Evaluation of Neutrophil-Lymphocyte Ratio in Early Diagnosis of Severe Acute Pancreatitis using the Computed Tomography Severity Index as Reference Standard

Objective: To evaluate the Neutrophil-Lymphocyte ratio (NLR) in the early diagnosis of severe acute pancreatitis (SAP) and to assess the disease severity as determined by Computed Tomography Severity Index (CTSI). Study Design: Cross-sectional study Place and Duration of Study: Surgery department of Combined Military Hospital, Rawalpindi, Pakistan, from Jan to Jul 2021. Methodology: A total of 107 patients diagnosed with acute pancreatitis, aged 18-70 years of either gender, were included. Patients with diseases such as chronic pancreatitis, diabetes, cardiovascular diseases, trauma, ERCP (iatrogenic), hypertriglyceridemia, alcohol, and end-stage renal and hepatic diseases were excluded. Laboratory investigations included CBC, LFT, serum amylase, serum lipase, and abdominal ultrasound. Amylase and lipase levels greater than three times normal, and ultrasonographic evidence of cholelithiasis, were reviewed by a surgical specialist to confirm the diagnosis of acute biliary pancreatitis. Results: Out of 107 participants, 41(38.31%) came out to be true positives and 7(6.54%) false positive respectively in the positive NLR group. Out of 59(55.14%) who were NLR below cut-off, 55(55.40%) were true negatives and 4(3.73%) false negatives. The positive predictive value was 85.42% whereas the negative predictive value was 93.22%. Sensitivity and specificity were 91.11% and 88.71% respectively. Conclusion: It is concluded that NLR remains a highly effective, minimally invasive, and reproducible method in predicting the outcome of acute pancreatitis, especially in the first few hours of presentation.