Influence of different ventilation strategies during cardiopulmonary resuscitation on the return of spontaneous circulation in out-of-hospital cardiac arrest: a retrospective study from the German resuscitation registry.

Abstract

To evaluate the association of different intra-arrest ventilation strategies with return of spontaneous circulation (ROSC), hospital admission, and 24-h survival among adult OHCA patients. This retrospective cross-sectional study analyzed data from the German Resuscitation Registry. Adult patients (≥18 years) with non-traumatic out-of-hospital cardiac arrest (OHCA) between March 2016 and March 2023 were included if they received CPR, endotracheal intubation during CPR, and had a documented ventilation strategy. Four ventilation modes were compared: Intermittent Positive Pressure Ventilation (IPPV), Chest Compression Synchronized Ventilation (CCSV), biphasic positive airway pressure (BIPAP), and manual bag-valve ventilation (Manually). ROSC observed (ROSC_obs) was compared with expected ROSC (ROSC_exp) based on the ROSC after cardiac arrest score (RACA). Secondary outcomes were hospital admission status and 24-hour survival. Among 3,195 patients (IPPV: 1,865; CCSV: 194; BIPAP: 81; Manually: 1,055), ROSC occurred in 44 % (IPPV), 40 % (CCSV), 49 % (BIPAP), and 39 % (Manually). IPPV showed a significant positive deviation from ROSC_exp (+2.7 %, p = 0.0005). No other strategy reached statistical significance. Patients ventilated with CCSV had a lower rate of admission with ROSC (24 %) and higher rates of admission under ongoing CPR (34 %). In the manual bag-valve ventilated group more patients died on scene (59 %). Respirator controlled ventilation with IPPV modestly but significantly exceeded expected ROSC rates in patients with non-traumatic OHCA. CCSV, the mode designed specifically for ventilation during CPR, does not seem to be superior to manual bag-valve ventilation. Randomized controlled trials are needed to refine mechanical ventilation strategies in CPR.