Karski J M, Teasdale S J, Norman P, Carroll J, VanKessel K, Wong P, Glynn M F
Department of Anesthesia, Toronto Hospital General Division, University of Toronto, Canada.
J Thorac Cardiovasc Surg. 1995 Sep;110(3):835-42. doi: 10.1016/S0022-5223(95)70118-4.
This prospective, double-blind, randomized trial assessed the effectiveness of high-dose tranexamic acid given in the preoperative period on blood loss in patients undergoing cardiopulmonary bypass. One hundred fifty patients scheduled to undergo cardiac operations with cardiopulmonary bypass were randomized into three groups of equal size. The first group received 10 gm of tranexamic acid intravenously over 20 minutes before sternotomy and a placebo infusion over 5 hours. The second group received 10 gm of tranexamic acid over 20 minutes and then another 10 gm infused intravenously over 5 hours. The control group received a placebo bolus and a placebo infusion over 5 hours (0.9% normal saline solution). The blood loss after the operation was measured at 6 hours and 24 hours. The homologous blood and blood products given during and up to 48 hours after operation were recorded. Eighteen percent of the control group patients shed more than 750 ml blood in 6 hours compared with only 2% in both tranexamic acid groups. Patients who shed more than 750 ml blood required 93% more red blood cell transfusions than patients without excessive bleeding. Tranexamic acid (10 gm) given intravenously in the period before cardiopulmonary bypass reduced blood loss over 6 hours by 50% and over 24 hours by 35%. Continued tranexamic acid infusion (10 gm over 5 hours) did not reduce bleeding further. There was no difference in the coagulation profile before operation between patients with and without excessive bleeding. However, coagulation tests done in the postoperative period indicated ongoing fibrinolysis and platelet dysfunction in patients with excessive bleeding.
这项前瞻性、双盲、随机试验评估了术前给予高剂量氨甲环酸对接受体外循环手术患者失血情况的影响。150例计划接受体外循环心脏手术的患者被随机分为三组，每组人数相等。第一组在胸骨切开术前20分钟静脉注射10克氨甲环酸，并在5小时内输注安慰剂。第二组在20分钟内输注10克氨甲环酸，然后在5小时内再静脉输注10克。对照组接受一次安慰剂推注，并在5小时内输注安慰剂（0.9%生理盐水溶液）。术后6小时和24小时测量失血量。记录术中及术后48小时内输注的同源血液和血液制品。对照组中18%的患者在6小时内失血超过750毫升，而氨甲环酸组的这一比例仅为2%。失血超过750毫升的患者所需的红细胞输注量比无大量出血的患者多93%。在体外循环前静脉注射氨甲环酸（10克）可使6小时内失血量减少50%，24小时内减少35%。持续输注氨甲环酸（5小时内输注10克）并未进一步减少出血。大量出血患者与无大量出血患者术前凝血指标无差异。然而，术后凝血检查表明大量出血患者存在持续的纤维蛋白溶解和血小板功能障碍。
