DESCRIPTION

• Gas gangrene or clostridial myonecrosis
• An acute, rapidly progressive, gas-forming necrotizing infection of muscle and subcutaneous tissue
• Can be seen in post-traumatic or postoperative situations
• Progressive invasion and destruction of healthy muscle tissue

ETIOLOGY

• Clostridial organisms:
  • Facultative anaerobic, spore-forming, gram-positive bacillus
  • Produces a number of toxins; the most prevalent and lethal is α-toxin.
• Clostridium perfringens is the most common bacterium; found in 80–90% of wounds.
• Other clostridial bacteria include Clostridium novyi, Clostridium septicum, Clostridium histolyticum, Clostridium bifermentans, and Clostridium fallax.
• 2 distinct mechanisms for introduction of clostridial organisms:
  • Traumatic and postoperative
  • Nontraumatic associated with diabetes mellitus, peripheral vascular disease, alcoholism, IV drug abuse, and malignancies

[Outline]

• DESCRIPTION
• ETIOLOGY

SIGNS AND SYMPTOMS

• Sudden severe pain of extremity or involved area
• Low-grade fever
• Tachycardia out of proportion to fever
• Bronzing of the skin over involved area; later can turn purple or red
• Crepitus
• Formation of blebs and bullae
• Thin, serosanguinous exudate and sweet odor
• Rapid local extension
• Obtunded sensorium
• Systemic toxicity

ESSENTIAL WORKUP

• History and physical exam with special attention to clinical evidence of crepitus in soft tissue
• Soft tissue x-rays of involved area to detect gas dissecting along fascial planes:
  • The absence of gas does not exclude significant disease.
• Stat Gram stain of wound exudate for gram-positive bacillus with paucity of leukocytes

DIAGNOSIS TESTS & INTERPRETATION

Lab

• CBC with differential, electrolytes, BUN, and creatinine
• Coagulation studies
• Evaluate for hemolysis
• Stat Gram stain of wound exudates
• Anaerobic cultures of wound or tissue biopsy

Imaging

• Radiographs may reveal soft tissue gas.
• CT if area involves abdomen or flank.

Diagnostic Procedures/Surgery

All patients with gas gangrene must undergo surgical débridement.

DIFFERENTIAL DIAGNOSIS

• Cellulitis
• Necrotizing fasciitis
• Nonclostridial myositis and myonecrosis
• Other causes of gas in tissues, as from dissection from respiratory or GI tracts

[Outline]

• SIGNS AND SYMPTOMS
• ESSENTIAL WORKUP
• DIAGNOSIS TESTS & INTERPRETATION
• DIFFERENTIAL DIAGNOSIS

PRE-HOSPITAL

Establish IV and infuse isotonic fluids

INITIAL STABILIZATION/THERAPY

Manage airway and resuscitate as indicated:

• Rapid sequence intubation as needed.
• Supplemental oxygen:
  • Cardiac and oxygen saturation monitors should be placed.
• IV access; consider central venous pressure monitoring; sepsis protocol is appropriate
• Aggressive volume expansion, including crystalloid, plasma, packed RBCs, and albumin if there is septic shock.

ED TREATMENT/PROCEDURES

• Parenteral antibiotic therapy:
  • Initial empiric therapy should cover Clostridium species and group A Streptococcus as well as mixed aerobes and anaerobes
  • Primary definitive therapy: Penicillin G + clindamycin
  • Alternative: Ceftriaxone or erythromycin
  • If mixed infection: Penicillin + clindamycin, metronidazole, or vancomycin and gram-negative coverage with gentamicin
  • Follow local sepsis protocols
• Surgical consultation:
  • Débridement, amputation, or fasciotomy is required.
• Hyperbaric oxygen (HBO) as adjunctive therapy:
  • Early transfer to hyperbaric facility may be lifesaving.
  • Lack of randomized trials with HBO but nonrandomized studies suggest benefit
• Tetanus prophylaxis
• Observe for major complications including ARDS, renal failure, myocardial irritability, and DIC.
• Polyvalent antitoxin is not made in US and studies have not demonstrated efficacy:
  • Because of the unacceptable hypersensitivity reactions, it is not routinely recommended.

MEDICATION

• Ceftriaxone: 2 g (peds: 100 mg/kg/24h max. 4 g) IV q12h
• Clindamycin: 900 mg (peds: 40 mg/kg/d q6h) IV q8h
• Erythromycin: 1 g (peds: 50 mg/kg/d q6h) q6h IV
• Gentamicin: 2 mg/kg (peds: 2 mg/kg IV q8h) IV q8h
• Metronidazole: 500 mg (peds: Safety not established) IV q8h
• Penicillin G: 24 million IU/24h (peds: 250,000 IU/kg/24h) IV q4–6h
• Tetanus immune globulin: 500 IU IM
• Tetanus toxoid: 0.5 mg IM

First Line

Primary definitive therapy for clostridial species; combination of penicillin G and clindamycin

[Outline]

• PRE-HOSPITAL
• INITIAL STABILIZATION/THERAPY
• ED TREATMENT/PROCEDURES
• MEDICATION

DISPOSITION

Admission Criteria

• All patients with gas gangrene and evidence of myonecrosis must be admitted for surgical débridement and IV antibiotics.
• Use of HBO therapy is an important adjunct.

Discharge Criteria

No patient with acute gangrene should be discharged.

Issues for Referral

After stabilization with antibiotics and surgical débridement, consider referral for HBO treatment as an adjunct.

• Bacteremia occurs in about 15% and can progress quickly to intravascular hemolysis.
• HBO as adjunctive therapy to surgical débridement and early antibiotics if patient is hemodynamically stable

ICD9

• 040.0 Gas gangrene
• 785.4 Gangrene

ICD10

• A48.0 Gas gangrene
• I96 Gangrene, not elsewhere classified

[Outline]

• ICD9
• ICD10

• Bakker DJ. Clostridial myonecrosis (gas gangrene). Undersea Hyperb Med. 2012;39(3):731–737.
• Bryant AE, Stevens DL. Clostridial myonecrosis: New insights in pathogenesis and management. Curr Infect Dis Rep. 2010;12(5):383–391.
• Headley AJ. Necrotizing soft tissue infections: A primary care review. Am Fam Physician. 2003;68(2):323–328.
• Pinzon-Guzman C, Bashir D, McSherry G et al. Clostridium septicum gas gangrene in a previously healthy 8-year old female with survival. J Pediatr Surg. 2013;48(4):e5–e8.
• Stevens DL, Aldape MJ, Bryant AE. Life-threatening clostridial infections. Anaerobe. 2012;18(2):254–259.

Stephen R. Hayden