Influence of different airway devices on intra-arrest ventilation during bag-valve-device ventilation - a prospective randomized controlled cadaver study.

BACKGROUND: Out-of-hospital cardiac arrest remains a major challenge due to its high incidence and low survival rates. In recent decades, research has focused on the performance of chest compressions and improvements in early defibrillation, while the optimal ventilation strategy remains unclear. Despite the lack of monitoring systems, manual bag-valve-device ventilation is still common. Given the potential impact of both the applied volumes and the ventilation pressures on hemodynamics and resuscitation efforts, the present study investigated the effects of various airway devices on the target parameters of ventilation therapy during manual intra-arrest ventilation. METHODS: Thiel-embalmed human cadavers were included in a standardized resuscitation scenario. Ventilation was performed in a randomized order using various airway devices (tracheal tube (ET), supraglottic airway devices (SGA): laryngeal mask airway, laryngeal tube, i-gel® laryngeal mask) and manual bag-valve-device ventilation. Chest compressions were performed via Corpuls-CPR. Ideal (Vtideal), expiratory (Vte) and inspiratory (Vti) tidal volumes; leakage volume (Vleak); and peak (Ppeak) and mean (Pmean) pressures were recorded. The primary efficacy endpoint was the difference between Vtideal and Vte (∆Vt). RESULTS: Eleven cadavers were included (mean age at the time of death: 84 ± 3.7 years, male = 7 [63.6%]). During ventilation with ET, the following mean values were measured: ΔVt, 142.2 ± 125.5 ml; Vte, 245.1 ± 91.2 ml; Vleak, 17.9 ± 15.3%; Pmean, 4.0 ± 1.5 mbar; and Ppeak, 47.7 ± 14.9 mbar. During ventilation with SGA, however, the mean values were ΔVt, 202.0 ± 153.1 ml; Vte, 183.8 ± 122.1 ml; Vleak, 39.0 ± 23.5%; Pmean, 3.1 ± 1.0 mbar; and Ppeak, 39.0 ± 10.0 mbar. Comparison of the two groups revealed lower ΔVt values (regression coefficient [RC] = -61.07 ml, 95% confidence interval [95% CI] = [-93.58;-28.55], p = 0.0003) and Vleak values (RC = -20.98%, 95% CI = [-26.63;-15.33], p<0.0001), but higher Vte values (RC = 61.14 ml, 95% CI = [28.63;93.65], p = 0.0003), Pmean values (RC = 0.90 mbar, 95% CI = [0.59;1.21], p<0.0001), and Ppeak values (RC = 11.46 mbar, 95% CI = [8.65;14.26], p<0.0001) in the ET group. There was no evidence for differences in ΔVt among the cadavers in the SGA group. CONCLUSION: The ∆Vt was lower in the ET group than the SGA group, whereas there was no evidence for differences in ∆Vt among the devices in the SGA group. TRIAL REGISTRATION: clinicaltrials.gov; Unique identifier: NCT06306898, Registration date: 5 March 2024.