Complications of extracorporeal membrane oxygenation for treatment of cardiogenic shock and cardiac arrest: a meta-analysis of 1,866 adult patients

Background: Venoarterial extracorporeal membrane oxygenation (ECMO) has been used successfully for treatment of cardiogenic shock or cardiac arrest. The exact complication rate is not well understood, in part because of small study sizes. In the absence of large clinical trials, performance of pooled analysis represents the best method for ascertaining complication rates for ECMO.

Methods: A systematic PubMed search was conducted on ECMO for treatment of cardiogenic shock or cardiac arrest in adult patients only, updated to November 2012. Studies with more than 10 patients published in the year 2000 or later that reported complication rates for ECMO were included. Specific complications analyzed included lower extremity ischemia, fasciotomy or compartment syndrome, amputation, stroke, neurologic complications, acute kidney injury, renal replacement therapy, major or significant bleeding, rethoracotomy for bleeding or tamponade, and significant infection. For studies that included overlapping patients, the largest study was included and the others excluded. Cochran's Q and I-squared were calculated. A more conservative random-effects model was chosen for all analyses.

Results: Twenty studies were included in the analyses encompassing 1,866 patients. Seventeen studies reported survival to hospital discharge, with a cumulative survival rate of 534 of 1,529, and a range of 20.8% to 65.4%. Analyses encompassed 192 to 1,452 patients depending on the specific complication analyzed. The pooled estimate rates of complications with 95% confidence intervals were as follows: lower extremity ischemia, 16.9% (12.5% to 22.6%); fasciotomy or compartment syndrome, 10.3% (7.3% to 14.5%); lower extremity amputation, 4.7% (2.3% to 9.3%); stroke, 5.9% (4.2% to 8.3%); neurologic complications, 13.3% (9.9% to 17.7%); acute kidney injury, 55.6% (35.5% to 74.0%); renal replacement therapy, 46.0% (36.7% to 55.5%); major or significant bleeding, 40.8% (26.8% to 56.6%); rethoracotomy for bleeding or tamponade in postcardiotomy patients, 41.9% (24.3% to 61.8%); and significant infection, 30.4% (19.5% to 44.0%).

Conclusions: Although ECMO can improve survival of patients with advanced heart disease, there is significant associated morbidity with performance of this intervention. These findings should be incorporated in the risk-benefit analysis when initiation of ECMO for cardiogenic shock is being considered.