The Lewis A. Conner Memorial Lecture

Abstract

Among the unsolved physiologic problems arising from the use of an extracorporeal circulation for open cardiac surgery are: 1. On the initiation of total by-pass, is the blood flow to the body increased or decreased in relation to the previous cardiac output? 2. What is the volume of blood in the lungs before, during, and after total by-pass? 3. When the normal direction of blood flow through the aorta is reversed, do peizometric effects obtain in any of the major branches? 4. How long may high oxygen tensions be maintained in the blood without toxicity? 5. What is the relation of metabolic to respiratory acidosis? 6. What is the best method of producing cardiac arrest and how long can it be safely maintained? 7. What are the factors concerned in postoperative pulmonary dysfunction? Technical methods exist for the solution of all these problems.