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oa Out-of-hospital ECPR
- Source: Qatar Medical Journal, Volume 2017, Issue 1 - Extracorporeal Life Support Organisation of the South and West Asia Chapter 2017 Conference Proceedings, Feb 2017, 26
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- 14 February 2017
Abstract
Veno-arterial extracorporeal membrane oxygenation (ECMO) has been used successfully for several years in refractory cardiogenic shock. Of note, the survival rate is markedly affected by the underlying patient condition, and especially their capacity to recover. Combes et al.1 demonstrated a short- and a long-term survival rate (11 months of median follow-up time) of, respectively, 42 and 36% in a large series of patients with cardiogenic shock of various origins, including fulminant myocarditis (30%), post-cardiotomy (24%), post-myocardial infarction (15%), and shock after heart transplantation (15%). In that study,1 implantation during cardiopulmonary resuscitation (CPR) was associated with a marked increase in the risk of death (OR 20.68 (1.09–392.03)).
As the probability of achieving return to spontaneous circulation (ROSC) decreases rapidly when the duration of cardiopulmonary resuscitation CPR exceeds 10 min and dramatically after 30 min,2 some clinicians questioned whether ECMO could also be used to restore flow in patients not responding to classical resuscitation procedures. Data of ECMO for out-of-hospital cardiac arrest (OHCA) or extracorporeal CPR (ECPR) are scarce and conflicting. Several case reports and small series suggested some benefits but these were subject to publication bias. The first large study of 51 patients with OHCA showed a very low survival rate, with only two survivors.3 Recently, some other teams reported more favorable outcomes. In 42 patients with OHCA, Kagawa et al.4 reported a 30-day survival of 24%, with a favorable neurological outcome of 21% in the group of OHCA patients who received intra-arrest percutaneous coronary intervention (PCI). One of the explanations for the variability of the results is the duration from cardiac arrest to ECMO initiation. Leguen et al.3 reported a 4% of survival with a time to ECMO of 120 min, while studies with more favorable outcomes reported a shorter time to ECMO (40 min [25–51]) in the trial by Kagawa et al.,4 and systematic implementation of intra-arrest PCI. Indeed, the difference in outcome between in-hospital and OHCA results depends more on the duration of cardiac arrest than on the location of the cardiac arrest itself.
Importantly, all series mentioned that selection of candidates for ECPR seems to be crucial, especially in the setting of OHCA: witnessed cardiac arrest, with a no-flow period < 5 min, whenever possible bystander CPR or a very rapid response team, a pre-hospital care policy prompting to alert a specialized hospital with an ECMO team, and rapid transport after initiation of CPR (scoop and run strategy). In addition, good quality CPR should be provided from the start up to the initiation of ECMO flow.5,6
In conclusion, when used, all efforts should be made to minimize the time from cardiac arrest to ECMO flow, as the latter is a critical determinant of outcome. Organ donation might be considered in patients with poor neurological outcomes, but experiencing full recovery of organ function.