经口咽前路寰枢椎复位钢板内固定的外科解剖学研究

目的为经口咽前路寰枢椎复位钢板内固定设计和应用提供解剖学依据。方法对10例新鲜的头颈部标本使用经口咽前入路进行逐层的显微外科解剖,观察咽后壁的层次、椎动脉的走行、寰枢椎的解剖毗邻关系和寰枢椎前路钢板内固定的相关解剖参数等。结果(1)咽后壁分两层和两个间隙粘膜层、椎前筋膜层,咽后间隙和椎前间隙;(2)经此入路可显露从枕骨大孔前缘至C3椎体的范围;(3)寰椎和枢椎椎动脉距中线的距离分别为寰椎(252±23)mm和枢椎(184±26)mm;(4)寰椎和枢椎可显露宽度分别为(394±22)mm和(390±21)mm,寰椎进钉点(侧块中点)间距(a)为(314±33)mm,寰椎进钉点连线与枢椎进钉点(枢椎前表面中部上关节面内缘连线与前唇下缘线之间的等距离线位于矢状中线两侧旁开3～4mm的位置)连线的垂直间距(b)为(187±27)mm,a/b比值为15～17。结论经口咽前入路行寰枢椎前路钢板内固定可行,钢板的设计应以上述测量数据为依据。     

内窥镜下经口咽入路寰枢椎手术的可行性研究

目的探讨内窥镜下经口咽入路进行寰枢椎手术的可行性。方法测量50套寰枢椎标本的寰椎前弓长度,枢椎齿突高度、最大横径及矢状径,枢椎上关节面最大横径及矢状径。在20具完整头颈部标本上分别按传统及内窥镜下方法行寰枢椎模拟手术,手术完成后将标本解剖,研究内窥镜下经口咽入路的手术方法、减压效果及手术“安全区域”。结果寰椎前弓长度为(19.8±2.3)mm,齿突高度为(15.9±1.9)mm、最大横径为(10.5±0.6)mm、最大矢状径为(11.5±1.9)mm,枢椎上关节面最大横径为(15.1±1.6)mm、最大矢状径为(17.7±1.3)mm,均满足内窥镜下手术要求。内窥镜下寰枢椎手术可以寰椎前结节为定位标记,行寰椎前弓、齿突切除,侧块关节面打磨。寰椎前弓切除可采用由寰椎前结节向两侧磨除或前结节两侧磨断后完整摘除前结节两种方法;齿突则由尖部向下顺行磨削切除;打磨侧块关节面时需平移或倾斜工作通道,关节面打磨宽度应在12mm以内,深度不宜超过10mm。内窥镜下手术减压范围宽度(14.8±0.8)mm,高度(16.1±0.7)mm,深度(19.1±1.0)mm,与传统组差异无显著性。内窥镜下经口咽入路寰枢椎手术的“安全区域”位于寰枢椎前面,近似矩形,宽(45.9±3.6)mm、高(29.4±2.5)mm。结论内窥镜下经口咽入路行寰枢椎手术对局部解剖结构显露清晰,操作精细,     

人工寰齿关节设计依据及可行性分析

目的:通过解剖和X线观察,测量国人寰齿关节以获取形态学参数,为研制能替代寰齿关节功能的人工寰齿关节提供解剖数据。方法:用电子游标卡尺和量角器测量32套正常成年人寰齿关节新鲜标本的相关参数,包括寰椎前弓宽度、前弓下缘与C2上关节面前缘间距、枢椎侧块内缘与齿状突外缘间距、寰椎前结节厚度和高度、寰椎侧块中点高度和长度、寰椎侧块宽度、齿状突高度、齿状突横径和前后径、齿状突后倾角和齿面角等23项内容。并进行统计学分析,为研制人工寰齿关节提供形态学参数范围。据此设计仿生人工寰齿关节,在3具成人尸体标本进行模拟人工寰齿关节置入手术。结果:测得寰椎前弓宽度平均为(20.45±1.53)mm,前弓下缘与C2上关节面前缘间距平均为(2.12±1.22)mm,枢椎侧块内缘与齿状突外缘间距平均(2.51±2.18)mm,寰椎前结节厚度和高度分别平均为(9.43±1.93)mm和(10.23±1.32)mm,寰椎侧块中点高度和宽度分别平均(13.68±1.38)mm和(12.98±1.52)mm,齿状突高度平均为(15.25±2.11)mm,齿状突横径和前后径平均分别为(9.69±1.38)mm和(11.26±1.02)mm,齿状突后倾角平均为(12.23±4.27)°、齿面角平均为(65.48±2.17)°。人工关节由寰椎部件、枢椎部件和配件构成。模拟手术中无椎动脉损伤和假体压迫脊髓。结论:人工寰齿关节的研制在形态学上具有可行性。人工寰齿关节的研制是既能重建寰枢关节稳定性,又能保留寰枢关节旋转功能的可行性技术。为了安放牢固、操作方便、保持运动功能以及避免副损伤,各部件参数有一定的选取范围。     

经口咽入路人工寰齿关节置换术的解剖学研究

目的为经口咽入路处理斜坡至上颈椎腹侧病变和人工寰齿关节设计及应用提供解剖学依据。方法对8具新鲜成人头颈部标本经口咽入路进行逐层解剖,观察咽后壁的层次、椎动脉的走行、寰枢椎的解剖毗邻关系和人工寰齿关节置换术的相关解剖参数等。另选32套成人新鲜寰枢椎骨性标本,测量寰椎前弓骨窗宽、枢椎椎体骨窗宽、寰椎部件上位进钉点间距、寰椎部件下位进钉点间距、枢椎部件上位进钉点间距、枢椎部件下位进钉点间距等。结果寰椎和枢椎可显露宽度分别为(40.2±3.5)mm和(39.3±3.7)mm。咽后壁可显露宽度和高度分别为(40.1±5.2)mm和(50.2±4.6)mm。寰椎上位进钉点间距和下位进钉点间距分别为(28.0±2.9)mm和(24.0±3.5)mm,枢椎上位进钉点间距和下位进钉点间距分别为(18.0±3.3)mm和(16.0±3.5)mm。经口咽入路手术可以达到斜坡下缘至C3椎体上缘。咽后壁由浅至深可分五层结构和两个间隙。结论经口咽入路手术处理斜坡下缘到上颈段腹侧病变具有手术路径短、显露好、减压效果肯定等优点。人工寰齿关节的设计可以上述测量数据为依据。     

后路寰枢椎侧块关节融合器置入的临床应用解剖

目的了解国人寰枢椎侧块关节周围血管、神经的解剖关系,为后路寰枢椎侧块关节融合器准确、安全置入提供解剖学依据。方法选用成人尸体标本20具,冠状面上观察寰枢椎侧块关节后缘周围解剖关系;平枢椎侧块上关节面后缘测量C1、2间椎动脉内缘至颈髓硬脊膜外缘的距离,确定手术冠状位的"安全操作空间";测量枢椎下关节突后内缘的纵垂线与枢椎椎弓上缘交点(G点)至枢椎椎弓根上缘中线延长线的水平距离,确定手术切入点。结果 "安全操作空间"为(19.72±1.84)mm,水平距离为(2.23±0.45)mm。寰枢椎后膜下的静脉丛主要集中在寰枢椎侧块关节的外缘、上方和内缘,其下方尤其枢椎椎弓根上缘的静脉丛稀疏。位于寰椎椎弓根下方、寰枢椎侧块关节内上侧的C2神经根,距颈硬脊膜外缘5~7 mm处膨大成颈神经节,并发出前、后支。结论 G点恒定在枢椎椎弓根上缘中线延长线的内侧2.5 mm处,以此点向外水平旁开2.5 mm,向上推开寰枢后膜,内上骨膜下剥离并沿枢椎椎弓根上缘中线一并剥离枢椎椎弓根骨膜和寰枢椎侧块关节囊,即可显露寰枢椎侧块关节并置入融合器。以此入路在"安全操作空间"内置入融合器,可避免切开寰枢后膜而损伤血管和神经,保证了手术的安全。     

脊柱前路手术入路

脊柱外科的手术治疗可经不同的入路来完成 ,而对手术入路的选择常取决于脊柱外科医师的手术技能。脊柱前路手术已作为许多脊柱疾患的常规治疗方法而逐渐普及 ,本文就脊柱前路手术的入路及术中、术后应注意的事项进行介绍。1　枕颈部 (枕骨～颈 3)1 1　经口入路沿咽后壁正中纵行切开 ,即可显露颅底至颈 3椎体 (图 1) ,必要时还可切开悬雍垂及软腭以便向上扩大显露。用刮匙和骨膜剥离器剥离枕骨斜坡、寰椎前弓、齿状突基底部和枢椎椎体前方的软组织 ,用磨钻和咬骨钳仔细切除寰椎前弓的下 1/3～ 2 /3以使齿状突基底部得到满意显露 ,同时还应注…     

椎动脉Ⅴ3段的解剖研究及在寰枢椎椎弓根置钉中的应用

目的 为临床置入寰枢椎椎弓根钉如何避免损伤椎动脉寻找解剖学依据。方法 成人头颈部尸体标本10具20侧,解剖观察椎动脉V3段走行特点并研究其相对寰枢椎椎弓根的空间位置关系。结果 椎动脉V3段在椎动脉沟内走行时,椎动脉与椎动脉沟底部距离从外向内逐渐增大,最窄处为椎动脉沟外缘,此处与相应椎动脉下缘的距离为（1.46±0.98）mm,距中线为（20.45±2.19）mm。寰椎椎弓根钉进钉点处椎动脉下缘距椎动脉沟底部的距离为（1.99±0.85）mm。枢椎横突孔內缘与椎动脉內缘的距离为（2.3±0.4）mm。发现寰枢椎椎弓根处VA变异不适合置钉者各一侧。结论 大部分寰枢椎椎弓根钉进钉点是安全的,但由于寰枢椎发育及椎动脉V3段变异并不少见,椎弓根钉置入时应尽量个体化。     

经口咽寰枢椎侧块关节复位块状骨支撑植骨治疗颅底凹陷症并寰枢椎脱位

目的:探讨经口咽寰枢椎侧块关节牵开复位、三面皮质块状骨支撑植骨、内固定治疗颅底凹陷症合并寰枢椎脱位的价值.方法:2009年12月～2011年12月我院收治33例合并寰枢椎脱位的颅底凹陷症患者,均有脊髓压迫症状.术前寰齿间隙(ADI)3.8～12.1mm (7.9±3.9mm),齿状突顶部与Chamberlain线的垂直距离(DCL) 3.0～15.6mm (9.3±6.2mm),寰枢椎垂直脱位指数(VAAI)0.35～0.51 (0.46±0.07),颈髓延髓角(CMA)112°～145°(127°±13°),JOA评分7～10分.均采用经口咽寰枢椎侧块关节牵开复位、三面皮质块状髂骨支撑植骨、TARP内固定术治疗.记录手术时间、手术出血量等,观察并发症发生情况.术后随访8～23个月,平均11.5个月,复查影像学评价寰枢椎脱位复位和脊髓压迫改善情况,采用JOA评分改善率对脊髓功能改善情况进行评价,在CT扫描图像上观察螺钉位置及植骨融合情况.结果:手术时间110～185min (145±35min),出血量35～85ml(58±18ml).共置入寰椎侧块螺钉66枚,枢椎逆向椎弓根螺钉41枚,枢椎椎体螺钉25枚.术后钉道扫描显示,寰椎螺钉均位于侧块内,2枚逆向枢椎椎弓根螺钉偏外进入椎动脉孔,导致椎动脉孔闭塞,小脑缺血梗死,其余枢椎螺钉均无偏差.术后发生咽后壁感染1例,将钢板取出后改行后路手术获得愈合.术后CT重建图像显示陷入枕骨大孔的齿状突获得较理想复位,脊髓受压解除,ADI改善为0.2～4.5mm( 2.3±2.1 mm),VAAI改善为0.6～0.84(0.74±0.08),CMA改善为140°～178°(157°±15°),与术前比较均有显著性差异(P＜0.01).植骨块镶嵌在寰枢侧块关节间隙,术后6～11个月均获骨性愈合.术后患者肢体麻木、肌肉无力等症状均较术前有明显改善,术后3个月复查JOA评分恢复至13～16分(15.2±0.9分),末次随访时为13～17分(15.3±0.8分),与术前比较均有显著性差异(P＜0.01).结论:经口咽寰枢椎侧块关节牵开复位三面皮质块状髂骨支撑植骨内固定术是治疗颅颈交界区病变的有效方法,但有一定风险和难度,应在严格掌握手术适应证和严格围手术期处理的条件下合理应用.     

前后路联合手术治疗齿状突骨折畸形愈合伴难复性寰枢椎脱位

目的:探讨经口前路松解齿状突部分切除与后路复位固定融合治疗齿状突骨折畸形愈合伴难复性寰枢椎脱位的疗效。方法:2008年1月～2011年1月我院共收治7例齿状突骨折畸形愈合致难复性寰枢椎脱位患者,男5例,女2例,年龄21～51岁,平均36.4岁。术前神经功能JOA评分为5～9分,平均7.3±2.1分;脊髓有效空间(space available for the cord,SAC)为4～12mm,平均8.34±3.68mm。均行经口前路松解、齿状突部分切除,一期后路寰枢椎椎弓根螺钉系统进一步提拉复位、固定、融合术,术后观察神经功能改善情况,并行X线、CT、MRI检查观察复位及植骨融合情况。结果:手术时间280～360min,平均310min。术中出血510～930ml,平均670ml。术中无脊髓神经损伤;1例术中置入枢椎椎弓根螺钉时损伤椎动脉,经原钉道拧入螺钉后完成止血,术后随访无椎动脉损伤的临床表现;1例术中置入寰椎椎弓根螺钉时寰椎后弓下壁破裂,未改变钉道,继续沿椎弓根方向置入螺钉,术后随访无寰枢椎的再失稳和移位。所有患者均获得满意复位。随访9～36个月,平均19.6个月。均在术后6个月获得骨性融合,随访期间未发现螺钉松动、移位、断裂,无寰枢椎再移位、失稳现象。末次随访时,JOA评分为11～15分,平均13.1±2.1分,与术前比较有统计学差异(P<0.05),改善率为78.8%～93.5%,平均87.4%;末次随访时的SAC为11～18mm,平均14.78±2.15mm,与术前比较明显增大(P<0.05)。结论:对于齿状突骨折畸形愈合伴难复性寰枢椎脱位患者,经口咽前路松解齿状突部分切除与后路复位固定融合术可获得好的复位效果,近期疗效满意。     

枢椎逆向椎弓根螺钉在经口咽入路治疗寰枢椎脱位中的应用

目的 探讨枢椎逆向椎弓根螺钉在经口咽入路治疗寰枢椎脱位中的应用价值.方法 选择2009年3月至2011年10月收治的25例寰枢椎脱位患者,男11例,女14例;年龄17～65岁,平均39岁;其中创伤性寰枢椎脱位17例,游离齿状突合并寰枢椎脱位8例.均实施经口咽入路松解、复位、内固定手术,寰椎采用前路侧块螺钉固定,枢椎采用逆向椎弓根螺钉固定.术后CT扫描观察术后钉道情况,测量螺钉的外倾角、下倾角、螺钉长度等.通过比较手术前、后日本矫形外科学会(JOA)评分、寰齿间隙(ADI)评估疗效.结果 25例患者共置入枢椎逆向椎弓根螺钉50枚,平均手术时间145 min,平均出血量94 mL.枢椎椎弓根螺钉的平均外倾角为20°、下倾角为15 °、螺钉长度为28 mm.24例患者术后获得10～25个月(平均16个月)随访,术后3个月JOA评分(15.7±1.1)分和末次随访时(16.0±0.7)分较术前(8.9±1.7)分均明显提高,差异有统计学意义(P＜0.05).ADI由术前(8.7±1.5) mm改善为术后(0.8±0.9)mm,差异有统计学意义(t=2.937,P＜0.05).结论 经口咽入路实施枢椎逆向椎弓根螺钉是可行的,但该技术具有一定风险,可以在有条件的医院审慎开展.     

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.     

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.     

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.     

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.