Extracorporeal oxygenation with various experimental venoarterial bypasses during prolonged apnea

This work compares various conventional venoarterial closed-chest circuits where satisfactory oxygenation of myocardium and brain in total apnea with extracorporeal circulation is concerned. Eleven dogs were studied during 3 hours of curare-induced apnea. We used single and double vena caval drainages connected to an oxygenator. A single-vein drainage yielded approximately 50 per cent and a double-vein drainage 75 per cent bypass. Two separate roller pumps fed arterialized blood variously into carotid and femoral arteries. In single-vein drainage, the oxygen partial pressure in the coronary artery was consistently poor and carotid oxygen partial pressure was poor for 100 per cent femoral infusion while more and more arterialized blood reached the carotid arteries in the other single-vein drainage circuits. In double-vein drainage, the coronary oxygen partial pressure for 100 per cent femoral infusion remained poor while, for the other circuit types, the coronary arteries received arterialized blood except where 100 per cent carotid infusion was concerned. The carotid oxygen partial pressure was sound for all groups in the double-vein drainage except for some obtained in 100 per cent femoral infusion. Consequently, where the bypass was large and the carotid and femoral arteries received a share of arterialized blood, both heart and brain received sound oxygenation.