The Annals of Thoracic Surgery, Vol 47, 297-299, Copyright © 1989 by The Society of Thoracic Surgeons
Prediction of post-cardiopulmonary bypass cardiac output
RS Chung, DJ Magilligan Jr, RR Eisiminger, MA Fried, JA Serwatowski and KS Gerdeman
Division of Cardiac and Thoracic Surgery, Henry Ford Hospital, Detroit, Michigan 48202.
The ability to predict cardiac output (CO) before termination of
cardiopulmonary bypass (CPB) allows identification of potential
complications once the patient is off bypass. We have previously
demonstrated that CO early after CPB can be reliably predicted by a plot of
venous oxygen saturation at various flow rates on CPB, based on in-line
monitoring of venous oxygen saturation. In this study, we evaluated a
simplified technique for predicting CO with a series of 50 patients on CPB.
When CPB weaning began, patients were normothermic, anesthetized, and
paralyzed. Venous oxygen saturation and arterial blood flow were recorded.
At low pump flow just before termination of CPB, the final venous oxygen
saturation was recorded. Assuming a proportional relationship between
venous oxygen saturation and arterial blood flow, CO early after CPB was
predicted. The simplified CO prediction was compared with the
thermodilution CO immediately after CPB. The simplified technique reliably
predicted CO early after CPB compared with the thermodilution technique.
The simplicity and reliability increase the clinical value of the CO
prediction.
