Red cell distribution width and ratio of red cell distribution width-to-total serum calcium as predictors of outcome of acute pancreatitis

Background: Current severity assessment scores of acute pancreatitis (AP) include multiple variables, the results of which are available only after 48 h of admission. Red cell distribution width (RDW) and total serum calcium (TSC) are simple routine parameters related to inflammatory status and results of which are readily available. Aim: The aim of this study was to evaluate RDW and RDW: TSC within 24 h of hospital admission as predictors of outcome (severity and mortality) and intervention (medical/percutaneous drainage/surgical) required by patients of AP. Materials and Methods: All the patients diagnosed with AP at a tertiary care hospital were enrolled for the study. Values of RDW and TSC along with data regarding the treatment given were collected. Diagnosis and severity were defined according to the revised Atlanta classification 2012. Results and Interpretation: Cutoff value for RDW (area under the receiver operating characteristic curve [AUROC]: 0.997; P = 0.000) to predict the severity of AP was 16.25% (sensitivity - 100% and specificity - 97.1%,) (sensitivity - 100% and specificity - 97.1%, positive predictive value - 92.31%, negative predictive value - 100%, and Youden Index - 0.971), while that of RDW:TSC (AUROC: 1; P = 0.000) was 2.42 (sensitivity - 100%; specificity - 100%, positive predictive value - 100%, negative predictive value - 100%, and Youden Index - 1.00). Similarly, the cutoff value for RDW (AUROC: 0.947; P = 0.000) to predict mortality in AP was 17.20% (sensitivity - 100%; specificity - 87.4%, positive predictive value - 38.89%, negative predictive value - 100%, and Youden Index - 0.874) and that of RDW-to-TSC ratio (AUROC: 0.975; P = 0.000) was 2.9 (sensitivity - 100%; specificity - 96.6%, positive predictive value - 70%, negative predictive value - 100%, and Youden Index - 0.966). Conclusion: Our study found that RDW and RDW: TSC were quick, convenient, economic, sensitive, and dependable prognostic predictors of severity and mortality in patients with AP.