Impact of preexisting organ dysfunction on extracorporeal life support for non-postcardiotomy cardiopulmonary failure.

BACKGROUND: Extracorporeal life support (ECLS) is associated with a high mortality rate in patients with preexisting multiple organ failure. To achieve better outcomes of ECLS in this high risk group, an understanding of the real impact of preexisting organ dysfunction on ECLS-associated mortality is necessary.
METHODS: From January 2003 to March 2007, a total of 45 patients (mean age: 48 years) were placed on ECLS for acute cardiopulmonary failure and survived longer than 24h. The medical records of these 45 patients were retrospectively reviewed. The indications for ECLS were acute respiratory distress syndrome (n=23), acute myocarditis (n=10) and acute myocardial infarction (n=12). Organ failure was assessed based on the Sequential Organ Failure Assessment (SOFA) score, which was calculated daily until ECLS termination. The demographic variables, SOFA score variables, and ECLS-related complications, including renal dialysis, severe brain damage and limb ischemia, were analysed.
RESULTS: Twenty-seven patients (60%) were weaned from ECLS and 21 (47%) survived to discharge. Multivariate analysis revealed that the necessity of renal dialysis was an independent risk factor associated with failure to wean and non-survival, and the necessity of cardiopulmonary resuscitation (CPR) before ECLS was an independent risk factor for non-survival. Preexisting organ dysfunction, quantified by the pre-ECLS SOFA score, was predictive of survival to discharge. A pre-ECLS SOFA score greater than 14 predicted mortality in this study.
CONCLUSIONS: SOFA score is a practical assessment tool and is predictive of ECLS-associated mortality in non-postcardiotomy patients. Patients having cardiac arrest requiring CPR or acute renal failure requiring dialysis before ECLS may have inferior ECLS outcomes.