Abstract Background Out-of-hospital cardiac arrest (OHCA) remains a major cause of mortality, with low survival probabilities to hospital discharge. Despite the frequent use of airway management and mechanical ventilation during resuscitation, there is limited evidence regarding the optimal ventilation strategy to improve oxygen delivery and patient outcomes. The present study aims to investigate the effects of positive-end-expiratory-pressure (PEEP) set at 5 mbar compared to zero-end-expiratory-pressure (ZEEP) on the return of spontaneous-circulation (ROSC) in adult patients with OHCA. Methods This is a prospective, multicenter, cluster-randomized controlled trial conducted across emergency medical services (EMS) in the regions of Gütersloh, Minden-Lübbecke, and Osnabrück. Adult patients (≥ 18 years) with OHCA who are undergoing mechanical ventilation through an airway device will be enrolled. The clusters (regional districts) will be randomized into two groups: one group will receive ventilation with PEEP set at 5 mbar (intervention group), while the other group will receive ventilation with ZEEP (control group). The study’s primary endpoint is the occurence of ROSC. Secondary endpoints include occurence of re-arrest, death during pre-hospital care phase, hospital admission during ongoing resuscitation, hospital admission with spontaneous circulation, peripheral oxygen saturation, and endtidal CO 2 at hospital admission. Discussion Optimal ventilation strategies during OHCA have not been well established. The use of PEEP may improve oxygenation and oxygen delivery. This study aims to provide crucial data on whether the application of PEEP at 5 mbar vs. 0 mbar can improve the probability of ROSC without adversely affecting hemodynamics. The findings could inform future guidelines on ventilation strategies in resuscitation. Trial registration The trial is registered on ClinicalTrials.gov under the registration number NCT06836830. 24.02.2025 https://clinicaltrials.gov/study/NCT06836830?term=gerrit%20jansen&rank=2 .
Vaseekaran et al. (Wed,) studied this question.