A retrospective comparison of mechanical cardio-pulmonary ventilation and manual bag valve ventilation in non-traumatic out-of-hospital cardiac arrests: a study from the Belgian Cardiac Arrest Registry.

BACKGROUND: The optimal ventilation modalities to manage out-of-hospital cardiac arrest (OHCA) remain debated. A specific pressure mode called cardio-pulmonary ventilation (CPV) may be used instead of manual bag ventilation (MBV). We sought to analyse the association between mechanical CPV and return of spontaneous circulation (ROSC) in non-traumatic OHCA.

METHODS: MBV and CPV were retrospectively identified in patients with non-traumatic OHCA from the Belgian Cardiac Arrest Registry. We used a two-level mixed-effects multivariable logistic regression analysis to determine the association between the ventilation modalities and outcomes. The primary and secondary study criteria were ROSC and survival with a Cerebral Performance Category (CPC) score of 1 or 2 at 30 days. Age, sex, initial rhythm, no-flow duration, low-flow duration, OHCA location, use of a mechanical chest compression device and Rankin status before arrest were used as covariables.

RESULTS: Between January 2017 and December 2021, 2566 patients with OHCA who fulfilled the inclusion criteria were included. 298 (11.6%) patients were mechanically ventilated with CPV whereas 2268 were manually ventilated. The use of CPV was associated with greater probability of ROSC both in the unadjusted (odds ratio: 1.28, 95% confidence interval [CI]: 1.01-1.63; p=0.043) and adjusted analyses (adjusted odds ratio [aOR]: 2.16, 95%CI 1.37-3.41; p=0.001) but not with a lower CPC score (aOR: 1.44, 95%CI 0.72-2.89; p=0.31).

CONCLUSIONS: Compared with MBV, CPV was associated with an increased risk of ROSC but not with improved an CPC score in patients with OHCA. Prospective randomised trials are needed to challenge these results.