Novel predictors of mortality in emergency bowel surgery: a single‐centre cohort study

Abstract

Pre-operative risk stratification is a key part of the care pathway for emergency bowel surgery, as it facilitates the identification of high-risk patients. Several novel risk scores have recently been published that are designed to identify patients who are frail or significantly unwell. They can also be calculated preoperatively from routinely collected clinical data. This study aimed to investigate the ability of these scores to predict 30-day mortality after emergency bowel surgery. A single centre cohort study was performed using our local data from the National Emergency Laparotomy Audit database. Further data were extracted from electronic hospital records (n = 1508). The National Early Warning Score, Laboratory Decision Tree Early Warning Score and Hospital Frailty Risk Score were then calculated. The most abnormal National or Laboratory Decision Tree Early Warning Score in the 24 or 72 h before surgery was used in analysis. Individual scores were reasonable predictors of mortality (c-statistic 0.699-0.740) but all were poorly calibrated. A National Early Warning Score ≥ 4 was associated with a high overall mortality rate (> 10%). A logistic regression model was developed using age, National Early Warning Score, Laboratory Decision Tree Early Warning Score and Hospital Frailty Risk Score as predictor variables, and its performance compared with other established risk models. The model demonstrated good discrimination and calibration (c-statistic 0.827) but was marginally outperformed by the National Emergency Laparotomy Audit score (c-statistic 0.861). All other models compared performed less well (c-statistics 0.734-0.808). Preoperative patient vital signs, blood tests and markers of frailty can be used to accurately predict the risk of 30-day mortality after emergency bowel surgery.

Death is not the worst that can happen: risk scoring and outcomes in emergency laparotomy

“…Darbyshire et al. present a novel scoring system that performs as well as the NELA score but only requires information available before surgery, addressing one of the limitations of the NELA score [6]. The model they have developed uses routinely collected and accessible patient data, and no subjective assessment is required.…”

Assessing risk in emergency laparotomy

“…It was developed from one of the largest modern contemporaneous datasets of patients undergoing emergency laparotomy and validated in other populations [3,4]. Darbyshire et al describe a new model to predict 30-day mortality after emergency laparotomy [5]. The authors suggest their risk model has advantages as it uses only objective pre-operative data rather than including subjective values such as surgical urgency, anticipated findings or ASA physical status score, and performs almost as well as the NELA score (c statistic 0.827 vs. NELA 0.861).…”

Early warning scores to assess risk before emergency laparotomy

“…I read with great interest the excellent study from Portsmouth describing a new ‘evidence‐based’ PRE‐OP model to predict mortality before emergency bowel surgery [1]. The PRE‐OP score showed good discrimination and was well calibrated.…”

“…The dramatic reported reduction in NEWS2 performance (ROC < 0.71) in patients undergoing emergency bowel surgery is cause for concern [1]. It challenges the basic premise that identical NEWS2 escalation thresholds are not disadvantageous to surgical patients.…”