通过血栓弹力图(TEG)评估止血带应用与否对全膝关节置换术(TKA)后早期凝血状态的影响。

纳入徐州医科大学附属医院骨科2019年1月至2020年5月拟行初次单侧TKA的160例膝关节骨关节炎患者；排除合并严重内科疾病、既往血栓病史或术前下肢动静脉彩超示DVT阳性、术前凝血功能异常或存在抗凝禁忌、围术期输注凝血因子或血小板的患者。随机分成止血带组和无止血带组，每组80例。分别于术前和术后7 d检查下肢动静脉彩超，术前、术后1 d和术后7 d检测常规凝血指标和TEG，对比两组患者的总失血量、血栓发生情况及常规凝血指标和TEG参数变化。输血率、静脉血栓发生情况等，使用卡方检验；常规凝血指标如纤维蛋白降解产物(FDP)和凝血酶时间(TT)及TEG各值如凝血反应时间(R)、血块形成时间(K)、凝固角(Alpha)、最大振幅(MA)、凝血指数(CI)比较使用t检验，不同时间点的参数比较使用重复测量方差分析。

通过Gross方程计算患者的预计总失血量，得出止血带组总失血量(1 036±238)ml大于无止血带组(852±220)ml (t ＝4.713，P<0.001)。两组输血率和血栓发生率差异无统计学意义(χ²＝0.538，0.132，P>0.05)。止血带组内不同时间点FDP、D-二聚体和TEG的R、MA和CI差异均有统计学意义，无止血带组内不同时间点FDP、D-二聚体、K、Alpha和CI差异均有统计学意义(均为P<0.05)，术后7 d止血带组TT显著低于无止血带组(F＝15.818，P<0.05)，FDP和D-二聚体高于无止血带组(F＝18.795、U＝1 314，均为P<0.05)。术后7 d止血带组R低于无止血带组(F＝4.438)，MA(F＝87.088)和CI(F＝5.282)显著高于无止血带组(均为P<0.05)。

在TKA术中，全程使用止血带不影响输血率和血栓发生率，但会增加预计总失血量，并且加剧术后早期血液高凝状态。

To investigate the influence of tourniquets on the earlypostoperative coagulation status in total knee arthroplasty (TKA) evaluated by thrombelastography (TEG).

From January 2019 to May 2020, 160 patients with knee osteoarthritis undergoing primary unilateral TKA in Department of Orthopaedics of the Affiliated Hospital of Xuzhou Medical University were randomly assigned to the tourniquet group and the non-tourniquet group with 80 patients in each group. The patients with serious medical comorbidities, history of thrombosis, positive ultrasound results for preoperative DVT, preoperative coagulant function abnormality, anticoagulant therapy contraindications and perioperative transfusion of blood coagulation factors or platelets were excluded. Lower extremity doppler ultrasonography was performed before operation and seven days after the operation, conventional coagulation tests and TEG were performed before operation, one day after operation and seven days after operation. The calculated blood loss, the occurrence of venous thrombosis, the parameters of conventional coagulation tests and TEG were compared between the two groups. The chi-square test was used to compared the transfusion rate and the incidence of thrombosis, etc. The conventional coagulation test and TEG variables, including fibrin degradation products (FDP), thrombin time(TT), reaction time (R), clotting time (K), α-angle (alpha), maximum amplitude (MA), coagulation index (CI), between the two groups were analyzed by t test, and repeated measurement analysis of variance was used for comparison at different time points.

The tourniquet group had significant higher blood loss [(1 036±238)ml vs. (852±220)ml, t=4.713, P<0.001], which were calculated by the Formula of Gross. There was no statistically significant difference in the transfusion rate and the incidence of thrombosis between the two groups (χ²=0.538, 0.132, both P>0.05). There was a significant difference in terms of FDP, D-dimer, R, MA and CI among the three time points in the tourniquet group, while in the non-tourniquet group, statistically significant differences were observed with regard to FDP, D-dimer, K, Alpha and CI(all P<0.05). At seven days after operation, the level of TT in the tourniquet group was lower than that of the non-tourniquet group(F=15.818, P<0.05), and the levels of FDP and D-dimer of the tourniquet group were higher than those of the non-tourniquet (F=18.795, U=1 314, both P<0.05). At seven days after operation, with regard to TEG, R value of the tourniquet group was significantly lower than that of the non-tourniquet group(F=4.438), whereas MA(F=87.088) and CI(F=5.282)in the tourniquet group was significantly higher than those in the non-tourniquet group (both P<0.05).

The use of a tourniquet during the whole TKA does not affect the transfusion rate and the incidence of thrombosis, but it may increase calculated total blood loss, and exacerbate the early postoperative blood hypercoagulability.