Meta-analysis on extracorporeal life support during cardiac arrest: do not compare apples and oranges

In a recent issue of Intensive Care Medicine, Ouweneel et al. provided a meta-analysis on extracorporeal life support (ECLS) during cardiac arrest (CA) and cardiogenic shock (1). Cardiogenic shock analysis compared ECLS vs. Impella, TandemHeart, or intra-aortic balloon pump (IABP). As these devices have various support levels, different specifications, and therefore different clinical indications, results issued from this analysis are clinically questionable. In addition, based on the recent IABP Shock II trial (2), current European guidelines on cardiogenic shock no longer support routine IABP therapy use, except for mechanical complications (class IIaC). As reported by the authors, caution is required in interpreting this part of the meta-analysis and our interest was therefore focused on the evaluation of ECLS during CA.