur or he couldn’t have
a hematoma that effectively serves as a tamponade.
8. “I saw a pulsatile bleeding vessel, and it was
easy to see, so I clamped it off for hemostasis.” Clamping of a vessel is ill-advised, as you’re
likely to damage a closely approximated nerve
and will damage the vessel end, making reanastomosis more difficult. You could have used
a tourniquet or direct pressure instead!
December 2011 • www.ebmedicine.net
23
Emergency Medicine Practice © 2011
ing surgery.124 Fractures can occur from direct injury
caused by the projectile, but bony fragments can also
act as secondary missiles and lead to concomitant
neurovascular injuries. Fractures caused by gunshot
wounds are classified similar to other blunt trauma
fractures. Incomplete fractures typically involve
the epiphysis and metaphysis and have 3 patterns:
drill hole (seen in cancellous bone injury), unicortical (usually in long bone metaphysis), and chip
fractures. Complete fractures frequently involve the
diaphyseal bone and have a butterfly pattern.34,113
High-velocity gunshot wounds to the bone are
the most significant because severe comminution and
devitalized bone fragments are often present. Lowvelocity gunshot wound fractures, however, often
behave similarly to closed blunt-trauma fractures.
Ballistic injuries to the joints can have devastating short- and long-term sequelae. An isolated gunshot wound to a joint is rare but requires immediate
operative evaluation and management. These types
of injuries are a risk for severe posttraumatic arthritis, and if left in place, retained fragments can lead to
plumbism.125
While arterial injuries are the greatest threats to
life and limb, overall, skeletal muscle and soft tissue
are the predominant tissue types injured in gunshot
wounds. High-velocity and shotgun injuries are
typically the most severe. Low-velocity wounds are
not typically associated with significant tissue damage and are generally lower-risk for infection.125,126
Management Of Soft Tissue Injuries
Soft tissue wounds are often managed in the ED,
either by the emergency clinician or a consultant.
High-velocity and shotgun wounds are the exception, as they often need meticulous debridement and
frequently require second-look procedures. Smaller,
isolated wounds to skin, subcutaneous tissue, and
muscle are very amenable to simple irrigation and
debridement. A large retrospective review by Ordog
et al examined outcomes of gunshot wound patients
managed with simple wound debridement, antibiotic ointment, and oral antibiotics. They found only
a 1.8% incidence of wound infections, and 60% of
the patients in this study were managed as outpatients.127 A small, retrospective observational study
by Byrne and Curran examined the rate of successful ED management of isolated gunshot wounds to
the lower extremity. They found a significantly low
rate of complications compared to inpatient management, as well as significant savings in terms of total
inpatient hospital days.109
When assessing injuries to the soft tissue and
muscle of the involved extremity, general principles of wound care apply. The approach to wound
closure must include evaluation of the degree of
contamination, the timing of closure, the wound
Emergency Medicine Practice © 201124
size and depth, and injury to underlying structures.
Direct closure of the wound is generally not advised,
so as to allow for an outlet of potential infection.
Discharged patients will need to be followed for
wound checks. Wounds that are large and/or deep,
are not amenable to delayed closure, have significant
potential cosmetic implications, or are > 8 hours old
may require consultation and admission for operative treatment. In the interim, cover these wounds
with saline-soaked gauze and consider a course
of antibiotics. The extent of the wound should be
noted, especially if the fascia is violated, as some
surgeons use this to determine whether the patient
needs to have formal operative debridement.128
With many penetrating injuries, compartment
syndrome is possible. In particular, lower extremity vascular injuries above the knee and proximal
tibia fractures are at high risk for compartment
syndrome.115 The gold standard to assess intracompartmental pressure is by direct measurement of
pressures within the affected compartment as well
as all adjacent compartments. Pressure measurements should be performed using sterile technique
and within 5 cm of the fracture site to avoid a falsely
low reading. A compartment pressure > 30 mm Hg
is considered positive. When the threshold pressure is crossed, fasciotomy is indicated. Delays in
fasciotomy can have dire consequences, as found by
Ritenour, who noted in a study of combat casualties
between January 2005 and August 2006 that patients
undergoing fasciotomy after evacuation from Iraq
had higher rates of muscle excision (25% vs 11%),
amputation (31% vs 15%), and overall mortality
(19% vs 5%) versus those who had a fasciotomy
prior to evacuation.129
Documentation Of Gunshot Wounds
Emergency clinicians are uniquely situated to observe and record ballistic injuries before the wounds
are disturbed by surgical or medical intervention.
While documentation is very important for both
medical and legal purposes, documentation should
not compromise patient care or interrupt resuscitation efforts. When done properly, ballistic documentation can be performed quickly and accurately,
but many EDs do not focus on the documentation
aspect of ballistic injury. One study found that of 93
gunshot wounds treated at a Level I trauma center,
the wound size was documented only 8.6% of the
time. Additionally, wound shape was documented
only 1% of the time, and anatomic location was
documented only 39.8% of the time.130 Implementation of an easy-to-use, standardized gunshot wound
description form was found to drastically improve
gunshot wound documentation in this same trauma
center.130 (See Figure 4 and Figure 5.) Proper documentation of a gunshot wound inwww.ebmedicine.net • December 2011
cludes the anatomic location, size, shape, and characteristics of the wound. Emergency clinicians should
avoid speculating on the caliber of weapon or bullet
type that caused the wound. In addition, wounds
should not be described as “entrance” or “exit,”
because this determination can be very difficult to
make.131 Other characteristics of the wound should
be described such as burns, bruising, abrasions, or
soot around the wound edges. Carbonaceous material
around the wound should be described as “soot.” The
term “powder burn” is no longer considered accurate
or appropriate terminology.131 Medical photography
is an easy and accurate way to document ballistic
injury. Consent must be obtained prior to obtaining
pictures, and most hospitals have specific protocols
addressing medical photography, which must be followed. Place a ruler in the photograph to provide a
scale of measurement. If a ruler is not available, use a
standard-sized, well-known object such as coin.132 All
documentation should be purely factual. The emergency clinician should avoid recording any speculation or opinions in the medical chart. If the patient expresses an opinion that is pertinent to the record, this
should be recorded in the patient’s own words and in
quotation marks. Remember that the medical chart is
a legal document and may be used as evidence in a
criminal trial.
Figure 4. Gunshot Entrance Wound
Use Of Antibiotics
Controversies And Cutting Edge
With the exception of an open fracture, antimicrobial
treatment for penetrating extremity wounds is often
a source of controversy. Generally accepted indications for empiric antibiotic therapy are associated
fractures, shotgun injuries, or wounds with large
associated soft-tissue involvement. Studies by Ordog
and Dickey demonstrated that patients with lowvelocity missile injuries can be successfully treated
as outpatients, without antibiotics.127,133 When antibiotics are deemed necessary, Knapp et al found no
difference in outcomes when comparing oral and IV
antibiotics.134 Risk factors for infection include delays in wound care, inadequate wound care, wounds
> 2 cm in length, gross contamination, poor patient
compliance, diabetes, and vascular injury.127,133
Patients with grossly contaminated injuries, high-velocity weapon injuries, and shotgun injuries should
be admitted for surgical debridement.
When fractures are present, antibiotics are indicated. In a study of 1104 open fracture wounds, Patzakis and Wilkins found the key to reducing infections
was early antibiotic administration.135 Fackler stated
that one should strive to achieve adequate circulating
blood levels of a penicillin-spectrum antibiotic in all
gunshot wound patients as soon as possible.136 Surgical debridement for open fractures is typically done
within 6 hours, but recent studies have shown that
extending this window up to 24 hours has shown no
change in the rate of osteomyelitis as long as antibiotics have been started in the ED.137
Figure 5. Gunshot Exit Wound
Cervical Spine Clearance
Many patients with gunshot wounds arrive with
cervical collars in place despite a lack of neck trauma
by history, and many more patients have cervical
collars placed at the time of arrival to the ED. Two
retrospective studies suggest that cervical collars
do not need to be applied to patients with isolated
gunshot wounds to the head because blast and fall
injuries are generally not present, and the spinal stabilization only increases the difficulty with airway
These are images of the entrance and exit wound of a patient who
was shot in the back of the leg, with an exit wound on the front of the
leg, according to the patient’s history. Despite the patient’s history,
the wounds were described in the record as follows:
“In image 3, note the small < 1 cm diameter puncture wound without
active bleeding to the right of the gloved hand. In image 4, there is
a large 2.5 cm in diameter circular wound with active bleeding and
beveled edges.”
Images used with permission from David Bruner, MD.
December 2011 • www.ebmedicine.net
25
Emergency Medicine Practice © 2011
control.138,139 Another study suggests that cervical
collars do not need to be placed in patients with penetrating trauma to the head, neck, or torso if they are
asymptomatic of spinal injuries.140
Thoracotomy
Emergency department thoracotomy (EDT) can be a
potentially life-saving intervention for patients with
penetrating thoracic injuries, but it has been used in
certain instances for penetrating abdominal injuries
as well. While large studies are lacking because of
the relative infrequency of EDTs, some retrospective analysis suggests that it may have a limited role
for penetrating abdominal trauma when clamping
of the aorta may allow time to find the source and
stop the bleeding. A recent study of prelaparotomy
EDT found that of the 50 patients with abdominal
exsanguinations from penetrating trauma, 8 patients
survived neurologically intact to hospital discharge,
thus suggesting a role for EDT in penetrating abdominal trauma.141 Another recent study by Moore
et al suggested that an EDT should be considered
futile in any penetrating trauma when CPR has been
ongoing for 15 minutes or more.142
Synthetic Blood Substitutes
Synthetic hemoglobin-derived, disease-free, oxygen-carrying substitutes have been suggested to
be useful in trauma patients when allogenic blood
products are not available or in patients who cannot receive blood products. Several studies have
addressed the use of these products over the last decade with primarily favorable results. For example,
Gould et al first examined this topic by comparing a
synthetic blood substitute (PolyHeme®) to allogenic
blood transfusion in trauma patients. They found
that there were no adverse side effects in the synthetic hemoglobin group, and they required fewer
units of transfused blood. The synthetic group did,
however, have a lower overall hemoglobin.143
A recent multicenter trial evaluated the role
of 6 units of synthetic hemoglobin within the first
12 hours of injury versus prehospital crystalloid
and standard in-hospital blood product use in 714
trauma patients. This prospective trial found less allogenic blood product use in the experimental group
and suggested that synthetic hemoglobin would be
useful when blood products were not available. The
study concluded that the synthetic blood product
group did not have statistically different adverse
events, but it did have a 3% risk of myocardial
infarction compared to 1% in the allogenic blood
product group. However, mortality was slightly
higher in the synthetic group (13.4% vs 9.6%), and
multiple organ failure was higher as well (7.4% vs
5.5%).144 This study suggests that if traditional blood
products are not available, the risk-to-benefit ratio
favors using synthetic hemoglobin.
Emergency Medicine Practice © 201126
Summary
Ballistic weapons cause many deaths and critical injuries worldwide. Knowledge of the physics behind
these weapons can help emergency clinicians better
understand the magnitude of their patients’ injuries.
Understanding the type of projectile fired, the distance from the target, and the number of shots fired
will help determine the pattern of injury. While the
velocity of the projectile is important, the injury patterns are similar regardless of the speed of the bullet,
and higher-velocity weapons do not necessarily
impart greater injuries. The permanent cavity causes
obvious tissue damage, but the temporary cavity
can also have devastating effects to surrounding
tissues. Each area of the body is at risk for various
and different injuries depending on the tract of the
bullet, and emergency clinicians must be aware of
the specific risks with each region of the body and be
prepared to treat accordingly. The field of ballistics
and the physics behind penetrating injuries is improving. Newer techniques, such as ballistic gelatin,
are able to better explain the various injury patterns,
allowing the treatment of these wounds to improve,
based on evidence.
Case Conclusions
The 25-year-old male with the gunshot wound to the
upper abdomen and the left-lower-lobe injury was taken
to the operating room immediately. On visual inspection
during thoracotomy, he was found to have a diaphragmatic injury. He required a left-lower-lobe resection but
did not have any other intra-abdominal injuries, and he
recovered slowly over several weeks.
The 18-year-old male with the shotgun wound to the
left leg had multiple small fragments in that leg and APIs
of 0.8. Given the extent of his injuries, he was taken to the
operating room by an orthopedic surgeon for an external
fixator and to wash out and clean up his wounds. He had
a preoperative CTA of his left leg that did not reveal a
vascular injury. He was eventually discharged for further
outpatient orthopedics care.
The 38-year-old man with a gunshot wound to
the head was found at the CT scanner to have massive
intraparenchymal hemorrhage and significantly increased
ICP, collapsing the ventricles and causing herniation. The
bullet was in his left temporal lobe. Despite attempts to
control his ICP, his injuries were not survivable. Comfort
care was provided, and he died in the ICU.
Note
The views expressed in this presentation represent
those of the author and do not necessarily reflect the
official policy or position of the Department of the
Navy, Department of Defense, or the United States
Government.
www.ebmedicine.net • December 2011
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29
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www.ebmedicine.net • December 2011
5. For patients with elevated ICP, a reasonable
initial dose of hypertonic saline is:
a. 10 mL/kg of 7% saline solution
b. 100 mL of 3% saline solution
c. 2 mL/kg of 7.5% saline solution
d. 50 mL/kg of 0.9% saline solution
CME Questions
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6. Imaging options for arterial neck injury include all of the following EXCEPT:
a. CT angiography
b. Contrast-enhanced CT of the neck
c. Duplex ultrasonography
d.Angiography
1. Wounds from low-velocity firearms are always
less severe than wounds from high-velocity
firearms.
a.True
b.False
7. Which of the following is not an indication
for emergency thoracotomy after a penetrating
gunshot wound to the chest?
a. Loss of vital signs in the trauma bay
b. Massive hemothorax
c. Loss of protective airway reflexes
d. Cardiac tamponade
2. Which of the following is NOT a ballistic zone
of injury as described by Wang?
a. Primary wound zone
b. Contusion zone
c. Concussion zone
d. Infection zone
8. Vomiting blood is indicative of what type of
injury from an abdominal gunshot wound?
a. Esophageal or gastric injury
b. Colon or bowel injury
c. Kidney injury
d. Pelvic injury
3. “Secondary wounding” is caused by
a. A second bullet
b. Internal or external objects accelerating through tissue
c. The pressure wave in front of the missile
d. Powder burns
9. Appropriate documentation of gunshot
wounds includes all the following EXCEPT:
a.Size
b. Entrance versus exit wound
c.Location
d.Shape
4. What is the imaging modality of choice for
gunshot wounds to the head?
a. Cranial x-rays
b.MRI
c. Noncontrast CT
d.Ultrasound
December 2011 • www.ebmedicine.net
31
Emergency Medicine Practice © 2011
Physician CME Information
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