Necrotizing Soft Tissue Infection

Necrotizing soft tissue infections (NSTIs) encompass a spectrum of deep soft tissue infections including necrotizing fasciitis, necrotizing myositis, and Fournier gangrene (perineal necrotizing infection), all characterized by rapid tissue destruction, systemic toxicity, and high mortality without emergent surgical intervention. The pathophysiology involves bacterial invasion of the subcutaneous tissue and fascia, with bacterial toxins and enzymes causing direct tissue destruction, thrombosis of nutrient blood vessels leading to tissue ischemia and necrosis, and intense systemic inflammatory response. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score uses six laboratory values (CRP, WBC, hemoglobin, sodium, creatinine, glucose) to stratify risk, with a score greater than or equal to 6 suggesting NSTI. Clinical findings that distinguish NSTI from simple cellulitis include pain disproportionate to appearance, rapid progression despite antibiotics, skin changes (dusky discoloration, hemorrhagic bullae, crepitus from gas-producing organisms), systemic toxicity (fever, tachycardia, hypotension), and failure to respond to initial antibiotic therapy. The nurse performs serial wound assessments with erythema margin marking, recognizes clinical deterioration and escalates immediately, prepares for emergent surgical exploration and debridement, administers broad-spectrum antibiotics (covering aerobic, anaerobic, and MRSA organisms),...