Twenty minutes after initiating circulatory support, arterial partial pressure of oxygen (PaO2) was 23.0 ± 1.5, 50.6 ± 5.2, and 110.7 ± 29.8 mmHg at bypass flow rates of 1, 2, and 3 L/min, respectively. Similarly, arterial partial pressure of carbon dioxide (PaCO2) was 62.1 ± 2.8, 46.1 ± 2.3, and 38.9 ± 2.8 mmHg at bypass flow rates of 1–3 L/min, respectively.