Backrest Position and Outcome in Comatose Survivors of Out‐of‐Hospital Cardiac Arrest: Protocol for a Multi‐Center Randomized Comparison Within the Danish Out‐of‐Hospital Cardiac Arrest ( <scp>DANOHCA</scp> ) Trial

BACKGROUND: Intensive care following resuscitation from out-of-hospital cardiac arrest (OHCA) is based on a set of interventions, all of which are intended to reduce anoxic brain injury and improve outcomes, including sedation, mechanical ventilation, circulatory optimization, and temperature control protocols. The backrest position impacts intracranial pressure and cerebral blood flow in traumatic brain injury, and the optimal position for improving outcomes after OHCA is unknown; guidelines advocate for an elevated backrest position. This trial compared outcomes of two backrest positions. METHODS: The Danish Out-of-Hospital Cardiac Arrest (DANOHCA) trial is an investigator-initiated, multicenter, randomized, controlled trial evaluating four interventions, including two different backrest positions, for improving outcomes. Comatose adult patients with OHCA of presumed cardiac cause and sustained return of spontaneous circulation will be included. Patients were randomized 1:1 to a backrest positioned at 5° or 35° straight elevation of backrest in the Semi-Fowler's position (elevated lower limb position) during the initial 72 h or until extubation. The primary outcome was mortality within 90 days of cardiac arrest. Inclusion began in June 2023, and the study aims to include 1000 patients from five sites over an estimated time period of 3-4 years. Kaplan-Meier curves with Cox regression will be used for statistical analyses. The trial is registered at clinicaltrials.gov (identifier: NCT05895838) and euclinicaltrials.eu (2024-515997-28-00). PERSPECTIVES: Post-resuscitation care of comatose cardiac arrest is complex, and each part should be tested in randomized trials. This part of the DANOHCA trial will provide evidence on one of these factors, namely position of the patients' head relative to the heart. TRIAL REGISTRATION: EudraCT number 2016-003265-26; EU CTIS no 2024-515997-28-00; ClinicalTrials.gov identifier: NCT05895838.