Ensayo clínico para determinar si el momento de administración del ácido tranexámico en la cirugía de prótesis total de rodilla con torniquete influye en el sangrado perioperatorio

Background and objectivesThe ideal timing of tranexamic acid administration in total knee arthroplasty with tourniquet remains unclear. Our primary objective was to prove if administering it before surgical incision, instead of before releasing the tourniquet, reduces postoperative bleeding. A second objective was to determine whether a second dose reduces post-operative bleeding.Material and methodsA prospective, double-blind clinical trial was performed on 212 patients scheduled for total knee arthroplasty. They were randomised into 4 groups. Tranexamic acid was administered before the surgical incision in “pre-induction groups” (1 and 2), and just before the tourniquet release in “pre-release groups” (3 and 4). Groups 2 and 4 received a second dose 3 hours post-surgery. Main outcome was postoperative bleeding (visible blood loss and calculated total bleeding). Secondary outcomes were haemoglobin variations, complications and transfusion rate.ResultsThe mean calculated total bleeding was 1563 ml (95%CI: 1445 to 1681) in preinduction groups versus 1576 ml (95%CI: 1439 to 1713) in pre-release groups (P = .9); 1579 ml (95%CI: 1452 to 1706) in single-dose groups versus 1559 ml (95%CI: 1431 to 1686) in double-dose groups (P = .82). One patient was transfused. The mean haemoglobin at discharge was 10.4 g/dl (95%CI: 10.2 to 10.7) in singledose groups versus 10.8 (95%CI: 10.6 to 11.1) in double-dose groups (P = .06).ConclusionsThere were no differences in bleeding or transfusion regarding the time of tranexamic acid administration. The second dose had not impact on outcomes.Trial registration: EudraCT 2016-000071-24.     

止血带联合子宫下段横和“U”字缝合术在凶险型前置胎盘剖宫产术中的应用

【目的】探讨止血带联合子宫下段横向“U”字缝合术在凶险型前置胎盘（PPP）剖宫产术中止血的效果及临床应用价值。【方法】将本院因PPP行剖宫产术的患者共53例,按单双号分为两组,观察组27例患者采用止血带环扎联合子宫下段横向“U”字缝合术止血,对照组26例患者常规手术方式,比较两组手术时间、术中出血量、子宫切除率及感染病率。【结果】观察组患者术中出血量少于对照组患者,差异具有统计学意义（ P ＜0．05）。观察组患者子宫切除率少于对照组患者,差异具有统计学意义（ P ＜0．05）。【结论】PPP剖宫产术中止血带环扎联合子宫下段横U字缝合术,能明显减少出血,降低子宫切成率,值得临床推广。     

上肢手术气囊止血带个体充气压力的研究

目的探讨上肢手术时气囊止血带适宜的个体充气压力。方法对30例健康成年志愿者,按右上臂周径大小分为S组(≤25cm)、M组(26～30cm)和L组(＞30cm),用彩色多普勒超声血流显像仪分别测定肱动脉血流100%和50%阻断时气囊止血带充气压力值。以周径和测定值为依据确定充气压力：周径≤25cm者,充气压力为25 kPa(IkPa=7．5mm Hg),＞25cm者。以肢体周径(cm)作为个体充气压力(kPa)值,最大值≤40kPa。用上述方法应用于上肢手术150例,并观察术中创面止血效果和术后止血带副损伤发生情况。结果30例右侧肱动脉血流100%和50%阻断时气囊止血带充气压力参考值分别为：S组[(19．17±1．95)kPa,(?)±s,下同]和(11．50±1．98)kPa,M组(21．18±2．09)kPa和(13．45±1．86)kPa,L组(27．00±4．12)kPa和(16．43±1．13)kPa,各组阻断压力差异有统计学意义(P＜0．01)。手术应用150例中,上臂周径平均为(28．13±3．53)cm,气囊止血带充气压力平均为(28．19±3．03)kPa。手术应用个体充气压力,止血效果优147例,良3例,术后均无止血带副损伤。结论以上肢缚扎止血带处肢体周径(cm)作为充气压力的参考值(kPa),是上肢手术适宜的个体充气压力。     

止血带对初次全膝关节表面置换作用的Meta分析

目的：应用Meta分析系统总结评价止血带对初次全膝关表面节置换术（ TKA ）的作用。方法计算机检索Medline、Embase、Cochrane Library等数据库,纳入2000年1月至2013年4月间止血带与非止血带对TKA影响的临床随机对照研究。根据改良Jadad评分量表评价纳入研究质量,并采用RevMan 5.1软件进行Meta分析。结果共纳入13篇临床随机对照研究,共计662位患者。其中止血带组325例,非止血带组337例。结果显示使用止血带减少TKA术中失血量232.4ml （WMD＝-232.43,95％CI：[-328.83,-156.03]）,但增加了总体并发症发生率（RR＝2.11,95％CI：[1.06,4.18]）,两者差异均有显著性。两组间术后显性失血量（WMD ＝-5.80,95％CI：[-176.25,164.64]）、总失血量（ WMD ＝67.36,95％CI：[-58.74,193.46]）及血栓事件发生率（RR＝3.50,95％CI：[0.75,16.44]）的差异无统计学意义。结论使用止血带可减少TKA术中失血量,但不能减少总失血量。止血带的使用增加了术后并发症的发生率。使用止血带与否不影响术后血栓事件发生率。     

气囊止血带阻断下肢血流压力值的研究

目的探讨下肢手术时气囊止血带适宜的个体充气压力。方法选择30例健康成年志愿者,按站立时右大腿围分为S组(<45cm)、M组(45~60cm)、L组(>60cm),用彩色多普勒超声血流显像仪分别测定右腘动脉血流100%和50%阻断时的气囊止血带充气压力值。以下肢周径和测定值为依据确定手术时充气压力,以缚扎止血带处肢体周径(cm)作为个体充气压力(kPa)值,最大值≤50kPa。用上述方法应用于下肢手术700例,观察术中创面的止血效果和术后止血带损伤发生情况。结果30例右侧腘动脉血流100%和50%阻断时气囊止血带充气压力参考值分别为:S组(35.70±3.16)kPa和(18.90±2.77)kPa,M组(34.40±2.72)kPa和(19.10±2.18)kPa,L组(39.60±1.90)kPa和(22.90±3.21)kPa,各组阻断压力差异有统计学意义(P<0.01)。下肢手术应用700例,止血效果达优690例,良10例,术后均无止血带损伤。结论以下肢缚扎止血带处肢体周径(cm)作为气囊止血带充气压力参考值(kPa),是下肢手术适宜的个体充气压力。     

Tourniquet application after local forearm warming to improve venodilation for peripheral intravenous cannulation in young and middle-aged adults: A single-blind prospective randomized controlled trial

BackgroundLocal forearm warming before tourniquet application is often used to promote venodilation for peripheral intravenous cannulation; however, few studies have compared the effect of tourniquet application with and without local warming on vein size.ObjectiveTo evaluate the effectiveness of tourniquet application after local forearm warming with that of tourniquet application alone in young and middle-aged adults.DesignA single-blind, prospective, parallel group, randomized controlled trial.SettingA national university in Japan.ParticipantsSeventy-two volunteers aged 20–64 years.MethodsParticipants were randomly allocated to one of two groups: tourniquet application for 30 s after forearm application of a heat pack warmed to 40 °C ± 2 °C for 15 min (active warming group; n = 36) or tourniquet application for 30 s after applying a non-warmed heat pack for 15 min (passive warming group; n = 36). The primary outcomes were vein cross-sectional area on the forearm, measured after the intervention by blinded research assistants using ultrasound. Secondary outcomes were shortest diameter, and longest diameter of vein on the forearm, forearm skin temperature, body temperature, pulse, systolic blood pressure, and diastolic blood pressure. All outcomes were assessed at the same site before and immediately after the intervention, once per participant.ResultsVein cross-sectional area, shortest vein diameter, and longest vein diameter were significantly increased in the active warming group compared with the passive warming group (p < 0.01). Tourniquet application after local warming was superior to tourniquet application alone in increasing vein cross-sectional, shortest diameter, and longest diameter (between-group differences of 2.2 mm², 0.5 mm, and 0.5 mm, respectively), and in raising skin temperature (between-group difference: 5.2 °C). However, there were no significant differences in body temperature, pulse, or systolic or diastolic blood pressure between the groups. There were no adverse events associated with either intervention.ConclusionTourniquet application after local warming was associated with increased forearm vein size when compared with tourniquet application alone, and was demonstrated as being safe. Thus, with demonstrable effects on vein size, we recommend local warming before tourniquet application as a safe and effective technique for improving venodilation.     

七氟醚和异丙酚对骨科手术患者止血带诱发肢体缺血再灌注损伤影响的比较

目的 比较七氟醚和异丙酚对骨科手术患者止血带诱发肢体缺血再灌注损伤的影响.方法 择期行膝关节韧带修复术患者54例,性别不限,年龄18～64岁,体重44 ～ 85 kg,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将患者随机分为3组(n=18)∶对照组(C组)、异丙酚组(P组)和七氟醚组(S组).行腰丛联合坐骨神经阻滞后,P组静脉注射异丙酚2 ～4 mg/kg麻醉诱导,并置入喉罩,术中静脉输注异丙酚2～4 mg·kg-1·h-1维持麻醉.S组吸入8％七氟醚麻醉诱导,并置入喉罩,术中吸入2％七氟醚维持麻醉.异丙酚或七氟醚给药15 ～ 20 min时,C组于相应时点,应用止血带,充气压力为300mm Hg,术毕时放气.术后口服美洛昔康或肌肉注射哌替啶镇痛,维持VAS评分＜3分.分别于入室后(T1)和止血带放气后30 min (T2)时采集血样,测定血浆MDA和TNF-α浓度,计算其增长率.术后记录止血带相关不良事件的发生情况和术后24 h内镇痛药用量.结果 患者均未见止血带相关不良事件发生.与C组比较,P组和S组T2时血浆MDA和TNF-α浓度及其增长率降低(P＜0.05)；与P组比较,S组血浆MDA和TNF-α浓度及其增长率差异无统计学意义(P＞0.05)；与T1时比较,P组和S组T2时血浆MDA和TNF-α浓度差异无统计学意义(P＞0.05),C组明显升高(P＜0.05)；3组患者术后24 h内镇痛药用量比较差异均无统计学意义(P＞0.05).结论 七氟醚和异丙酚均可减轻骨科手术患者止血带诱发下肢缺血再灌注损伤,其效果无差异.     

止血带对全膝关节置换术中股骨远端旋转定位时髌骨轨迹的影响

目的 探讨止血带对全膝关节置换术中以外科髁上轴线为股骨远端旋转定位线的髌骨轨迹的影响.方法 2002年12月至2008年8月,首选以外科髁上轴线为股骨远端旋转定位标志的初次全膝关节置换349例(526膝),男124例(155膝),女225例(371膝);年龄33～84岁,平均68岁.膝内翻387膝,膝外翻94膝.均使用同一种保留后十字韧带的活动平台假体,由同一位手术医生操作.采用前内侧髌旁入路,以外科髁上轴线为股骨远端旋转定位线,以no thumb test检测髌骨轨迹.对髌骨轨迹不良者,缝合髌骨内上缘支持带并松开止血带.对再次检查髌骨轨迹不良者行外侧支持带松解术.术后3个月患者能够极度屈曲膝关节时摄X线片检查髌骨轨迹.结果 术中no thumb test阳性138膝,其中半脱位12膝(膝外翻),髌骨倾斜126膝(膝外翻74膝).缝合髌骨内上缘支持带并松开止血带后,no thumb test阳性40膝,其中半脱位8膝(膝外翻),髌骨倾斜32膝(膝外翻29膝).髌骨外侧支持带松解率7.6%(40/526),膝外翻松解率39.4%(37/94).结论 在全膝关节置换术中,高压止血带对髌骨轨迹有干扰作用.术中缝合髌骨内上缘支持带并松开止血带,可降低外侧支持带松解率.     

三种止血带动脉止血对犬束扎肢体静脉血气的影响

目的 通过动物实验观察三种止血带在控制犬下肢动脉出血时静脉血气指标的变化,分析并比较不同止血带对束扎侧组织的损伤程度.方法 将18只犬完全随机分为三组,并制作成后肢股动脉出血模型.采用橡皮管止血带、卡式止血带和多功能自控加压止血绷带(简称止血绷带)三种止血带对三组犬进行股动脉止血.分别测量三组犬止血带下压力并在止血后0.5,1,3,6 h检测束扎肢体静脉血气指标.结果 (1)止血绷带组的带下压力为0.74 kg,显著小于橡皮管止血带组(1.46 kg)和卡式止血带组(2.09 kg)(P＜0.05).(2)止血后1 h,止血绷带组静脉血氧分压(PvO2)为(36.45±10.45)mm Hg,橡皮管止血带组为(28.73±9.07)mm Hg,均高于卡式止血带组的(21.87±4.30)mmHg(P＜0.05);止血后3,6 h,止血绷带组二氧化碳分压(PvCO2)分别为(50.67±9.31)mm Hg和(60.02±10.85)mm Hg,橡皮管止血带组分别为(16.85±16.51)mmHg和(60.02±10.85)mm Hg,均低于卡式止血带组(P＜0.05或0.01).结论 止血绷带在较小压力下能有效止住犬的股动脉出血;在三种止血带中,止血绷带对束侧组织的损伤最小.     

Evaluation of emergency tourniquets for prehospital use in China

Objective

Massive hemorrhage is life-threatening during armed conflicts. Tourniquets are important medical devices used to reduce severe bleeding in trauma. The aim of this study was to empirically evaluate the current tourniquets used in China and provide information to emergency nurses in selecting the appropriate tourniquet.

Methods

Five tourniquets were self-applied by 20 healthy participants. The blood flow distal to the tourniquet site was assessed using vascular Doppler ultrasound. Application time, pain, numbness, and other parameters were evaluated.

Results

The bladder tourniquet and windlass tourniquet effectively occluded arterial blood flow with success rates higher than 75% in both the upper and lower extremities. The Cargo-strap was the fastest to apply, taking (7.22±2.30) s for the upper extremity and (6.48±2.40) s for the lower extremity. The rubber tube was the most painful, and the improvised tourniquet was the least efficient. The success rates were higher in the lower extremity than in the upper extremity (P<0.05, X²=5.714).

Conclusions

The bladder tourniquet and the windlass tourniquet are efficient tourniquets, although the windlass is superior with respect to portability and pain. The Cargo-strap and rubber tourniquets have several disadvantages that reduce their suitability for field use. The improvised tourniquet is not recommended because of low efficiency and severe pain during implementation.