The Modified Early Warning Score (MEWS): an instant physiological prognostic indicator of poor outcome in acute pancreatitis.

Context: The Modified Early Warning Score (MEWS) is a bedside scoring system that is non-invasive, simple and repeatable to reflect dynamic changes in physiological state.

Objective: This study aims to assess accuracy of MEWS and determine an optimal MEWS value in predicting severity in acute pancreatitis (AP).

Methods: A prospective database of consecutive admissions with AP to a single institution was analysed to determine value of MEWS in identifying severe acute pancreatitis (SAP) and predicting poor outcome. Receiver operator curves (ROC) were used to determine optimal accuracy. Sensitivity, specificity, negative predictive value (NPV), and positive predictive values (PPV) were calculated for the optimal MEWS values obtained.

Results: One-hundred and 42 patients with AP were included. The optimal highest MEWS per 24 hours period (hMEWS) and mean MEWS per 24 hour period (mMEWS) in predicting SAP as determined by ROC were 2.5 and 1.625 respectively; with hMEWS ≥3 and mMEWS >1 utilised in this cohort as MEWS scores are whole numbers. On admission, sensitivity, specificity, NPV, PPV, and accuracy of hMEWS ≥3 was 95.5%, 90.8%, 99.0%, 65.6% and 92.0%; and for mMWES >1 was 95.5%, 87.5%, 99.0%, 58.3% and 88.7%, both superior than the Imrie score: 31.5%, 92.1%, 88.9%, 40.0% and 83.5%. The accuracy of hMEWS ≥3 and mMEWS >1 increased over the subsequent 72 hours (days 0-2) from 92 to 96%, and 89% to 94%, respectively.

Conclusions: MEWS provides a novel, easy, instant, repeatable, reliable prognostic score that may be superior to existing scoring systems. A larger cohort is required to validate these findings.