Predicting the mortality of necrotizing fasciitis with blood pressure and white blood cell count

Abstract

AimEven with modern care, necrotizing fasciitis (NF) is a life‐threatening emergency disease. The present study attempts to identify simple clinical admission characteristics or laboratory tests to differentiate between high‐ and low‐mortality risk groups in patients with NF.Patients and MethodsThe records of 272 patients who received debridement were reviewed. The χ 2‐test (or the Mann–Whitney U‐test) and C4.5 decision tree were utilized to analyse 23 clinical characteristics and laboratory tests. The main outcome measure was in‐hospital mortality.ResultsThe overall mortality rate was 17 per cent. Three independent predictors of mortality – white blood cell (WBC) count; left shift in the differential WBC count, with an increase in immature neutrophils (band form); and hypotension – were determined using the C4.5 decision tree. From these predictors, a decision tree was produced to classify patients with NF into high‐ and low‐mortality risk groups. The accuracy of the C4.5 decision tree with cross‐validation was 84.2 per cent (95 per cent confidence interval: 80.3–88.1 per cent).ConclusionUsing routine blood pressure measurements and simple laboratory tests of WBC count and differentials, clinicians can rapidly identify patients with high‐mortality risk.