From arrest to circuit: Mapping twenty years of progress and pitfalls in ECPR implementation, patient selection, and initiation timing☆.

backgroundAlthough the literature on extracorporeal cardiopulmonary resuscitation (ECPR) has grown substantially, coherent integrative paradigms remain limited. This study synthesizes two decades of research to elucidate knowledge gaps and orient future inquiry.

methodsA mapping review of studies from 2004 to 2024 was performed via PubMed and EMBASE. Only studies comparing ECPR to conventional cardiopulmonary resuscitation were included. Data were extracted and synthesized thematically.

resultsA total of twenty studies were included, the majority being retrospective and observational design, including three interventional studies. Mortality rates following ECPR remain high and more or less constant, up to 86%. To improve chances of survival, several factors need to be considered. First is patient selection: age limit, initial cardiac rhythm, bystander resuscitation with sufficient efficacy, and maximum low-flow time are common criteria, although inconsistently applied. Some studies suggest higher ECPR survival rates in specific clinical scenarios, but none of the previous studies have yet succeeded in formulating an algorithm that facilitates the identification of the most suitable candidates. The second factor affecting outcomes is the pathophysiologic processes during ECPR. This is largely unexplored territory, with current knowledge limited to observational studies of low-flow injury. Most studies do not report on factors including temperature management during support, pump flow, target mean arterial pressures, and oxygenation strategies. Lastly, and potentially most significantly, is the timing of ECPR initiation. Timely restoration and maintenance of circulation and oxygenation halt the accumulation of oxygen debt and commence oxygen debt repayment. To date, data on optimal initiation timing thresholds remains undetermined.

conclusionCurrent ECPR literature lacks knowledge across three interdependent domains that require an integrated approach: validated selection criteria, a mechanistic understanding of ischemia-reperfusion injury, and precise initiation-timing strategies. A multidisciplinary research agenda is needed to unlock the true value of ECPR in cardiac arrest care.