前交叉韧带重建术中胫骨侧止点无撞击区的定位研究

目的探讨前交叉韧带(ACL)重建术中胫骨隧道无撞击重建区的定位。方法选用10具正常新鲜冷冻尸体膝关节标本,膝关节完全伸直时,标记髁间窝顶延长线和ACL胫骨附着处的交点。膝关节屈曲90°时,测量ACL胫骨附着处上标记点与ACL前缘间的距离及标记点与胫骨棘间区后缘间的距离。然后,再测量标记点前部分的前后径、后部分的前后径和内外径,并计算后部分的面积。结果由ACL胫骨附着处前缘到胫骨棘间区后缘的前后径平均为(21.40±1.17)mm。ACL胫骨附着处标记点前部分的前后径平均为(8.90±0.74)mm(占总前后径的41.59%)。胫骨附着处标记点后部分的前后径平均为(12.50±0.85)mm(占总前后径的58.41%),内外径平均为(10.65±0.97)mm,面积平均为(133.80±21.01)mm2。结论ACL胫骨附着处上标记点的后部分是胫骨隧道无撞击区,位于胫骨棘间区的后缘中点与该点前12.50mm之间,在该区域行ACL重建可以避免移植物与髁间窝顶部的撞击。绝对撞击区位于ACL胫骨附着部前缘与其后8.90mm之间,应尽量避免在此区域内定位胫骨隧道。     

前交叉韧带重建术中胫骨骨道定位的应用解剖研究

[目的]探究前交叉韧带(anterior cruciate ligament,ACL)于胫骨止点处的解剖形态以及测量髁间窝顶线与胫骨平台交汇点至后交叉韧带前缘的距离对胫骨骨道定位的解剖学意义,为ACL重建术提供理论依据。[方法]选取新鲜成人膝关节标本8例,仔细剔除关节周围肌肉、后关节囊等结构,保留前后交叉韧带及两侧侧副韧带,保证膝关节正常屈伸范围。在屈伸膝关节时按照ACL纤维张力区将其分为前内束和后外束,在胫骨附着处将ACL切断制备ACL损伤模型。用测量工具和Phontoshop软件获取ACL基本解剖参数以及髁间窝顶线与胫骨平台的交汇点、ACL前缘、ACL胫骨止点的中心点分别至后交叉韧带前缘的距离。[结果]ACL平均体部直径为(11.21±0.76)mm,ACL在胫骨止点处的平均最大横径为(11.34±0.79)mm,平均最大前后径为(16.54±0.82)mm。前内束和后外束在胫骨止点处的平均面积分别为(113.35±29.65)mm~2和(83.29±16.99)mm~2。髁间窝顶线与胫骨平台的交汇点、ACL前缘以及ACL胫骨止点的中心点至后交叉韧带前缘的距离分别为(12.13±0.96)mm,(21.14±0.83)mm和(8.82±0.77)mm。[结论]利用胫骨平台骨道定位ACL在股骨的解剖止点现实可行,在ACL重建术中具有重要意义。     

膝关节伸直位X线片测量在前交叉韧带损伤诊断中的价值

目的探讨膝关节伸直位X线片在前交叉韧带(ACL)损伤诊断中的价值。方法51例单纯、单侧膝关节ACL损伤的病人,双膝关节侧位X线片并进行测量。①测量Blumensaats线的延长线与胫骨平台相交点B到胫骨平台前缘A的距离和胫骨平台前后缘的距离AC,并计算AB与AC的比值;②测量股骨髁间窝顶点Blumensaats线的延长线与胫骨平台的夹角(顶-平台角);③测量股骨干纵轴与胫骨平台的夹角(股骨-平台角)。结果①健侧Blumensaats线的延长线与胫骨平台相交点B到胫骨平台前缘A的距离为12.21mm±2.02mm,顶-平台相交率为22.17%±3.86%,患侧Blumensaats线的延长线与胫骨平台相交点B到胫骨平台前缘A的距离为18.09mm±3.56mm,顶-平台相交率为31.33%±5.34%,两者比较有显著的统计学意义(P<0.01);②顶-平台角健侧为56.06°±4.23°,患侧为60.10°±4.81°,有统计学意义(P<0.01);③股骨-平台角健侧为97.92°±3.68°患侧为98.19°±3.44°,经统计学处理,P>0.05,没有统计学意义。结论X线平片在ACL损伤诊断中有明显的实用价值。在动力位的膝关节X线侧位平片上,ACL损伤侧膝关节的顶-平台相交率和顶-平台角均高于健侧。X线片测量方法易于推广,因此可以作为ACL损伤病人的常规检查方法和诊断依据。     

膝关节半月板根部附着区的解剖学测量

目的:测量国人膝关节内外侧半月板前后根部附着区的解剖学数据,为临床修复半月板根部损伤提供解剖学基础。方法:选取30个国人成人尸体膝关节标本,其中男16例,女14例;死亡年龄35～68(55.6±7.8)岁。对半月板根部附着区结构进行解剖,测量内外侧半月板根部附着区中心点与胫骨内外侧髁间棘、后交叉韧带前缘、内侧胫骨平台软骨后方外侧缘及外侧胫骨平台软骨后方内侧缘等标志点的位置关系和各个附着区的面积。结果:内侧半月板后根部附着区:中心点位于胫骨内侧髁间棘后方(11.73±3.10) mm、外侧(2.77±0.86) mm,后交叉韧带前缘前(2.76±0.76) mm,内侧平台软骨外侧缘外(3.92±0.22) mm,附着区面积(31.29±5.18) mm~2。内侧半月板前根部附着区:中心点位于胫骨内侧髁间棘前方(25.40±5.27) mm、外侧(3.01±0.86) mm,附着区面积(46.18±11.60) mm~2。外侧半月板后根部附着区:中心点位于胫骨外侧髁间棘后方(4.51±1.35)mm、内侧(1.85±0.34) mm,后交叉韧带前缘前(6.91±1.11) mm,外侧平台软骨内侧缘内(3.16±0.96) mm,附着区面积(44.10±6.23) mm~2。外侧半月板前根部附着区:中心点位于胫骨外侧髁间棘前方(12.97±2.92) mm、外侧(1.31±0.22) mm,附着区面积(60.84±14.98) mm~2。结论 :该试验定量描述内外侧半月板前后根部附着区的面积以及其中心点与相应标志点的位置关系,为临床修复半月板根部损伤提供一定的解剖学参考。     

前交叉韧带重建术中隧道定位对移植物等距特性影响的研究

目的探讨前交义韧带(ACL)重建术中股骨和胫骨隧道定位变化对移植物等距特性的影响。方法选用10具正常新鲜冷冻尸体膝关节标本,在股骨取3个定位点,第一个定位点位于右膝11点(左膝1点)过顶点前方5～6 mm处,作为前束点；第二点位于前束点前5 mm处,作为误差点；第三点位于屈膝90°时,ACL附着区长轴与经股骨-胫骨接触点的垂直线的交点,作为后束点。在ACL胫骨附着区的前后径上取3个定位点,一个位于原ACL附着区中心,称为中心点；一个位于中心点后5 mm处,称为5 mm后点；一个位于中心点后10 mm处,称为10 mm后点。模拟ACL重建步骤,经各个股骨和胫骨定位点分别钻直径为2 mm的骨隧道,通过测量钢丝和等距测量仪来检测膝关节屈曲过程中各个股骨隧道内口相对于各个胫骨隧道内口的距离变化。结果相对于某一个固定的股骨隧道内口,胫骨隧道内口的前后移位变化对移植物等距特性的影响差异无显著性意义(P＞0．05)；相对于某一个固定的胫骨隧道内口,股骨隧道内口位置的变化对移植物等距特性的影响差异有极显著性意义(P＜0．01)。从膝关节完全伸直到极度屈曲的过程中,如果股骨隧道内口选择在前束点,则两内口间移植物长度变化在生理等距范围内；若选择在误差点,则两内口间移植物长度变化表现为超出生理等距范围的延长；若选择在后束点,则两内口间移植物长度变化表现为超出生理等距范围的短缩。结论ACL重建时,胫骨隧道内口在ACL附着区中心与棘间区后缘之间的前后移位对移植物等距特性无明显影响,股骨隧道内口的移位对移植物的等距特性有明显影响。     

双源CT三维重建前交叉韧带胫骨止点印迹的临床研究

目的通过双源CT(dual-source computed tomography,DSCT)三维重建前交叉韧带(anterior cruciate ligament,ACL)胫骨止点印迹,测量印迹相关参数,为临床解剖重建提供依据。方法对55名志愿者双侧共110个膝关节进行DSCT扫描,其中男32例,女23例,年龄20～50岁。64排工作站(GE,Volume Share2-AW4.4版本软件)三维重建膝关节胫骨平台,再现胫骨平台ACL印迹,测量印迹面积,长短轴,印迹中心点在胫骨平台相对位置等。结果男性ACL胫骨印迹面积(200.99±30.42)mm2显著大于女性(170.30±26.94)mm2(t=5.471,P=0.000)。男性ACL胫骨印迹短轴(9.25±1.56)mm显著长于女性(8.30±1.46)mm(t=3.235,P=0.002)。男性ACL胫骨印迹长轴(14.00±1.76)mm与女性(13.63±1.65)mm无统计学差异(t=1.116,P=0.267)。男性ACL胫骨矢状面位置(48.35±6.13)%与女性(47.53±4.34)%比较无统计学差异(t=0.778,P=0.439)。男性ACL胫骨冠状面位置(49.70±2.37)%与女性(49.00±2.68)%比较无统计学差异(t=1.446,P=0.151)。结论双源CT三维重建可再现ACL胫骨止点自然印迹,其形态、位置存在个体化差异,要实现ACL解剖重建必须采用个体化重建技术。     

前交叉韧带胫骨平台止点的MRI测量及临床意义

目的应用MRI测量前交叉韧带（ACL）胫骨平台止点,为临床生理等长重建ACL提供参考。方法选择100例正常的膝关节磁共振检查结果,在适当的切面上绘制并测量胫骨平台前缘至后交叉韧带（PCL）前缘之间直线距离（AP）、在该径线上ACL胫骨侧止点中心至胫骨平台前缘之间距离（IA）、ACL胫骨止点中心至PCL前缘切线距离（DL）,并计算IA/AP的比值。结果IA为（19.5±2.8）mm,AP为（38.5±3.6）mm,IA/AP为（50.6±4.8）%,DL为（16.3±2.0）mm。结论MR I可用于测量ACL胫骨侧止点,重建ACL胫骨侧止点定位于胫骨平台中点稍后方可能更为合理。     

股骨Blumensaat线的MRI测量及其对重建ACL的意义

目的应用MRI对股骨Blumensaat线的测量,为重建前交叉韧带(anterior cruciate ligament,ACL)提供参考。方法通过选择100例正常的膝关节伸直位磁共振检查结果,在适当的切面上绘制Blumensaat线延长线与胫骨平台的交点,测量其在胫骨矢状径位置及其与后交叉韧带(posterior cruciate ligament,PCL)的距离,并与ACL胫骨侧生理止点中心和PCL的距离比较。结果 Blumensaat线延长线与胫骨平台的交点在胫骨矢状径上距前缘(51.9±7.3)%,与PCL距离(14.2±2.5)mm,较ACL生理止点中心靠后。结论为避免髁间窝前方撞击,重建ACL胫骨侧止点定位于胫骨平台生理性止点中心后方或PCL前方8～10mm,个别人需更后方。     

红外线计算机导航辅助关节镜下前十字韧带重建中骨隧道定位的准确性研究

 目的 探讨红外线计算机导航对辅助关节镜下行前十字韧带(anterior cruciate ligament, ACL)重建中股骨、胫骨隧道定位的准确性及可行性。方法 回顾性分析2012年1月至2013年6月,采用红外线计算机导航辅助关节镜下定位股骨、胫骨隧道行ACL重建术治疗35例ACL损伤患者资料,男26例,女9例;年龄18~53岁,平均26.8岁;合并半月板损伤21例,内侧副韧带损伤3例。所有患者均采用股薄肌、半腱肌编织缝合作为移植物,骨端均采用羟基磷灰石挤压螺钉、门形钉及微孔钢板固定。术后行KT-1000和Lachman试验,并采用Lysholm和Tegner膝关节评分系统评价膝关节功能及运动水平。结果 35例患者均获得随访,随访时间12～17个月,平均16个月。术后股骨、胫骨隧道位点测量结果平均值分别为63.8%±6.6%、45.7%±4.2%。1例患者术后3个月在胫骨固定追踪器针孔处出现轻度异位骨化,关节活动无明显受限。Lachman 试验由术前1 例Ⅱ度、30例Ⅲ度、4例Ⅳ度改善至术后33例Ⅰ度、1例Ⅱ度、1例;KT-1000试验,术前(6.47±0.75) mm,术后(1.01±1.14) mm。术前双膝关节松弛度差异>5 mm 32 例、3～5 mm 3例;术后0～3 mm 31 例、3～5 mm 2 例、<0 mm 2例。Lysholm和Tegner评分分别由术前(52.74±10.91)分和(4.64±1.34)分提高至术后(93.97±4.13)分和(6.56±0.81)分;术前膝关节活动范围由85.6°±11.2°提高至术后118.3°±5.7°;其中33例无屈、伸受限;2例膝关节屈、伸受限< 10°,经直腿抬高训练、本体感受功能训练,术后6个月膝关节活动范围恢复正常。结论 红外线计算机导航系统辅助关节镜下ACL重建术是根据解剖标志点与运动学数据进行导航,通过检测和记录膝关节的运动学数据,选定隧道位点进行手术,该方法定位股骨、胫骨隧道位置精确,术后疗效评价优良。     

前交叉韧带股骨止点的解剖学研究

[目的]通过股骨干性标本研究前交叉韧带(ACL)股骨止点的形态、位置及大小,提出新的形态学分类,为临床重建ACL提供解剖学依据。[方法]对67副已知性别成人股骨干性标本的ACL股骨止点进行解剖研究。测量ACL股骨附着点的面积、形态以及与周围结构的关系。应用SPSS10.0统计软件对数据进行统计学分析。[结果]ACL股骨止点面积:男(104.4±30.8)mm2,女(81.4±29.1)mm2,性别差异有显著性意义(P0.01)。ACL股骨附着区形态中椭圆形49例,占36.6%,新月形39例,占29.1%;圆形20例,占14.9%;长条形17例占12.7%,不规则形9例,占6.6%。[结论]ACL股骨止点有椭圆形、新月形、长条形、不规则形等多种形态,股骨止点面积有性别差异,重建ACL应结合股骨附着区的形态、位置、大小、性别等特点进行个体化重建。     

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.     

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.     

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.     

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.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.