Journal List > Ewha Med J > v.20(3) > 1083387

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

Abstract

Objectives

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.

Methods

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.

Results

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).

Conclusion

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.

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