The Effects of Perioperative Ketorolac Infusion on Platelet Function and Blood Loss: Comparison of Anesthesia Methods

Background: The purposes of this study were to investigate the effects of perioperative continuous infusion of ketorolac on platelet function and blood loss under either general or spinal anesthesia. Methods: The patients under general anesthesia received saline 1 ml (C group) or ketorolac 30 mg (GK group) intravenously 10 min before skin incision, followed, respectively, by a continuous infusion of saline (4 ml/h) or ketorolac (2.5 mg/h) for 24 h. The patients under spinal anesthesia (SK group) received the same amount of ketorolac as that of the GK group. Blood loss was collected and measured at 3 h, 6 h, 12 h and 24 h postincision. Platelet count, hemoglobin, platelet aggregometry (PA) with adenosine diphosphate (ADP) and collagen, and bleeding time (BT) were measured at 30 min before skin incision and at 3 h and 24 h postincision. Blood coagulation status was analysed using thromboelastography (TEG) at 30 min before skin incision and at 3 h postincision. Results: BT in the SK group at postincision increased significantly compared to preoperative value and were significantly higher than those of the GK and C group. PA with collagen at 3 h after skin incision was lower in the SK group than in the C group. There were no significant differences in any of the TEG variables among the three groups. No significant differences were observed in blood loss among the three groups. Conclusions: Blood loss was not increased by ketorolac under either general or spinal anesthesia, although platelet function was impaired under spinal anesthesia.