Extracorporeal membrane oxygenation to support adult patients with cardiac failure: predictive factors of 30-day mortality

Abstract

Adult patients supported on extracorporeal membrane oxygenation (ECMO) are very sick and many complications are often present in each single patient; therefore, it is not always easy to find some risk factors that can predict the early outcome. This retrospective study reports our experience in ECMO support treatment in adult cardiac patients suffering from cardiac failure (CF) in which one or more predictive factors of 30-day mortality were analyzed. Between January 2002 and August 2009, 42 consecutive adult cardiac patients with cardiogenic shock (mean age 64.3+/-11.3 years) were supported on ECMO for >2 days. They were divided into patients who had a survival <30 days (n=20) and patients who survived >30 days (n=22). Twenty-nine patients (69%) survived on ECMO. Sixteen patients were discharged with a survival rate of 38.1%. The overall mean ECMO duration was 7.9+/-5.3 days. The following variables were significantly different between the two groups: number of platelets and packed red blood cells (PRBCs) transfused per day during ECMO (P=0.002 and P=0.003), blood lactate levels 48 h and 72 h after the initiation of ECMO (P=0.01 and P=0.04), indexed blood flow after 48 h and 72 h (P=0.01 and P<0.0001), liver failure (P=0.001) and multiorgan failure (P=0.002). Stepwise logistic regression identified that blood lactate levels at 48 h and number of PRBCs transfused were associated with 30-day mortality [P=0.019, odds ratio (OR) =2.16; 95% confidence interval (CI)=1.13-4.14 and P=0.008, OR=1.08; 95% CI=1.02-1.14, respectively]. The predicted probability of mortality would be 52% when blood lactate levels are >3 mmol/l after 48 h. The blood lactate level at 48 h and PRBCs transfused per day can be considered as important parameters to predict the mortality in adult cardiac patients supported by ECMO for CF.