Neutrophil to Lymphocyte Ratio (NLR) and Platelet to Lymphocyte Ratio (PLR) Versus Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) as Predictors of Outcome in Necrotising Fasciitis

Abstract

Necrotizing fasciitis (NF) is an aggressive infection with substantial morbidity and mortality despite advanced medical care, possibly due to non-specific clinical features in the initial stages. Prognostic indicators help in early diagnosis, risk stratification and decision-making. We analysed a historical cohort of 122 patients with biopsy-proven NF. Receiver operating characteristic (ROC) curve analysis was performed to find the cutoff levels for neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) as predictors of mortality, need for re-debridement and intensive care unit (ICU) stay. Patients were grouped according to cutoff levels of NLR, PLR and Laboratory Risk Indicator for NECrotizing fasciitis score (LRINEC) and their outcomes were compared. A multivariate logistic regression analysis was performed to assess the association between significant independent predictors of outcome in NF. Of the 122 patients who were studied, the mean age was 59.9 ± 14.1 years, with 81 (66.3%) patients being male. Among them, 112 (91.8%) were survivors and 9(8.2%) were non-survivors. Non-survivors were diabetics (100%), hypertensive (100%), had ischemic heart disease (77%) and had higher values of CRP (p < 0.001), creatinine (p = 0.003), LRINEC (p < 0.001), and NLR (p = 0.005). Patients who required repeat surgeries were older (p = 0.032), had higher white cell counts (p = 0.002), CRP (p = 0.01), LRINEC (p < 0.001), NLR (p < 0.001) and lower haemoglobin (p = 0.02). A multivariate logistic regression analysis revealed that NLR (p = 0.001), LRINEC (p = 0.002), creatinine (p = 0.002) and the presence of IHD (p = 0.002) were reliable predictors of poor outcome. LRINEC is a reliable predictor of outcome according to our study. The preoperative NLR (but not PLR) may be used as a potential and easy biomarker for prognostication in patients with necrotising fasciitis.