Association of pre-intubation bag-valve-mask ventilation with hypoxemia and regurgitation in the ED: A multicenter cohort study

Background: The effectiveness of pre-intubation bag-valve-mask (BVM) ventilation for rapid sequence intubation (RSI) in the emergency department (ED) remains uncertain. In this study, we investigated whether pre-intubation BVM ventilation was associated with a lower risk of peri-intubation hypoxemia. Methods: We analyzed data from a multicenter prospective observational study conducted in 14 EDs across Japan. Adult (≥18 years) patients who underwent RSI between 2020 and 2023 were included. The primary outcome was peri-intubation hypoxemia (SpO₂ <90%), and the secondary outcome was regurgitation. Missing data were imputed using multiple imputations. Propensity scores were estimated using predefined covariates (age, sex, body mass index, COVID-19, modified LEMON score, intubation indication, device, intubator's specialty, preoxygenation method, pre-intubation SpO₂, and participating institutions). Treatment effects were evaluated using stabilized inverse probability of treatment weighting (IPTW) and sensitivity analysis with 1:1 matching. Results: Among the 1481 patients, 589 (40%) received pre-intubation BVM. Overall, 204 patients (14%) experienced peri-intubation hypoxemia. The BVM group had a lower unadjusted risk of hypoxemia than the non-BVM group (10% vs. 16%; p < 0.001). However, after stabilized IPTW, BVM ventilation was not significantly associated with hypoxemia (adjusted risk difference −3.2%; 95% CI, −7.8% to 1.5%). Sensitivity analysis using 1:1 matching yielded consistent results (risk difference 0.9%; 95% CI, −3.8% to 5.6%). There was no significant difference in the incidence of regurgitation between the BVM and non-BVM groups (1% vs. 1%; p = 0.24). Conclusion: In this multicenter study, pre-intubation BVM ventilation during RSI in the ED was not associated with a reduced risk of peri-intubation hypoxemia.