Background Excessive ventilation during cardiopulmonary resuscitation (CPR) may compromise hemodynamics by elevating intrathoracic pressure and reducing venous return. Standard adult self-inflating bags often deliver tidal volumes exceeding American Heart Association (AHA) and European Resuscitation Council (ERC) guidelines(6-7ml/kg of Predicted Body weight (PBW)). We hypothesized that employing a paediatric self-inflating bag during extended CPR in intubated adult cardiac arrest patients would yield tidal volumes more in line with guideline recommendations. Method This was a single blinded, non-randomized controlled study conducted from October 2022 to October 2023 at a tertiary academic Emergency Department(ED) after ethical committee approval. (Trial registration: ISRCTN10909864). Asynchronous ventilation was delivered during CPR using an adult self-inflating bag (1600 mL) in patients who were endotracheally intubated. For patients meeting termination-of-resuscitation(TOR) criteria, extended CPR was delivered using a pediatric self-inflating bag (750 mL). Ventilatory metrics were recorded via a CITREX H3 Gas Flow Analyzer connected between the endotracheal tube and the bag. The primary objective was to compare the inspired (VTi) and expired (VTe) tidal volumes delivered by the two devices, while the secondary objective was to determine the VTi required to achieve visible chest rise. Results Of 224 patients screened for eligibility, 132(59%) were enrolled after excluding 2 (1.5%) patients who achieved return of spontaneous circulation (ROSC), 130(98.5%) patients were included in the final analysis. The adult self-inflating bag delivered a median VTi of 8.7 mL/kg of PBW IQR 7.5–10.3, significantly higher than the pediatric bag (6.4 mL/kg PBW IQR 5.45–7.7 (p < 0.001). VTe delivered by adult bag was also higher (7.66 mL/kg PBW IQR 6.23–9.13 vs pediatric 5.82 mL/kg PBW IQR 4.59–7.07 (p < 0.001). Case-average VTi within the 2015 ERC guideline range (6–7 mL/kg per PBW) was achieved more frequently with the pediatric self-inflating bag than with the adult bag (32 24% vs 14 11% cases), with significantly higher odds of target VTi delivery (matched-pair odds ratio 2.29; 95% CI 1.23–4.25; p < 0.01). For VTe, there was no significant difference in target range achievement between the pediatric and adult bags (2116% vs 2418% cases; matched-pair odds ratio 0.88; 95% CI 0.49–1.57; p =0.77). Additionally, the median VTi necessary for a visible chest rise was 190 mL IQR 164.8–217.0 . Conclusion In intubated adults during CPR, pediatric self-inflating bags delivered case-average tidal volumes per predicted body weight closer to weight-based ventilation targets (ERC 2015 guidelines), with higher odds of achieving the target tidal volume range compared with standard adult bags. However, clinical outcomes were not evaluated.
Kowsthubha et al. (Mon,) studied this question.