A study on the prognostic value of red cell distribution width to total serum calcium ratio in acute pancreatitis and comparison with Ranson’s and BISAP score - a prospective observational study from a tertiary care center in Chennai

Background: Acute pancreatitis (AP) is a severe inflammatory condition with variable outcomes, and current scoring systems have limitations in predicting its severity. Our study aimed to determine the prognostic value of the red cell distribution width (RDW) -to-total serum calcium ratio in patients with AP. Methods: This single-center prospective observational study included 100 patients at Madras Medical College, Rajiv Gandhi Government General Hospital between September 2023 and 2024. 16 patients with severe AP were compared to 84 mild AP cases by assessing demographics, aetiology, comorbidities, laboratory results, arterial blood gas, and RDW at 0 and 24 hours. The RDW-to-total serum calcium ratio was evaluated against the established prognostic scores within 24 h of admission. Results: A total of 100 patients with acute pancreatitis were included in the study, of which 84 (84%) had mild AP, and 16 (16%) had severe AP. The RDW/TSC ratio demonstrated excellent predictive value for mortality, with an area under the receiver operating characteristic curve (AUROC) of 0.909, sensitivity of 95.40%, and specificity of 85.70%. This outperformed RDW at 0 hours (AUROC=0.789), bedside index of severity in acute pancreatitis (BISAP) (AUROC=0.764), and Ranson’s score (AUROC=0.711). RDW at 24 hours showed no significant predictive value (AUROC=0.529). Conclusions: RDW and RDW 0h-to-TSC ratio are cost-effective, non-invasive markers that predict acute pancreatitis (AP) severity and mortality more effectively than Ranson and BISAP scores. An RDW 0 hours >14.15 and RDW 0 hours-to-TSC ratio >1.45 were strong predictors of AP severity.