An Observational Study on The Effectiveness of LRINEC (Laboratory Risk Indicators For Necrotising Fascitis) Scoring System in The Diagnosis of Necrotising Fascitis Among Patient Presenting With Soft Tissue Infection
Keywords:
necrotizing fasciitis; LRINEC score; soft tissue infection; early diagnosis; diagnostic accuracy.Abstract
Background: Necrotizing fasciitis (NF) is an aggressive, rapidly progressing life-threatening soft tissue infection that is associated with higher mortality if diagnosed late. Clinical signs of early NF are like cellulitis or an abscess, so an easy and cheap bedside tool is required. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is based on six common laboratory values. Its diagnostic utility in the patient with soft tissue infections was tested.
Methods: This is a prospective, observational study of 50 consecutive patients with SSTIs over a period of two years at a tertiary care centre. At presentation, the LRINEC score was computed and the patients divided into low risk (≤5), intermediate risk (6-7) and high risk (≥8). Biopsy results were used as the reference standard. Patients with and without NF were compared, and a receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance.
Results: The mean age was 52.78 ± 14.12 years and 72% of patients were male. In the study, 17 patients (34%) were diagnosed with NF by biopsy. The mean LRINEC score was significantly higher in NF (9.65 ± 2.17 vs 3.73 ± 2.05; p<0.0001). There were significant differences in C-reactive protein, total leukocyte count, serum creatinine, serum sodium and blood glucose levels but not in haemoglobin levels between the groups. The area under the ROC curve was 0.979 (95% CI 0.891–0.999). The ROC derived cutoff point of >6 had a sensitivity of 94.12% and specificity of 90.91%. The sensitivity was 100% and specificity 84.85% with positive predictive value of 77.27%, negative predictive value of 100% and accuracy of 90% at the conventional cut-off ≥6.
Conclusion: LRINEC score was found to be a simple and reliable tool to differentiate NF from other soft tissue infections in this cohort. It must be used in conjunction, not in place of, clinical judgment.
