The prediction of postoperative potassium excretion after cardiopulmonary bypass.

Potassium excretion following cardiopulmonary bypass has been studied in 11 patients. After an initial period of 4 to 5 hours, potassium excretion was found to be directly related to urine flow provided diuretics had not been administered. Triamterene altered the slope of the regression line so that, for any given urine flow rate, less potassium was excreted. A simple program for postoperative potassium therapy is described.