Download blunt abdominal trauma

Abdominal Trauma
Abdominopelvic Cavity
• Ventral body cavity
• Thoracic
• Abdominopelvic
• Abdominopelvic
• Abdominal
• Liver
• Stomach
• Kidneys
• Pelvic cavity
• Bladder
• Some reproductive
organs
• Rectum
Abdominopelvic
Cavity
• The two cavities are
continuous
• Most organs
surrounded by a
peritoneal cavity
• Visceral peritoneum
• Serous peritoneum
• Peritoneal cavity
Abdominal Quadrants
• 4 quadrants
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Right upper quadrant
Left upper quadrant
Left lower quadrant
Right lower quadrant
Abdominal Trauma
• First aid
• Resuscitation
• Transport
• Diagnosis
• Treatment
Abdominal Trauma
Blunt wounds
Penetrating abdominal taruma
stab wounds
Ballistic trauma
blunt abdominal trauma
• Blunt abdominal trauma is regularly encountered in the emergency
department
• Victims of blunt trauma often have both abdominal and extraabdominal injuries
• The integrity of the abdomen does not deteriorate
MECHANISM OF INJURY
• Several pathophysiologic mechanisms can occur in
patients with blunt abdominal trauma.
• A sudden and pronounced rise in intra-abdominal
pressure created by outward forces can rupture a
hollow viscus.
• Passengers wearing a lap-belt without a shoulder
attachment can sustain injury from such a mechanism
when the belt forcefully compresses the abdomen.
• Solid organs (eg, spleen and liver) are particularly
susceptible to laceration or fracture by this
mechanism
• Retroperitoneal structures, such as the duodenum or
pancreas, may be injured.
HISTORY
• Important
EVALUATION AND
MANAGEMENT
• Initial management of the
trauma patient is directed at
rapid stabilization and
identification of life
threatening injuries, as
described in Advanced
Trauma Life Support (ATLS)
protocols.
• Primary assessment (ie, the
primary survey) follows the
ABCDE pattern: Airway,
Breathing, Circulation,
Disability (neurologic
status), and Exposure
• If evidence of extra-abdominal injury exists, the emergency clinician
must assess for intra-abdominal injury, even in hemodynamically
stable patients without abdominal complaints.
• In the hemodynamically unstable patient, concurrent resuscitation
and assessment are paramount.
The physical examination findings most strongly
associated with intra-abdominal injury following
BAT are the following;
• Seat belt sign
• Rebound tenderness
• Hypotension
• Abdominal distension
• Abdominal guarding
• Concomitant femur fracture
Laboratory tests
• Hematocrit – A hematocrit below 30 percent increases the likelihood of intra-abdominal injury in
the setting of BAT (blunt abdominal trauma)
• Leukocyte count – In BAT, the white blood cell (WBC) count is nonspecific and of little value
• Pancreatic enzymes – Normal serum amylase and lipase concentrations cannot exclude significant
pancreatic injury
• Liver function tests – Hepatic injury is associated with elevations in liver transaminase
concentrations
• Urinalysis – Gross hematuria suggests serious renal injury and mandates further investigation
• Base deficit and lactate – A prospective, nonrandomized study of BAT patients in two trauma
centers found that a base deficit less than -6 was associated with intra-abdominal hemorrhage
and the need for laparotomy and blood transfusion
• Additional tests – It is reasonable to obtain a pregnancy test in women of childbearing age with
BAT. Clinical circumstance should determine the need for further testing (eg, patient taking
anticoagulant or antiplatelet medications would likely prompt coagulation studies).
Radiologic studies
• Patients who have sustained blunt trauma to the torso are at risk for intrathoracic as well as intraabdominal injury, and plain radiographs of the chest may be helpful depending upon the clinical
circumstances. The indications and use of chest imaging in patients with blunt thoracic trauma is
reviewed separately
Computed tomography
• computed tomography has become the primary method for identifying intra-abdominal injury
• The use of MDCT remains largely restricted to hemodynamically stable patients who are at low risk for
decompensating while in the CT scanner.
CT scanning's benefits include:
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Noninvasive
Better defines organ injury and potential for nonoperative management of splenic and liver injuries
Detects not only the presence but the source and amount of hemoperitoneum
Active bleeding often detectable
Retroperitoneum and vertebral column can be assessed in conjunction with intra-abdominal structures
Additional imaging can be performed when needed (eg, head, cervical spine, chest, pelvis).
CT scanning's disadvantages include:
• Despite improvements in image resolution, MDCT remains an insensitive test for mesenteric, bowel, and pancreatic duct
injuries
• IV contrast is needed; oral contrast is NOT needed as it rarely adds to diagnostic accuracy and may delay imaging
• Relatively high cost
• Can be unobtainable or harmful to obtain in unstable patients
• Radiation exposure
Ultrasound
• Bedside ultrasound (US) is an integral component of trauma management used primarily
to detect free intraperitoneal blood after blunt trauma. The trauma US examination
focuses on dependent intraperitoneal sites where blood is most likely to accumulate: the
hepatorenal space (Morison's pouch), the splenorenal recess, and the inferior portion of
the peritoneal cavity (including pouch of Douglas). These studies, when combined with
evaluation of the pericardium (which must not be neglected in the setting of BAT), are
referred to as the FAST exam (Focused Assessment with Sonography for Trauma).
Limitations of ultrasound in the setting of BAT include:
• Injury to solid parenchyma, the retroperitoneum, or the diaphragm is not well seen
• Uncooperative patients, obesity, bowel gas, and subcutaneous air interfere with image quality
• Low sensitivity in comparison to CT (82%, CI 75-89%); cannot exclude intra-abdominal injury based
on normal study
• Blood cannot be distinguished from ascites or urine
• Subcapsular injuries cannot be detected
• Insensitive for detecting bowel injury
Diagnostic peritoneal lavage (DPL)
• Diagnostic peritoneal lavage (DPL), formerly a
mainstay in the diagnosis and management of blunt
abdominal trauma (BAT), has been almost entirely
replaced by ultrasound and multidetector helical CT
(MDCT) scanning. As the role of non-operative
management and selective embolization for
abdominal injuries has expanded, the importance of
DPL in modern trauma care has dramatically
declined, particularly with BAT. The procedure may
be necessary in some cases, such as the hypotensive
BAT patient with equivocal results on FAST
examination and multiple potential sources of blood
loss, and in resource poor settings where advanced
imaging is unavailable. The role and performance of
DPL is discussed separately
Clinical indications for laparotomy
• Nonoperative management (NOM) has become standard for all but the
most severely injured BAT patients. Immediate laparotomy after injury
from a blunt mechanism is rarely based solely on clinical parameters.
Potential indications include the following:
• Unexplained signs of blood loss or hypotension in a patient who cannot be
stabilized and in whom intra-abdominal injury is strongly suspected
• Clear and persistent signs of peritoneal irritation
• Radiologic evidence of pneumoperitoneum consistent with a viscus rupture
• Evidence of a diaphragmatic rupture
• Persistent, significant GI bleeding seen in nasogastric drainage or vomitus
abdominal stab wounds
• Any instrument that can impale may inflict a stab wound (SW).
• Typically these are narrow, sharp, knife-like implements, but items
that can inflict stab wounds range from scissors to coat hangers to
animal horns. The given instrument can injure any tissue it traverses,
including skin, fascia, solid organ, hollow viscus, blood vessel, and
bone.
ANATOMIC ZONES
HISTORY
Answers to the following questions help to guide the clinician in
assessing potential injuries from abdominal stab wounds:
• What instrument was used?
• How long and how wide was the instrument?
• How was the patient positioned during the stabbing?
• What path (or paths in the event of multiple wounds) did the
implement travel?
EVALUATION
• It is important to completely undress any patient who sustains a stab
wound (SW).
• SWs can often be obscured by body habitus, clothing, or bleeding, or
be "hidden" in the axilla, scalp, perineum, or groin.
• Examine the patient carefully for evidence of more than one stab
wound.
immediate laparotomy
Patients with hemodynamic instability, evisceration, peritonitis, impalement,
or frank blood from a nasogastric tube or on rectal examination typically
undergo immediate laparotomy.
• Patients without apparent indications for laparotomy may be evaluated by
a combination of the following:
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Local wound exploration (LWE)
Plain radiograph
Computed tomography (CT)
Serial physical examinations (SPE)
Diagnostic peritoneal lavage (DPL)
Ultrasonography
Laparoscopy
Local wound exploration
• Since the entire abdominal wall is encased in a layer of fascia, stab
wounds (SWs) are often amenable to local wound exploration (LWE)
to evaluate their depth and tract.
• This procedure is quickly and safely performed at the bedside in
patients with SWs to the anterior abdomen.
• However, this approach should not be used for wounds over the chest
wall due the risk of injury to the underlying viscera (lungs) and
intercostal vessels.
Plain radiographs
• Plain radiographs typically add little to the management of abdominal
SWs.
• If free intraperitoneal air is seen on an upright chest or lateral
decubitus radiograph, then the peritoneal cavity has been violated,
but this does not confirm hollow viscus injury.
• Thus, plain radiographs lack sensitivity and specificity for significant
injuries and are rarely employed in this setting.
Computed tomography and magnetic
resonance imaging
• triple contrast (intravenous, oral, and rectal),
• Multidetector computed tomography (MDCT) is a noninvasive and rapidly
performed imaging study that enables clinicians to identify peritoneal
penetration and delineate visceral injury
• advantage of MDCT is that it enables the identification of intraperitoneal
injuries, such as hepatic lacerations, that may be amenable to
nonoperative management
• magnetic resonance imaging (MRI) has greater sensitivity for some injuries
and may play a useful role in the evaluation of hemodynamically stable
patients
• MRI may also be useful for evaluating the stable pregnant patient in need
of intraabdominal or thoracoabdominal imaging following penetrating
injury
Serial physical examination
• It is well accepted that serial physical examination (SPE) is a safe and
reliable means to detect significant intra-abdominal injuries after stab
wounds to the abdomen, if performed by experienced clinicians on
appropriate patients. Ideally, the same clinician should perform each
examination.
Ultrasound
• Bedside Focused Abdominal Sonography for Trauma (FAST)
examination is frequently used to determine the presence of
hemopericardium, hemoperitoneum, pneumo or hemothorax, or
some combination thereof.
• Overall, the specificity of the FAST examination for identifying signs of
internal injury from a stab wound appears to be high but sensitivity is
limited.
• The use of ultrasound in evaluating patients with abdominal trauma is
described in detail separately.
diagnostic peritoneal lavage
• Although invasive, diagnostic peritoneal tap and lavage is a rapid and easily
performed bedside procedure that offers information about peritoneal
penetration and injury to solid organs, bowel, and the diaphragm.
• However, the widespread use of CT and ultrasound imaging has led to a
diminishing role for this procedure
In the setting of abdominal stab wounds, diagnostic peritoneal tap and
lavage is generally used for one or more of three indications:
• Need to rapidly determine the presence of hemoperitoneum in unstable patients
• Need to identify intraperitoneal injuries that may require laparotomy in stable
patients
• Need to diagnose diaphragm injury (eg, unclear if a stab wound to the lower chest
has penetrated the peritoneum)
Diagnostic laparoscopy
• Diagnostic laparoscopy (DL) is most useful for inspecting the
diaphragm in thoracoabdominal wounds, although some studies
suggest it may be useful in evaluating the depth of wound tracts and
identifying visceral injury in patients with equivocal peritoneal
penetration
INITIAL MANAGEMENT
• General approach and indications for
laparotomy
Prophylactic antibiotics
• Broad spectrum antibiotics are generally given to patients with
penetrating abdominal injury requiring surgical management; routine
antibiotic administration is not warranted in most injured patients,
including those with penetrating abdominal injury, who are managed
nonoperatively
SPECIAL CONSIDERATIONS
• Flank and back
• Identification of structures injured from
penetrating wounds to the flank and back is
difficult. Stab wounds (SW) to these regions
can injure both retroperitoneal and
intraperitoneal structures.
• Approximately 40 percent of penetrating flank
wounds result in significant internal injury.
• Triple contrast CT (3CT) has become the
diagnostic modality of choice for stable
patients and may allow for safe triage to
nonoperative management.
• Local wound exploration (LWE), ultrasound
(US), diagnostic peritoneal lavage (DPL), and
diagnostic laparoscopy (DL) are not ideal for
evaluation of retroperitoneal structures.
SPECIAL CONSIDERATIONS
• Thoracoabdominal
• Thoracoabdominal wounds
present a diagnostic challenge as
movement of the diaphragm
makes prediction of the Stab
wounds (SW) tract difficult .
• If the wound is close to the lower
chest, intrathoracic and
diaphragmatic injuries must be
considered and evaluated in
addition to intraabdominal injury.
• Potential intrathoracic injuries
include pneumothorax,
hemothorax, and pericardial
tamponade
SPECIAL CONSIDERATIONS
• Right upper quadrant injury
• Patients with a right upper quadrant
stab wound who remain
hemodynamically stable and remain
free of abdominal tenderness on
reliable, repeated examinations may
be managed without laparotomy.
• Most patients with injuries of this
nature have sustained grade I or grade
II hepatic injuries and do not require
operative intervention.
• However, these patients should be
admitted for a period of observation.