单节段与双节段椎弓根螺钉固定胸腰椎单椎体骨折的生物力学比较

目的:比较单节段与双节段椎弓根螺钉固定术固定胸腰椎单椎体骨折的生物力学效果。方法:在16具新鲜小牛胸腰椎标本(T11-L3)的L1椎体上制作不完全爆裂骨折模型,分为两组,分别行单节段与双节段椎弓根螺钉固定,对固定后的标本施加扭矩为4Nm的疲劳载荷共2000次,加载频率为0.5Hz,经脊柱三维运动测量系统测量正常、损伤、固定和周期性加载后固定节段前屈/后伸、左/右侧弯和左/右旋转运动时固定节段的运动范围。结果:单节段固定组前屈、后伸、侧屈、旋转稳定指数(SPI)分别为0.78、0.80、0.92、0.83,双节段固定组SPI分别为0.88、0.89、0.95、0.85,在前屈方向单节段固定组明显小于双节段固定组(P<0.01);疲劳后,单节段固定组SPI在前屈、后伸、侧屈、旋转方向分别降低0.05、0.03、0.05、0.11,降低值均大于双节段固定组,且在旋转和侧屈方向有显著性差异(旋转:P<0.01;侧屈:P<0.05)。结论:两种术式均可重建脊柱骨折即刻稳定性,效果无明显差异。在旋转、侧屈方向,双节段椎弓根螺钉固定术抗疲劳载荷效果优于单节段固定术。     

脊柱失稳节段经椎弓根螺钉内固定器固定后对邻近节段三维运动的影响

目的研究经椎弓根螺钉内固定器固定脊柱失稳节段后对邻近节段三维运动范围的影响.方法在7例新鲜成人尸体T10～L4脊柱标本上,模拟L1骨折后安放经椎弓根螺钉内固定器,在10.0N@m载荷下进行三维运动测试.分析脊柱固定阶段(T12～L2)、邻近节段(T11～T12、L2～L3)和总节段(T11～L3)的前屈、后伸、轴向旋转和侧弯运动范围.结果经椎弓根螺钉内固定器固定后能使固定节段屈伸、侧弯运动方向上运动范围减少,轴线旋转运动恢复至正常完整节段运动范围.但同时邻近节段屈伸、侧弯运动运动范围增加,轴向旋转运动范围无明显变化.固定后总节段比正常完整总节段屈伸、侧弯运动运动范围增加,轴向旋转运动范围无明显变化.结论经椎弓根螺钉内固定器固定使邻近节段屈伸和侧弯运动范围代偿性增加,但不能代偿丢失的运动范围,对邻近节段的轴向旋转无明显影响.     

利用成年猪脊柱制作胸腰段后凸畸形模型进行脊柱三维运动实验

[目的]探讨应用成年猪脊柱制作胸腰段后凸畸形模型进行生物力学实验研究的可行性,以及胸腰段后凸畸形对腰椎三维运动的生物力学影响.[方法]收集24例成年家猪胸腰椎脊柱新鲜标本,随机分为三组,制造两个Cobb角度水平的胸腰段后凸畸形和相应的腰椎过度前凸模型,进行脊柱三维运动实验,测量L2、3和L4、5的前屈/后伸、左/右侧弯、左/右旋转的运动范围( ROM)以及所对应的中性区(NZ)的大小,对各组数值进行方差分析,用snk(q检验)法对分组变量进行多重比较.[结果]后凸的胸腰段对邻近运动节段(L2、3)矢状面上的运动(前屈/后伸)ROM以及NZ的影响更明显,P＜0.05,而左/右侧弯、左/右旋转的ROM及NZ没有统计学差异,P＞0.05;而下腰椎运动节段(L4、5)的前屈/后伸、左/右侧弯、左/右旋转的ROM及NZ均没有统计学差异,P＞0.05.[结论]利用成年猪脊柱制作胸腰段后凸畸形模型进行脊柱三维运动实验是可行、简便、有效的;腰椎前屈/后伸运动范围的过度增大,是胸腰段后凸畸形后为维持脊柱矢状面平衡的一个重要代偿改变,且ROM的增大以上腰椎的改变更为明显.     

前路单节段融合内固定治疗伴椎弓根断裂的Denis B型胸腰椎爆裂骨折生物力学研究

目的探讨前路单节段融合内固定治疗伴椎弓根断裂的Denis B型胸腰椎爆裂骨折后的脊椎生物力学稳定性。方法取6具新鲜成人尸体胸腰椎标本(T11~L3)作为正常组(A组),采用椎体切除法依次建立L1Denis B型爆裂骨折模型并行前路单节段融合内固定,分别为椎弓根完整组(B组)、单侧椎弓根切断组(C组)和双侧椎弓根切断组(D组)。通过脊柱三维运动机依次测定各组在8.0 N·m纯力偶矩下屈伸、左右侧弯及左右旋转活动度(range of motion,ROM)。结果 B、C、D组T12、L1脊柱运动单元前屈、后伸、左右侧弯ROM均显著低于A组(P0.05),D组显著高于B、C组(P0.05),B、C组间差异无统计学意义(P0.05);B、C组左右旋转ROM均显著低于A、D组(P0.05),B、C组间及A、D组间比较差异无统计学意义(P0.05)。各组间L1、L2脊柱运动单元前屈、后伸、左右侧弯、左右旋转ROM比较,差异均无统计学意义(P0.05)。结论前路单节段融合内固定治疗Denis B型胸腰椎爆裂骨折伴一侧椎弓根断裂时,在屈伸、侧弯及旋转方向能提供足够初始生物力学稳定性,而伴双侧椎弓根断裂时生物力学稳定性差。     

脊柱坚强内固定与动态内固定对邻近节段影响比较的生物力学研究

目的研究经椎弓根坚强固定与弹性固定脊柱节段对邻近节段三维运动范围的影响。方法把24例小牛L1~S2脊柱标本随机分成4组:A组为坚强固定组(对照组),B组为固定旋转及屈伸,但不限制侧弯(简称侧弯组);C组为固定旋转及侧弯,但不限制屈伸(简称屈伸组);D组为固定侧弯及屈伸,但是不限制旋转(简称旋转组)。固定L3~5节段,在2.0N.m载荷下进行三维运动测试,分析各组条件下邻近节段(L2、3)在前屈后伸、侧弯及旋转上的运动范围变化。结果侧弯组与坚强固定组的邻近标本节段活动范围(ROM)比较,前屈后伸、旋转活动范围差异无统计学意义(P>0.05),侧弯活动范围差异有统计学意义(P<0.01);屈伸组与坚强固定组的邻近标本节段活动范围(ROM)比较,旋转侧弯活动范围差异无统计学意义(P>0.05),但屈伸活动范围则差异有统计学意义(P<0.05);旋转组与坚强固定组的邻近标本节段活动范围(ROM)比较,旋转侧弯及屈伸活动范围差异无统计学意义(P>0.05)。结论脊柱的坚强固定及放开旋转的脊柱固定,均会导致应力的集中,不利于应力的分散;而放开侧弯及屈伸的脊柱固定则均有利于应力的分散,应力分散方向与放开的脊柱固定方向相一致。     

单侧小关节分级切除对腰椎稳定性影响的三维有限元分析

目的研究单侧小关节分级切除对腰椎稳定性的影响。方法采用三维有限元法建立腰椎活动节段（L4～5）的数学力学模型。结果a）在前屈和后伸状态下,各实验切除组与正常对照组无显著性差异（P〉0．05）;b）在左／右侧弯和左／右轴向旋转状态下,小关节切除1／2以上的各组均与正常组有显著性差异（P〈0．05或P〈0．01）。结论a）单侧小关节分级切除对腰椎节段的前屈、后伸稳定性无显著性影响;b）当腰椎小关节切除范围超过1／2,对腰椎节段侧弯运动有显著性影响,尤其以向对侧侧屈为甚;c）当一侧小关节切除超过1／2后,由于失去了小关节和关节囊的限制,导致腰椎活动节段轴向旋转范围增加显著。     

退变性脊柱侧凸不同方式长节段固定融合术后邻近节段生物力学变化的有限元分析

目的:探讨退变性脊柱侧凸(degenerative scoliosis,DS)不同方式长节段固定融合术后脊柱活动度及固定邻近节段椎间盘和关节突软骨的应力变化。方法:基于DS患者T12～S1上段连续的CT扫描图像,导入E-feature Biomedical Modeler软件,从三维实体模型直接划分生成腰椎各节段的高质量体网格,根据DS的病理特点赋予模型特定的材料属性,将三维有限元模型导入ANSYS 12.0有限元分析软件,对其去除L4棘突、全椎板、部分关节突,行L4/5椎间融合后,分别采用L2~L4椎板融合+L2～L5 8枚椎弓根螺钉固定(方案一)、L1～L4椎板融合+L1～L5 10枚椎弓根螺钉固定(方案二)、L1～S1椎板融合+L1～S1 12枚椎弓根螺钉固定(方案三),在前屈、后伸、左侧弯、右侧弯、左旋转、右旋转六种工况下对术后模型进行加载,计算和分析三种手术方案术后脊柱的活动度及固定邻近节段椎间盘和关节突软骨的应力变化,并与术前DS模型进行比较。结果:三种手术方案固定融合后脊柱活动范围均减小,方案三<方案二<方案一;三种手术方案对固定邻近节段椎间盘应力均有影响,前屈、旋转时三种方案均可使固定上位节段椎间盘的应力减少,侧弯时三种方案均可使上位节段椎间盘的应力增加,后伸时对上位椎间盘的应力减少明显;前屈、侧弯及左旋转时方案一、二均可使下位节段椎间盘应力增加,后伸、右旋转时方案一、二均可使下位节段椎间盘应力减少,但三种方案对固定邻近上、下位节段椎间盘应力的影响差异不明显。方案三的固定相邻节段关节突软骨最大应力达到532.98MPa,方案二为494.08MPa,方案一为63.27MPa,即方案二、三固定相邻节段的关节突软骨容易出现较大的应力集中情况,方案一影响较小。结论:治疗DS固定融合的节段越多,对术后脊柱活动度及固定相邻节段椎间盘和关节突软骨的应力影响越大,对于长节段固定融合术治疗DS时,在能够解除症状、达到脊柱稳定的前提下应尽可能减少固定节段。     

椎体成形在胸腰椎压缩性骨折后的三维稳定性测试

目的评估在胸腰椎骨折后椎体成形术对恢复脊柱单元即刻三维稳定性的作用。方法7具新鲜胸腰段脊柱标本。测试前屈、后伸、左侧弯、右侧弯、左旋转、右旋转的中性区（neutral zone,NZ）和运动范围（range of motion,ROM）。程序：①完整状态;②骨折后状态;③椎体成形后;④3000次循环疲劳后。结果骨折后中性区和运动范围均明显增大。椎体成形后屈伸、侧弯、旋转在NZ及ROM均明显减少。疲劳后虽然有增加,但较骨折后明显减少。运动范围在椎体成形后和损伤前完整时比较无差别。结论骨水泥椎体成形在离体常规负荷下可恢复脊柱运动单元的三维稳定性。     

胸腰椎三柱同时损伤内固定方法的实验与临床初步观察

利用传感器及电测技术,采用新鲜人体胸腰段脊柱标本,评价后路短节段内固定器Steffee钢板、前路Kaneda器械、前路Kaneda与后路CD棒联合应用及后路节段性椎板下钢丝固定哈氏撑开棒四种手术在植骨状态下,治疗脊柱完全性三柱损伤提供的生物力学稳定能力。Steffee、Kaneda器械及节段性椎板下钢丝固定的哈氏撑开棒手术在这种严重损伤类型各有力学弱点,Steffee后伸、Kaneda前屈、节段性椎板下钢丝固定的哈氏撑开棒旋转明显失稳,前后路联合手术在轴压、前屈、后伸、侧弯、旋转五种运动方式皆能提供良好的稳定性。以此方法治疗1例腰椎半椎体切除与1例腰椎肿瘤全切除,随访1年,脊柱稳定,植骨融合满意。作者建议,在脊柱三柱损伤时宜采用前后路联合固定手术。     

胸腰椎爆裂骨折三种后路内固定方法的稳定性生物力学研究

[目的]比较长节段固定术、短节段固定术和短节段结合椎体成形固定术治疗胸腰椎爆裂骨折的稳定性。[方法]收集6具新鲜尸体的脊柱(T9～L5)标本,对每一具标本依次按完整状态、骨折状态、长节段固定、短节段固定和短节段结合椎体成形的顺序进行测试,计算其在屈曲、背伸、左右侧弯和左右旋转6个方向的运动范围,比较各组间差异。[结果]骨折后脊柱在6个方向上的运动范围均增加(P<0.05);各内固定组的运动范围均小于完整组(P<0.05);长节段固定和短节段结合椎体成形固定的运动范围小于单纯短节段固定组(P<0.05);短节段结合椎体成形固定在屈曲和左右侧屈方向上的运动范围与长节段固定无差别(P>0.05),而在背伸和左右旋转方向上的运动范围短节段结合椎体成形固定则大于长节段固定(P<0.05)。[结论]通过延长固定节段与联合椎体成形均能够增加短节段固定的稳定性,在屈曲和左右侧屈方向上短节段联合椎体成形已经能够达到长节段固定所能够达到的稳定性。     

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.