维氏显微压痕技术测量人体枢椎硬度

目的 :探讨成人新鲜尸体枢椎的显微压痕骨硬度的分布特征及生理意义。方法 :取3具新鲜尸体标本(62岁男性,45岁女性,58岁男性)的枢椎,通过X线和定量CT检查除外影响骨量的疾病,将其分为齿状突椎体区和附件区2个测量部位,每个区域使用高精慢速锯精确切取1片厚约3mm的标本,3块枢椎共计6片。齿状突椎体区选取上侧、下侧、前侧和后侧四个部位的皮质骨区域以及中部松质骨区;附件区选取椎弓根、横突、椎板和侧块皮质骨区域以及中部侧块松质区。每块枢椎选取10个区域,合计30个区域。标本固定于纯平玻片上,应用维氏显微硬度测量仪测量标本表面硬度,每个区域随机选取5个有效硬度值,合计获得150个有效压痕硬度值。记录并分析枢椎的显微硬度分布规律。结果:枢椎整体硬度变化范围为17.70～40.60HV,其中皮质骨硬度范围17.70～40.60HV,平均硬度30.10±4.96HV;松质骨硬度范围20.40～37.40HV,平均硬度29.06±4.42HV;齿状突椎体区皮质骨平均硬度30.25±5.06HV,松质骨平均硬度28.78±4.17HV;附件区皮质骨平均硬度29.95±4.90HV,松质骨平均硬度29.33±4.79HV;同一部位的皮质骨硬度值均高于该部位的松质骨硬度值。附件区硬度值最高为椎弓根皮质(32.92±4.06HV),组间比较差异具有统计学意义(F=3.5832,P=0.014)。齿状突椎体区硬度值最高为后侧皮质(33.23±4.80HV),组间比较差异具体统计学意义(F=3.363,P=0.025)。结论:齿状突椎体区的后侧皮质硬度值与附件区椎弓根皮质硬度值均较高,可能与枢椎后侧皮质区域和椎弓根区域较其他部位承受着更大的应力有关。     

桡骨显微骨硬度分布特征的实验研究

目的研究人体桡骨显微骨硬度分布特征,并探讨其与解剖结构、骨折流行病学等相关关系。 方法将3个新鲜桡骨标本分为桡骨头、桡骨颈、桡骨粗隆、桡骨干1~9、桡骨远端、桡骨茎突14个部位,并垂直其长轴切取骨组织切片。于骨组织切片的前、后、内、外4个区域各选取5个测量位点,通过显微维氏硬度仪测量每个部位的显微骨硬度。 结果桡骨硬度最硬部位位于桡骨干8,硬度值为（43.82±5.20）HV,硬度最小的部位位于桡骨头,硬度值为（33.30±3.60）HV。桡骨近端的硬度值为（34.15±6.48）HV,桡骨干的硬度为（42.54±5.59）HV,桡骨远端的硬度为（35.24±5.17）HV。 结论桡骨最硬处位于桡骨干下段,桡骨近、远端硬度相近,都低于桡骨干。桡骨干的硬度值高于桡骨近端及桡骨远端,差异有统计学意义,桡骨近端与桡骨远端硬度值差异无统计学意义。桡骨前、后、内、外侧差异无统计学意义。桡骨远端骨折高发除与解剖外形和损伤机制有关外,此处硬度骤降也应视为因素之一。     

肱骨近端显微骨硬度分布特征的实验研究

背景:测量分析肱骨近端显微骨硬度分布规律可以较好地评价该部位骨组织不同区域的物理性能。目的:探讨肱骨近端不同部位骨硬度的分布特征及其意义。方法:共选用了62岁男性、45岁女性和58岁男性3具遗体捐献者标本,于肱骨肩关节盂水平及外科颈水平垂直其长轴取多层面标本,使用显微硬度计在样品表面不同区域进行维氏硬度测试,统计分析骨骼硬度的分布规律。结果:3具标本的肱骨近端共测量84个部位,测得肱骨近端区域总体硬度为(37.62±8.82)HV,硬度最大处为肱骨外科颈内侧(45.82±5.55)HV,其次为外科颈外侧与后侧,此三处硬度大于肱骨近端其他部位(P<0.05);硬度最小处为大结节处松质骨(28.32±4.35)HV。从解剖部位来看,外科颈硬度为(44.07±6.45)HV,大于肱骨头及大、小结节硬度(P<0.001);大结节硬度最小为(29.56±5.68)HV(P<0.01)。肱骨头前半部硬度大于后半部,小结节硬度大于大结节,肱骨外科颈前方硬度低于其他方位(P<0.05)。结论:肱骨近端不同区域骨硬度的分布具有规律性;肱骨近端骨硬度分布数据可为肱骨近端内固定策略的选择、新型植入材料的研究提供基础,并为3D打印仿生骨的设计开辟新的视角。     

人体髋臼前后柱骨硬度分布特征研究

目的研究人体髋臼前柱和后柱的硬度分布特征,探索骨硬度分布的科研价值及临床应用前景。 方法本研究所用两男一女3具标本均由河北医科大学解剖教研室提供,选取3对髋臼前后柱样本,取出全部髋骨后剔除软组织,运用微型台锯将髋骨分割为髋臼前柱和后柱,后用高精慢速锯将髋臼前后柱切割成若干厚3 mm的骨组织切片,固定在载玻片后用砂纸打磨。使用维氏硬度仪测试骨组织切片不同解剖区域皮质骨和松质骨的硬度值。本研究采用50 g力加载50 s、维持12 s标准操作方法测定,组间数据比较采用配对t检验。 结果本研究在人体髋臼前柱和髋臼后柱随机切取骨片,代表了髋臼前后柱纵向的不同位置,测量共计450个有效值,3个样本髋臼前柱总体硬度范围在18.9～33.8 HV,均值(25.2±3.1)HV;髋臼后柱硬度范围在23.1～39.1 HV,均值(31.9±3.8) HV。男性捐献者髋臼前、后柱总体硬度范围分别为18.8～33.8 HV及23.1～39.1 HV;女性捐献者髋臼前、后柱总体硬度范围分别为19.4～33.8 HV及24.6～38.9 HV,所有标本中后柱平均骨硬度值均大于前柱,且差异有统计学意义(t＝7.502、4.724、5.487,P<0.01),研究数据表明男性和女性髋臼前柱与后柱均存在硬度分布差异。 结论人体髋臼前后柱骨硬度值个体间存在差异,但均为后柱骨硬度大于前柱。骨硬度值的研究可为髋臼骨折内植物的置入位置、置钉长度及方向等提供参考,同时为研发符合人体梯度弹性模量的内植物及骨盆髋臼假体提供可靠的数据支撑。     

椎体皮质骨下脱壳样骨折1例报告

脊柱骨折的分型能有效地指导临床治疗。我院收治1例少见的腰椎皮质下脱壳样骨折脱位患者,现报告如下:1　临床资料患者尚某,男,2 5岁,农民,住院号0 317,于2 0 0 0年12月31日,其在井下 煤时被石块压伤腰背,双下肢麻痹,当日入院。体查:胸腰段脊柱后凸畸形。L1棘突皮下可扪及骨擦感,压痛。其上方凹陷空虚。浅感觉平面在腹股沟区,双下肢瘫痪,腱反射消失,肛门括约肌反射消失。X -ray显示:腰椎正位片见L1椎体上半皮质骨轮廓及后方附件存在;侧位片示L1椎体上1/2皮质骨及椎体附件于原位,下方椎体向后方完全脱位(图1)。CT显示L1椎体上1/2骨皮质呈空…     

腰椎屈曲压缩骨折椎体松质骨内应力分布的特点

目的研究腰椎在屈曲压缩载荷作用下松质骨内应力分布特点。方法运用三维ANSYS 6.0软件建立正常人体胸腰段(T_(12)~L_2)运动节段的数字力学分析模型。将L_1椎体中间3个层面的松质骨划分成6个力学统计区,分别测量6个统计区内的平均应力值。在同一等级载荷下对中间3个层面内6个统计区的平均应力值进行比较,分析腰椎椎体松质骨内屈曲载荷作用下应力分布情况。结果在不同等级屈曲载荷作用下,每一等级载荷均出现:A(M)区松质骨应力值与其余5区[A(L)、A(R)、P(L)、P(M)、P(R)]的松质骨应力值比较差异均有统计学意义(P0.05)。结论腰椎体内松质骨在屈曲压缩载荷作用下,松质骨内应力分布存在着集中趋势,应力集中的部位在松质骨前缘中间区域。     

椎弓根皮质骨螺钉固定与传统椎弓根螺钉固定钉道周围骨质CT值比较

目的 :比较椎弓根皮质骨螺钉固定与传统椎弓根螺钉固定钉道周围骨质的平均CT值,为椎弓根皮质骨螺钉的应用提供理论依据。方法:调取我院2014年1月~2016年10月21~70岁男女性腰椎高分辨率CT扫描影像资料,每10岁一个年龄组,单组随机抽取30例共300例数据。将各组数据导入Mimics 18.0中进行骨组织三维重建,在L4和L5椎体上模拟椎弓根皮质骨螺钉与传统椎弓根螺钉的置入,分割出各模拟螺钉与骨质相交的感兴趣区域并测量其平均CT值。结果:同年龄段同性别同种置钉方式L4、L5椎体感兴趣区域平均CT值均无统计学差异,皮质骨螺钉置钉与传统椎弓根螺钉置钉钉道周围感兴趣区域的平均CT值21~30岁组男性分别为547.4±48.2Hu和311.1±20.3Hu,女性为517.3±56.0Hu和279.1±41.7Hu;31~40岁组男性分别为519.6±48.9Hu和258.7±26.5Hu,女性为521.5±58.8Hu和287.8±33.2Hu;41~50岁组男性分别为490.9±69.8Hu和249.7±37.5Hu,女性为500.7±81.0和262.0Hu±72.1Hu;51~60岁组男性分别为436.5±65.7Hu和217.4±20.8Hu,女性为438.8±45.8Hu和222.1±22.6Hu;61~70岁组男性分别为396.1±40.0Hu和204.0±36.4Hu,女性为364.5±73.6Hu和153.5±27.1Hu;两种置钉方式各年龄组同性别间比较均有统计学差异(P0.05),皮质骨螺钉为传统螺钉的1.7~2.3倍。同种置钉方式不同性别间平均CT值比较,传统螺钉置钉在21~30岁、31~40岁和61~70岁组有统计学差异(P0.05);皮质骨螺钉置钉在21~30岁和61~70岁组有统计学差异(P0.05)。结论 :椎弓根皮质骨螺钉固定钉道周围骨质CT值明显高于传统椎弓根螺钉固定,椎弓根皮质骨螺钉固定具有更高骨-螺钉界面强度。     

上下颌牙槽骨不同部位骨密度的螺旋CT研究

目的运用螺旋CT测量上下颌牙槽骨不同部位的骨密度,为种植体支抗的安全植入提供参考。方法选取2008年7月至12月在新疆医科大学第一附属医院医学影像中心进行螺旋CT扫描的44例汉族男女性患者,年龄范围20～50岁,要求扫描范围包括上下颌牙齿、牙槽骨及基骨,应用ADW4.2独立影像诊断工作站在CT横断面图像上确定测量部位(切牙区、尖牙区、双尖牙区、磨牙区)后,然后在冠状位及矢状位图像上选取自该区域牙槽嵴顶向根方6 mm处为该区骨密度测量区域,获得其唇(颊)侧、舌(腭)侧皮质骨及松质骨骨密度的CT值。结果 1)上颌骨前磨牙区颊侧皮质骨骨密度高于上颌其他区域颊侧皮质骨,腭侧骨密度最高处为尖牙区,颊侧及腭侧各测量区域之间皮质骨骨密度有统计学差异,松质骨骨密度之间无统计学差异;2)下颌骨自切牙区至磨牙区颊侧皮质骨骨密度逐渐增加,舌侧皮质骨骨密度亦显示出类似的趋势,松质骨骨密度之间无统计学差异;3)比较同一区域上下颌骨皮质骨密度,除了切牙区皮质骨密度差异不大,下颌各区域皮质骨骨密度均高于上颌同区域皮质骨骨密度,松质骨骨密度之间无统计学差异。结论根据不同区域的骨密度,种植体的设计及植入方式有所区别。     

椎弓根螺钉钉道对椎体强度影响的有限元分析

[目的]应用有限元分析评价椎弓根螺钉取出术后钉道对椎体生物力学稳定性的影响,为临床置钉方式的选择提供参考。[方法]选取20例椎弓根钉取出术后1年患者,分别测量带钉道椎体的皮质骨、松质骨及钉道壁的CT值。比较不同骨质之间的CT值差异。随后选择1位25岁健康男性志愿者,采用64排螺旋CT对腰椎节段进行薄层扫描(层厚0.75 mm),利用Mimics 16.0及hypermesh 13.0软件建立正常胸腰椎三维四面体网格有限元模型,并分别建立单个正常、单侧和双侧有钉道椎体模型,进行边界约束后施加不同大小的垂直压力载荷。比较各模型在不同情况下的受力情况。[结果]钉道壁的CT值为(375.08±51.87),与皮质骨的CT值(403.31±52.73)的差异无统计学意义(P=0.149)。建立的正常腰椎三维四面体网格有限元模型外观逼真,几何相似性好,经验证有效。各个椎体模型中,椎体本身的皮质骨最先达到极限应力值。当皮质骨达到最大应力时,双钉道、单钉道、正常椎体模型所能承受的载荷分别为:3.97 MPa、3.83 MPa和3.78 MPa,而松质骨趋势则相反。在钉道壁达到极限应力时,单、双侧钉道椎体模型所能承受载荷分别为:22.83 MPa和23.02 MPa。单双侧椎弓根螺钉钉道所受应力主要集中在螺钉钉道的中后部。随着钉道孔径的逐渐增大,椎体模型皮质骨达到最大应力时,椎体所能承载的载荷逐渐增大,而松质骨和钉道则相反。[结论]椎弓根螺钉钉道能增加椎体的抗载荷能力,且随着钉道直径的增加,椎体所承载的载荷增大。     

纳米压痕技术观察骨微观力学特性变化的实验研究

目的 探讨骨质疏松皮质骨和松质骨微观力学特性的动态变化.方法 20只10月龄雌性SD大鼠随机分为5组:假手术对照组,去势3月组,去势6月组,去势9月组,去势12月组,每组4只.分别于去势不同时间点,取双侧股骨和腰3、4椎体标本,测量骨密度值.采用纳米压痕技术分别测量各组皮质骨和松质骨的微观硬度和弹性模量.结果 随去势时间的增加,皮质骨和松质骨的硬度和弹性模量均呈递减趋势(P＜0.05).各去势组皮质骨内骨板的弹性模量和硬度均比同组的外骨板高,而皮质骨硬度均高于松质骨,假手术对照组和去势3月组皮质骨的弹性模量高于松质骨,去势6月、9月、12月组松质骨的弹性模量高于皮质骨.结论 骨质疏松症皮质骨和松质骨的微观硬度、弹性模量同步降低,这是导致骨骼力学强度下降的重要因素.     

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.     

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.