保留修复后方关节囊及韧带对防止人工髋关节置换术后脱位的作用

目的 探讨保留并修复后方关节囊及韧带对防止后方入路人工髋关节置换术后髋关节后脱位的作用。方法 将503例采用髋关节后方入路的初次人工髋关节置换的患者分为两组:A组298例保留并修复后方关节囊及韧带,B组205例切除关节囊及韧带。比较两组术后髋关节后脱位发生率。结果 A组发生髋关节后脱位2例,发生率0.67%,B组发生髋关节后脱位6例,发生率2.93%,A组比B组术后髋关节后脱位发生率明显降低(P<0.05)。结论 保留并修复后方关节囊及韧带用以加强人工髋关节后方软组织支撑力量,有助于恢复髋关节的软组织平衡,增加关节稳定性,对防止后方入路人工髋关节置换术后髋关节后脱位有较为重要的作用。     

全髋关节置换术后早期后脱位的易发因素及防治

目的探讨人工全髋关节置换术后早期后脱位的易发因素及防治措施。方法对401例（432髋）采用后外侧入路行人工全髋关节置换术后出现的14例早期后脱位的临床资料进行回顾性分析。结果脱位多发生在术后1—6周。X线显示：髋臼位置不良6例、髋周软组织不平衡8例。发生率3．24％，保守治疗10例，手术治疗4例。结论假臼位置不良、软组织不平衡是目前引起全髋关节置换术后早期后脱位的主要因素。闭合复位对大多数早期病例效果良好。精确的假体置入、充分的软组织修复及正确的护理可降低脱位的发生。     

两种髋关节入路的THA术后髋关节本体感觉的分析

目的关节的不稳定大致可分为机械性不稳和功能性不稳。据报道全髋关节置换术后脱位常发生在后侧入路,可能是由于关节周围软组织损伤引起的功能性不稳所致。因此我们对比了采用不同入路进行髋关节置换手术患者的髋关节位置觉,用以了解不同手术入路是否对术后脱位产生影响。方法 58例(116个髋关节)于我院接受髋关节置换的患者纳入研究,健康的没有影像学改变的对侧髋关节作为对照组。男性10例,女性48例;年龄40~84岁,平均年龄63.1岁。后外侧入路39个髋关节,前外侧入路30个髋关节,对照组是37个髋关节。结果前外侧入路(anterolateral approach,AL)组中的主动外旋的绝对复位角度误差明显低于后外侧入路(posterolateral approach,PL)组中的绝对复位角度误差,在AL组和对照组中被动内旋、外旋和主动内旋的相对复位角度误差明显低于PL组。结论在前外侧入路置换中由于关节周围软组织的保留,髋关节具有更好的位置觉。     

保留关节囊的后侧入路人工全髋关节置换术

目的探讨保留关节囊的后侧入路人工全髋置换术(total hip arthroplasty,THA)临床意义和手术方法。方法对2006年1~12月的29例股骨颈骨折患者(保留组),行后路THA,术中行关节囊保留修复,并与2005年全年施行的32例行后路常规关节囊切除的THA病人(常规组)在手术时间、术中出血量以及术后脱位发生率进行回顾性比较。结果保留组平均手术时间和术中出血量分别为(96±14)min和(240±50)ml,少于常规组的(132±16)min,(410±100)ml(P<0.05)。保留组术后未发生脱位,常规组术后2例发生脱位。结论THA术中保留修复关节囊,可以减少手术时间和术中出血,不增加手术风险,可以重建髋关节后侧软组织平衡,对预防术后髋关节脱位的发生有一定临床意义。     

外侧入路全髋关节置换手术后的并发症与分析

目的探讨外侧入路全髋关节置换术后的并发症，给出目前可采用的预防措施。方法对2000年1月至2006年1月本组360例采用外侧入路行全髋关节置换术的患者进行回顾性分析，术后随访时间为1．5～7年。结果外侧入路与后侧入路全髋关节置换术后的并发症主要有：感染，假体松动，髋臼磨损，髋关节脱位，双下肢不等长，下肢深静脉血栓，骨折，异位骨化等。外侧入路全髋关节置换术的术后髋关节脱位及坐骨神经损伤发生率均低于后侧入路。结论外侧入路全髋关节置换术后并发症的发生与围手术期处理、手术操作、假体设计及选择、患者个体差异等因素有关。     

Crowe Ⅲ及Ⅳ型髋关节发育不良全髋关节置换术的软组织松解与平衡探讨

目的探讨分步髋周软组织松解与平衡重建髋臼后,行全髋关节置换术（THA）治疗成人CroweⅢ～Ⅳ型髋关节发育不良的效果。方法2001年1月至2006年1月,对29例（31髋）CroweⅢ～Ⅳ型成人髋关节发育不良患者行THA,其中男性7例,女性22例,患者平均年龄53岁（38～65岁）。CroweⅢ型22髋,Ⅳ型9髋,Harris评分术前平均42．6分。全部患者均为手术外侧人路,采用分步髋周软组织松解延长患肢,真臼位置重建髋臼后,行THA。结果患肢延长2．5～4．5cm,1例因髋臼外展角稍大出现术后脱位。29例患者术后随访1～5年,平均3．2年。Harris评分术后平均85．4分,关节疼痛缓解,活动功能满意,元假体松动和翻修病例。结论在重度髋关节发育不良THA中,通过有效的软组织松解和平衡,在真臼位置重建关节,可以最大程度地恢复患髋解剖形态和生理功能。     

手术治疗18例复杂髋臼骨折

目的：探讨复杂髋臼骨折手术治疗的效果。方法：本组骨折切开复位采用前后联合入路12例,延伸髂腹股沟入路4例,改良S－P入路2例,结果：平均随访3年。11例解剖复位,疗效优,5例复位满意,4例优,1例良;2例陈旧性骨折复位不满意,疗效差,结论：手术可有效复合固定此类骨折,恢复髋关节的稳定性和正常的头臼关系。     

微创小切口后外入路髋关节置换术软组织修补的临床研究

目的探讨微创小切口技术及后路软组织修补对髋关节置换术后关节稳定性的影响。方法30例半髋置换患者均采用小切口后外入路,分别原位缝合切断的关节囊、短外旋肌群(梨状肌、闭孔内肌、上下肌),加强关节的稳定性。结果27例获得6个月~3年的随访,无一例发生后脱位。与传统手术组相比,在失血量、输血量、引流量、术后疼痛、术后功能锻炼开始时间、辅助行走时间、重返正常活动时间、术后并发症等方面存在显著差异。结论微创小切口入路较传统手术入路具有创伤小、显露时间短、出血量少,以及恢复时间短等优点。同时,微创小切口髋后壁软组织修补可增强髋关节稳定性,防止后脱位。     

改良后外侧入路髋关节置换术治疗老年股骨颈骨折

目的 探讨改良后外侧入路(SuperPATH入路)髋关节置换术治疗老年股骨颈骨折的疗效。方法 将48例老年股骨颈骨折患者根据治疗方法不同分为观察组(24例，采用SuperPATH入路髋关节置换术治疗)和对照组(24例，采用传统后外侧入路髋关节置换术治疗)。比较两组手术情况、假体安装情况、疼痛VAS评分及髋关节Harris评分。结果 两组各失访1例；46例患者获得随访，时间7～18个月。切口长度、手术时间、术中出血量、术后下地时间观察组均优于对照组(P<0.05)。两组术后臼柄位置均在正常范围内，髋臼前倾角、髋臼外展角、偏心距及其恢复率比较差异均无统计学意义(P>0.05)。疼痛VAS评分、髋关节Harris评分：术后3 d观察组均优于对照组(P<0.001);术后1个月、末次随访时两组比较差异均无统计学意义(P>0.05)。结论 SuperPATH入路髋关节置换术治疗老年股骨颈骨折创伤小，并发症少，髋关节功能早期恢复好。     

直接前入路与后入路初次全髋关节置换术的疗效比较

目的比较直接前入路与后入路行初次全髋关节置换术(THA)的临床疗效与并发症。方法回顾性分析自2010-01—2013-01符合选择标准的171例初次全髋关节置换术患者的临床资料。根据手术入路不同,将患者分为前入路组(采用直接前入路行TKA)和后入路组(采用后入路行THA)。比较2组手术时间、出血量、切口长度、住院天数、臼杯外展角及前倾角、股骨柄中置率、疼痛视觉模拟VAS评分、UCLA评分及Harris髋关节评分及术后并发症。结果所有患者获得平均48.9(24~60)个月随访。2组手术时间、失血量、切口长度、臼杯外展角、臼杯前倾角、股骨柄中置率、及术后并发症发生率等比较,差异均无统计学意义(P0.05)。与后入路组相比,前入路组住院时间较短(P0.05)、术后第1天VAS评分较低(P0.05)、术后6周时UCLA评分及HHS评分较高(P0.05),但在之后随访中2组VAS、UCLA评分及HHS评分相似,差异无统计学意义(P0.05)。结论直接前入路行THA术后早期疗效优于后入路,但术后晚期2种入路具有相似的临床疗效。     

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.