Mortality in patients with necrotizing fasciitis.

Background: The prognostic factors that determine outcome in patients with necrotizing fasciitis remain poorly understood. The aim of this study was to analyze the variables that affect the mortality and morbidity of patients with necrotizing fasciitis and to create a simple method for estimating the probability of mortality.

Methods: The authors undertook a retrospective review of all patients with necrotizing fasciitis treated in three tertiary care hospitals in Ontario, Canada, between January of 1994 and June of 2001. Demographic, comorbid illness, and disease-specific data were collated and analyzed for associations with outcome. Using logistic regression analysis, probability estimates for the prediction of mortality were developed, based on three contributing independent factors.

Results: Ninety-nine patients satisfied the inclusion criteria. Overall mortality was 20 percent. Sixteen patients suffered from amputation or organ loss. The most common comorbidities were diabetes (30 percent), immunocompromised status (17 percent), and chickenpox (11 percent). Advanced age (odds ratio, 1.04; 95 percent confidence interval, 1.01 to 1.08; p = 0.012), streptococcal toxic shock syndrome (odds ratio, 10.54; 95 percent confidence interval, 2.80 to 39.44; p < 0.001), and immunocompromised status (odds ratio, 3.97; 95 percent confidence interval, 1.04 to 15.19; p = 0.044) were independent predictors of mortality and were used to design a formula for the probability of mortality.

Conclusions: Age, streptococcal toxic shock syndrome, and immune status are significant determinants of mortality and can predict the probability of death from necrotizing fasciitis soon after admission. This objective information can guide clinicians in communication with patients and in making clinical decisions.