Purpose: Recent basic life support (BLS) guidelines recommend 30:2 compression-to-ventilation ratio (CV ratio) or chest compression-only (CC) cardiopulmonary resuscitation (CPR); however, there is an inevitable risk for the interruption of high-quality CPR in 30:2 CV ratio and hypoxemia in CC. In this study, we compared the short-term outcomes between CC, 30:1 and 30:2 CV ratio CPR.
Materials and methods: 42 pigs were randomly assigned to CC, 30:1 and 30:2 CV ratio groups. After induction of ventricular fibrillation (VF), we observed pigs for two minutes without any intervention. Thereafter, BLS was started according to the assigned method and performed for eight minutes. Defibrillation was performed after BLS and repeated every two minutes, followed by rhythm analysis. Advanced cardiac life support including continuous chest compression with ventilation every 6 seconds and intravenous (IV) injection of 1 mg epinephrine every 4 minutes were performed until the return of spontaneous circulation (ROSC) or 22 minutes after VF induction. Hemodynamic parameters and arterial blood gas profiles were compared between groups. ROSC, 24-hour survival, and neurologic outcome were evaluated at 24 hours.
Results: The hemodynamic parameters during CPR did not differ between groups. The partial pressure of oxygen in the arterial blood and arterial oxygen saturation were lowest in the CC group compared to those in the other groups during the BLS period (p=0.040 and <0.001, respectively). Favorable neurologic outcome (swine CPC 1 or 2) was most frequently observed in the 30:1 CV ratio group compared to the other groups (p=0.044).
Conclusion: The 30:1 CV ratio group showed a significantly higher rate of favorable neurologic outcome than 30:2 CV ratio and CC CPR.

6 - A 30:1 compression-to-ventilation ratio promotes better neurologic outcome compared to chest compression-only cardiopulmonary resuscitation or a 30:2 ratio