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Audio-Digest GENERAL SURGERY
®
Volume 60, Issue 01
January 7, 2013
INFECTIONS IN GENERAL SURGERY
Highlights from Trauma, Critical Care, and Acute Care Surgery, presented by the Trauma and Critical Care Foundation
intensive care unit (ICU) or operating room; consistent use of
Injury-Related Infection
strict sterile technique in placement of pleural tubes required
Frederick A. Luchette, MD, MSc, the Ambrose and Gladys
even in emergency situations (best performed by surgeon)
Brower Professor of Surgery, Loyola University of ChiMeningitis: life-threatening highly fatal complication of head
cago, Stritch School of Medicine, Chicago, IL
trauma, particularly with penetrating injury or violation of skin
and dura during craniotomy; often related to cerebral spinal
Gas gangrene: Clostridium perfringens — releases collagenase
and hyaluronic acid, which cause digestion of tissue; mortalfluid fistula; Staphylococcus most common pathogen; diagity can occur in hours to days; risk factors — primary closure
nosis usually confirmed with lumbar puncture (LP), but most
of dirty wounds with inadequate debridement of devitalized
patients require CT before LP to rule out mass lesions above
tissue; open tibial fractures; diabetes; clinical signs — spikforamen magnum; management — antibiotics that rapidly pening temperatures (103°-104°F); confusion and anxiety; tachyetrate subarachnoid space (fourth-generation cephalosporins
cardia (120-130 bpm); foul-smelling “dirty water” drainage
and vancomycin typically used)
from wounds; treatment — considered surgical emergency;
Blood transfusion: more discriminate use seen in last 10 yr;
aggressive debridement, with amputation of limb if necessary;
testing and screening not adequate to identify all pathogens
maximal doses of penicillin in divided doses (clindamycin or
in all samples; risk for hepatitis B due to blood transfusion
metronidazole if patient allergic to penicillin); use of hyperdecreasing; no new case of hepatitis C due to blood transfusion
baric oxygen therapy controversial
reported since 1994
Osteomyelitis: currently, most commonly associated with trauIntra-abdominal abscess: colonic injury most common risk facmatic injuries, except in pediatric population (open epiphyses
tor; incidence increases with delay of repair of colonic injury
can become infected with bacteremia); develops in wounds
for >12 hr; abscesses polymicrobial (including Bacteroides,
caused by frontal or lateral high-impact trauma; nidus always
Escherichia coli, and Klebsiella); multidrug-resistant organin avascular segment of bone; risk factors — diabetes; periphisms major concern in hospitalized patients; clinical signs
eral vascular disease; use of tobacco; consumption of alcohol;
include tachycardia, fever, and increasing abdominal pain;
diagnosis — requires high index of suspicion; most common
risk for multi-organ failure increases with delay in diagnosis;
clinical sign break in incision or skin wound with intermittent
abscesses identified by CT; most intra-abdominal abscesses
drainage of fluid; magnetic resonance imaging (MRI) or comdrained percutaneously; multiseptate abscesses, thick fluid, and
puted tomography (CT) may help in diagnosis (show thickened,
no improvement after tube placement indicate open drainage
inflamed, and edematous periosteum); definitive diagnosis made
via surgical exploration and debridement of devitalized bone
Fungal Infections in the ICU
Septic arthritis: infection of joint; usually due to penetrating
Robert C. Mackersie, MD, Professor of Surgery, Univerinjuries, but may occur with blunt trauma; common mechanism trauma with violation of joint, with resulting soft tissue
sity of California, San Francisco, School of Medicine, and
infection that invades joint; destruction of cartilage due to
Director, Trauma Services, San Francisco General Hospiinflammation causes long-term morbidity; known complicatal and Trauma Center
tion of open fractures that involve joints; commonly seen with
Background: fungal cells parasitic; cell walls made of polysacpatellar injuries, tibial plateau fractures, and fractures at elbow
charide; 200,000 species exist; yeast — single-celled organover ulna; management requires aggressive irrigation, debrideisms;
reproduce via asexual budding, or fusion; have aerobic
ment of devitalized fragments, and stabilization of fracture to
respiration; associated with fermentation; dull-colored, with
reduce ongoing ischemia; presentation — joint pain and swellround or oval shape; molds — composed of multicelled filaing; treatment — arthrotomy (arthroscopy preferred, but open
mentous structures (hyphae); have primarily aerobic respiraprocedure may be required); long-term antibiotics to allow
tion; Aspergillus primary mold in fungal infections in ICU;
penetration through synovial fluid to treat infected cartilage
candidal species primary yeast in ICU
Empyema: risk factors — retained hemothorax (chest tubes must
Epidemiology: incidence of infection highly dependent on
completely remove blood from pleural space); study by DemeICU; incidence of fungal infection reported as 17%; 85% to
triades — CT superior to chest X-ray for identifying residual
90% of invasive fungal infections (IFIs) in ICU candidal speblood in pleural space; study — incidence 33% when chest tubes
cies (>50% of these Candida albicans); species vary based
inserted in prehospital emergency setting; incidence decreases
to 9% if inserted in emergency department (ED), and to 6% in
on population of ICU (eg, whether transplantation or trauma
Educational Objectives
Faculty Disclosure
The goal of this program is to improve the management of
infections encountered in general surgery. After hearing and
assimilating this program, the clinician will be better able to:
1. Recognize signs and symptoms of injury-related infections.
2. Select an appropriate therapeutic approach and medications to treat invasive fungal infection.
3. Evaluate the evidence from comparisons of interventions
for colonic obstruction.
4. Determine whether a patient with Clostridium difficile
colitis is a candidate for surgical treatment.
5. Follow appropriate vaccination protocols.
In adherence to ACCME Standards for Commercial Support,
Audio-Digest requires all faculty and members of the planning
committee to disclose relevant financial relationships within
the past 12 months that might create any personal conflicts of
interest. Any identified conflicts were resolved to ensure that
this educational activity promotes quality in health care and
not a proprietary business or commercial interest. For this program, the faculty and planning committee reported nothing to
disclose. In his lecture, Dr. Wisner presents information related
to the off-label or investigational use of a therapy, product, or
device.
AUDIO-DIGEST GENERAL SURGERY 60:01
predominates); overall mortality rate for IFIs 50% to 70%
(47% in US hospitals)
Consensus definition of IFI: recovery of fungus (yeast or mold)
via sterile procedure from normally sterile site (eg, mold cultured
from urine [normally sterile]), with associated clinical and radiologic abnormalities consistent with infectious disease process
Diagnosis: positive blood cultures — sensitivity only 50%;
serologic assays — 1,3--D-glucan assay has sensitivity as
high as 80%; candidal galactomannan assay has shown 100%
sensitivity in some studies; polymerase chain reaction — still
under development; not widely available; systemic inflammatory response (SIRS) — patients with high risk plus fever,
tachycardia, and leukocytosis should be targeted for evaluation; “educated guess” — derivation of indices possible from
number of sites colonized with noninvasive fungal infection or
infection plus SIRS
Therapeutic approaches: based on fungal culture; presumptive — patients with SIRS plus risk factors and fungal colonization; empiric — “blind” therapy chosen for patients with SIRS
risk factors who fail to improve on initial therapies; prophylactic — preventive therapy based on risk factors only; study — mortality increases 50% to 70% each day initiation of therapy delayed
Risk factors for IFI: prolonged use of antibiotics; immune suppression; steroids; burns; malnutrition; renal failure; prolonged
indwelling central venous catheters; multisystem trauma; prolonged total parental nutrition (TPN); prolonged mechanical
ventilation; elevated Acute Physiology and Chronic Health
Evaluation (APACHE) II score; neutropenia
Presumptive treatment: 1994 study — derived colonization
index (number of positive sites per number sites cultured);
threshold 50%; negative predictive value for colonization
100%; critical care study — created predictive model for IFI
with Candida by looking at sepsis, colonization, TPN, and surgery; positive predictive value 16%; captured 81% of IFIs
Empiric treatment: 2008 study — positive predictive value 36%
to 38%; authors concluded approach did not improve outcomes
Prophylactic treatment: studies show potential for prevention of
Candida infections; utility dependent on likelihood of fungal infection in particular ICU (requires tailoring to individual populations)
Antifungal agents: amphotericin — highly toxic; lipid-complex
amphotericin — liposomal B least toxic and most efficacious;
triazoles — fluconazole most common; efficacious against C
albicans, but other Candida resistant; extended-spectrum triazoles effective against other species, but have multiple drug
interactions; relatively inexpensive; echinocandins — available
since 2008; broad spectrum (effective for yeast and molds);
show minimal drug resistance and relatively few drug interactions; as effective as triazoles in some settings; use limited
by current high cost; stop production of 1,3--D-glucan; have
potential for combination therapy; no dose adjustments for
renal function required
Sample treatment algorithm: for patient with yeast in blood,
no recent treatment with antifungal agents, and no major organ
dysfunction, start treatment with fluconazole; if not candidal
species, change to echinocandin or extended-spectrum triazole;
use echinocandins if patient compromised, or species resistant;
additional amphotericin used as rescue therapy
Comparative studies: find triazoles and echinocandins to be appropriate for first-line treatment of IFI with Candida; amphotericin
effective but more toxic alternative (used for rescue therapy)
Acute Colorectal Crises
David H. Wisner, MD, Professor and Vice Chair of Surgery, University of California, Davis, School of Medicine,
Sacramento
Acute colonic obstruction: management options — manual decompression; placement of irrigation catheters above obstruction and
irrigation of colon; randomized study — outcomes similar with
use of either methodology
Primary anastomosis: retrospective study — included equal
numbers of patients with obstruction or perforation, and smaller
number with sepsis; most patients with obstruction treated with
primary anastomosis; patients treated with diversion procedure had higher morbidity and mortality rates; relatively low
leak rate seen in patients with anastomosis; patients selected
for anastomosis likely those less severely ill; single-institution
study — patients with acute obstructing cancer of colon or rectum treated with anastomosis vs diversion and stoma; some
patients did not have reconstruction as planned; no differences
seen in mortality or 5-yr survival rates; patients treated with
Hartmann surgery had longer lengths of stay
Stenting: review study — clinical and technical success rates
>90%; stenting allowed subsequent surgery in 75% of patients;
rate of migration 12%; rate of reobstruction associated with
quality of original stenting and time to definitive treatment; rate
of perforation 4%; multi-institution study — patients with leftsided colon malignancies randomized to stenting vs emergency
surgery; no differences seen in short- or long-term outcomes;
several stent-related perforations seen; nonsignificant number
of patients with stents had leakage after subsequent anastamosis surgery
Bevacizumab (Avastin): monoclonal antibody against vascular
endothelial growth factor (VEGF); used in treatment of multiple
cancers, including colon cancer; MD Anderson study — 1.5%
to 2% of patients treated with bevacizumab developed bowel
perforation; 30-day mortality 12%; patients who require surgery for perforation have high rate of wound complications;
hold bevacizumab 1 to 2 mo before abdominal surgery; ensure
all wounds healed before starting new intervention
Clostridium difficile colitis: study — over 11-yr period, 4% of
hospitalized (ICU admission or surgical) patients had serious C difficile colitis; patients with persistent infection have
higher mortality rate; surgical treatment requires careful consideration; however, delay in decision making increases risk
for death; indications for surgery — older age; very high or
low white blood cell counts; patient on vasopressors or intubated; patient has not been treated with oral vancomycin; evidence suggests colectomy likely to save patient’s life; requires
removal of entire colon (down to peritoneal reflection)
Vaccination Protocols
Karen J. Brasel, MD, MPH, Professor of Surgery, Bioethics, and Humanities, Medical College of Wisconsin,
Milwaukee
Tetanus: children — diphtheria and tetanus or diphtheria, tetanus, and pertussis; dosages differ for adults; adults — tetanus
and diphtheria; tetanus, diphtheria, and pertussis; recommendations — after 11 yr of age, tetanus vaccination only needed
once; repeating every 10 yr no longer recommended if patient
has no risk factors for tetanus (but no harm if given); liberal
recommendations for tetanus immunization arise from concerns about herd immunity for diphtheria and pertussis (ie,
outbreaks of diphtheria and pertussis more problematic than
infection with tetanus); tetanus toxoid not recommended for
any primary or secondary immunization or tetanus-prone
wound unless patient has documented allergy to diphtheria
or pertussis component of combination vaccine
Vaccination of trauma patients: determine patient’s history
of tetanus immunization (if available) and type of wound;
tetanus-prone wounds include compound fractures, foreign
bodies, extensive devitalization or crush injuries, and reimplantation of teeth; give tetanus vaccine if patient immunized
between 5 and 10 yr ago; if vaccination >10 yr ago, vaccinate
regardless of wound type; tetanus immune globulin required
only if history uncertain and wound tetanus-prone
AUDIO-DIGEST GENERAL SURGERY 60:01
Rabies: most often contracted through bite from infected animal (in United States, most commonly from bats; worldwide,
most commonly from unvaccinated dogs); timing between
bite and development of symptoms extremely variable
(ranges from 24-48 hr to 1 mo); symptoms (pain, fatigue,
fever, seizures, paralysis, and death) often attributed to other
etiologies; untreated rabies almost universally fatal; high
fatality rate accounts for almost 30,000 postexposure vaccinations given each year; recommendation — only 2 doses
of vaccine required if previously vaccinated for rabies; vaccinate immediately after bite and repeat after 3 days; 4 doses
required if patient has had no previous vaccination (give
immediately and subsequently over 2 wk, in addition to
rabies immune globulin)
Treatment of rabies (Milwaukee protocol): patient 15 yr of age
bitten by bat; symptoms began 1 mo after exposure; treating physicians realized giving vaccine would stimulate host
reaction and worsen outcome; patient treated with sedation, mitochondrial supplementation (tetrahydrobiopterin
and coenzyme Q10) and antiviral drugs; electroencephalography, CT angiography, viral titers in cerebral spinal fluid
continuously monitored; conclusion — avoid rabies immune
globulin and vaccination in patients treated for rabies after
development of symptoms; use sedation during treatment;
however, if bite known and no symptoms have yet developed,
vaccination series strongly recommended
Cholera: 01 and 0139 subtypes of Vibrio cholerae cause epidemics and reportable; found in contaminated water, fish, and
shellfish (person-to-person transmission rare); safe food and
water precautions and routine hand washing recommended for
prevention; only 60 cases reported in United States over last
10 yr; symptoms ranged from asymptomatic to life-threatening
diarrhea; as vaccination painful and provided poor immunity,
recommendation for immunization dropped, even for persons
traveling to endemic areas; oral vaccines developed and available outside of United States (recommended only for relief
workers in endemic areas)
Acknowledgements
Drs. Luchette, Mackersie, Wisner, and Brasel were recorded at Trauma, Critical Care and Acute Surgery, held March 26-28, 2012, in
Las Vegas, NV, and sponsored by the Trauma and Critical Care Foundation. To attend the next Trauma, Critical Care, and Acute Care
Surgery Conference, to be presented March 17-20, 2013, in Las Vegas, NV, please visit www.trauma-criticalcare.com. The Audio-Digest
Foundation thanks the speakers and the Trauma and Critical Care Foundation for their cooperation in the production of this program.
Suggested Reading
Ansaloni L et al: Guidelines in the management of obstructing
cancer of the left colon: consensus conference of the world society of emergency surgery (WSES) and peritoneum and surgery
(PnS) society. World J Emerg Surg 5:29, 2010; Badgwell BD et
al: Management of bevacizumab-associated bowel perforation:
a case series and review of the literature. Ann Oncol 19:577,
2008; Hermsen ED et al: Validation and comparison of clinical prediction rules for invasive candidiasis in intensive care unit
patients: a matched case-control study. Crit Care 15:R198, 2011;
Kedzierska A et al: Current status of fungal cell wall components in the immunodiagnostics of invasive fungal infections in
humans: galactomannan, mannan and (1 — >3)-beta-D-glucan
antigens. Eur J Clin Microbiol infect Dis 26:755, 2007; Koss K
et al: The outcome of surgery in fulminant Clostridium difficile
colitis. Colorectal Dis 8:149, 2006; Lim JF et al: Prospective,
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continuing education by the American Academy of Nurse Practitioners
randomized trial comparing intraoperative colonic irrigation with
manual decompression only for obstructed left-sided colorectal
cancer. Dis Colon Rectum 48:205, 2005; Nigg AJ et al: Overview, prevention and treatment of rabies. Pharmacotherapy
29:1182, 2009; Patel GP et al: The effect of time to antifungal therapy on mortality in Candidemia associated septic shock.
Am J Ther 16:508, 2009; Synnott K et al: Timing of surgery for
fulminating pseudomembranous colitis. Br J Surg 85:229, 2008;
Velhamos GC et al: Predicting the Need for Thoracoscopic
Evacuation of Residual Traumatic Hemothorax: Chest Radiograph Is Insufficient. J Trauma 46:65, 1999; Zaragoza R et al:
Multidisciplinary approach to the treatment of invasive fungal
infections in adult patients. Prophylaxis, empirical, preemptive
or targeted therapy, which is the best in the different hosts? Ther
Clin Risk Manag 4:1261, 2008.
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AUDIO-DIGEST GENERAL SURGERY 60:01
INFECTIONS IN GENERAL SURGERY
To test online, go to www.audiodigest.org and sign in to online services.
To submit a test form by mail or fax, complete Pretest section before listening and Posttest section after listening.
1. Which of the following statements about wound infections due to Clostridium perfringens (gas gangrene) is true?
(A) Risk for mortality increases 2 to 3 wk after infection
(B) Hyperbaric oxygen is considered standard therapy
(C) Should be treated as a surgical emergency**
(D) Associated with low-grade fevers
2. All the following statements about osteomyelitis are true, except:
(A) Tends to occur in highly vascularized segments of bone**
(B) Often occurs after frontal or lateral high-impact trauma
(C) Thickened and inflamed periosteum may be seen on imaging studies
(D) Surgical exploration and debridement is the definitive diagnostic examination
3. Which of the following statements about injury-related infections are true?
1. Septic arthritis is a known complication of open fractures that involve joints
2. Chest x-ray and computed tomography (CT) are equally efficacious for identifying blood in the pleural space
3. CT is not necessary before performing lumbar puncture
4. Since 1994, there have been no new cases of hepatitis C due to blood transfusion
5. The incidence of intra-abdominal abscess increases with >48 hr delay before repair of colonic injury
(A) 1,2
(B) 3,4
(C) 1,4,5**
(D) 2,3,5
4. Choose the correct statement(s) about invasive fungal infections (IFIs) encountered in the intensive care unit.
(A) Most are due to species of Aspergillus
(B) Include molds cultured from nonsterile wounds
(C) A and B
(D) Neither A nor B**
5. According to studies of patients with IFIs, a colonization index had 100% _______ predictive value for colonization; no
improvement in outcome was found with the use of _______ therapy.
(A) Negative; prophylactic
(C) Positive; prophylactic
(B) Negative; empiric**
(D) Positive; empiric
6. Fluconazole is efficacious against most candidal species other than Candida albicans.
(A) True
(B) False**
7. According to studies of patients with colonic obstruction, which of the following statements is true?
(A) Patients treated with primary anastomosis had higher morbidity and mortality, compared to patients treated with
colonic diversion
(B) Patients treated with Hartmann surgery (diversion and stoma) had shorter lengths of stay
(C) Migration of stents is extremely rare in patients treated with stenting
(D) No difference was seen in short- and long-term outcomes between patients with colon malignancies treated with
stenting and those who had emergency surgery**
8. All the following are indications for surgery in patients with Clostridium difficile colitis, except:
(A) Previous treatment with oral vancomycin**
(C) Very high white blood cell count
(B) Older age
(E) Treatment with vasopressors
9. Tetanus immune globulin is required only if:
(A) The patient’s vaccination history is uncertain
(B) The patient has a tetanus-prone wound
(C) A and B **
(D) Neither A nor B
10. According to the Milwaukee Protocol, which of the following is not recommended for a patient who has symptoms of rabies after being bitten by an infected animal?
(A) Continuous monitoring of electroencephalography
(B) Rabies immune globulin**
(C) Antiviral drugs
(D) Sedation
Answers to Audio-Digest General Surgery Volume 59, Issue 24: 1-D, 2-A, 3-A, 4-B, 5-D, 6-B, 7-A, 8-A, 9-B, 10-B
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