19例原位肝移植术中凝血弹性图变化及与ACT相关性的临床研究

目的 探讨国人原位肝移植术中凝血弹性图（TEG）的变化及其与激活全血凝块形成时间（ACT）的相关性。方法 19例病人分为急性肝衰组（8例）与肝肿瘤组（11例）,接受原位肝移植术,无肝期采用体外静脉－静脉转流。两组病人分别于术前、无肝前（手术开始后120min,I 120)、无肝的30min（Ⅱ 30）、新肝前5min（Ⅲ－5）、新肝后5min（Ⅲ＋5）、30min（Ⅲ＋30）、60min（Ⅲ＋60）、120min（Ⅲ＋120）,8个时间点,分别观察硅燥土激活的全血TEG及ACT的变化。19例病人中有6例于新肝后5min同时观察肝素酶修正后的TEG与非肝素酶修正后的TEG及ACT的变化。结果 肝衰组TEG值（r、r k、αlpha角或α、MA）的变化主要在Ⅱ＋30min、Ⅲ－5min、Ⅲ＋5min,肝肿瘤组TEG值（r、r k、αMA）的变化均在新肝后5min、30min、60min。与术前值相比,两组TEG值的表现为r与r k延长,α与MA减小（P＜0．05、0．01）。相关研究表明,两组r k与ACT均呈正相关（r分别为0．743及0．634,P＜0．01）。其中6例于新肝后5min,有肝素酶与无肝毒酶的全血TEG值差异亦显著（P＜0．01）,后者经静注鱼精蛋白50－75mg后,两组TEG值差异无统计学意义（P＞0．05）。结论 TEG提示原位肝移植术中的凝血紊乱主要发生在无肝期及新肝早期,TEG指标r k与ACT有相关性。肝素酶修正后的全血TEG可提示新肝期体内存在肝素化效应,需用鱼精蛋白拮抗。     

凝血弹性图应用于同种原位肝移植术中凝血功能的评价

目的 应用凝血弹性图(thrombelastograghy,TEG)监测原位肝移植术中患者的凝血功能，指导术中凝血功能的诊断及用药。方法 25例肝移植患者按原发疾病分成两组，肝硬变组15例，肝癌组10例，接受原位肝移植术，无肝期体外静脉—静脉转流。两组患者分别于术前、无肝期前(手术开始后120min)、无肝期后30m：n、新肝期前5min和新肝期后5min、15min、30min、60min及120min9个时点，分别观察硅燥土激活的全血TEG的参数改变，即反映第一块纤维蛋白凝块形成的时间(r)，血凝块强度达到20min振幅的时间(K)，纤维蛋白和血凝块加固速度(α)，以及纤维蛋白凝块最终强度(MA)。25例中有8例于新肝期后5min同时观察了肝素酶修正后的TEG的变化。结果 肝硬变组TEG值4项参数的变化主要发生在无肝期和新肝早期，肝肿瘤组TEG值4项参数的变化均在新肝期后5min、15min、30min及60min。与术前值相比，两组TEG值均表现为r与K延长，α与MA减小(P＜0．05，P＜0．01)。其中8例新肝期后5min，有肝素酶与无肝素酶的全血TEG值差异亦有显著性意义(P＜0．01)，后者的r和K明显延长，α和MA明显减小；后者经静脉注射鱼精蛋白50一75mg后，两组TEG值差异无统计学意义(P＞0．05)。结论 原位肝移植术中的凝血紊乱主要发生在无肝期及新肝早期，肝素酶修正后的全血TEG可提示新肝期体内存在肝素化效应，需用鱼精蛋白拮抗。     

血栓弹力图在评价膝关节置换患者术后下肢深静脉血栓形成的临床价值研究

目的探讨血栓弹力图(TEG)在评价膝关节置换术后下肢深静脉血栓形成的价值。方法收集本组2010年3月至2013年9月行人工膝关节置换术患者116例,分别于麻醉前(T0)、手术开始后2h(T1)、术后第1天(T2)和术后第3天(T3)采集患者静脉血进行TEG检测,采用重复测量方差分析比较两组患者各采集点时TEG的R、K、α、MA、G和CI等6个参数值。结果患者在围手术期间均呈现高凝状态,且表现为进行性加重。与各指标正常值比较,膝关节置换术患者TEG指标中R和K缩短,α角、MA以及G值增大,CI增大与麻醉前T0比较,R值逐渐下降,其中T2和T3时的R下降显著;K值也成逐渐下降趋势,但不具统计学差异;α角、MA以及G值则显著性升高;CI无显著性变化。TEG诊断对照组患者深静脉血栓的准确性为66.67%,观察组患者深静脉血栓诊断准确性为77.78%,卡方检验表明差异无统计学意义(P>0.05)。结论 TEG是判断行膝关节置换手术患者围手术期血液高凝状态的敏感指标之一,值得临床推广。     

血栓弹力图与常规凝血参数在糖尿病肾病中的对比分析

目的:评估血栓弹力图(TEG)与常规凝血对糖尿病肾病患者凝血状态的价值。方法:选取2016年08月~2017年08月在青岛市市立医院住院的2型糖尿病肾病患者160例,根据是否服用阿司匹林将入选患者分为Ⅰ组(非阿司匹林组),Ⅱ组(阿司匹林组);并按照尿微量白蛋白肌酐比(UACR)将每组患者分为ⅠA组、ⅡA组(UACR 30 mg/mmol),ⅠB组、ⅡB组(UACR 30~300 mg/mmol),ⅠC组、ⅡC组(UACR 300 mg/mmol)。观察以上6组患者TEG和常规凝血的变化,分析TEG相关指标与UACR的相关性。结果:(1)ⅠC组较ⅠB组:TEG观察反应时间(R值)、凝血时间(K值)明显降低,凝血指数(CI值)、血栓最大弹力度(MA值)明显升高(P均0. 05);ⅠC组较ⅠA组:R值、K值降低,MA值、CI值、纤维蛋白原(Fib)升高(P均0. 05);ⅠB组较ⅠA组:R值、K值降低,MA值升高(P均0. 05)。其余各项常规凝血指标在ⅠA、ⅠB、ⅠC三组间差异无统计学意义(P均 0. 05)。(2)ⅠA组较ⅡA组:MA值、Angel角均升高(P均0. 05),ⅠB组较ⅡB组:MA值升高(P均0. 05),ⅠC组较ⅡC组:MA值、CI值均升高,(P均0. 05)。(3) Pearson相关分析显示:Ⅰ组患者中TEG观察MA值、Angel角、CI值与UACR呈正相关(r值分别为0. 573、0. 567、0. 758,P均0. 05); R值、K值与其呈负相关(r值分别为-0. 681、-0. 701,P均0. 05)。结论:在糖尿病肾病患者的凝血检测中,TEG相对于常规凝血更为敏感,且随着UACR增加,凝血活性有不断增高的趋势; TEG能够更好的评价糖尿病肾病中服用阿司匹林患者的凝血状态,并指导阿司匹林的临床应用。     

血栓弹力图预测髋膝关节置换术后血液高凝状态的价值分析

目的分析血栓弹力图(thromboelastography,TEG)预测髋膝关节置换术后病人血液高凝状态的价值。方法前瞻性纳入2019年3月至2019年12月于重庆医科大学附属第一医院拟行髋膝关节置换的204例病人,分析病人围术期的反应时间(R值)、血块形成时间(K值)、血块形成速率(α角)、最大振幅(MA值)、凝血指数(CI)的变化,评估TEG在诊断高凝状态方面与常规凝血试验的差异性和一致性,分析术后血液高凝的危险因素。结果相对于常规凝血试验,TEG诊断高凝状态的阳性率更高(P<0.001),两者具有一定的相关性和一致性。R值与国际标准化比值(international normalized radio,INR)、血小板计数(platelet counts,PLT)呈负相关,与活化部分凝血酶原时间(activated partial thromboplastin time,APTT)呈正相关;K值与PLT呈负性相关;α角与纤维蛋白原(fibrinogen,FIB)、PLT呈正相关;MA值与FIB、PLT呈正相关;CI值与FIB、PLT呈正相关,与D-二聚体(D-Dimer,D-D)呈负相关。术前高凝病人术后第1、3、5天的血液高凝发生率明显高于术前凝血功能正常者,差异均有统计学意义(P均<0.05)。根据术后第5天TEG诊断的凝血状态,年龄≥65岁[OR=8.938,95%CI(3.917,20.397),P<0.001]、围术期输血[OR=12.379,95%CI(5.304,28.893),P<0.001]是髋膝关节置换术后血液高凝的独立危险因素。结论TEG是预测术后高凝的有效指标,对于指导髋膝关节置换围术期个体化抗凝具有重要意义。     

剖宫产术前急性高容量血液稀释对产妇高凝状态的影响

目的 观察羟乙基淀粉(HES)术前急性高容量血液稀释(AHHD)对剖宫产产妇高凝状态的影响.方法 择期行剖宫产的产妇40例,随机均分为两组.术前30 min内输注15 ml/kgHES 200/0.5(H组)或复方乳酸钠(RL)(R组).抽取静脉血标本,采用血栓弹力描记仪检测麻醉前(T0)、AHHD结束后即刻(T1)、1 h(T2)、4 h(T3)时的凝血状态.结果 与T0比较,H组与R组产妇的TEG参数R值在T1时明显延长(P＜0.05);H组的TEG参数ANG、MA、CI在T1、T2、T3时明显减小(P＜0.05),R组仅在T3时明显增加(P＜0.05).与R组比较,H组在T1～T3时的TEG参数ANG、MA、CI明显减小(P＜0.05).结论 剖宫产术前采用HES 200/0.5行AHHD能减轻剖宫产围术期产妇的高凝状态,对预防术后静脉血栓形成可能有一定的作用.     

用血栓弹力图比较不同麻醉方法对患者围术期凝血及纤溶功能的影响

目的 比较全身麻醉和硬膜外麻醉对患者围术期凝血及纤溶功能的影响。方法 80例择期单侧膝关节置换术患者,随机分为全麻组和硬膜外组。分别于术前、术中、术后抽取静脉血检测TEG(Thromboelastography),参数包括反应时间(R)、K时间、α角、最大振幅(MA)、凝血指数(CI)及LY30。同时采用彩色多普勒观察术后下肢深静脉血栓(DVT)形成情况。结果 全麻组R、K术中及术后均低于术前,其中R值术后组内明显低于术前(P<0.05),组间明显低于硬膜外组(P<0.05);全麻组α、MA、CI及LY30术中及术后均高于术前,其中术后组内明显高于术前(P<0.05),组间明显高于硬膜外组(P<0.05);LY30硬膜外组术后组内明显高于术前(P<0.05)。结论 全身麻醉对患者围术期凝血功能有明显促进作用,可使血液处于高凝状态,而硬膜外麻醉可在一定程度上防止术后血液高凝状态;全身麻醉和硬膜外麻醉对患者围术期纤溶功能均有一定促进作用且前者作用更强。     

股骨骨折术前血栓弹力图的价值

目的:采用血栓弹力图(thrombelastograph,TEG)评价股骨闭合骨折术前的凝血状况,并探讨TEG在评价股骨骨折术前高凝状态的意义.方法:I组为对照组,11例健康献血员,清晨空腹静脉采血.Ⅱ组为实验组,26例,为未经抗凝治疗的股骨闭合性骨折患者,分别于骨折第2天(Ⅱ2d)和第8天(Ⅱ8d)清晨空腹静脉采血.实验采用双盲法,专人检测.两组静脉血样均进行TEG检测.结果:I组TEG的各参数结果正常.Ⅱ组中Ⅱ2d和Ⅱ8d的TEG:α角、血栓最大幅度MA值、血栓硬度G值均增大,与I组比较差异有显著性意义;Ⅱ组中Ⅱ8d与Ⅱ2d比较,血栓最大幅度MA值和血栓硬度G值增大,均有统计学差异.结论:股骨骨折第2天和第8天均存在不同程度的高凝状态,而且有逐步加重趋势;TEG是创伤骨折及术前预测和判断血液高凝状态的有力指标,如TEG揭示高凝状态存在,应采取有力措施预防下肢深静脉血栓的形成,并尽早防治.     

血栓弹力图评估利伐沙班预防全髋关节置换术后高凝状态

[目的]通过血栓弹力图(TEG)评估利伐沙班应用于全髋关节置换术后抗凝治疗的疗效。[方法]选取2017年1月～2018年6月行全髋关节置换术的60例患者,随机分成利伐沙班组、依诺肝素钠组,每组30例。利伐沙班组口服利伐沙班10 mg,1次/d,术后6 h首次给药,连续应用35 d。依诺肝素钠组皮下注射依诺肝素钠4 000U,1次/d,术后6 h首次给药,连续治疗7 d,后改为口服利伐沙班10 mg,1次/d,共治疗35 d。分别比较两组间常规凝血功能指标、D-二聚体、纤维蛋白原降解产物、TEG指标和深静脉血栓发生情况。[结果]利伐沙班组内不同时间点TEG的K值、Alpha角、MA值和CI值差异均有统计学意义(P0.05)。依诺肝素组内不同时间点R值、K值、Alpha角、MA值和CI值差异均有统计学意义(P0.05)。术后7 d利伐沙班组D-二聚体低于依诺肝素钠组,差异有统计学意义(P0.05)。术后7 d利伐沙班组R值显著高于依诺肝素钠组,MA值和CI值显著小于依诺肝素钠组,差异有统计学意义(P0.05)。然而两组间传统凝血指标的差异无统计学意义(P0.05)。[结论]利伐沙班预防THA患者术后高凝状态的疗效强于依诺肝素。动态监测TEG可以评估THA术后应用利伐沙班预防高凝状态的疗效,弥补了传统凝血检测的不足。     

不同院前创伤评分联合血栓弹力图对骨折合并多发伤患者伤情评估中的应用价值探讨

目的 探讨不同院前创伤评分联合血栓弹力图对急诊骨折合多发伤患者伤情评估中的应用价值。方法 回顾性分析2018年1月至2021年12月中国人民解放军陆军第七十二集团军医院急诊科收治的多发伤患者162例临床资料，根据Crams评分将所有患者按照伤情情况分为重度创伤组（n=36）与轻度创伤组（n=126），对比两组急性生理学及慢性健康状况评分（APACHE-Ⅱ）、创伤严重程度评分（AISISS），同时分析两组血栓弹力图（TEG）指标[凝血反应时间（R）、血块形成速率（K）、血块生成率（α角）、最大宽度值（MA）、凝血综合指数（CI）]。分析不同院前创伤评分与血栓弹力图的相关性，绘制ROC曲线分析不同院前创伤评分联合血栓弹力图对急诊多发伤患者伤情评估中的应用价值。结果 轻度组Crams评分比重度组高，而APACHE-Ⅱ、AIS-ISS评分均较重度组低（P<0.05）。轻度组R、K值均小于重度组，而α角、MA及CI值均较重度组大（P<0.05）。Crams评分与R、K、CI呈负相关（r<0,P<0.05），与α角、MA呈正相关（r>0,P<0.005）。APA...     

In vitro evidence of gender-related heparin resistance

Coagulability varies among men, women, and pregnant women, along a spectrum where the blood of men is the least and that of pregnant women the most coagulable. The effects of differences in coagulation status on the action of heparin cannot be measured by specific laboratory tests such as aPTT or anti-Factor Xa assay. Thromboelastography which measures whole blood coagulation can assess the effect of heparin against differing backgrounds of coagulation. The aim of this in vitro study was to explore differences in heparin effect between men, women and pregnant women. Fifteen male and female staff volunteers, and 15 pregnant women approaching term, donated venous blood, which was added to four cups in two TEG 5000 analysers. In the cups of the analysers was 0.03 mL of saline control, or heparin 0.4, 0.6 or 1 unit/mL. TEG variables r and k, angle and MA were compared across the groups using two way ANOVA. All subject groups demonstrated a significant heparin effect, which was least in the control group and greatest with 1 unit/mL (P < 0.0001). Across the subject groups, from men to pregnant women, increasing coagulability was seen, with shortening of r and k (P < 0.04), and increasing angle and MA (P < 0.0001). A relationship between gender and heparin was significant for r and k (P < 0.02) but not for angle and MA. This result assists the case against a one-size-fits-all approach to policies on heparinisation.     

Does hemodilution enhance coagulability?

Recent publications reported enhanced coagulability in hemodilution determined by TEG. In contrast, earlier reports have shown prolongation of in-vivo bleeding time in anemia. In order to take a closer look at this discrepancy undiluted and diluted anticoagulated blood samples (20 % with saline solution, hydroxyl-ethyl starch 6 % (HES), autologous platelet poor plasma (PPP)) were investigated by TEG (n = 10), ball (n = 10), and hook coagulometer (n = 15) as well as tests simulating primary hemostasis ex vivo (Platelet Function Analyzer PFA-100, n = 10). RESULTS: Dilution with plasma changed TEG parameters in a way, when started by recalcification of the blood sample, which is characteristic of enhanced coagulability (r decreased in all and k in 8 of 10 samples, maximal amplitude increased in 9 out of 10). With HES, changes in TEG parameters mainly indicated reduced coagulability (k increased in 7 out of 10, MA decreased in 10 out of 10). When the coagulation was additionally activated by PTT reagent (InTEG) the TEG parameters also mainly showed hypocoagulation with the three dilution solutions. Coagulation times with ball and hook coagulometers were significantly prolonged by dilution especially with saline (+ 25 % and + 17 %, p < 0.001). Dilution always significantly (often abnormally) prolonged closure time in PFA-100 (saline + 41 +/- 18 %, PPP + 37 +/- 20 %, HES + 69 +/- 24 %) demonstrating disturbance of primary hemostasis, particularly with HES. Conclusions: From the results obtained it can be concluded that the changes in the classical TEG (without addition of PTT-reagent), suggesting an enhanced coagulability, may be caused methodically as they are also found with autologous PPP. On the other hand, a disturbance of the primary hemostasis in hemodilution has to be taken into account from the results seen with the PFA-100 and a number of published data.     

血栓弹力图评估肾肿瘤患者术前凝血状态的临床价值研究

目的 采用血栓弹力图(TEG)和常规凝血功能检测来评估肾肿瘤患者术前的凝血功能状态,评估肾肿瘤患者术前凝血状态过程中TEG的临床应用价值,探讨TEG与凝血五项指标的相关性.方法 选取2016年1月至2019年3月在本院行肾占位性病变手术的患者142例,并根据术后病理结果将患者分为肾癌组(97例)与肾良性疾病组(45例)...     

Intraoperative changes in blood coagulation and the effectiveness of ulinastatin during liver resection

The blood coagulation status of 16 patients undergoing liver resection was monitored by thrombelastograph (TEG). Coagulation test by TEG was performed at three different times: before and one hour after induction of anesthesia and after liver resection. The four variables such as r (reaction time), k (coagulation velocity), ma (maximum amplitude) and me (maximum elasticity) were measured. In 8 patients, Ulinastatin was not administered during the operation and FFP was transfused after the second measurement of TEG (group I). The other 8 patients were administered totally 300,000 units of Ulinastatin after induction until the second measurement of TEG, thereafter FFP was transfused (group II). The TEG showed poor preoperative coagulation state in both groups. In group I, TEG variables showed coagulopathy was exacerbated significantly during liver resection. In group II TEG variables showed no significant changes during operation. Between the two groups there were statistical differences in the TEG variables during the operation. The TEG was useful for monitoring coagulation function during liver resection. It was impossible to improve TEG data by only replacement of FFP. Ulinastatin was useful in normalizing the coagulation function and in preventing the changes in TEG measurements during liver resection.(Okida M, Masako O, Maruya H, et al.: Intraoperative changes in blood coagulation and the effectiveness of Ulinastatin during liver resection. J Anesth 5: 43–47, 1991)     

Pro-coagulant effect of in vitro haemodilution is not inhibited by aspirin

We have conducted an in vitro coagulation study, using the thrombelastograph (TEG), to determine if the enhanced coagulability of whole blood after haemodilution with normal saline can still be demonstrated after administration of an antiplatelet agent. Aspirin inhibits the platelet-endothelial interaction that is part of the coagulation process. We investigated the role of aspirin in the phenomenon of haemodilution-induced coagulability to identify if the platelet-endothelial system is involved in the process. Previous work showed that the TEG is not altered by oral ingestion of aspirin. Blood from 20 volunteers was divided into two aliquots of 4 ml each. One sample was diluted by 20% by addition of 0.9% saline 1 ml while the other was not diluted and served as a control. Coagulation studies were performed using the TEG and enhanced coagulation was seen in the saline diluted samples. Subjects then received soluble aspirin 375 mg daily for 3 days, after which the tests were repeated. There was no difference in the control TEG values and saline enhancement of coagulation was preserved in all subjects after 3 days of aspirin administration. We conclude that aspirin had no effect on the observation that haemodilution with saline enhances the coagulability of whole blood.      

Changes in blood coagulability as it traverses the ischemic limb

OBJECTIVE: We undertook this study to determine whether changes in blood coagulability associated with peripheral arterial occlusive disease are due to contact with the atherosclerotic arterial wall or passage through distal ischemic tissue. METHODS: Thirty patients with peripheral arterial occlusive disease undergoing angiography participated in the study. Ankle-brachial pressure index was recorded before intervention. Blood samples taken from the aorta, common femoral artery, and common femoral vein were analyzed at thromboelastography. Angiograms were scored for stenotic disease by a radiologist blinded to the other results. RESULTS: When femoral artery samples were compared with aortic samples there was a decrease in reaction time (R; P <.05), an increase in maximum amplitude (MA; P <.05), and an increase in coagulation index (CI; P <.002), indicating an increase in coagulability as blood flowed down the iliac segment. These changes also correlated (DeltaR, r = 0.442, P <.05; DeltaMA, r = 0.379, P <.05; DeltaCI, r = 0.429, P <.05) with the severity of disease in the ipsilateral iliac segment. Significant differences in R (P <.05), angle (P <.05), MA (P <.005), and CI (P <.001) between common femoral arterial and venous samples confirmed that venous samples were more coagulable in this group of patients. This difference in Thromboelastography parameters across the arteriovenous segment correlated inversely with the degree of ischemia (represented by ankle-brachial pressure index; DeltaCI, r = -0.427, P <.05; DeltaMA, r = -0.370, P <.05) in the puncture side limb. CONCLUSION: Passage of blood down an atherosclerotic artery leads to an increase in coagulability proportional to the degree of stenosis in that vessel. Passage of blood through ischemic tissue may also contribute to increased coagulability in peripheral arterial occlusive disease.     

In vitro effects of propofol on blood coagulability and fibrinolysis by the use of thromboelastograph technique

BACKGROUND: To investigate the in vitro effects of propofol on blood coagulability and fibrinolysis by the use of thromboelastograph (TEG) technique. METHODS: The blood samples, obtained from 14 healthy volunteers, were divided into two groups: propofol (n = 7) and intralipid (n = 7), and 360 microliters volumes of whole blood were incubated with 2 microliters of 1% propofol and with its solvent intralipid, respectively. The incubated sample was then used for TEG measurements. RESULTS: The maximum amplitude (MA), which reflects coagulability, in the intralipid group significantly increased by about 7% and 16% compared to the control and propofol groups, respectively (P < 0.05), whereas the MA in the propofol group did not change. The fibrinolytic rate (FR) in the propofol group significantly increased by about 170% and 210% compared to the control and intralipid groups, respectively (P < 0.05), whereas the FR in the intralipid group did not change. CONCLUSIONS: Propofol, per se, has at the concentration of 55.6 micrograms.ml-1 an in vitro accelerative effect on blood fibrinolysis detected by TEG.     

Intraoperative coagulation monitoring and small bowel transplantation: a way to explore

BACKGROUND: The existence of coagulation disorders during intestinal transplantation is getting more important for a correct anesthetic management. Both a condition of hypocoagulation and hypercoagulation can happen during the intraoperative course. Thromboelastography (TEG), a test on whole blood coagulation, allows measurement of different phases of coagulation function. The aims of our study were to evaluate coagulation derangements during bowel transplantation using TEG. MATERIALS AND METHODS: We measured cold ischemia time in 19 patients who underwent general anesthesia for intestinal transplantation. We measured five TEG indicators (R, K, angle, MA, CL50) at defined intervals: dissection phase (T1), vascular anastomosis phase (T2), 30' (T3) and 120' (T4) after reperfusion during the intestinal reconstruction. RESULTS: We found a statistically significant difference between MA measured at T1 versus T3 and T4. There was no significant relation between MA derangements and ischemia time. CONCLUSIONS: Patients showed hypocoagulation pattern during all periods. MA indicator variation between the initial value and the value after reperfusion may relate to release of hypocoagulation factors. We observed important coagulation derangements during small bowel transplantation, particularly on platelet function after graft reperfusion. The derangements did not depend on ischemia time.     

Surgical/tourniquet pain accelerates blood coagulability but not fibrinolysis

Tissue damage during surgery induces coagulation factors and activates platelets. Surgical pain may provoke release of catecholamines, leading to hypercoagulability. We have investigated the effect of surgical pain on blood coagulability and fibrinolysis in orthopaedic operations using tourniquets in 22 patients undergoing total knee replacement. Patients were allocated to one of two groups to receive extradural anaesthesia (EA; n = 11) or general anaesthesia (GA; n = 11). The EA group received lumbar extradural block with lidocaine. The GA group received only general anaesthesia, maintained with 1.5-2.5% sevoflurane and 66% nitrous oxide in oxygen. Using a thrombelastogram technique, blood coagulability and fibrinolysis were measured. Mean maximum amplitude (MA), which reflects coagulability, increased after tourniquet inflation (11%) in group GA whereas MA in group EA did not change. After tourniquet deflation, MA values in both GA and EA groups increased significantly (10% and 20%, respectively) (P < 0.05), and there was also a significant difference in MA between groups (P < 0.05). The fibrinolytic rate did not change in either group during tourniquet inflation, but increased significantly (160%) after tourniquet deflation. There was no significant difference in fibrinolytic rate between the groups. We conclude that the hypercoagulability seen in group GA could have been caused by surgical or tourniquet pain, or both, and that extradural anaesthesia is a useful technique to prevent hypercoagulability.