Prehospital initiation of extracorporeal life support for refractory out-of-hospital cardiac arrest–results of a prospective observational study
摘要
Despite advances in cardiopulmonary resuscitation (CPR), survival after out-of-hospital cardiac arrest (OHCA) remains low. Use of veno-arterial extracorporeal membrane oxygenation (VA ECMO) as extracorporeal CPR (ECPR) may improve outcomes in refractory OHCA. We evaluated the effect on hospital discharge rate and neurological function of integrating on-scene ECPR into routine emergency care for refractory OHCA. Besides that we assessed predictors of unfavorable outcomes.
MethodsA prospective observational study was conducted from October 2013 to September 2023 in Regensburg, Germany. A dedicated ECMO team was alerted 24/7 in parallel with standard emergency medical services for suspected OHCA. On-scene VA ECMO was initiated based on predefined inclusion/exclusion criteria. Patients were transported to a university medical center for guideline-based post-resuscitation care. Clinical data, including CPR parameters, initial physiology, and outcomes, were recorded and analyzed.
ResultsOver ten years, 11,235 alerts resulted in 2,655 (23.6%) on-scene evaluations of OHCA. VA ECMO was initiated in 213 patients with refractory OHCA (8.0% of on-scene CPR evaluations). The median time between beginning of CPR and start of VA ECMO was 45 min (IQR: 35–63). Median ECMO duration was 2 days (IQR 1–4). Survival to hospital discharge was 34.7% (74/213), with 89.2% (66/74) achieving a good neurological outcome and an independent daily living. In multivariable analysis restricted to on-scene variables, independently associated with unfavorable outcomes were: bilaterally dilated pupils (OR 5.79 [1.85–19.8]; p = 0.003), absence of bystander CPR (OR 4.38 [1.23–18.2]; p = 0.029), use of mechanical CPR devices (OR 5.53 [2.09–15.9]; p < 0.001), initial asystole (OR 35.0 [5.24–731]; p = 0.002), and CPR-to-ECMO interval > 45 min (OR 3.07 [1.09–9.14]; p = 0.037).
ConclusionsPrehospital ECPR is feasible and can be integrated into a regional emergency medical system when performed by a highly experienced team. Survival rates in this selected cohort exceeded typical OHCA outcomes, with a high proportion of patients achieving favorable neurological recovery. Early VA ECMO initiation and several on-scene factors are key determinants of prognosis.
Trial registrationGerman Clinical Trials Register. (DRKS00035400; URL: https://www.drks.de/search/de/trial/DRKS00035400)
Graphical abstract