气压止血带在初次膝关节置换术中的临床应用

膝关节置换术是终末期膝关节骨关节炎患者有效的治疗方式之一,手术中使用止血带可减少出血,提供良好术野,且有利于关节假体与截骨面贴合。但是,术中使用止血带也会引起缺血再灌注损伤、下肢深静脉血栓等并发症,不利于患者术后康复。部分学者提出了优化使用止血带以减轻不利影响的策略,并得到验证。该文对初次膝关节置换术中止血带应用的研究进展进行综述。     

膝关节镜手术中止血带充气压设定探讨

目的 探讨膝关节镜手术中使用气压止血带充气压力的设定范围.方法 选择2010年11月至2011年3月在山西医科大学第二医院骨科住院接受膝关节镜手术患者66例,按接受手术时间分成实验组和对照组两组.实验组患者下肢气压止血带充气压力设定:止血带充气后肢体动脉血流阻断压(LOP)加8～10 kPa;对照组患者压力设定:止血带...     

气压止血带对人工全膝关节置换术围术期失血量的影响

目的研究气压止血带对人工全膝关节置换术(total knee arthroplasty,TKA)围术期失血量的影响。方法回顾分析2018年1月—2019年1月收治的116例60岁以上因重度膝关节骨关节炎行TKA治疗的患者临床资料。根据术中是否使用气压止血带分为试验组(49例,术中未使用气压止血带)和对照组(67例,术中使用气压止血带)。两组患者性别、年龄、体质量指数、侧别、病程、术前血红蛋白等一般资料比较,差异均无统计学意义(P0.05),具有可比性。记录并比较两组患者手术时间,实际总失血量、显性失血量、隐性失血量和隐性失血百分比,术后3 d膝关节肿胀度及术后2周膝关节活动度。结果试验组手术时间显著长于对照组,差异有统计学意义(t=14.013,P=0.000)。试验组实际总失血量、隐性失血量和隐性失血百分比均显著低于对照组,差异有统计学意义(P0.05);两组显性失血量差异无统计学意义(t=-1.293,P=0.200)。试验组术后3 d膝关节肿胀度显著低于对照组,术后2周膝关节活动度显著大于对照组,差异均有统计学意义(P0.05)。结论 TKA术中应用气压止血带可有效缩短手术时间,但可能增加围术期隐性失血量,加重术后早期患肢肿胀,对术后早期关节功能恢复产生不利影响。     

全膝关节置换术中是否使用止血带Meta分析

目的：用Meta分析的方法评价止血带在全膝关节置换术中的疗效以及安全性。方法：检索MEDLINE、EMBASE、OVID和ScienceDirect等数据库并结合手工检索,时间从建库至2013年7月,查找有关全膝关节置换术中是否采用止血带的临床随机对照试验,采用RevMan 5.1软件进行Meta分析。结果：使用止血带可以减少全膝关节置换术中出血量[WMD=-203.62,95%CI（-281.74,-125.49）],但会增加术后出血量[WMD=79.43,95%CI（13.40,145.45）],使用止血带并没有明显缩短手术时间[WMD=-6.36,95%CI（-13.62,0.90）],两者深静脉血栓形成及肺栓塞发生率亦没有统计学差异（均P＞0.05）。结论：全膝关节置换术中是否使用止血带,对总失血量、手术时间及血栓性栓塞病的发生率没有影响。     

高凝血状态患者人群全膝关节置换术中应用止血带的对照研究

目的探讨高凝血状态患者人群全膝关节置换术中不同止血带应用方式对围手术期出血的影响。 方法采用随机对照研究,对比观察92例使用不同止血带应用方式的全膝关节置换术患者,纳入标准：血浆D-二聚体>1 000 μg/L(酶联免疫荧光法),随机分为半程止血带组(n＝46)和全程止血带组(n＝46),半程止血带组在安装假体时使用止血带,全程止血带组手术全程使用止血带,记录两组患者手术时间、术后引流量、隐性失血量、失血总量、血红蛋白丢失量、输血率、平均输血量、膝关节活动度、疼痛评分、膝关节活动度、肢体肿胀及并发症情况,用SPSS 19.0软件对两组结果进行比较,手术时间和引流量等计量资料采用t检验,并发症等计数资料采用χ²检验。 结果半程止血带组术后引流量、隐性失血量、总失血量、血红蛋白丢失量、疼痛评分、肢体肿胀及并发症发生率显著低于全程止血带组(t＝－7.432、－15.72、－2.205、－2.746、－3.070、－5.525,P<0.05),半程止血带组手术时间、膝关节活动度显著高于全程止血带组(t＝8.098,t＝2.290,P<0.05),两组术后输血率和平均输血量比较差异无统计学意义(χ²＝0.956,t＝－0.329,均为P>0.05)。所有患者均无症状性肺栓塞、感染及伤口皮缘坏死发生。 结论高凝血状态患者行全膝关节置换术中半程使用止血带止血效果优于全程止血带,止血带相关并发症发生率低于全程使用止血带组。     

全膝关节置换术中止血带应用的研究进展

全膝关节置换术(TKA)是治疗重度骨关节退行性疾病、重建膝关节功能的重要手段,使用止血带是手术过程中的常规操作。一般认为,使用止血带能减少膝关节置换术中出血,更加清晰的暴露术野,减少神经及血管等医源性损伤。但由于止血带本身的一些特性,使用止血带可能带来神经压迫损伤、血管内皮细胞的缺血再灌注损伤以及全身血流动力学的改变等。近年来,对于TKA术中使用止血带的应用研究报道逐渐增多,本文对此做一综述。     

止血带对全膝关节置换术后深静脉血栓形成的影响

目的 探讨止血带对全膝关节置换术后深静脉血栓形成的影响.方法 采用随机对照研究,将连续入院的拟行初次全膝关节置换的80例患者随机分为两组:一组使用止血带(止血带组,40例),一组不使用止血带(非止血带组,40例).全部采用后十字韧带替代型骨水泥固定人工膝关节(Smith-Nephew),手术由同一组医生完成.比较两组患者围手术期失血量、深静脉血栓和肺动脉栓塞发生率、术中栓子面积百分率%Ae(即总栓子面积占右心房面积的百分率).术前及术后第1～10天行彩色多普勒超声检查,观察双下肢深静脉血栓的发生;术中使用经食道超声心动图监测右心房,评估止血带释放后的%Ae.结果 止血带组患者术中失血最小于非止血带组患者,但两组患者围手术期总失血量比较差异无统计学意义.止血带组患者和非止血带组患者深静脉血栓发生率比较无统计学差异,两组均未发生肺动脉栓塞.止血带组患者%Ae在释放止血带后的1 min达到高峰;非止血带组患者%Ae仅在扩髓和植入假体时出现高峰,然后缓慢下降;止血带组患者%Ae在释放止血带后大于非止血带组患者.结论 止血带的使用对全膝关节置换术围手术期总失血量并无明显影响,不增加深静脉血栓和肺栓塞的发生风险.     

止血带对全膝关节置换术后深静脉血栓形成的影响

目的 探讨止血带对全膝关节置换术后深静脉血栓形成的影响.方法 采用随机对照研究,将连续入院的拟行初次全膝关节置换的80例患者随机分为两组:一组使用止血带(止血带组,40例),一组不使用止血带(非止血带组,40例).全部采用后十字韧带替代型骨水泥固定人工膝关节(Smith-Nephew),手术由同一组医生完成.比较两组患者围手术期失血量、深静脉血栓和肺动脉栓塞发生率、术中栓子面积百分率%Ae(即总栓子面积占右心房面积的百分率).术前及术后第1～10天行彩色多普勒超声检查,观察双下肢深静脉血栓的发生;术中使用经食道超声心动图监测右心房,评估止血带释放后的%Ae.结果 止血带组患者术中失血最小于非止血带组患者,但两组患者围手术期总失血量比较差异无统计学意义.止血带组患者和非止血带组患者深静脉血栓发生率比较无统计学差异,两组均未发生肺动脉栓塞.止血带组患者%Ae在释放止血带后的1 min达到高峰;非止血带组患者%Ae仅在扩髓和植入假体时出现高峰,然后缓慢下降;止血带组患者%Ae在释放止血带后大于非止血带组患者.结论 止血带的使用对全膝关节置换术围手术期总失血量并无明显影响,不增加深静脉血栓和肺栓塞的发生风险.     

TKA术中不使用止血带对早期假体稳定性及膝关节功能的影响

目的探讨全膝关节置换(TKA)术中使用止血带和不使用止血带对早期假体稳定性及膝关节功能的影响。方法回顾性分析自2015-04—2016-03行人工膝关节置换术的58例单侧膝关节骨性关节炎,分别在术中使用或不使用止血带,比较2种术中处理后的早期疗效。结果 48例获得满意随访,随访时间均为3年。止血带组骨水泥在骨组织的渗透厚度比非止血带组大,差异有统计学意义(P 0.05)。术后1周时,止血带组WOMAC评分高于非止血带组,差异具有统计学意义(P 0.05),术后3年复查时,两组WOMAC评分差异无统计学意义(P0.05)。结论全膝关节置换术中是否使用止血带并未影响假体早期的稳定性,不使用止血带可以减轻患者术后疼痛及肢体肿胀,加快康复速度,值得提倡。     

全膝关节置换术个性化止血带压力设置

[目的]探讨全膝关节置换术中,应用彩色多普勒超声技术个性化设定止血带充气压力对其临床疗效的影响。[方法]将2017年3月～2017年8月在全麻下行初次单侧全膝关节置换术的71例患者随机分为两组。个性化压力组36例,便携式彩超探头置于腘动脉处,当腘动脉血流峰图完全消失时的充气压力为个性化止血带压力值;固定压力组35例采用传统固定止血带压力值为270 mmHg。比较两组止血带压力值、止血带使用时间、围手术期失血量、切口及止血带部位VAS疼痛评分、止血带部位周径、膝关节功能(HSS)评分、切口和止血带并发症。[结果]个性化压力组止血带的压力值、术后引流量、隐性失血量、总失血量、术后第1、3 d切口及止血带部位VAS评分、术后止血带部位周径、止血带部位及切口部位并发症均显著低于固定压力组(P0.05);术后1周膝关节功能评分,个性化压力组显著高于固定压力组(P0.05)。而在术中失血量和止血带使用时间方面,两组差异无统计学意义(P0.05)。[结论]在全膝关节置换术中应用彩色多普勒超声仪设定个体化止血带的压力值,不仅可确保止血效果,而且可有效减少不良反应的发生率,从而提升使用止血带时的安全性,更有利于患者术后快速康复。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.