Red Cell Distribution Width-to-Albumin Ratio as an Early Predictor of Intensive Care Requirement and Mortality in Acute Pancreatitis

TL;DR

This study suggests that a blood test measuring red cell distribution width-to-albumin ratio (RAR) could help predict the need for intensive care and mortality in acute pancreatitis patients.

Contribution

The study introduces RAR as a novel, inexpensive biomarker for early prediction of ICU admission and mortality in acute pancreatitis.

Findings

RAR showed good predictive performance for ICU admission with an AUC of 0.781.

RAR demonstrated high predictive performance for in-hospital mortality with an AUC of 0.927.

RAR outperformed BISAP score in predicting ICU admission but not other scoring systems like PASS, HAPS, or SIRS.

Abstract

Background and Objectives: Acute pancreatitis (AP) is an acute inflammatory disease ranging from mild, self-limiting forms to severe presentations associated with high morbidity and mortality. Early prognostic assessment is crucial for guiding clinical management. This study aimed to evaluate the prognostic value of the red cell distribution width-to-albumin ratio (RDW/Alb, RAR) in relation to clinically relevant outcomes, including intensive care unit (ICU) admission and in-hospital mortality, in patients with AP. Materials and Methods: This retrospective study included 282 patients diagnosed with AP who were hospitalized at Mersin University Hospital between January 2019 and February 2024. Clinical, laboratory, and radiological data were retrospectively analyzed. The predictive performance of RAR was evaluated and compared with established clinical scoring systems, including bedside index for severity in acute pancreatitis (BISAP), systemic inflammatory response syndrome (SIRS), harmless acute pancreatitis score (HAPS), and pancreatitis activity scoring system (PASS). Results: The median RDW-to-albumin ratio (RAR) was 3.9 (range: 2.6–36.7). Receiver operating characteristic (ROC) curve analysis demonstrated that RAR showed good predictive performance for ICU admission (Area Under the Curve (AUC): 0.781; p < 0.001; optimal cut-off: 4.15) and high predictive performance for in-hospital mortality (AUC: 0.927; p < 0.001; optimal cut-off: 5.26). RAR exhibited limited but statistically significant discriminatory performance when compared with the BISAP score (AUC: 0.591; p = 0.017), whereas no significant predictive performance was observed in relation to PASS, HAPS, or SIRS scores. Conclusions: Within the context of this retrospective cohort, RAR is a simple, inexpensive, and readily available biomarker that may be associated with ICU admission and in-hospital mortality in patients with AP. Given the absence of standard severity endpoints such as persistent organ failure or pancreatic necrosis, these findings should not be interpreted as evidence of conventional disease severity prediction but rather as hypothesis-generating observations that warrant validation in larger prospective studies.

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