[Arachidonic acid metabolism and effectiveness of aprotinin treatment during cardiopulmonary bypass].

Arachidonic acid metabolism was investigated in 30 open heart cases, utilizing nonpulsatile cardiopulmonary bypass (CPB), consisted of 15 untreated cases (Group I) and 15 cases treated with aprotinin mostly given into CPB circuit during CPB (Group II). In group I, arterial blood concentration of thromboxane B2 (TXB2, stable metabolite of thromboxane A2, pg/ml) significantly increased from 45.9 +/- 40.5 preoperatively to 560.2 +/- 381.5 (p less than 0.01) at 30 minutes of CPB (total bypass) and to 830.5 +/- 591.1 (p less than 0.005) at the end of CPB (partial bypass). TXB2 levels in pulmonary artery (PA) and left atrium (LA) did not significantly increase just before, 5 minutes of CPB as compared with preoperative value. At the end of CPB TXB2 levels in PA (625.0 +/- 186.3) and LA (817.0 +/- 320.0) were significantly higher than preoperative value. However there was no significant difference between PA and LA values. Contrarily in group II TXB2 levels were significantly suppressed as compared with the value at each corresponding time in group I. beta-thromboglobulin levels also changed almost parallel to TXB2 levels in both groups. In conclusion, arachidonic acid metabolic disorders could occur in CPB circuit rather than in pulmonary circulation during CPB. Aprotinin administration into CPB circuit suppressed to some extent the platelet activation.