[Serum nitroglycerin concentrations during extracorporeal circulation with a membrane oxygenator incorporated with a...

The effect of a cardiopulmonary bypass circuit (CPB) on serum nitroglycerin (TNG) concentrations was studied in eight patients scheduled for cardiac surgery. The CPB consisted of polyvinyl chloride tubes and polypropyrene membrane oxygenator. TNG was administered intravenously at a rate of 1 microgram.kg-1.min-1 after induction of anesthesia. Blood samples were obtained from the radial artery, central vein, venous inlet of the CPB, and arterial outlet of the CPB. No significant difference in serum TNG concentration was found between the venous inlet of the CPB and arterial outlet of the CPB. Serum TNG concentration tended to increase during complete extracorporeal circulation. This suggests that the hypothermic inhibition of TNG metabolism may be greater than the adsorption of TNG by the CPB.