SP10.1.2 Novel Predictors of Mortality in Emergency Bowel Surgery: A Single Centre Cohort Study

Abstract

Abstract Aims 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. A limitation of current risk models is that they utilise operative data in their calculation and are not designed to provide pre-operative risk-predictions. This study aimed to investigate the ability of variables that are routinely available pre-operatively to predict 30-day mortality after emergency bowel surgery. Methods A single centre cohort study was performed using local National Emergency Laparotomy Audit database (01/12/2013 to 31/01/2020). Further data was then extracted from electronic hospital records (n=1,561). The National Early Warning Score (NEWS), Laboratory-Decision-Tree-Early-Warning Score (LDTEWS) and Hospital Frailty Risk Score (HFRS) were then calculated. The most abnormal NEWS/LDTEWS scores in the 24/72-hours prior to surgery were used in analysis. Results Individual NEWS, LDTEWS and HFRS scores were reasonable predictors of mortality (c-statistic 0.689–0.735) but all poorly calibrated. NEWS scores of ≥4 were associated with a high overall mortality rate (>10%). A logistic regression model (Pre-Op) was developed using age, NEWS, LDTEWS and HFRS scores as predictor variables. The Pre-Op model demonstrated good discrimination (c-statistic 0.778) and excellent calibration, but was outperformed by the NELA score (c-statistic 0.855). Interestingly, APACHE II and P-POSSUM displayed poor calibration and fair-to-good discrimination (c-statistic 0.687–0.789). Conclusion Pre-operative 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.