Evaluation of the Sufficiency of Tissue Oxygenation During Cardio-Pulmonary Bypass and Hypothermia Using the Rygg/Kyvsgaard Pump Oxygenator

Abstract

Forty-nine examinations were performed in 15 patients during extracorporeal circulation with the Rygg/ Kyvsgaard heart-lung machine to evaluate the sufficiency of oxygenation with the technique used. In 11 cases, moderate to deep hypothermia was used. Oxygenation seems to have been adequate, judging by the absence of non-respiratory acidosis, the absence of increase in oxygen consumption following hypothermia and perfu-sion, and the presence of “normal” mixed venous oxygen tension in most cases. The use of mixed venous temperature as representative for “body temperature”, and the reliability of temperature correction factors for oxygen and carbon dioxide tension and pH are discussed.