Unwashed shed blood infusion causes deterioration in right ventricular function after coronary artery surgery

We investigated right ventricular function after infusion of unwashed shed blood collected from mediastinal and chest tube drainage. Changes in thromb oxane B-2 (TXB2) and 6-keto-PGF(1 infinity) which ale stable metabolites of thromboxane A(2) (TXA(2)) and prostacyclin respectively, were also investi gated The amount of infused shed blood was 484+/-76 ml (mean +/-SD). Right ventricular ejection fraction decreased rapidly after the infusion and did not return to its original level until 120 minutes later (P<0.05). Mean pul monary artery pressure rose after infusion of the shed blood (P<0.05). The TXB2 level in the unwashed shed blood was about 20,000 times higher than th e preoperative plasma level. The plasma TXB2 level at 30 minutes after the infusion was significantly elevated (P<0.05), and at 120 minutes it had ret urned to the original level. Unwashed shed blood may contain vasoactive sub stances that induce the release of TXA(2) and increase right ventricular af terload.