The hemodynamic and metabolic changes following tourniquet release during halothane anesthesia

We measured the hemodynamic and metabolic changes following the release of lower limb tourniquet during halothane anesthesia, and discussed the cause of reduction in the blood pressure and the effective method for prevention. Cardiac index decreased transiently following the release, and gradually increased afterward. Systemic vascular resistance index decreased continuously and progressively until 10 minutes after the release. These results indicate that the causative factors of reduction in the blood pressure are temporary decrease in cardiac output and subsequent decrease in systemic vascular resistance. In mixed venous blood, pH decreased, PCO2 increased and HCO3- remained unchanged after the release. It seems that pH reduction was chiefly caused by the increase in PO2. Thus, the preventive method for reduction in the blood pressure following the tourniquet release may be as follows; 1) intravenous fluid loading, 2) hyperventilation, 3) elevation of lower limb, 4) lightning the anesthesia, and 5) finally giving vasopressors.     

The pneumatic tourniquet in arthroscopic surgery of the knee

In a randomized study 56 patients undergoing arthroscopic surgery of the knee were randomly allocated to one of 2 groups: surgery with a tourniquet and surgery without a tourniquet. No significant difference was found between the 2 groups with regard to operating times, technical intraoperative difficulties, identification of intraarticular structures, postoperative pain or postoperative complications. In neither group was the procedure abandoned due to technical difficulties. The pain scores in the non-tourniquet group were lower than those in the group of patients operated on with the use of a pneumatic tourniquet. The study suggests that the use of a tourniquet in arthroscopic surgery of the knee is unnecessary.     

The hemodynamic and metabolic effects of shivering during acute normovolemic hemodilution

To assess the hemodynamic and metabolic effects of shivering during extreme normovolemic hemodilution, we anesthetized 16 pigs with fentanyl-midazolam-pancuronium. Mild hypothermia (36.5 degrees +/- 0.1 degrees C) was induced by surface cooling, and the animals were randomized to either a control group (hemoglobin 118 +/- 3 g/L) or a hemodilution group (hemoglobin 52 +/- 2 g/L). In the latter group, blood was replaced with an isotonic Ringer's acetate/dextran 70 solution. Shivering was allowed to occur by a controlled decrease in the infusion rate of pancuronium. Shivering increased oxygen consumption (VO(2)) in both groups (P < 0.001). Initially, this was predominantly compensated for by an increased oxygen extraction ratio (ER), but when VO(2) was 2.3 +/- 0.2 times baseline, critical levels of mixed venous oxygenation (SVO(2) = 18% +/- 2%; PVO(2) = 22.5 +/- 1.5 mm Hg) and ER (82% +/- 3%) were recorded in anemic animals. Control animals did not reach critical levels until VO(2) was maximal (3.7 +/- 0.3 times baseline). Maximal attained VO(2) was less (2.9 +/- 0.1 times baseline) in the anemic animals (P = 0.01), and at this stage two of these pigs had myocardial lactate production, one of which died in ventricular fibrillation. Coronary perfusion pressure was significantly less (P < 0.001) in the anemic animals. We conclude that in this experimental model, maximal shivering as measured by VO(2) was limited in hemodiluted animals, and left ventricular oxygen balance was marginal, as evidenced by a decreased lactate uptake and extraction. IMPLICATIONS: The effect of acute increases in oxygen consumption (shivering) on severely anemic individuals has not been evaluated. In this experimental model, left ventricular oxygen balance was marginal, as evidenced by decreased lactate extraction.     

全膝关节置换术中放开止血带并缝合内上缘支持带对髌骨轨迹的影响

目的 探讨在初次全膝关节置换术(TKA)中放开止血带且缝合内上缘支持带对髌骨轨迹的影响.方法 选择2006年3月至2008年2月初次行TKA的83例患者136侧膝关节.使用前内侧髌旁人路,检测髌骨轨迹.对于不良的髌骨轨迹,术中松开止血带且仅用一针缝合髌骨内上缘支持带.再次检查髌骨轨迹.最后,对残留不良髌骨轨迹的患者行外侧支持带松解术,以求获得满意的髌骨轨迹.采用no-thumb试验作为检测髌骨轨迹的标准.结果 在初次行TKA的83例患者136侧膝关节中,在未松开止血带前,髌骨轨迹不良率为64.7%(88/136).放开止血带且缝合髌骨内上缘支持带后,髌骨外侧支持带松解率为26.5%(36/136),差异有统计学意义(X2=38.55,P＜0.01).其中,膝外翻畸形患者的松解率为58.6%(17/29),膝内翻和无明显畸形患者的松解率为17.8%(19/107).结论 高压止血带对行前内侧髌旁人路TKA的患者髌骨轨迹的干扰作用非常明显.术中松开止血带且缝合髌骨内上缘支持带明显降低了外侧支持带的松解率,从而降低了其可能带来的并发症.     

去甲肾上腺素对重症瓣膜病瓣膜置换术的血流动力学影响

目的研究去甲肾上腺素(NA)对重症瓣膜病患者CPB下行心脏瓣膜置换术的血流动力学影响。方法择期CPB下行心脏瓣膜置换术患者27例,根据所使用的血管活性药物分为:NA+多巴酚丁胺(Dob)组(NA组,n=12);肾上腺素(AD)+Dob组(AD组,n=15)。术中监测脉搏指示剂连续心排血量(PiCCO)和动脉血气分析对两组血流动力学的影响。分别在术前(T0)、CPB结束时(T1)、术后6h(乳酸最高时,T2)、术后24h(T3)记录HR、MAP、CVP、连续心排血量(CCO)、心脏指数(CI)、每搏量指数(SVI)、外周血管阻力指数(SVRI)、血管外肺水指数(EVLWI)、肺毛细血管通透性(PVPI)、中心静脉氧饱和度(ScvO2),动脉氧分压(PaO2)、乳酸(Lac)及其清除率(LCR),并对供氧量(DO2)、耗氧量(VO2)、氧摄取率(ERO2)进行计算和比较。结果 T2、T3时两组CI持续升高,且AD组明显高于NA组(P<0.05),NA组SVRI明显高于AD组(P<0.05);HR慢于AD组(P<0.05)。T2,T3两组DO2差异无统计学意义。与AD组比较,T3时NA组的VO2、ERO2明显升高(P<0.05),而LCR和尿量差异无统计学意义。结论重症瓣膜患者术后循环衰竭应用去甲肾上腺素时无HR增快,减少心脏做功,提高CPB后组织氧利用能力,但需要PiCCO监测下调整其输注剂量及速度。     

The metabolic effects of fasting and surgery

This review discusses the metabolic changes that occur during fasting, especially in relation to surgical stress. Currently available evidence on the relevance of different aspects of perioperative nutritional support are presented. Attenuation of surgical stress and insulin treatment in insulin-resistant patients after surgery and trauma have been shown to markedly affect stress metabolism as well as patient morbidity and mortality. Avoiding preoperative fasting has been shown to be related to a substantial reduction in postoperative stress and insulin resistance. Implementation of a standardized programme with a multimodal approach using evidence-based perioperative routines has been shown to further reduce surgical stress and to markedly enhance functional recovery also after major surgical procedures.     

止血带的不同使用方法在膝关节置换术中的研究

目的探讨全膝关节置换术中止血带不同的使用方法的作用。方法2009年9月至2011年6月,对45例骨关节炎患者行单侧膝关节置换手术,根据止血带不同的使用方法分为两组,A组24例,在安装假体前至安装假体后骨水泥硬松开止血带;B组21例,在手术开始至安装假体完毕,骨水泥硬化后松开止血带,术野止血后关闭伤口。观察两组病例的手术时间、术中和术后出血量、术后患肢肿胀情况和术后HSS评分。结果手术时间（t=3．0,P〈0．05）、术中（t=9．2,P〈0．05）和术后（t=13．5,P〈0．05）出血量均有统计学差异,但是总出血量（t=0．6,P〉0．05）间的差异无统计学意义,术后患肢肿胀情况（t=2．3,P〈0．05）两组间差异具有统计学意义。结论减少使用止血带时间可能利于患者早期恢复。     

The effects of propofol or halothane on free radical production after tourniquet induced ischaemia-reperfusion injury during knee arthroplasty

BACKGROUND: Ischaemia-reperfusion injury following tourniquet release is a good in vivo model for evaluating acute conditions. The aim of the study was to investigate the effects of propofol or halothane anaesthesia on oxidative stress by determining malondialdehyde (MDA) levels during knee arthroplasty. METHODS: Thirty patients undergoing orthopaedic surgery were divided into two groups. Anaesthesia was induced with either fentanyl 100 microg and propofol 2 mg kg(-1) (Group 1) or fentanyl 100 microg and thiopentone 5 mg kg(-1) (Group 2) and maintained with infusion of propofol in Group 1 or inhalation of halothane in Group 2. ECG, SpO2, EtCO2, and mean arterial pressure (MAP) were monitored. Venous and arterial blood samples were obtained at different measurement times for MDA and blood gas analyses. RESULTS: There was a significant decrease in MAP in the 1st and 5th minutes after tourniquet release (ATR) when compared with the 5th minute before tourniquet release (BTR) in both groups. Heart rate (HR) increased significantly in the 1st minute ATR in Group 1 only. EtCO2 increased significantly in the 1st and 5th minutes ATR, SpO2 decreased in the 1st minute ATR in both groups. There was a significant decrease in pH and increase in pCO2 at 1, 5 and 30 min ATR in both groups. pO2 values decreased in the 1st minute ATR in Group 1 only and returned to control values at 5 min ATR and decreased at 30 min ATR in the recovery room in both groups. The differences in SaO2 were similar to SpO2. MDA levels decreased before and after release of tourniquet when compared to baseline in both groups. However, there was a statistically significant decrease only in Group 1. CONCLUSION: Propofol may be a good choice of anaesthetic when an ischaemia-reperfusion injury is anticipated as in orthopaedic surgery requiring a tourniquet, due to its antioxidant properties, but halothane needs further study.     

Effect of tourniquet on hemodynamic variables

The aim of this study is to identify the effect of time and pressure of tourniquet in blood pressure and pulse rate immediately after the releasing of tourniquet in the upper and lower extremity of the orthopedic surgeries. This retrospective study examined 206 consecutive patients. Comparisons of the systolic and diastolic pressure and heart rate were made before the induction of anesthesia and tourniquet inflation, and immediately after the deflation. In general, there was no significant difference in hemodynamic changes between the upper- and lower-limb with regard to the type of anesthesia. There was no significant correlation between systolic blood pressure and tourniquet pressure, while by increasing the tourniquet time significantly, the systolic blood pressure decreases immediately after the deflation. Interestingly, the considerable increase in age paralleled with a significant decrease in the systolic blood pressure. The effect of tourniquet time is more than the age. There was no significant correlation between the tourniquet pressure and tourniquet time with diastolic blood pressure. Simply the increase in age significantly paralleled with the mild decrease in diastolic blood pressure Orthopedic surgeons are recommended not to rely on the benefits of tourniquet to raise blood pressure due to hypotensive conditions after the deflation especially in the old.     

The effects of propofol or sevoflurane on free radical production after tourniquet induced ischaemia-reperfusion injury during knee arthroplasty

BACKGROUND: We studied the effects of anesthesia with propofol or sevoflurane on the production of free oxygen radicals during total knee arthroplasty performed with the use of an ischemic tourniquet by measuring the levels of malondialdehyde (MDA). METHODS: We studied two groups of patients (20 patients in each group) who underwent total knee arthroplasty. To maintain anesthesia we delivered 66% nitrous oxide plus sevoflurane or propofol. Blood samples for the determination of the MDA levels were drawn before the application of the ischemic tourniquet and 5 and 30 minutes after its release. RESULTS: There were no differences between groups in regard to age, weight and duration of the tourniquet application. MDA levels decreased significantly in the propofol group 30 minutes after the release of the tourniquet (1.7 micromol litre(-1) vs 1.57 micromol litre(-1), Friedman's ANOVA, P = 0.007). In contrast, there was a small rise of the MDA levels in the sevoflurane group (1.82 micromol litre(-1) vs 1.96 micromol litre(-1), Friedman's ANOVA, P = 0.007). CONCLUSION: Propofol may have anti-oxidant properties in orthopaedic surgery requiring tourniquet application, but sevoflurane needs further study.     

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。     

高血压病人在全膝关节置换术中不同时期应用止血带的临床效果比较

目的 探讨止血带在高血压病人全膝关节置换术（total knee arthroplasty, TKA）中的使用效果,分析合并高血压的TKA病人在不同时期使用止血带对术中失血、术后失血、术后康复锻炼以及术后并发症等方面的影响。方法 2015年3月至2018年3月因膝骨关节炎于我院接受初次TKA的60例高血压病人,根据止血带使用时间的不同分为三组,其中A组20例病人在切皮前开始使用气囊止血带,缝合完毕加压包扎后松开;B组20例病人在安放水泥型膝关节假体前开始使用气囊止血带,缝合完毕加压包扎后松开;C组20例病人在安放水泥型膝关节假体前开始使用气囊止血带,骨水泥凝固后松开。分别记录3组病人术中、术后失血量,围手术期输血量。采用疼痛视觉模拟量表（visual analogue scale, VAS）评价病人疼痛情况、美国膝关节协会评分（knee society score, KSS）评价病人术后3 d、3周、1年的膝关节功能。结果 A组的术中失血量为（170.81±34.83） ml,B组为（194.95±24.96） ml,C组为（248.88±25.86） ml,差异有统计学意义（F=5.834,P=0.022）;A组总失血量为（923.56±197.79） ml,B组为（773.67±183.76） ml,C组为（827.50±182.79） ml,差异有统计学意义（F=4.733,P=0.031）。A组术后3 d肿胀率及VAS评分［9.93%±0.97%、（7.32±1.26）分］明显高于B组［6.03%±0.85%、（4.72±0.82）分］及C组［5.91%±0.73%、（4.94±0.63）分］;术后3周时,A组的KSS评分为（46.74±6.72）分,明显低于B组的［（69.72±7.93）分］、C组的［（68.83±7.86）分］;上述差异均有统计学意义（P均＜0.05）。术后1年,3组之间的KSS评分差异无统计学意义（F=2.314,P=0.834）。A组有1例发生深静脉血栓,有1例发生术后贫血,2例发生肌间静脉血栓,B组无并发症出现,C组有1例发生肌间静脉血栓。结论 安放水泥型膝关节假体前开始使用止血带,缝合完毕加压包扎后松开,可明显改善病人的术中出血量及术后近期功能效果,术后并发症少,但远期临床疗效有待进一步观察。     

The effect of a tourniquet on intraoperative patellofemoral tracking during total knee arthroplasty

A prospective investigation was performed on the effect of the tourniquet on intraoperative patellofemoral tracking during primary total knee arthroplasty (TKA). A total of 75 TKAs in 67 patients were performed by 1 surgeon in a consecutive series using the same technique. Using strict criteria, patellar tracking was assessed both before and after tourniquet release. Patients were placed into 1 of 3 groups: Group I were knees that tracked properly both before and after tourniquet release. Group II were knees that maltracked with the tourniquet inflated and subsequently corrected with the tourniquet released. Group III were knees that maltracked both before and after tourniquet release, therefore requiring a lateral release. Knees were categorized as group I, 34 of 75 (45.3%); group II, 36 of 75 (48.0%); and group III, 5 of 75 (6.7%). Using this criterion, lateral release was avoided in all group II knees. Tourniquet application alters intraoperative patellofemoral tracking during TKA. When contemplating lateral release, tourniquet deflation and reevaluation of patellofemoral tracking should be considered.     

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

Objective To explore, the influence of tourniquet application on patellar tracking with using the surgical transepieondylar axis as distal femur alignment in total knee arthroplasty (TKA). Methods From December 2002 to August 2008, 349 cases (526 knees) of primary TKA were performed. There were 124 males and 225 females with an average age of 68 years from 33 to 84 years. A total of 387 knees had varus deformity and 94 had valgus deformity. All of prosthesis were rotating platform with posterior cruciate ligament retaining provided by Gemini MK Ⅱ. All patients underwent anterior medial parapatellar approach. The surgical transepieondylar axis had been principally used as the distal femur alignment. Patellar tracking was checked with no thumb test. For maltracking ones, we prefered to use a single retinacular closing stitch at the superior medial arthrotomy and deflate tourniquets. Patellar tracking was checked again. Finally, later-al retinaeular releases (LRR) had been performed to obtain optimizing patellar tracking. Results Intraoper-atively, no thumb test were positive in 138 knees, including patellar subluxation (vaigus deformity) in 12 knees and patellar inclining (74 of valgns deformity and 52 of varus deformity) in 126 knees. After using a single retinacular closing stitch at the superior medial arthrotomy and deflating tourniquets, no thumb test were positive in 40 knees, including patellar subluxation (valgus deformity) in 8 knees and patellar inclining (29 of valgns deformity) in 32 knees. The total rate of LRR was 7.6% (40/526), the rate of LRR in valgus deformity was 39.4% (37/94) and that in yarns deformity and no deformity was 0.7% (3/432). Conclusion There was significant influence of tourniquet application on patellar tracking during the TKA. We were not falsely correcting patellar tracking problems with using a single retinaeular closing stitch at the superior me-dial arthrotomy anti deflating tourniquets intraoperatively and reducing the rate of LRR.     

The effect of surgical approaches and tourniquet application on patellofemoral tracking in total knee arthroplasty

The purpose of this study was to assess the influences of surgical approaches and tourniquet application on the lateral retinacular tension (LRT). Single-setting bilateral total knee arthroplasty was performed in 10 patients, and the medial parapatellar and midvastus approaches were randomly performed on each knee using tourniquet application. The LRT was measured using the buckle transducer before and after each approach. Next, the tourniquet was deflated and the measurement was repeated. After the parapatellar approach, LRT was significantly decreased. Conversely, no significant change was seen after the midvastus approach with the tourniquet inflated. However, in the midvastus approach, LRT was significantly decreased after tourniquet deflation. We concluded that both the parapatellar and midvastus approaches influence patellar tracking and LRT.     

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.     

Rational application of the pneumatic tourniquet in the knee joint endoprosthesis

Two different methods of the pneumatic tourniquet application were used while the knee joint prosthesis in two groups of patients: during the all operation and during the stage of implantation of artificial joint components. It is preferent to reduce the pneumatic tourniquet application duration to realize its positive qualities, to secure optimal adhesion of cement and costal bed and also to make less severe the consequences of intra- and postoperative period. The data obtained trust that the procedure, used by us, constitutes an optimal method of the pneumatic tourniquet application while the knee joint cement prosthesis.