Wet gangrene

Background

Gangrene General Info

• A form of tissue necrosis characterized by critically insufficient blood supply leading to tissue death.
• Primarily divided into wet gangrene vs dry gangrene. Other, specific forms of gangrene include Fournier's gangrene, gas gangrene, and necrotizing fasciitis.
• Most commonly occur in distal extremities, clasically the feet.
• Main risk factors are diabetes, smoking, and peripheral arterial disease.

Clinical Features

Wet gangrene with presumed gas.

Wet gangrene of foot.

• Usually due to peripheral arterial or venous disease, but can also be sequelae of trauma or burns causing vascular injuries.
• Presents with swollen, pale, soft tissue, often with a putrid smell and purulent discharge.
• As tissue is infected, wet gangrene presents a higher risk of systemic infection than dry gangrene.

Differential Diagnosis

Foot infection

• Gout
• PsuedoGout
• Cellulitis
• Gangrene
  • Dry gangrene
  • Wet gangrene
• Trench foot
• Abscess
• Necrotizing soft tissue infections
  • Necrotizing fasciitis
  • Necrotizing myositis
  • Necrotizing cellulitis
• Osteomyelitis
• Diabetic foot infection
• Charcot Foot

Look A-Likes

• Peripheral artery disease
• Sporotrichosis
• Deep venous thrombosis

Evaluation

Workup

• CBC
• Chemistry
• Consider:
  • X-ray
  • blood cultures
  • lactate

Diagnosis

• History and physical examination are usually sufficient to make the diagnosis.
• Given higher risk for systemic infection, patients should be evaluated for signs/symptoms of sepsis

Management

• Requires surgical consultation as rapid debridement or amputation of necrotic tissue is required to prevent further spread of infection.

Antibiotics

Requires broad spectrum antibiotic coverage, as these are often polymycrobial infections. Examples:

• Ceftriaxone 1g IV q24h [infuse first] + vancomycin 1g IV or per pharmacy + metronidazole 500mg IV q8h (+ clindamycin 900mg IV q8h if suspect streptococcal toxic shock syndrome)

Antibiotics

Coverage	Drugs
Broad-spectrum (typical start)	Piperacillin-tazobactam OR meropenem OR cefepime + metronidazole
MRSA	Add vancomycin or linezolid
Anaerobic/gas gangrene	Penicillin G + clindamycin
Polymicrobial (common in diabetics)	Carbapenem monotherapy or combo therapy (e.g., ceftriaxone + metronidazole + vancomycin)

Disposition

• Admission

See Also

• Gangrene