The First Hour After ROSC: Impact Of Early Ventilation And Gas Exchange On Neurologic Outcome After Cardiac Arrest

Abstract

Background Cardiac arrest remains associated with high mortality and neurological morbidity. The early post-resuscitation phase is critical for cerebral recovery – ventilatory management may represent a modifiable determinant of outcome.

Methods We performed a retrospective analysis of adult patients admitted to the Department of Emergency Medicine at the Medical University of Vienna, a certified cardiac arrest center, after out-of-hospital cardiac arrest with sustained return of spontaneous circulation (sROSC) between May 2022 and December 2024. Patients treated with extracorporeal life support were excluded. The primary outcome was favorable neurological recovery defined as cerebral performance category 1 or 2. Ventilator and gas-exchange parameters (tidal volumes, driving pressure, peak airway pressure, ventilation frequency, PEEP, F_IO₂, PaO₂ and PaCO₂) from the first hour post-ROSC were analyzed as time-weighted means. Associations with neurological recovery were assessed using multivariable logistic regression adjusted for cardiac arrest characteristics. The ethics approval number is 1990/2025.

Results Patients with favorable neurological outcomes (n = 136; 47.9 %) had lower driving pressures and PaCO₂ levels and more frequently presented with shockable rhythms and signs of life. Time-weighted mean driving pressure during the first hour after sROSC remained significantly associated with neurological recovery (OR 0.88, 95 % CI: 0.79–0.96; p = 0.005). Findings were consistent across adjusted models.

Conclusion Ventilatory management within the first hour after cardiac arrest may influence neurological recovery. Prospective studies are needed to determine the clinical benefits of a structured respiratory care bundle in the early post-ROSC phase.