Department of Orthopaedics, Peking University Third Hospital, Beijing 100191, China.
Research Center of Clinical Epidemiology, Peking University Third Hospital, Beijing 100191, China.
Chin Med J (Engl). 2018 Mar 20;131(6):638-642. doi: 10.4103/0366-6999.226884.
Total knee arthroplasty (TKA) is the most frequently performed procedure in treating advanced knee osteoarthritis. Excessive perioperative blood loss can sometimes lead to postoperative anemia. Tranexamic acid (TXA) is a potent fibrinolysis inhibitor which has been extensively used at the surgical incision and closure to lower overall blood loss in adult reconstruction surgery. Our previous study suggested that about two-thirds of the total blood loss (TBL) came from hidden blood loss (HBL) on postoperative days 1 and 2. The role of reducing HBL with TXA administration in postoperative TKA patients is unknown. The current study was designed to evaluate the efficiency and safety of supplemental intravenous (IV) TXA in further reducing HBL after primary TKA.
A prospective pilot study was conducted at a single institution on 43 consecutive patients who underwent unilateral TKA from September 2014 to February 2015. All patients were given 1 g of IV TXA 10-15 min before operation and another 1 g of IV TXA at the time of wound closure on the day of surgery. On postoperative days 1 and 2, the supplemental group (n = 21) was given additional 1 g of TXA intravenously twice a day, whereas the control group (n = 22) received an equal volume of saline. Drain output, hemoglobin (Hb), and hematocrit (HCT) were recorded preoperatively and 5 consecutive days postoperatively in both groups. HBL was calculated with the Gross formula. Pre- and post-operative lower extremity Doppler venous ultrasound was performed in all patients to detect deep vein thrombosis (DVT). The indexes were compared using the Mann-Whitney test, whereas the results of Hb and HCT were analyzed by repeated-measures analysis of variance. The difference was considered statistically significant if P < 0.05.
The demographics and surgical characteristics of the two groups were comparable. Supplemental group had higher Hb level on postoperative days 1-5 compared to the control; however, the difference was not significant (F = 2.732, P = 0.106). The HCT of the supplemental group was significantly higher than that of the control group on postoperative day 5 (F = 5.254, P = 0.027). No significant difference was found in drainage volume and TBL, but the HBL was reduced in the supplemental group (supplemental 133.1 [71.8, 287.3] ml and control 296.0 [185.3, 421.4] ml, Z = 2.478, P = 0.013, median [interquartile range]). There was one DVT in the control group and none in the supplemental group. All patients were followed at 1 year after surgery, and no further complications were reported.
Based on the current study, additional doses of IV TXA could potentially further reduce HBL after primary TKA without increasing the risk of venous thromboembolism.
全膝关节置换术（TKA）是治疗晚期膝关节骨关节炎最常进行的手术。围手术期过多失血有时会导致术后贫血。氨甲环酸（TXA）是一种有效的纤维蛋白溶解抑制剂，已广泛应用于手术切口和闭合处，以降低成人重建手术的总失血量。我们之前的研究表明，总失血量（TBL）的三分之二左右来自术后第 1 天和第 2 天的隐性失血（HBL）。TXA 给药减少 HBL 在术后 TKA 患者中的作用尚不清楚。本研究旨在评估在初次 TKA 后补充静脉（IV）TXA 进一步减少 HBL 的效率和安全性。
在 2014 年 9 月至 2015 年 2 月期间，在一家单中心对 43 例连续单侧 TKA 患者进行了前瞻性试点研究。所有患者在手术前 10-15 分钟给予 1g IV TXA，在手术当天伤口闭合时再给予 1g IV TXA。在术后第 1 天和第 2 天，补充组（n=21）每天静脉给予 1g TXA 两次，而对照组（n=22）给予等量生理盐水。两组患者均在术前和术后 5 天记录引流量、血红蛋白（Hb）和血细胞比容（HCT）。根据 Gross 公式计算隐性失血量（HBL）。所有患者均行下肢多普勒静脉超声检查以检测深静脉血栓形成（DVT）。使用 Mann-Whitney 检验比较指标，Hb 和 HCT 的结果采用重复测量方差分析。如果 P＜0.05，则认为差异具有统计学意义。
两组患者的一般资料和手术特点相似。与对照组相比，补充组在术后第 1-5 天的 Hb 水平更高，但差异无统计学意义（F=2.732，P=0.106）。补充组的 HCT 在术后第 5 天明显高于对照组（F=5.254，P=0.027）。两组的引流量和 TBL 无显著差异，但补充组的 HBL 减少（补充组 133.1[71.8，287.3]ml，对照组 296.0[185.3，421.4]ml，Z=2.478，P=0.013，中位数[四分位距]）。对照组有 1 例 DVT，补充组无 DVT。所有患者均在术后 1 年进行随访，无进一步并发症报告。
根据本研究，在初次 TKA 后补充静脉 TXA 可能会进一步降低 HBL，而不会增加静脉血栓栓塞的风险。
