Various cardiac and hypoxic aetiologies dominated. In two-thirds of IHCA episodes, the underlying cause was correctly identified by the ET, i.e. according to the findings of the aetiology study group.

BackgroundFew patients survive after out‐of‐hospital cardiac arrest and any measure that improve circulation during cardiopulmonary resuscitation is beneficial. Animal studies support that resuscitative endovascular balloon occlusion of the aorta (REBOA) during cardiopulmonary resuscitation might benefit patients suffering from out‐of‐hospital cardiac arrest, but human data are scarce.Methods and ResultsWe performed an observational study at the helicopter emergency medical service in Trondheim (Norway) to assess the feasibility and safety of establishing REBOA in patients with out‐of‐hospital cardiac arrest. All patients received advanced cardiac life support during the procedure. End‐tidal CO 2 was measured before and after REBOA placement as a proxy measure of central circulation. A safety‐monitoring program assessed if the procedure interfered with the quality of advanced cardiac life support. REBOA was initiated in 10 patients. The mean age was 63 years (range 50–74 years) and 7 patients were men. The REBOA procedure was successful in all cases, with 80% success rate on first cannulation attempt. Mean procedural time was 11.7 minutes (SD 3.2, range 8–16). Mean end‐tidal CO 2 increased by 1.75 kPa after 60 seconds compared with baseline (P<0.001). Six patients achieved return of spontaneous circulation (60%), 3 patients were admitted to hospital, and 1 patient survived past 30 days. The safety‐monitoring program identified no negative influence on the advanced cardiac life support quality.ConclusionsTo our knowledge, this is the first study to demonstrate that REBOA is feasible during non‐traumatic out‐of‐hospital cardiac arrest. The REBOA procedure did not interfere with the quality of the advanced cardiac life support. The significant increase in end‐tidal CO 2 after occlusion suggests improved organ circulation during cardiopulmonary resuscitation.Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT03534011.