The Simplified Acute Physiology Score II as a Predictor of Mortality in Patients Who Underwent Extracorporeal Membrane Oxygenation for Septic Shock

Abstract

The use of extracorporeal membrane oxygenation (ECMO) for patients with septic shock is controversial. The outcomes are favorable in children but heterogeneous in adults. The present study aimed to analyze the outcomes of adult patients who underwent ECMO for septic shock, and to determine the factors associated with prognosis. We respectively reviewed the medical records of patients who underwent ECMO for septic shock between January 2007 and December 2013. Patients were divided into survivor and nonsurvivor groups based on survival to hospital discharge. The patient characteristics before and during ECMO were compared between the groups. Independent risk factors for mortality were evaluated using multivariate logistic regression, receiver-operating characteristic curves, and Kaplan-Meier analysis. Twenty-eight patients were treated with venoarterial (n= 21), venovenous (n= 4), or venoarteriovenous (n= 3) mode ECMO. The overall survival rate to hospital discharge was 35.7%. The Simplified Acute Physiology Score II (SAPS II) and prealbumin were predictors of survival to hospital discharge. The optimal cutoff value for SAPS II was 80 (area under the curve 0.80, p= 0.010). Kaplan-Meier survival curves showed that the cumulative survival rate at hospital discharge and at 54-month follow-up was significantly higher among patients with SAPS II of 80 or less compared with patients with SAPS II greater than 80 (66.7% versus 12.5% and 58.3% versus 12.5%, respectively; p= 0.001). It is still difficult to conclude whether ECMO should be recommended as therapy for adult patients with septic shock. However, a SAPS II score of 80 or less may be an indicator of favorable outcomes with the use of ECMO.