Oxygen Consumption and Convective Transport during Cardiopulmonary Bypass

Abstract

Described here are the progressive changes in blood-flow distribution that accompany four-hour heart-lung bypass in dogs and the effects of perfusion rate on flow distribution and oxygen consumption. The corresponding changes produced by anesthesia alone and by the thoracotomy needed for a bypass procedure are also shown for comparison purposes. These data indicate that the bypass procedure itself puts a very significant stress on the test animals and that perfusion rates in excess of resting cardiac output are required to prevent hypoxia induced irreversible tissue damage.