Pulse pressure as a prognostic marker in patients receiving extracorporeal life support.

Background: It is not easy to predict the prognosis of patients receiving extracorporeal life support (ECLS) because of the highly variable situation around its implementation. We evaluated the role of pulse pressure (PP), which is available on real-time basis, as a hemodynamic prognostic marker during ECLS.

Methods: From January 2009 to August 2011, data from 69 patients who were treated with ECLS for at least 6h in a single center for any cause was collected. We calculated the mean PP over the first 6h after ECLS implantation and examined if there was any correlation between mean PP and the study endpoints, in-hospital death and ECLS weaning failure.

Results: The causes of ECLS were of cardiac origin in 36 patients (52%). 27 patients (39.1%) weaned off ELCS and 13 patients (18.8%) survived to discharge. In Cox regression analysis (with age, Killip class ≥3, ECLS implementation during cardiopulmonary resuscitation (CPR), CPR duration, out-of-hospital arrest, initial laboratory results including blood gas analysis, initial systolic blood pressure (SBP), mean SBP over the first 6h after ECLS implantation, mean PP over the first 6h after ECLS implantation as independent variables), mean PP over the first 6h after ECLS implantation (hazard ratio [95% confidence interval]=0.96[0.94-0.98], P<0.001) and out-of-hospital arrest (HR[95%CI]=2.04[1.14-3.62], P=0.02) were independent predictors of in-hospital mortality and mean PP over the first 6h after ECLS implantation (HR[95% CI]=0.95[0.93-0.98], P<0.001) was the sole independent predictor of weaning failure.

Conclusion: Higher mean PP over the initial 6h after ECLS implementation independently predicted successful weaning and survival. Our findings may help better predict and analyze prognosis in patients receiving ECLS.