Clostridial myonecrosis (gas gangrene)
Clostridial myonecrosis is a fulminant, toxin-mediated necrotizing infection of skeletal muscle, most often from Clostridium perfringens, presenting with pain out of proportion, bullae, and gas in the tissue. Diagnosis is confirmed at surgery. Treatment is emergent surgical debridement plus penicillin and clindamycin.
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What this article covers
- Overview
Clostridial myonecrosis, commonly called gas gangrene, is a rapidly progressive, toxin-driven necrotizing infection of skeletal muscle caused by spore-forming, anaerobic Clostridium species.
- Epidemiology
Overall rarity: uncommon relative to cellulitis or streptococcal necrotizing fasciitis; no reliable population incidence exists, so it should be treated as rare but lethal, and excluded whenever pain is disproportionate.
- Risk factors
Penetrating or crush trauma: gunshot wounds, knife wounds, open fractures, and blast or crush injuries introduce spores into devitalized, hypoxic tissue.
- Pathophysiology
Clostridium perfringens, a gram-positive, spore-forming, anaerobic bacillus, is the leading cause of traumatic disease.
- Clinical features
Time course: traumatic disease can incubate in as little as 6 hours, with abrupt pain, discoloration, systemic toxicity, and bullae; spontaneous disease presents just as suddenly, with no preceding wound.
- Differential diagnosis
Necrotizing fasciitis (streptococcal or polymicrobial): shares pain out of proportion, bullae, and toxicity, but spreads along the superficial fascia and spares muscle until late; exploration distinguishes the two by which plane is dead.
- Diagnosis
What establishes the diagnosis: direct surgical exploration showing dead, noncontractile, gray to black muscle with thin, watery exudate and minimal bleeding at the cut edges, supported by Gram stain…
- Management
First, emergent surgical debridement: immediate, often repeated, radical debridement of all necrotic muscle, extending to viable, bleeding, contractile tissue; amputation is performed when…
- Complications
Septic shock and multiorgan failure: toxin-mediated vasodilation and myocardial depression can cause refractory hypotension within hours of onset.
- Prognosis
Rapid course: untreated or inadequately debrided disease can extend visibly within hours and cause death within a day, making time to surgery the dominant prognostic factor.
- Prevention
Wound irrigation and debridement at the time of injury: thorough removal of devitalized tissue, foreign material, and contamination reduces the anaerobic niche spores require.
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