Role of Laboratory Risk Indicator For Necrotizing Fasciitis (LRINEC) Score in Differentiating Necrotising Fasciitis From Soft Tissue Infections

Abstract

Introduction: Necrotizing fasciitis (NF) is a life-threatening soft tissue infection characterized by rapidly progressive necrosis of subcutaneous tissues and deep fascia planes, with resulting skin gangrene and severe systemic infection. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is used to distinguish NF from other soft tissue infections.

Methods: We conducted a prospective cohort study among 104 patients between July 2018 and June 2020. Ethical approval was obtained from the institutional review committee. A consecutive sampling method was used. The sensitivity, specificity, positive predictive value, and negative predictive value of cut-off scores of 6 and 8 were evaluated. Analysis was done using SPSS -20 and p value <0.05 was considered statistically significant

Results: Among 104 patients, 50(48.1%) patients were diagnosed with necrotizing fasciitis and 54 (51.9%) as severe cellulitis. The mean LRINEC score was 6.36 ± 2.58 for the NF group and 3.31 ± 2.48 for the severe cellulitis group, and the difference was statistically significant (p < 0.001). For a LRINEC cut-off score ≥6, the sensitivity was 68% (95% CI 53.30% to 80.48%), specificity was 74%(95% CI 60.35% to 85.04%), positive predictive value (PPV)  70.83% (95% CI 59.82% to 79.84%), and negative predictive value (NPV)  71.43% (95% CI 61.83% to 79.41%). The area under the receiver operating characteristic (ROC) curve for the accuracy of the LRINEC score was 0.798 (95% CI 0.714 to 0.881).

Conclusions: The Laboratory Risk Indicator for Necrotizing Fasciitis score is a useful tool for necrotizing fasciitis risk stratification and differentiation of necrotizing fasciitis from severe cellulitis.