钩椎关节应用解剖测量及辅助钩椎关节融合器参数设计

目的利用CT三维重建技术对钩椎关节区域进行应用解剖测量研究,并辅助钩椎关节融合器参数设计。方法通过病历与影像系统筛选,纳入符合选择标准的60例患者颈椎CT扫描数据,其中男30例,女30例;年龄39～60岁。将DICOM格式原始数据导入Mimics19.0软件进行三维重建,测量C_3～C_7双侧钩突高、钩突基底宽、钩突基底长、钩椎关节椎间孔部移行距离,C_3～C_7钩椎关节前缘间距、钩椎关节后缘间距,以及C_(2、3)～C_(6、7)钩椎关节间隙高度、椎间隙中心高度、椎间隙前后径。将上述测量结果用SPSS22.0统计软件计算均值、标准差、最小值和最大值,用于辅助钩椎关节融合器参数设计。结果 C_3～C_7各椎体钩突高、钩突基底宽、钩突基底长、钩椎关节椎间孔部移行距离以及C_(2、3)～C_(6、7)钩椎关节间隙高度左右侧比较,差异均无统计学意义(P0.05);钩椎关节间隙高度男女差异亦无统计学意义(P0.05)。C_3～C_7各椎体钩椎关节前缘间距均显著大于钩椎关节后缘间距(P0.05),钩椎关节向后呈内聚形状。各节段椎间隙中心高度男性高于女性,但仅C_(2、3)和C_(5、6)节段差异有统计学意义(P0.05);各节段椎间隙前后径男性均显著大于女性(P0.05)。椎间隙中心高度为(4.94±0.49) mm (3.81～5.90 mm),椎间隙前后径为(15.78±1.23) mm (12.94～18.85 mm),钩椎关节前缘间距为(17.19±2.39) mm (13.39～24.63 mm),钩椎关节后缘间距为(10.84±2.12) mm (7.19～16.64 mm)。根据上述测量结果设计钩椎关节融合器体部高度为5、6、7、8 mm 4种规格,深度为12、13、14、15、16 mm 5种规格,宽度为14～18 mm;两翼设计为弧形且宽2、3 mm两种规格。结论不同节段钩椎关节解剖测量指标存在一定差异,基于解剖研究测量结果设计的钩椎关节融合器规格能够满足不同患者需求。     

颈椎钩突的解剖学测量及临床意义

目的：观察颈椎钩突的形态，探讨钩突切除术的应用解剖学。方法：17例颈椎干骨标本，对C3-C7钩突的形态进行解剖学测量，包括高度、宽度、角度及钩突与横突孔间距等。结果：C3-C7颈椎突从外侧转为后外侧，钩突角度及宽度逐渐增大。但在C5，钩突与横孔内侧的距离较其它椎体小，而钩突高度反而明显。结论：C5钩突的形态学特点可能是其易退变的原因。钩突切除时，应注意了解其解剖学特点。     

下颈椎关节突关节的影像学观测及其临床意义

目的:观测下颈椎关节突关节面的形态及其三维空间角度,探讨其临床意义。方法:选取60例正常人行颈椎CT检查,螺旋CT三维重建后在横轴面、矢状面、冠状面上观察颈椎关节突关节面形态特点,并测量关节面的曲度、关节突关节角。结果:横轴面,C3上关节面及C7的下关节面直面形多见。C3、C4、C5Ⅱ型关节面曲度比较无显著差异,C5～C7关节突关节面曲度逐渐变小(P<0.05)。C3-C4、C4-C5、C5-C6、C6-C7、C7-T1关节突关节面与矢状面的夹角分别为91.98°±9.92°、96.64°±9.01°、99.46°±7.66°、94.20°±8.72°、94.83°±10.88°,C4-C5、C5-C6夹角较大(P<0.05)。冠状面,C6/7节段椭圆形多见,C2/3、C3/4节段圆形多见。矢状面,下颈椎C3～C7关节突关节倾角分别为52.09°±6.28°、48.14°±4.75°、45.81°±4.07°、55.65°±4.15°、58.32°±5.77°,C3、C6、C7与C5关节突关节倾角之间差异显著(P<0.05)。结论:正常人下颈椎关节突关节形态在诸节段及横轴面、冠状面不尽相同。横轴面上,C3～C7的上关节面的方向逐渐从朝向正中矢状面转向外侧,渐渐与胸椎的小关节相适应,矢状面上,C3～C7的关节倾角均为锐角,且以C5为中心分布。     

四级分析法评估成人颈椎关节突退变

目的探讨一种新的成人下颈椎关节突关节退变的评级方法,为临床观测提供量化的评级标准。方法选用20例在读学生为正常组和40例颈椎病患者为病理组,分别行螺旋CT扫描并重建,测量下颈椎关节突关节横断面长度、宽度及关节间隙大小,计算出正常值范围;制定下颈椎关节突关节退变的评级标准。数据用SPSS 13.0统计软件包进行统计学分析,计算正常组、病理组各数据的均数及标准差;同一关节突关节左右数据间比较行配对t检验,正常组和病理组同一节段的各数据比较用独立样本t检验。结果 （1）正常组下颈椎关节突关节各测量数据左右差异均无统计学意义,取双侧均值。C3-4、C4-5、C5-6、C6-7关节突关节横断面长度分别为：（10.84±0.94）mm、（11.57±0.85）mm、（11.83±0.96）mm、（12.57±0.88）mm;关节突关节横断面宽度分别为：（10.44±0.99）mm、（10.56±0.91）mm、（10.50±1.06）mm、（9.49±0.68）mm;关节间隙中部（J2）最大,分别为：（1.49±0.12）mm、（1.44±0.10）mm、（1.43±0.09）mm、（1.45±0.11）mm;关节间隙两侧（J1、J3）略窄且基本对称。（2）病理组下颈椎关节突关节各测量数据左右差异均无统计学意义,取双侧均值。C3-4、C4-5、C5-6、C6-7关节突关节横断面长度分别为：（10.83±0.83）mm、（11.44±0.85）mm、（12.26±0.70）mm、（12.67±0.74）mm;关节突关节横断面宽度分别为：（10.55±0.98）mm、（10.98±1.06）mm、（10.96±0.85）mm、（9.75±0.81）mm;关节间隙中部（J2病）最大,分别为：（1.34±0.17）mm、（1.30±0.27）mm、（1.34±0.17）mm、（1.25±0.12）mm;关节间隙两侧（J1病、J3病）略窄且基本对称。（3）正常组和病理组间比较：C5-6关节面长度间差别有统计学意义;C4-5、C5-6关节面宽度间差别有统计学意义;C3-4、C4-5、C5-6、C6-7关节间隙大小间差别均有统计学意义;病理组关节突关节退变的特征表现为：关节突肥大、骨赘形成、关节面不规则、关节间隙狭窄、软骨下骨坏死、软骨下骨囊性变。结论自行设计的一种新的下颈椎关节突关节退变的评级标准,分为0-Ⅲ级,该评级标准是一个简单实用的影像学评估方法。     

齿状突螺钉钢板内固定系统的研制及解剖学可行性分析

【摘要】 目的：自行设计与制作齿状突螺钉钢板内固定系统,并验证其解剖学可行性。方法：收集40例健康志愿者（其中男20例,女20例,年龄22～32岁,平均26岁）的颈椎CT数据,导入到Mimics 15.01中,通过Mimics软件测量枢椎（C2）、第3颈椎（C3）及C2/3椎间盘的相关解剖参数,包括：齿状突高度、齿状突前后径、齿状突横径、枢椎椎体前缘高度、枢椎椎体后缘高度、枢椎椎体前后径、枢椎椎体横径、枢椎前下唇的高度、枢椎前下唇的宽度、枢椎前唇与枢椎椎体后缘最高点连线与C2椎体下终板面的夹角、齿状突轴径与冠状面的夹角、在枢椎椎体横径测量平面测量该切面枢椎椎体前突部分的夹角、枢椎椎体矢状面前缘与C2~C3椎体前缘矢状面切线的夹角、C3椎体前后径、C3椎体横径、C3椎体前缘高度、C3椎体后缘高度、C3前下唇的高度、C2/3前部椎间盘厚度、C2/3中部椎间盘厚度、C2/3后部椎间盘厚度、C3椎体正中矢状位前缘最高点与后缘最低点连线与C3椎体上终板面的夹角、C3上终板面与C2~C3椎体前缘矢状面切线的夹角、齿状突理想钉道与C2~C3椎体前缘矢状面切线的夹角。并进行统计学分析,为齿状突螺钉钢板内固定系统的设计提供相关解剖参数范围,在此基础上设计与制作齿状突螺钉钢板内固定系统,并将其在Mimics软件上和尸体标本上进行模拟手术。在Mimics软件上模拟齿状突螺钉钢板内固定系统置入后,通过Mimics软件上的透明功能观察螺钉通道在C2和C3中的位置是否合理,尸体模拟手术后通过对标本行CT扫描和三维重建,观察钉道是否准确。结果：根据上述C2、C3及C2/3椎间盘的相关解剖参数测量结果设计、采用医用钛合金材质（Ti-6A1-4V）制作的齿状突螺钉钢板内固定系统,主要由螺钉固定板、C2/3椎间融合器和相关配件组成,其中配件包括齿状突固定部件、椎体锚定部件和锁定部件。齿状突螺钉钢板内固定系统在Mimics软件上和尸体标本上模拟手术置入后,通过透明功能和CT检查显示钉道位置合理。结论：自行研制的齿状突螺钉钢板内固定系统的置入在解剖学上具有可行性。     

脊髓型颈椎病颈椎曲度与矢状面参数间相关性分析

背景:脊髓型颈椎病会导致颈椎矢状位参数的改变,造成严重的临床症状。由于颈椎的灵活性,仅通过某一颈椎矢状面参数测量的结果不一定具有说服力。目的:探讨脊髓型颈椎病患者的C2-C7 Cobb角与颈椎矢状面参数的相关性以及责任椎间隙高度、椎间成角与颈椎曲度的相关性。方法:收集75例脊髓型颈椎病患者的临床资料进行回顾性病例对照研究,男38例,女37例,年龄60~67岁,平均(64.2±2.1)岁。根据C2-C7 Cobb角测量数据分为两组。评价影像学结果,Jackson应力切线法测量的颈椎生理曲度、颈部倾斜、T1斜度、胸廓入口角、C2-C7矢状面垂直轴、C7斜度、责任椎间隙的活动度、高度和角度。结果:在颈椎矢状面参数中,除胸廓入口角与C2-C7 Cobb角无相关性,其他参数和C2-C7 Cobb角之间均有一定的相关性,其中T1斜度与C2-C7 Cobb角的相关性最强。C4/5、C5/6、C6/7节段的椎间隙高度和椎间成角与C2-C7 Cobb角显著相关。但在C3/4节段,只有椎间成角随C2-C7 Cobb角的增大而增大。结论:颈椎矢状面各参数是衡量颈椎间盘退行性改变的重要参考数据,颈椎椎间高度和椎间成角均影响颈椎曲度的变化。对于脊髓型颈椎病患者,在评估颈椎正常弯曲度时,除胸廓入口角,其他颈椎矢状面参数与C2-C7 Cobb角相当;但椎间成角比椎间高度更有意义。     

跟骨前部的解剖测量与多层螺旋CT测量的比较研究及其临床意义

[目的]比较跟骨前部解剖测量和多层螺旋CT测量结果之间的关系,探讨多层螺旋CT在跟骨骨折个案化内固定置钉的应用价值.[方法]使用解剖测量法和多层螺旋CT法,测量40只成人跟骨前部湿性标本的数据,采用SPSS 10.0统计软件分析比较.[结果]解剖测量法测得的跟骨前部最大长度(28.32±2.76) mm,最小长度(9.01±1.88) mm,最大宽度(27.60±2.91) mm,最小宽度(20.35±1.78) mm,最大高度(28.75±2.33) mm,最小高度(19.64±1.93) mm.螺旋CT法测得的跟骨前部最大长度(28.11±3.03) mm,最小长度(9.32±1.32)mm,最大宽度(27.69±2.19) mm,最小宽度(21.10±1.56) mm,最大高度(27.99±2.77) mm,最小高度(18.98±2.34) mm.两种测量方法获得的数据具有一致性(P＞0.05).[结论]多层螺旋CT测量的数据反映了跟骨前部的实际大小.术前使用多层螺旋CT扫描测量并给予三维重建,可以客观地获得跟骨前部的基本数据,直观显示了跟骨前部的立体形态.根据测量的数据制定个案化置钉方案,提高跟骨骨折内固定效果.     

平山病患者与非平山病患者钩椎关节在CT上的形态学差异

【摘要】 目的：研究平山病患者和非平山病患者钩椎关节在CT上的形态学差异,提出平山病可能的发病机制。方法：选择2006年10月～2012年1月我院骨科诊治的平山病患者32例作为病例组,均为男性,年龄16～37岁,平均19.4±4.1岁;发病年龄14～27岁,平均16.8±2.5岁;病程1～120个月,平均31.7±23.7个月。选取同期因急性颈痛于我院急诊就诊且颈椎CT正常的32例患者为对照组,亦均为男性,年龄12～26岁,平均19.1±4.3岁。两组年龄无统计学差异（P＞0.05）。在GE-PACS系统上选取两组患者通过C3～C7横突孔中心的颈椎CT冠状截面图片,分别测量各节段左右两侧如下指标：①钩突基底宽,椎体上缘的延长线上钩突内外侧缘的间距;②钩突高,钩突尖至椎体上缘延长线的垂直距离;③钩突间距,双侧钩突尖间的直线距离;④钩突倾角,钩突与椎体上缘的夹角;⑤下终板倾角,被测量椎体下终板与同一椎体侧边的夹角。结果：平山病患者C3～C7同一节段左右两侧的钩突基底宽、钩突高、钩突间距、钩突倾角、下终板倾角均无显著性差异（P＞0.05）。平山病患者C3~C7之间的钩突高及钩突间距有显著性差异（P＜0.05）,其中钩突高C6最高、C4最低,其递减规律为C6＞C5＞C7＞C3＞C4,同时钩突间距则表现为C3~C7逐渐增宽;钩突基底宽、钩突倾角、上椎体下终板倾角（除C3外）在C3~C7之间无显著性差异（P＞0.05）。两组取左右两侧均值为相应节段的钩突基底宽、钩突高,并计算左右两侧钩突倾角总和、下终板倾角总和及相应节段的倾角总和之差（即钩突倾角总和-下终板倾角总和）,再计算均值及标准差。平山病患者C3～C7的钩突基底宽、钩突间距以及钩突倾角总和与对照组比较均无显著性差异（P＞0.05）,而同一节段钩突高度和上位椎体下终板倾角总和均明显小于对照组（P＜0.05）,且倾角总和之差均显著大于对照组（P＜0.05）。结论：平山病患者可能存在钩椎关节发育异常,表现为钩突的相关指标发育不平衡,同时具有较矮的钩突以及较小的下终板倾角,继而引发的颈椎不稳定在平山病的发生和发展过程中有重要意义。     

下颈椎棘突椎板螺钉固定的解剖学研究

目的:测量成人下颈椎棘突椎板的解剖学参数,探讨下颈椎棘突椎板固定的可行性。方法:取20具C3-C7尸体标本,仔细解剖以清楚地暴露椎板和棘突。分别采用手工和CT测量椎板高度、厚度;以棘突和椎板的交界处进钉,对侧椎板中上端背侧出钉,通过CT重建测量螺钉进钉角度、钉道长度及钉尖与椎动脉、脊髓的距离;随机抽取100例正常成年人下颈椎CT图像测量下颈椎棘突根部中缘宽度、棘突椎板交界处椎板中缘厚度,分析置钉可行性。结果:所有螺钉均成功置入,未发现螺钉侵犯椎管、横突孔。下颈椎标本各节段椎板高度、厚度的手工测量值与CT测量值比较无统计学差异(P>0.05);重建CT测量C3-C7节段椎板高度、厚度逐渐增大,分别为(12.4±1.2)～(13.7±1.3)mm和(4.5±0.9)～(5.4±1.1)mm,差异有统计学意义(P<0.05);螺钉钉道长度呈增大趋势(13.7±1.2)～(15.8±1.8)mm,差异有统计学意义(P<0.05);螺钉钉尖与椎动脉、脊髓的距离分别为(20.1±2.7)～(25.8±2.9)mm和(4.1±1.8)～(5.0±1.2)mm;横断面的前倾角度为(73.0±9.9)°～(85.3±10.1)°,差异无统计学意义(P>0.05);100例正常成年人下颈椎CT图像测量棘突根部宽度及椎板中缘厚度最小值均为C4,分别为(8.5±1.1)mm和(4.3±0.5)mm,最大值均为C7,分别为(14.5±2.0)mm和(6.0±1.1)mm。结论:下颈椎棘突椎板螺钉固定技术具有解剖学可行性,棘突椎板螺钉内固定存在一个安全、稳定的进钉区间。     

颈前路椎体次全切除范围与颈椎体解剖标志定位的关系

<正>临床上脊髓型颈椎病采用前路减压手术时往往行一个或多个椎体的次全切除,但手术中真正做到充分减压并不容易。我们对12具人体颈椎骨骼标本进行了观察和测量,发现颈椎前路减压范围与颈椎(C3～C7)的钩突解剖标     

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.     

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.     

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.     

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.