Out-of-hospital cardiac arrest outcomes, end-tidal carbon dioxide and extracorporeal cardiopulmonary resuscitation eligibility: New South Wales pilot data

Abstract

Objective: To describe on-scene times for out-of-hospital cardiac arrests (OHCA) transferred to hospital, the number of these that were extracorporeal cardiopulmonary resuscitation (ECPR) eligible and potential association between end-tidal carbon dioxide (ETCO₂ ) and survival so as to inform planned interventional studies.

Methods: Prospective cohort study of all OHCA, of suspected medical cause, where resuscitation was commenced and who were transported to participating hospitals from October 2020 to May 2021.

Results: One hundred and forty-nine OHCA were included. Forty-four (30%) patients survived to hospital discharge. Eighteen (8%) met ECPR inclusion criteria. Median on-scene time was 33 min (interquartile range [IQR] 24-44). Initial hospital ETCO₂ for non-survivors was 35 mmHg (IQR 19-50), survivors 36 mmHg (IQR 33-45); P = 0.215. No patient with an ETCO₂ less than 20 mmHg on hospital arrival to survived to hospital discharge.

Conclusions: Average on-scene time did not differ on survivorship. A small number of transferred patients with OHCA were ECPR eligible. ETCO₂ less than 20 mmHg portends adverse prognosis. Our data will be used for future interventional studies.

Keywords: ECPR; ETCO2; end-tidal carbon dioxide; out-of-hospital cardiac arrest; scene time.