Changes in whole body oxygen consumption associated with decreasea in systemic vascular resistance produced by Nipride (ssodium nitroprusside) infusion were measured in 15 patients during hypothermic extracorporeal circulation. When the body temperature was 29.3+/-2.16degrees C, mixed venous and arterial blood were sample simultaneously for the calculation of whole body oxygen consumption. Blood sample were withdrawn simultaneouely from the arterial outlet line and venous inlet line of the oxygenator for blood gas analysis. In each patient, whole body oxygen consumption at 29.3+/-2.16degrees C was determined as control. After then Nipride was infused until 10% decreasing of systemic vascular resistance was achieved and whole body oxygen consumption waa calculated. Body temperature, pump flow and hematocrit were maintained within a narrow range in each patients during studies. Arterial and mixed venous blood gases were analyzed at 37degrees C, uncorrected for body temperature(alpha-stat acid-base management). The result was that the whole body oxygen consumption changed from 43.3+/-12.12mL/min/m to 68.9+/-19. 16mL/min/m by Nipride infusion during hypothermic extracorporeal circulation. The 10% de- creasing of systemic vascular resistance by Nipride during hypothermic extracorporeal circulation lead to the 58+/-6.2% increasing of whole body oxygen consumption. We found that significant increase in whole body oxygen consumption hsd occured following Nipride infusion.
Bays ; Blood Gas Analysis ; Body Temperature ; Extracorporeal Circulation* ; Gases ; Hematocrit ; Humans ; Nitroprusside ; Oxygen Consumption* ; Oxygen* ; Oxygenators ; Vascular Resistance*