Manual bag-valve-mask ventilation during out-of-hospital cardiopulmonary resuscitation: a prospective observational...

Manual ventilation during cardiopulmonary resuscitation (CPR) in prehospital settings remains poorly documented, especially the tidal volumes actually delivered during basic life support (BLS) This study aimed to evaluate the quality of ventilation during out-of-hospital CPR.

This prospective observational study examined ventilation during 30:2 CPR performed by BLS teams. We utilized a ventilation monitoring device (EOlife®, Archeon Medical, France) with its display masked to rescuers to prevent performance bias. Primary outcome was expiratory tidal volume (Vte). Secondary outcomes were leak volume, ventilation rate, ventilatory times, inspiratory-to-expiratory (I/E) ratio, and chest rise. Generalized linear mixed models were used to identify factors associated with Vte and leakage.

From May 26 to November 1, 2023, 106 adult patients suffering from non-traumatic out-of-hospital cardiac arrest were enrolled in the study, with a total of 3,017 documented ventilations. Median Vte per-patient was 273[interquartile-range 225-350] mL for the first ventilations and 327[254-427] mL for the second; 79.2 % of per-patient ventilations delivered <400 mL. Leakage was common, with a median of 222[160-261] mL. Vte increased during resuscitation (+29 % after 15 min, p < 0.001) but remained below guideline targets. Higher leak-volume was associated with longer inspiratory time and an increased I/E ratio. Using a two-person technique reduced leak volume by approximately 6 %, but this difference was not statistically significant.

In prehospital CPR, bag-valve-mask ventilation frequently resulted in expiratory tidal volumes below guideline targets with substantial leakage. These results may encourage other EMS systems to assess population-specific variation in ventilation parameters to support targeted training and real-time feedback. (ClinicalTrials.gov: NCT05992454).