O20 Quick, simple and just as effective—comparing pm: L3 ratio to NELA, P-POSSUM and NSQIP scores in assessing mortality risk for emergency laparotomy

Abstract

Abstract Introduction Multiple tools (NELA, P-POSSUM, ACS-NSQIP) are available to assess mortality risks in patients requiring emergency laparotomy(1–3), but they are time-consuming to perform and have had limited uptake in routine clinical practice in many countries(4). Simpler measures, including psoas muscle: L3 vertebrae (PM: L3) ratio(5,6), may be useful alternates. This measure is quick to perform, requiring no special skills or equipment apart from basic CT viewing software. Method We performed an analysis on all patients in the Hunter Emergency Laparotomy Audit (HELA) database, from January 2016 to December 2017. HELA is a retrospective review of all emergency laparotomy undertaken in a discrete area in NSW, Australia. Patients with an available CT abdomen were included (N = 500/562). A single slice axial CT image at the L3 endplate level was analysed using ImageJ® software to measure the area of L3 and bilateral psoas muscles. This can be done using normal PACS software in routine practice. Result PM: L3 ratios in this cohort have a mean of 1.082 (95%CI 1.042–1.122; range 0.141–3.934). PM: L3 ratio is significantly lower (P < 0.00001) in those patients who did not survive beyond 30 days (mean 0.865 [95% CI 0.746–0.984]) and 90 days (mean 0.888 [95%CI 0.768–1.008]) compared to patients that survived these periods (30 day mean 1.106 [95% vs. 1.033–1.179], 90 day mean 1.112 [95% CI 1.070–1.154]). These associations are similar to those calculated by established risk assessment models. Conclusion PM: L3 ratio is a reliable, quick and easy risk assessment tool to identify high risk patients undergoing emergency laparotomy. Take-home Message PM: L3 ratio is a reliable, quick and easy risk assessment tool to identify high risk patients undergoing emergency laparotomy. It is comparable to NELA, P-POSSUM and ACS-NSQIP.