Aim Evidence guiding mechanical ventilation (MV) during CPR is limited, and device-calculated inspired tidal volume (VTi) during ongoing chest compressions may differ from the set volume during compressions. We compared VTi with protocolized MV and bag-valve ventilation (BVV) through an endotracheal tube for noninferiority. Methods This single-center randomized crossover noninferiority trial enrolled 104 intubated adults meeting termination-of-resuscitation criteria without return of spontaneous circulation to receive BVV and MV in randomized order within a 5-min peri-termination window. Device-calculated VTi was recorded for 1 min per method during ongoing compressions. The primary outcome was the between-treatment difference in per-participant median VTi; the noninferiority margin was −150 mL (MV minus BVV). Results Among 99 participants completing both periods, mean per-participant median VTi was 514.4 mL with BVV and 368.0 mL with MV; coefficients of variation were 40.1% and 28.3%. The adjusted mean difference was −146.2 mL (95% CI, −187.0 to −105.5). Because the lower bound crossed −150 mL, noninferiority was not demonstrated. Median VTi exceeded 10 mL/kg predicted body weight in 31.3% with BVV and 0% with MV, whereas values below 6 mL/kg occurred in 26.3% and 45.5%. Conclusions Protocolized MV produced lower and less variable device-calculated VTi than BVV but did not meet noninferiority. BVV had a wider upper tail, whereas MV more often produced values below 6 mL/kg. The unvalidated analyzer and absence of clinical outcomes limit interpretation. Clinical trial registration Clinical Trials Registry − India; CTRI/2024/08/072738.
