Department of Anesthesiology, Critical Care, and Pain Medicine (S.M.G., D.Z., M.E.M., R.M.B., and N.F.S.) and Department of Orthopaedic Surgery (M.P.G., D.H., L.I.K., J.B.E., and M.T.H.), Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
J Bone Joint Surg Am. 2018 Dec 5;100(23):2024-2032. doi: 10.2106/JBJS.18.00314.
Tranexamic acid (TXA) is an antifibrinolytic drug that reduces surgical blood loss. Evidence supporting its efficacy in surgery for adolescent idiopathic scoliosis is not robust. This trial was designed to validate the clinical efficacy of TXA in surgery for adolescent idiopathic scoliosis.
This institutional review board-approved prospective double-blinded trial involved 111 patients with adolescent idiopathic scoliosis who were randomized to receive either a placebo or TXA (50-mg/kg loading dose and 10-mg/kg/h infusion). Power analysis indicated that 50 patients per group would provide power to detect a >20% difference in blood loss. Two-way analysis of variance (ANOVA) was applied to compare blood loss rates (slopes) using the group-by-time interaction F test.
The risk of clinically relevant blood loss (>20 mL/kg) was more than twice as high in the placebo group than in the TXA group (44% versus 21%, relative risk = 2.1, 95% confidence interval = 1.2 to 3.7). Compared with the placebo group, the TXA group had a 27% reduction in intraoperative blood loss, a significantly lower rate of intraoperative bleeding per hour (mean and standard deviation, 190 ± 73 versus 230 ± 80 mL, p = 0.01; F = 9.77, p < 0.001) and per fused spinal level (82 ± 32 versus 110 ± 40 mL, p < 0.001), less intraoperative blood loss (836 ± 373 versus 1,031 ± 484 mL, p = 0.02), and less postoperative bleeding (in the drain) (498 ± 228 versus 645 ± 318 mL, p = 0.009). Six patients who received a placebo and no patient who received TXA required an allogenic blood transfusion. No perioperative adverse events, including thromboembolic events or seizures, were observed. Three independent factors were predictive of blood loss: TXA administration, duration of surgery, and number of levels fused. Greater intraoperative blood loss was the only independent variable predictive of a longer hospital stay.
Use of TXA in patients undergoing surgery for adolescent idiopathic scoliosis significantly reduced blood loss, by 27%, compared with that in the placebo group. The rate of intraoperative blood loss per hour and per level fused and the amount of postoperative blood loss were significantly lower in the TXA group. More placebo-treated patients received allogenic blood. Patients with greater intraoperative blood loss spent a longer time in the hospital.
Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
氨甲环酸（TXA）是一种抗纤维蛋白溶解药物，可减少手术出血。支持其在青少年特发性脊柱侧凸手术中有效性的证据并不充分。本试验旨在验证 TXA 在青少年特发性脊柱侧凸手术中的临床疗效。
这项经机构审查委员会批准的前瞻性双盲试验纳入了 111 例青少年特发性脊柱侧凸患者，他们被随机分配接受安慰剂或 TXA（50mg/kg 负荷剂量和 10mg/kg/h 输注）。功效分析表明，每组 50 例患者将有能力检测出血损失超过 20%的差异。使用组间时间交互 F 检验对失血率（斜率）进行双向方差（ANOVA）分析。
与安慰剂组相比，TXA 组的临床相关失血（>20 毫升/公斤）风险高出两倍以上（44%比 21%，相对风险=2.1，95%置信区间=1.2 至 3.7）。与安慰剂组相比，TXA 组术中失血量减少了 27%，每小时术中出血量（均值和标准差，190±73 与 230±80 毫升，p=0.01；F=9.77，p<0.001）和每融合脊柱水平的出血量（82±32 与 110±40 毫升，p<0.001）显著降低，术中总失血量（836±373 与 1031±484 毫升，p=0.02）和术后（引流中）出血量（498±228 与 645±318 毫升，p=0.009）均减少。6 例接受安慰剂的患者和 1 例接受 TXA 的患者均无需异体输血。未观察到围手术期不良事件，包括血栓栓塞事件或癫痫发作。有三个独立的因素可预测失血：TXA 给药、手术持续时间和融合的节段数。术中失血增加是唯一可预测住院时间延长的独立变量。
与安慰剂组相比，在接受青少年特发性脊柱侧凸手术的患者中使用 TXA 可显著减少 27%的失血。TXA 组术中每小时和每融合水平的失血量以及术后出血量均显著降低。更多接受安慰剂治疗的患者接受了异体输血。术中失血量较多的患者住院时间较长。
治疗性 I 级。请参阅作者说明，以获取完整的证据水平描述。
