The mechanism of blood flow in cardiopulmonary resuscitation--introducing the lung pump.

Abstract

The mechanism of blood flow in cardiopulmonary resuscitation remains controversial. Inconsistencies in the cardiac pump model necessitated the development of the thoracic pump. Neither hypothesis alone can account for blood flow during external massage. Using the postulates that a cyclical pump has three components, an inlet valve, a compression chamber and an outlet valve, we propose the lung pump hypothesis where these components are represented by the pulmonary valve; the lung vasculature/left atrium/left ventricle; and the aortic valve. We explore the mechanism and effect of this hypothesis and match it to previous observations. The implications to cardiopulmonary resuscitation are addressed.