Can the emergency surgery score (ESS) be used as a triage tool predicting the postoperative need for an ICU admission?

Abstract

© 2018 Elsevier Inc. Background: The emergency surgery score (ESS) is a preoperative risk calculator recently validated as a mortality predictor in emergency surgery (ES) patients. We sought to evaluate the utility of ESS as an ICU admission triage tool. Methods: A four-step methodology was designed. First, the 2007–2015 ACS-NSQIP database was examined to identify all ES patients using the “emergent” variable and CPT codes for “digestive system”. Second, we created a composite variable called ICUneed, defined as death or the development of one or more postoperative complication warranting critical care (e.g. unplanned intubation, ventilator dependent ≥48 h, cardiac arrest, septic shock and coma ≥24 h). Third, for each patient, ESS was calculated. Fourth, the correlation between ESS and ICUneed was assessed by calculating the model c-statistics (AUROC). Results: Out of a total of 4,456,809 patients, 65,989 patients were included. The mean population age was 56 years; 51% were female, and 71% were white. The overall 30-day postoperative mortality and morbidity were 8.2% and 31.7%, respectively. ESS gradually and accurately predicted ICUneed, with 1%, 40% and 98% of patients with ESS of 2, 9 and 16 requiring critical care, respectively. Only 6.2% of patients with ESS ≤7 had an ICUneed, while 97.2% of patients with ESS ≥15 had an ICUneed. The c-statistic of the predictive model was 0.90. Conclusions: ESS accurately predicts the need for postoperative critical care and ICU admission. In resource-limited settings, ESS may prove useful as an ICU triage tool ensuring a prompt rescue of the clinically deteriorating patient without unnecessary and burdensome ICU admissions.