Original Article

Effects of Decrease in Cardiac Output on the Changes of End-tidal Carbon Dioxide Partial Pressure in the Acute Hemorrhagic Dogs

Guie Young Lee
Author Information & Copyright
Department of Anesthesiology, Ewha Medical Reserch Center, College of Medicine, Ewha Woman's University, Korea.

Copyright ⓒ 1997. Ewha Womans University School of Medicine. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Published Online: Jul 24, 2015



It is well known that changes in end-tidal carbon dioxide partial pressure (PETCO2) can reflect changes in cardiac output during cardiopulmonary resuscitation. The present study was performed to evaluate quantitative relationship between the changes in PETCO2 and cardiac output in the acute hemorrahagic dogs.


Six anesthetized(isoflurane 1.0%), paralyzed, and mechanically constant ventilated dogs submitted to hemorrhage were studied. The dogs were hemorrhaged by progressive withdrawal of 50% of blood volume. After withdrawal of each 10% of blood volume, PETCO2, arterial carbon dioxide partial pressure(PaCO2), mean arterial pressure and cardiac output were measured.


After 40% blood loss, the percent decrease in PETCO2 decreased significantly. The percent decrease in PETCO2 correlated with the percent decrease in cardiac output(slope=0.33, r=0.7, P<0.001). The percent decrease in PETCO2 correlated with the percent decrease in cardiac output(slope=0.35, r=0.55, P<0.05).


There is a linear correlation between the percent decrease in PETCO2 and cardiac outpit with the ratio approximately 1:3 during acute hemorrhage in the constant tidal volume ventilation. The cause of PETCO2 change induced by cardiac output might be change in PaCO2. This finding suggests that PETCO2 monitoring can easily detect a critical reduction in cardiac output when ventilationis constant.

Keywords: Hemorrhage; End-tidal carbon dioxide partial pressure; Cardiac output