闭合与切开复位防旋型股骨近端髓内钉固定治疗老年股骨转子间骨折疗效比较侯

目的 比较闭合复位与切开复位防旋型股骨近端髓内钉（PFNA ）固定治疗老年股骨转子间骨折的疗效.方法 对87例老年股骨转子间骨折患者行PFNA固定治疗,切开复位32例,闭合复位55例.比较两组的切口长度、手术时间、术中失血量、骨折复位、内固定满意率、患肢部分负重时间、骨折愈合时间、并发症及髋关节功能情况.结果 切口长度、手术时间及术中失血量闭合复位组均明显短（少）于切开复位组（P〈0.01）,骨折复位满意率闭合复位组高于切开复位组（P〈0.05）.87例均获随访,随访时间：闭合复位组12～42个月,切开复位组12～48个月.部分负重时间闭合复位组明显早于切开复位组（P〈0.01）.并发症：切开复位组发生率为22%,闭合复位组无严重并发症（P〈0.01）.两组骨折全部愈合,愈合时间差异无统计学意义（P〉0.05）.末次随访时髋关节Harris评分闭合复位组高于切开复位组（P〈0.01）.结论 与切开复位PFNA固定比较,闭合复位PFNA固定治疗老年股骨转子间骨折手术操作简便,患者功能恢复更好.     

隐性失血量对老年股骨转子间骨折术后临床疗效影响的分析

[目的]探讨老年股骨转子间骨折围手术期隐性失血量对术后临床疗效的影响。[方法]回顾性分析2011年1月~2014年6月应用股骨近端锁定钢板内固定(PFLP)、动力髋螺钉(DHS)和股骨近端防旋髓内钉(PFNA)固定治疗的131例老年股骨转子间骨折患者资料,计算平均隐性失血量,依据内固定方式将患者分为三组:依据平均隐性失血量,将三组患者分别分为高隐性失血量组和低隐性失血量组,并分别比较患者下地负重时间、骨折愈合时间和髋关节功能评分。[方法]PFLP组内高隐性失血量组和低隐性失血量组的下床负重时间分别为(35.98±6.37)d、(35.58±4.46)d(P0.05);骨折愈合时间分别为(18.32±3.36)周、(16.48±2.35)周,Harris髋关节功能评分分别为(83.88±4.35)分、(83.88±4.35)分(P0.05);低隐性失血量组在患者术后骨折愈合时间及Harris评分方面均优于高隐性失血量组。DHS组内高隐性失血量组和低隐性失血量组下床负重时间分别为(35.41±5.21)d、(31.52±9.42)d,骨折愈合时间分别为(17.24±2.86)周、(15.30±1.45)周,Harris髋关节功能评分分别为(85.57±7.76)分、(92.82±6.82)分(P0.05);低隐性失血量组在术后下床负重时间、骨折愈合时间及Harris评分方面均优于高隐性失血组。PFNA组内高隐性失血量组和低隐性失血量组下床负重时间分别为(34.11±8.01)d、(30.25±7.42)d,骨折愈合时间分别为(16.74±2.31)周、(13.62±1.96)周,Harris髋关节功能评分分别为(87.07±7.21)分、(93.02±7.14)分(P0.05);低隐性失血量组在患者术后下床负重时间、骨折愈合时间及Harris评分方面均优于高隐性失血量组。[结论]隐性失血量影响老年股骨转子间骨折术后功能恢复;老年转子间骨折围手术期的低隐性失血量患者术后临床疗效优于高隐性失血量患者。     

老年股骨颈骨折与股骨转子间骨折围手术期失血量的临床对比研究

目的通过老年股骨颈骨折与股骨转子间骨折患者围手术期失血量的比较,为临床老年髋部骨折围手术期血液管理提供科学依据。 方法回顾性收集2018年7月至2020年4月间中国科学技术大学附属第一医院骨科收治的因低能量损伤导致的老年髋部骨折患者,共纳入69例。按照骨折类型分为股骨颈骨折组和股骨转子间骨折组,比较两组患者年龄、性别、骨折解剖部位以及术前合并症等基本信息,比较两组患者围手术期隐性失血量、显性失血量和总失血量。 结果股骨颈骨折组患者的平均年龄为（78±8）岁（男性10例,女性35例）,股骨转子间骨折患者的平均年龄为（75±10）岁（男性12例,女性12例）。两组患者术前隐性失血量[股骨颈骨折组：（238.33±97.82）ml ;股骨转子间骨折组：（344.80±130.01）ml,P<0.05]、围手术期隐性失血量[股骨颈骨折组：（314.46±130.30）ml;股骨转子间骨折组：（459.73±173.34）ml,P<0.05]、显性失血量[股骨颈骨折组：（77.78±27.29）ml;股骨转子间骨折组：（160.42±51.03）ml,P<0.05]和总失血量[股骨颈骨折组：（392.24±133.62）ml;股骨转子间骨折组：（620.15±171.11）ml,P<0.05]差异均具有统计学意义,股骨转子间骨折组均高于股骨颈骨折患者组。股骨转子间骨折组（半髋关节置换和PFNA内固定术）较股骨颈骨折组（全髋关节置换和半髋关节置换术）均有较多的显性失血量、术后隐性失血量、围手术期隐性失血量和总失血量（均P<0.05）。但两组内不同手术方式比较,差异无统计学意义。 结论老年股骨转子间骨折患者较股骨颈骨折患者有更多的围手术期隐性失血量、显性失血量和总失血量,在临床诊治中,尤其需要更加重视老年股骨转子间骨折患者的围手术期血液管理。     

不同髓内钉对老年股骨转子间骨折手术及预后的影响

目的 探讨联合加压交锁髓内钉（TriGen InterTAN）系统与股骨近端防旋髓内钉（PFNA）对老年股骨转子间骨折患者手术操作指标及预后的影响。方法 回顾性纳入本院2017年1月至2021年1月收治老年股骨转子间骨折患者共117例，根据术式分为两组，60例采用TriGen InterTAN治疗（A组），57例采用PFNA治疗（B组）；比较两组切口长度、术中失血量、手术时间、术后1 d疼痛评分、开始下地时间、开始负重时间、开始弃拐时间、并发症发生情况、骨折愈合时间及术后1年Harris评分。结果 B组术中失血量和手术时间分别为（64.27±9.10） m L,(55.36±10.52) min，均显著少于A组的（87.93±13.49） mL,(72.19±16.55) min(P<0.05);B组开始负重时间和去拐时间分别为（4.91±1.57）周，（21.20±1.75）周，均显著长于A组的（3.56±1.24）周，（17.09±1.30）周（P<0.05）;B组内固定相关并发症发生率为12.28%，显著高于A组的0.00%(P<0.05);B组骨折愈合时间为（...     

两种术中牵引复位SeinsheimerⅤ型股骨转子下骨折

[目的]比较下肢轴向牵引器（lower extremity axial distractor, LEAD）与牵引床辅助复位髓内钉内固定治疗SeinsheimerⅤ型股骨转子下骨折的临床疗效。[方法]回顾性分析2012年5月—2021年5月在本院行髓内钉内固定治疗的49例SeinsheimerⅤ型股骨转子下骨折患者的临床资料。根据术前医患沟通结果，29例使用LEAD复位（牵引器组），20例使用牵引床复位（牵引床组）。比较两组围手术期、随访及影像资料。[结果]牵引器组安装牵引装置时间[(4.0±1.1) min vs (14.0±3.6)min, P<0.05]、手术时长[(134.4±33.3) min vs (196.6±103.0) min, P<0.05]、术中失血量[(231.0±109.7) ml vs (380.0±247.3) ml, P<0.05]、术中透视次数[(28.5±4.7)次vs (31.8±4.0)次, P<0.05]均显著优于牵引床组。两组切口总长度、导针定位次数、闭合转切开复位率、切口愈合等级、住院时间、下地行走时间的差异均无统计学...     

人工关节置换术治疗高龄股骨转子间粉碎性骨折

目的探讨人工关节置换术治疗高龄股骨转子间骨折的方法及疗效。方法对38例高龄（≥75岁）股骨转子间粉碎性骨折患者用骨水泥型人工髋关节置换术治疗,术中尽量复位大小转子并张力带钢丝固定。结果手术时间58~98 min,出血量200~380 ml。无切口感染及肺栓塞发生,2例出现尿道感染。患者均获随访,时间12~48个月。骨折愈合时间为3~6（4.5±0.5）个月。术后12个月Harris评分为76~94（84±3）分。结论人工关节置换术治疗高龄股骨转子间骨折患者手术时间短、出血少、可早期下地行走、关节功能恢复快、近期效果满意,是高龄股骨转子间骨折患者的一种理想手术方式,但掌握手术适应证及操作要点是关键。     

三种内固定治疗伴骨质疏松不稳定型股骨转子间骨折的比较研究

目的：比较动力髋螺钉（dynamic hip screw, DHS）、锁定加压钢板（locking compression plate, LCP）和股骨近端防旋转髓内钉（proximal femoral nail antirotation, PFNA）治疗老年人伴骨质疏松不稳定型股骨转子间骨折的治疗效果。方法对2010年10月至2014年8月我们治疗的103例股骨转子间骨折伴骨质疏松患者进行回顾性分析,按照Evans分型,Ⅲa型43例,Ⅲb型35例,Ⅳ型20例,R型5例。其中42例采用DHS治疗,30例采用LCP治疗,31例采用PFNA治疗。通过分析比较DHS、LCP和PFNA治疗骨质疏松性不稳定型股骨转子间骨折患者的手术时间、术中失血量、下地行走时间、骨折愈合时间、术后并发症及髋关节功能评分等方面的疗效。结果所有患者术后随访时间为6~30个月,平均为（14.5±3.2）个月。三组患者在手术时间、术中失血量、下地行走时间、骨折愈合时间比较,差异均有统计学意义（均P＜0.05）。PFNA组术后髋关节功能评分优于DHS组（P＜0.05）。三组患者在术后并发症比较,差异均无统计学意义（均P＞0.05）。结论 DHS、LCP、PFNA对于Ⅲa、Ⅲb、Ⅳ型骨质疏松性不稳定型股骨转子间骨折均为可行方法。因为PFNA手术时间、术中失血量、下地行走时间、骨折愈合时间和优良率等方面均优于LCP与DHS,对于R型骨质疏松性不稳定型股骨转子间骨折,应选用PFNA。     

改良动力髋螺钉（DHS）治疗股骨转子间骨折的对比研究

目的比较改良前后动力髋螺钉（DHS）治疗股骨转子间骨折的临床疗效。方法 2007年6月～2009年8月,对DHS治疗股骨转子间骨折44例进行如下几方面的改良：术前重视骨牵引治疗提高骨折复位满意率;术前标示切口,从股骨上段外侧稍偏后入路便于术中操作;切口周围将无菌单与皮肤缝线固定保护伤口预防感染;应用撑开器显露伤口,避免人为拉钩;借助导向标示针提高穿针准确率;术后根据骨折类型、骨质疏松程度、术中骨折复位和空心螺钉安置的满意情况选择正确的负重时机。与2003年6月～2005年4月采用传统的DHS治疗股骨转子间骨折39例进行比较。手术由同一术者完成,记录2组术前骨牵引率、术中骨折复位满意率、术中定位导针穿针次数、术中穿针后X线曝光次数、手术时间、术中术后出血量、并发症发生率、术后12周髋关节功能评分及随访时间等相关数据,并进行统计分析。结果术后随访12～24个月,平均16个月。改良组术中骨折复位满意率[95.5%（42/44）vs.76.9%（30/39）,χ2=6.176,P=0.013],穿针次数（[1.4±0.4）次vs.（4.5±1.2）次t,=-16.163,P=0.000],术中穿针后X线暴露次数（[4.5±1.3）次vs.（10.5±1.5）次t,=-19.523,P=0.000],术中出血量（[186±28）ml vs.（412±36）mlt,=-32.110,P=0.000],手术时间（[85±16）min vs.（118±17）mint,=-9.107,P=0.000],术后引流量（[78±18）ml vs.（112±16）mlt,=-9.046,P=0.000],并发症发生率[0%（0/44）vs.17.9%（7/39）,P=0.004],术后12周Parker髋关节功能评分（[6.9±1.8）分vs.（5.3±1.3）分t,=4.589,P=0.000]方面明显优于传统组,2组骨折愈合时间差异无显著性（P〉0.05）。结论改良后DHS治疗股骨转子间骨折可以提高术中骨折复位满意率,提高术中穿针准确率及降低患者X线摄入量,缩短手术时间,减少失血量,降低并发症的发生率,改善髋关节的功能。     

动力髋螺钉与股骨近端防旋髓内钉治疗老年股骨粗隆间不稳定骨折的病例对照研究

目的：回顾对比应用动力髋螺钉（dynamic hip screw,DHS）和股骨近端防旋髓内钉（proximal femoral nail anti-rotation,PFNA）内固定治疗老年股骨粗隆间不稳定骨折疗效优劣。方法：2004年8月至2012年8月,采用DHS和PFNA内固定治疗股骨粗隆间不稳定骨折92例,其中DHS组50例,男27例,女23例,平均年龄（72．5±5．3）岁;PFNA组42例,男22例,女20例,平均年龄（72．8±5．8）岁。对两组手术时间、失血量（包括隐性失血和显性失血）、卧床时间、下地负重时间、术后并发症及髋关节评分等进行比较。结果：术后随访10～18个月,平均13．5个月。PFNA组较DHS组手术时间和显性失血少,隐性失血多。PFNA组并发症发生率低于DHS组,疗效优于DHS组。髋关节Harris评分PFNA组高于DHS组。结论：治疗高龄股骨粗隆间不稳定骨折,在髋关节功能恢复和减少并发症方面,PFNA效果更好;对于Ⅱa、IIb、Ⅲ型骨折采用DHS可获取良好疗效,在减少围手术期失血方面具有优势。     

髓内钉治疗老年股骨转子间骨折围手术期隐性失血的研究

目的研究闭合性复位股骨近端防旋髓内钉固定治疗老年股骨转子间骨折围手术期的隐性失血原因及防治。方法随机选取2017年5月至2018年5月本院收治的老年股骨转子间骨折患者40例,均接受闭合性复位股骨近端防旋髓内钉固定治疗,分析40例患者的手术时间、术中出血量、围手术期失血量、隐性失血量、围手术期隐性失血的影响因素。结果 40例患者手术时间40～90分钟,平均(59.1±10.4)分钟;术中出血量60～250ml,平均(75.6±10.5)ml;围手术期失血量500～1410ml,平均(610.0±100.5)ml;隐性失血100～600ml,平均(535.1±80.4)ml。输血、AO骨折分型A3型、手术类型切开性复位患者的隐性失血量、总失血量均分别显著高于未输血、A2型、闭合性复位患者(P0.05)。结论闭合性复位股骨近端防旋髓内钉固定治疗老年股骨转子间骨折围手术期的隐性失血原因为AO骨折分型复杂、手术切开性复位,闭合性复位能够对其进行有效防治,值得在临床推广应用。     

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 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.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

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.