para>Antibiotics given before cultures are obtained may alter lab findings
Plain radiographs may show SC air (rare; specific but not sensitive).
CT may reveal soft tissue swelling and gas in tissues.
MRI is useful for soft tissue imaging.
Imaging should not delay prompt surgical therapy.
Test Interpretation
- Frozen-section biopsy of the fascia is diagnostic. Do not delay treatment pending biopsy.
- Soft tissue necrosis, with polymorphonuclear cells and vascular thrombosis
TREATMENT
GENERAL MEASURES
- Prompt and wide surgical d ©bridement is the cornerstone of treatment.
- Hyperbaric oxygen (HBO) is an adjunct to antibiotics and aggressive surgical d ©bridement.
- HBO therapy in NF is controversial, no consistent survival benefit has been demonstrated.
- Do not delay surgical intervention for HBO.
- IV fluids with electrolyte repletion
- Tetanus prophylaxis
MEDICATION
First Line
- Precautions: Without surgical d ©bridement, antibiotics will not be effective.
- Important: Do not delay antibiotic treatment, even if smear, cultures, and tests are negative.
- Start with broad-spectrum antibiotics then tailor to culture results and organism sensitivities.
- For mixed infection: ampicillin-sulbactam or piperacillin-tazobactam plus clindamycin plus ciprofloxacin; OR carbapenem; OR cefotaxime plus metronidazole or clindamycin; for PCN allergy: clindamycin or metronidazole with an aminoglycoside or fluoroquinolone
- Clindamycin 600 mg QID IV works synergistically with penicillin 2 to 4 MU QID IV when large bacterial load is present and also binds group A streptococci toxin.
- For Streptococcus infection: penicillin plus clindamycin
- For S. aureus infection: nafcillin 1 to 2 g q4h IV, or oxacillin 1 to 2 q4h IV, or cefazolin 1 g q8h IV; vancomycin 30 mg/kg/day in 2 divided doses IV or linezolid 600 mg q12h if concern for MRSA
- For Clostridium infection: clindamycin or penicillin
- There may be a survival benefit with IV immunoglobulin therapy (binds toxins and superantigens to suppress inflammatory mediators)
- Unlike C. perfringens and group A β-hemolytic streptococci, Aeromonas sp. are uniformly resistant to penicillin G (but are reported to be highly sensitive to 3rd-generation cephalosporins).
- In high-risk patients with multiple comorbidities and risk factors for NF, start with a double antibiotic regimen.
SURGERY/OTHER PROCEDURES
- Necrotizing soft tissue infections are surgical emergencies. Take patients to the OR as soon as the diagnosis is clinically suspected or confirmed.
- All necrotic tissue should be resected. Dissection should be carried out along all involved fascial planes. Adequate d ©bridement takes priority over tissue preservation.
- Limb amputation may be necessary because of extensive fascial and SC soft tissue necrosis and overwhelming systemic toxicity.
- Adequate surgical treatment is rarely accomplished with a single operation. Repeated daily d ©bridement may be necessary. D ©bridement should continue until all necrotic tissue is removed.
- Negative-pressure suction dressing (i.e., vacuum-assisted closure dressing) may help with wound care and postoperative fluid management.
- Reconstruction can be undertaken once all nonviable tissue has been removed and the patient is stable.
INPATIENT CONSIDERATIONS
Nursing
- Following surgical d ©bridement, patients often require ICU-level care.
- Close contacts of patients and health care workers do not require chemoprophylaxis with antibiotics.
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
- May require ICU-level critical care
- Monitor for clinical signs indicating need for repeated d ©bridement.
- As clinically indicated, may include following cultures, electrolytes, drug levels
DIET
Depends on clinical scenario
PROGNOSIS
- Mortality for NF ranges from 10% to 20% (3)[B].
- Mortality from necrotizing soft tissue infections is decreasing, possibly due to improved recognition and earlier delivery of more effective therapy (4)[C].
- Increased mortality is associated with age >60 years, male, IV drug abuse, malnutrition, significant medical comorbidities (e.g., cardiac or pulmonary disease), carcinoma, and presence of bacteremia.
- Fournier gangrene in females may have increased risk for mortality (5)[B].
- Independent predictors of mortality include:
- Admission WBC count >30,000
- Creatinine level >2 mg/dL within 48 hours of admission
- Presence of clostridial infection
- Presence of heart disease
- Independent predictors of limb loss include:
- Shock (systolic pressure <90 mm Hg) on admission
- Clostridial infection
- Presence of heart disease
COMPLICATIONS
- Tissue and functional losses
- Amputation
- Septic shock
- Death
REFERENCES
11 Lancerotto L, Tocco I, Salmaso R, et al. Necrotizing fasciitis: classification, diagnosis, and management. J Trauma Acute Care Surg. 2012;72(3):560-566.22 Kaafarani HM, King DR. Necrotizing skin and soft tissue infections. Surg Clin North Am. 2014;94(1):155-163.33 Kao LS, Lew DF, Arab SN, et al. Local variations in the epidemiology, microbiology, and outcome of necrotizing soft-tissue infections: a multicenter study. Am J Surg. 2011;202(2):139-145.44 Ustin JS, Malangoni MA. Necrotizing soft-tissue infections. Crit Care Med. 2011;39(9):2156-2162.55 Czymek R, Frank P, Limmer S, et al. Fournier's gangrene: is the female gender a risk factor? Langenbecks Arch Surg. 2010;395(2):173-180.66 Kobayashi L, Konstantinidis A, Shackelford S, et al. Necrotizing soft tissue infections: Delayed surgical treatment is associated with increased number of surgical debridements and morbidity. J Trauma. 2011;71(5):1400-1405.
ADDITIONAL READING
- Faraklas I, Stoddard GJ, Neumayer LA, et al. Development and validation of a necrotizing soft-tissue infection mortality risk calculator using NSQIP. J Am Coll Surg. 2013;217(1):153-160.e3.
- Kim KT, Kim YJ, Won Lee J, et al. Can necrotizing infectious fasciitis be differentiated from nonnecrotizing infectious fasciitis with MR imaging? Radiology. 2011;259(3):816-824.
- Morgan MS. Diagnosis and management of necrotising fasciitis: a multiparametric approach. J Hosp Infect. 2010;75(4):249-257.
- Sarani B, Strong M, Pascual J, et al. Necrotizing fasciitis: current concepts and review of the literature. J Am Coll Surg. 2009;208(2):279-288.
- Sartelli M, Malangoni MA, May AK, et al. World Society of Emergency Surgery (WSES) guidelines for management of skin and soft tissue infections. World J Emerg Surg. 2014;9(1):57.
- Soh CR, Pietrobon R, Freiberger JJ, et al. Hyperbaric oxygen therapy in necrotising soft tissue infections: a study of patients in the United States Nationwide Inpatient Sample. Intensive Care Med. 2012;38(7):1143-1151.
- Wong CH, Khin LW, Heng KS, et al. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections. Crit Care Med. 2004;32(7):1535-1541.
CODES
ICD10
- M72.6 Necrotizing fasciitis
- L03.90 Cellulitis, unspecified
- A48.0 Gas gangrene
- N49.3 Fournier gangrene
ICD9
- 728.86 Necrotizing fasciitis
- 682.9 Cellulitis and abscess of unspecified sites
- 040.0 Gas gangrene
- 785.4 Gangrene
SNOMED
- Necrotizing fasciitis (disorder)
- cellulitis (disorder)
- Gas gangrene (disorder)
- Fournier's gangrene
- anaerobic cellulitis (disorder)
- Gangrenous disorder (disorder)
- Infection due to anaerobic bacteria
CLINICAL PEARLS
- Necrotizing infections are associated with potentially life-threatening rapidly progressive, widespread fascial necrosis.
- NF may be mono- or polymicrobial.
- Consider necrotizing soft tissue infection in patients who have pain out of proportion to the physical exam.
- Surgical d ©bridement and antibiotic therapy are the primary treatments for necrotizing soft tissue infections.
- A delay of >12 hours in surgical treatment is associated with an increased need for repeat surgical d ©bridements, septic shock, and acute kidney injury (6)[B].