Ventilation strategies and outcomes after out-of-hospital cardiac arrest: protocol for a pre-planned sub-analysis of the STEPCARE trial

Introduction: After resuscitation from out of hospital cardiac arrest (OHCA), mechanical ventilation (MV) and respiratory management are fundamental to support patients in the intensive care unit (ICU) and to minimise secondary brain injury. Best practices for MV and association with clinical outcomes in patients with OHCA remain unclear. Methods and analysis: This protocol describes a pre-planned respiratory-focused series of sub-analyses within the Sedation, Temperature and Pressure after Cardiac Arrest and Resuscitation (STEPCARE) trial, an ongoing interventional study evaluating 6-month mortality after randomisation in patients admitted to ICUs following OHCA. The primary aim is to describe real-world ventilator settings and gas-exchange targets during the first 72 hours after ICU admission in patients receiving invasive mechanical ventilation after OHCA. Secondary aims include to estimate the incidence of respiratory complications during ICU stay (eg, ventilator-associated pneumonia, acute respiratory distress syndrome, barotrauma); and to explore the association between early ventilator settings/gas-exchange parameters and 6-month outcomes (mortality and neurological status). Exploratory aim is to characterise weaning and extubation practices, including timing and failure rates.Eligible patients will include adult STEPCARE participants receiving invasive MV after return of spontaneous circulation with available respiratory data recorded within the STEPCARE database.Data collected in the STEPCARE trial that will be analysed include patients’ prehospital characteristics; clinical examination at hospital admission and at ICU admission; ventilator settings and arterial blood gases recorded at predefined time points during ICU stay. In particular: MV setting (mode, tidal volume, positive end-expiratory pressure, fraction of inspired oxygen, tidal volume, mechanical power, plateau/driving pressures), gas-exchange values (arterial partial pressure of oxygen and carbon dioxide, pH, arterial saturation of oxygen), timing of measurements and the occurrence/timing of respiratory complications and weaning outcomes. Ethics and dissemination: The STEPCARE study has been approved by the regional ethics committee at Lund University (Dnr 2022-02425-01, Approved IRB on 2022-06-18) and by all ethics boards in the participating countries. No additional ethical approval is required for this predefined secondary analysis, as no further data collection or interventions will be performed. Findings will be disseminated through publication in peer-reviewed journals and, where appropriate, conference abstracts and presentations. Patients and the public were not involved. ClinicalTrials.gov: NCT05564754.