... Oxygen flow (l/min) Total gas flow (l/min) Blue 24 2 4 51–1 02 White 28 4–6 44–67 Yellow 35 8–10 45–65 Red 40 10– 12 41–50 Green 60 12 15 24 –30 Humidified circuit 85 12 15 15 20 Figure 2. 4 Venturi mask ... and his pulse is 120 /min The attending doctor changes his oxygen to a 28 % Venturi mask because of his high CO2 and repeat blood gases show: pH 7 .2, PaCO2 9.0 kPa (69 .2 mmHg), PaO2 6.0 kPa (46.1 ... X-ray He is hypothermic (34°C) and arterial blood gases on 15 l/min via reservoir bag mask show: pH 7 .2, PaCO2 9.5 kPa (73 mmHg), PaO2 12. 0 kPa ( 92. 3 mmHg), st bicarbonate 27 .3 mmol/l, BE Ϫ2...