Metabolic response to cardiopulmonary bypass using a Bentley oxygenator.

The present investigation deals with the blood gases, serum lactic acid, serum and urine electrolytes, and urea and creatinine before, during, and after cardiopulmonary bypass. This study was conducted with 25 patients. There were significant increases in PO2, PCO2, HCO3-, serum creatinine, urine potassium, and urine chloride. However, there were no significant changes in serum sodium, potassium, chloride, blood pH, lactic acid, urea and urine creatinine, urine urea, urine index, and urine Na+ during cardiopulmonary bypass. On the first postoperative day there were significant increases in PCO2, HCO3-, serum creatinine and urea, urine creatinine, urea, potassium and chloride, and significant decreases in the blood pH and urine index. Other measured parameters did not change significantly. Most of the measured parameters returned toward normal within 5 days except for decreases in serum chloride and sodium and increases in urine, urea, and potassium. These results indicate that the use of a Bentley oxygenator during cardiopulmonary bypass does not affect the biochemical parameters adversely.