Necrotizing soft-tissue infections

Abstract

Objectives: To evaluate the causes of necrotizing soft-tissue infections (NSTls) and to determine the outcomes of patients with NSTls.

Design: A restrospective survey of the causes and factors associated with the outcomes.

Setting: An urban community hospital serving an indigent population.

Patients: A consecutive series of patients with NTSls who were treated between December 11, 1990, and December 28, 1995.

Interventions: Patients were treated with operative debridement, intravenous antibiotics, and supportive measures.

Main outcome measures: Patient outcomes, causes, the extent of infection, the health status of the patients, causative organisms, and treatment delays.

Results: Forty-five patients with NSTls were identified. Twenty-eight cases (62%) have occurred since January 13, 1994. Parenteral drug abuse, the causative event in 25 cases (56%), accounted for 21 (75%) of the 28 cases identified since January 13, 1994. Skin flora were the primary isolates in 18 (40%) of the cases; 78% of these flora were polymicrobial. Clostridial species were isolated in 8 (18%) of the cases. The overall mortality was 27%. Survivors had less extensive infections and were more stable hemodynamically than nonsurvivors. Patients with necrosis and cellulitis greater than 250 cm2 were less likely to survive than those with less extensive infections. Logistic regression analysis identified the extents of infection, the initial blood pressure, and the initial temperature as independent predictors of outcome in this patient series.

Conclusions: This is 1 of the largest reported series of patients with NSTls in which parenteral drug abuse is a prevalent causative factor. The proportion of NSTls attributable to the injection of illicit substances has increased notably in the past 2 years and has reached epidemic proportions. Survivors of NSTls had less extensive infections and were more often hemodynamically stable than nonsurvivors. Clostridial species were common in patients with NSTls related to parenteral drug abuse, underscoring the need for awareness of the potential for wound botulism in these patients.