The physiological range of respiratory rates and heart rates in neonates is approximately 40 per min and 120 per min, respectively, which yields a theoretical ventilation-compression ratio of 1:3ratherthan 1:5.
Thirty-six anesthetized pigs with an average body weight of 4–5 kg were used in the study. After establishing a steady state by artificial ventilation with 100% oxygen, a cardiac arrest was induced by an intravenous injection of potassium chloride. Following the cardiac arrest, the animals were resuscitated with ventilation rates of 30 and 40 per min, respectively, while external cardiac compression was performed at rates between 60 and 160 per min. Randomly selected animals were resuscitated with ventilation-compression ratios of 1:2, 1:3 and 1:4 for 10 min each, 6 animals each were ventilated using a ventilation rate of 30 per min, 40 per min, or positive end-expiratory pressure.