Prostaglandin synthesis inhibitor improves hypotension during normothermiccardiopulmonary bypass

Hypotension is a major systemic side effect during cardiopulmonary bypass ( CPB), especially at normothermia. We previously reported that prostaglandin (PG) might play a substantial role in hypotension. The purpose of this stu dy was to clarify whether a PG synthesis inhibitor (PGSI) could improve hyp otension during CPB. Thirty-six patients undergoing cardiac surgery with no rmothermic CPB (35-37 degreesC) were divided into two groups: a PGSI group (n = 18), whose members were given a PGSI before and during CPB, and a cont rol group (n = 18). In both groups, perfusion flow was sufficient and press ure was maintained at above 45 mm Hg by infusion of metaraminol, a vasocons trictor. The mean arterial pressure throughout CPB was significantly higher in the PGSI group than in the control group (57 +/- 4 vs. 48 +/- 3 mm Hg, p < 0.01), whereas the dose of infused metaraminol was significantly lower in the PGSI group (13 +/- 7 vs. 21 +/- 6 mg, p < 0.01). The blood base exce ss was not significantly different (1.0 +/- 1.6 vs. 1.7 +/- 1.9 mmol/L, p = 0.28), and urine output was significantly higher in the PGSI group (503 +/ - 179 vs. 354 +/- 112 ml/hr, p < 0.01). In conclusion, PGSI can improve hyp otension during CPB and increase urine output without impairing peripheral circulation.