Gas Gangrene (Clostridial Myonecrosis)

Alpha toxin is a zinc metalloenzyme that hydrolyzes phosphatidylcholine and sphingomyelin in cell membranes. This disrupts membrane integrity in muscle cells, erythrocytes, endothelium, and leukocytes.

Muscle cell membranes are destroyed, causing massive myonecrosis. Damaged muscle releases myoglobin, potassium, and creatine kinase. The tissue becomes non-contractile and non-bleeding.

Erythrocyte membranes are lysed, causing intravascular hemolysis. This leads to hemoglobinuria, jaundice, and renal failure. Hemolysis is a poor prognostic sign.

Endothelial damage causes increased vascular permeability, edema, and platelet aggregation. This creates a microenvironment of ischemia and anaerobiosis that favors further clostridial growth.

Severe pain at wound site, often described as bursting or tearing. Wound may appear unremarkable. Patient becomes restless and anxious. Tachycardia out of proportion to fever. This is the window for intervention.

Skin becomes tense and edematous. Color changes to bronze or bronze-brown. Hemorrhagic bullae may appear. Thin, foul-smelling dishwater discharge from wound. Pain remains severe. Systemic signs of sepsis develop.

Extensive skin necrosis with dusky/black discoloration. Crepitus may now be palpable. Patient is profoundly toxic - shock, confusion, jaundice. Muscle at wound is non-contractile, non-bleeding, and has characteristic mousy or sweet odor.

Without intervention: progressive shock, DIC, renal failure, respiratory failure. Mortality approaches 100% without surgery. Even with treatment, mortality 25-40% at this stage.

Do not delay for imaging, cultures, or HBO. Notify OR of emergency. Patient may require intubation for unstable airway or shock. Invasive monitoring (arterial line, central line). Blood products on standby.

Long incisions to fully expose all affected muscle compartments. Incisions must extend beyond clinical margins of disease. Skin flaps are not a priority - muscle is the target.

Remove all non-viable muscle (4 Cs assessment). Debride back to bleeding, contractile muscle. Be aggressive - under-debridement is the most common error. All infected tissue must be removed or patient will die.

Wounds are left open for planned second look. Pack loosely with saline-soaked gauze or apply VAC therapy. No primary closure - this traps infection.

Return in 6-24 hours for reassessment. Multiple debridements are usually required (average 3-4). Continue until no further necrotic tissue identified.