Necrotising soft tissue infection-risk factors for mortality

Abstract

Necrotising Soft Tissue Infection is a rapidly progressing fatal disorder, the prognosis of which depends on early diagnosis and management.

Objective: In this study, our objective was to assess the factors contributing to mortality due to NSTI.

Methods: A retrospective review of the records of all patients with NSTI involving fascia, skin or muscle between January 2007 and December 2011, was performed. The atiology, predisposing factors, risk factors, causative microbiological organisms and the clinical outcomes associated with mortality were studied. Statistical Data: Descriptive statistics comprising of proportion(%) presented. Chi-square test was employed to assess the statistical significance in the distribution of various known risk factors between the survivors and non-survivors. A 'p' value less than 0.05 was considered significant.

Results: Sixty patients records were reviewed. Fifty-one patients (85%) were males and nine (15%) were females. Mean age was 46.57 years (+/- 20.60) ranging from 15-83 years. All the patients were treated by debridement & wide spectrum antibiotics. Mono-microbial atiology being found in 27 patients (63.3%) and polymicrobial culture was isolated in 13 patients (36.7%), with E-coli and staphylococci being the most common organisms to be isolated. In most patients, multiple debridements were done. The overall mortality rate was estimated to be 25%. Age, aatiology, diabetes mellitus, hypoalbuminemia, alcohol, site of infection, bacteriology etc. were the risk factors associated with mortality, that were evaluated. Diabetes mellitus was the most common associated risk factor found in 32 patients (53.3%), though not statistically significant. Increasing age (>50 years, p value = 0.016), raised Serum Creatinine (>1.2mg/dl, p-value = 0.023) and delayed surgical intervention(>24 hours p value= 0.006) were the risk factors associated with Mortality in NSTI that were statistically significant.

Conclusion: Despite the use of appropriate antibiotic treatment, aggressive debridement & resuscitation, NSTI still leads to a high mortality & morbidity. In this series, there is high mortality associated with increasing age, raised serum creatinine and delayed surgical intervention. The mortality rate (25%) is comparable with other studies.

Keywords: Necrotising soft tissue infection; Necrotizing fasciitis.