Association between Case Volumes of Extracorporeal Life Support and Clinical Outcome in Out-Of-Hospital Cardiac Arrest

Abstract

Aim: Extracorporeal life support (ECLS) for out-of-hospital cardiac arrest (OHCA) is increasing. There is little evidence identifying the association between ECLS case volumes and outcomes in different populations received ECLS or conventional cardiopulmonary resuscitation (CPR). The goal of this investigation was to identify the association between ECLS cases volumes and clinical outcomes of OHCA patients.

Methods: This cross-sectional observational study used the National OHCA Registry for adult OHCA cases in Seoul between January 2015 and December 2019. If the ECLS volume during the study period was >20 times, the institution was defined as a high-volume ECLS centre (HV centre). Others were defined as low-volume ECLS centres (LV centres). Outcomes were good neurologic recovery (Cerebral Performance Category 1 or 2) and survival-to-discharge. We performed multivariate logistic regression and interaction analyses to assess the association between case volume and clinical outcome.

Results: 3,731 of 17,248 OHCA cases and 230 of 397 ECLS cases were transported to HV centres. Among the patients underwent ECLS, HV centres showed a higher neurologic recovery rate than low-volume centres (17.0% vs. 12.0%). The adjusted OR for good neurologic recovery was 2.22 (95% Confidence Interval (CI): 1.15–4.28) in HV centres compared to LV centres. For population with conventional CPR, HV centres also showed higher survival-to-discharge rates and an adjusted OR of 1.16 (95%CI: 1.01–1.34).

Conclusions: HV centres showed better neurological recovery in patients underwent ECLS. HV centres also had better survival-to-discharge rates than those transported to LV centres, despite not receiving ECLS.

Note:
Funding Declaration: This investigation was not supported by any fund.

Conflict of Interests: This study had no conflict of interest.

Ethical Approval: This study complied with the Declaration of Helsinki and its protocol was approved by the Institutional Review Board of the study institution. The requirement for informed consent was waived (IRB No: 1103- 153-357).

Keywords: out-of-hospital cardiac arrest, extracorporeal membrane oxygenation, case volume, extracorporeal life support, outcome