双后肢大鼠椎间盘退变动物模型的建立

目的　为椎间盘相关研究建立一种经济科学的椎间盘退变动物模型。方法　对 15 2只新生SD大鼠采用截除双前肢和特殊饲养的方法培育双后肢大鼠 ,以 10只正常同龄大鼠作为对照 ,18月龄时处死后通过光镜和电镜检查来观察两组大鼠L2～ 3 椎间盘的退变情况。结果　截除双前肢后 ,双后肢大鼠生长良好 ,术后 18个月存活 17只。光镜检查证实其椎间盘均发生了严重的髓核和纤维环退变。有 2例还出现了腰椎间盘突出。超微结构观察发现髓核中脊索细胞出现明显的退变和坏死 ,软骨样细胞中出现大量脂滴。基质中胶原纤维排列紊乱 ,出现大量板层样结构和团块。而正常大鼠的椎间盘仅发生轻度退变 ,胶原纤维排列整齐。结论　本造模方法简单经济、成功率高、重复性好 ,建立的双后肢大鼠模型符合人体椎间盘退变规律。     

实验性椎间盘退变的放射影像学与病理学观察

目的 研究椎间盘退变过程中，椎间盘退变的放射影像学与病理学改变。方法 选用40只新西兰大白兔随机分为2组，实验组切除兔腰椎间棘间、棘上韧带及棘突、关节突，造成力学失稳状态诱导形成椎间盘退变模型。术后一周、3个月、8个月时摄腰椎正、侧位X线片，观察腰椎影像学变化。第3个月、8个月时取腰椎间盘，进行组织检查，评定椎间盘退变的病理改变情况。结果 模型建立后，3个月、8个月的X线片显现对照组无明显改变，实验组腰椎后突畸形，椎间隙狭窄，随着时间延长椎体软骨终板钙化更加明显。组织学观察发现，实验组随术后时间延长，髓核由椎间盘内脱出，并伴有椎间盘两侧软骨终板的纤维化即软骨终板发生退变。结论 椎体软骨终板的退变是椎间退变早期的主要表现方式。     

大鼠正常与退变性髓核突出导致神经根性疼痛的对比研究

目的探讨正常与退变髓核突出对大鼠疼痛阈值以及背根神经节中TNF-α表达的影响,研究椎间盘退变与神经根性疼痛之间的关系。方法72只大鼠随机分为4组:正常对照组(n=18)、假手术组(n=19)、正常髓核(N-NP)组(n=16)和退变髓核(P-NP)组(n=19)。对P-NP组大鼠利用尾椎椎间盘纤维环穿刺的方法建立椎间盘退变模型。分别取出N-NP组和P-NP组大鼠自体的正常髓核与退变髓核组织,置于手术显露后的腰5左侧神经根处,建立髓核突出致神经根性疼痛动物模型。采用行为学测试的方法分别观察各组大鼠术前1天,术后1、4、7、10、14、21天机械刺激阈值与热刺激阈值的变化;采用免疫组化方法分别检测术后第4、14天各组大鼠背根神经节中TNF-α的表达。结果行尾椎间盘纤维环穿刺后2周,组织学与MRI检查均证实椎间盘组织发生明显退变。对照组和假手术组动物未出现明显的痛觉过敏现象,N-NP组和P-NP组大鼠机械性刺激阈值均显著下降,该痛觉过敏现象持续至术后2周消失;与正常髓核组织相比,退变髓核所致机械性刺激阈值下降程度更为严重。各实验组均未发生热刺激阈值的规律性变化。术后第4、14天对照组和假手术组背根神经节中未见TNF-α明显表达,而正常及退变髓核组TNF-α表达量均显著升高。结论大鼠尾椎纤维环穿刺是建立大鼠椎间盘退变模型的一种有效方法。与正常髓核组织相比,发生退变的髓核组织可导致神经根性疼痛的加重,提示椎间盘退变过程中释放的炎症因子在疼痛的发生机制中可能起到了重要作用。     

人工髓核柔性稳定系统对犬邻近颈椎间盘影响的实验研究

目的：比较人工髓核柔性稳定一体化系统与钢板内固定系统置入对犬施术节段邻近颈椎间盘退变的影响。方法：选择健康杂种犬23只,雌雄不限,犬龄1.5～2.5岁,体重20.0～30.0kg。预实验组5只,测量犬颈椎间盘压力正常参考值。18只实验用犬随机分为人工髓核柔性稳定组（A组,9只）及钢板内固定组（B组,9只）,均经前路行C3/4椎间盘摘除、内置物置入手术。术中测量邻近颈椎间盘（C4/5）压力,并计算施术前后C4/5椎间盘压力差作为撑开压力,t检验比较A、B组间压力差有无显著性差异。术后6个月处死动物,行影像学（Pearce标准）及组织学观察,评价邻近上位颈椎间盘（C2/3）退变程度。结果：A、B组间施术前后邻近颈椎间盘（C4/5）压力差无显著性差异（P〉0.05）。术后6个月,B组动力位X线片发现C2/3有失稳表现者4例（44.4%）。MRIT2加权像C2/3椎间盘Pearce分级A组（平均1.78级）低于B组（平均3.22级）;A组C2/3椎间盘退变组织学分级（平均1.56级）亦低于B组（平均2.78级）,且差异均有显著性（P〈0.05）。各组内撑开压力与椎间盘退变分级呈正相关（P〈0.05）。结论：过高的撑开压力易导致犬施术节段邻近颈椎间盘退变,应用人工髓核柔性稳定系统较钢板固定可以有效防止邻近节段的退变。     

退变椎体周边关节软骨产生碱性磷酸酶与骨赘形成的关系

目的：研究椎体骨赘形成的机理。方法：通过切除免颈棘上韧带及棘间和分离颈椎后旁两侧肌肉引起动物颈椎力学上的失衡,经３个月的时间的发展而造成免颈椎间盘退变模型。用生物化学方法分别测定每个动物颈椎间盘纤维环和髓核、椎体关系软骨、周边关节软碱性磷酸酶性结果：颈椎间盘退变动物椎体周边关节软骨中碱性磷酸酶活性明显升高。结论：研究结果在生物化学上支持椎体骨赘来自于周边关节软骨增殖、化生、钙化和骨化的组织学观察。     

实验性椎间盘退变的放射影像学与病理学观察

目的　研究椎间盘退变过程中 ,椎间盘退变的放射影像学与病理学改变。方法　选用 4 0只新西兰大白兔随机分为 2组 ,实验组切除兔腰椎间棘间、棘上韧带及棘突、关节突 ,造成力学失稳状态诱导形成椎间盘退变模型。术后一周、 3个月、 8个月时摄腰椎正、侧位X线片 ,观察腰椎影像学变化。第 3个月、 8个月时取腰椎间盘 ,进行组织检查 ,评定椎间盘退变的病理改变情况。结果　模型建立后 ,3个月、 8个月的X线片显现对照组无明显改变 ,实验组腰椎后突畸形 ,椎间隙狭窄 ,随着时间延长椎体软骨终板钙化更加明显。组织学观察发现 ,实验组随术后时间延长 ,髓核由椎间盘内脱出 ,并伴有椎间盘两侧软骨终板的纤维化即软骨终板发生退变。结论　椎体软骨终板的退变是椎间退变早期的主要表现方式。     

微创针刺旋切制备兔椎间盘退变模型

目的探讨微创针刺旋切制备兔椎间盘退变(intervertebral disc degeneration,IDD)模型的可行性。方法取40只新西兰大白兔,雌雄不限,体质量(2.9±0.3)kg;随机分为对照组和实验组(n=20)。对照组不予处理;实验组采用18G穿刺针在C臂X线机引导下经皮侧后方穿刺进入L4、5、L5、6椎间盘内,旋切髓核组织以促进椎间盘的退变。术后4、8、12、16周行大体观察、MRI观察并根据Pfirrmann分级法评价椎间盘退变情况,然后处死动物取材行Masson染色和番红O染色观察。结果实验组髓核组织颜色较对照组暗,弹性降低。对照组MRI T2加权像椎间盘信号强度早期未见明显改变,后期略减弱;实验组椎间盘信号强度随时间延长呈减弱趋势。根据Pfirrmann分级法评价椎间盘退变程度,两组随时间延长椎间盘退变程度均逐渐加重(P0.05);两组间比较除术后4周差异无统计学意义(P0.05)外,其余术后各时间点实验组椎间盘退变程度较对照组严重(P0.05)。Masson染色示随时间延长,对照组纤维环出现排列不规整,但结构仍完整;实验组纤维环排列紊乱,甚至出现断裂现象。番红O染色示对照组髓核细胞未见明显减少,实验组髓核细胞明显减少。结论微创针刺旋切法可成功制备兔IDD模型。     

"穿刺抽取髓核"诱导腰椎间盘退变的时间相关性评估

目的对穿刺纤维环抽取髓核诱导的腰椎间盘退变模型，进行时间相关的放射学和组织学评估，明确椎间盘退变程度的时间相关性。方法1岁山羊12只，以粗针穿刺纤维环抽取髓核（L1，2-15，6）建立腰椎间盘退变模型。术后第2、4、8、16周分别行放射学观察、髓核蛋白多糖（GAG）定量、组织学及微观结构评估。结果影像学示术后16周椎间隙高度显著降低（P〈0．01），但各椎间盘间差异无统计学意义（P〉0．05）。GAG定量示所有节段髓核内GAG含量随时间持续下降（P〈0．01），但与椎间盘序列间无相关性。大体标本及组织学观察显示，椎间盘退变组织学表现与抽取髓核后时间显著相关：术后2周组织学未见明显异常；4周始出现退变表现；16周时髓核已近完全纤维化。电镜观察示术后2—16周，髓核细胞从基本正常至大量凋亡，髓核基质逐渐纤维化。结论针刺抽取髓核法是较理想的腰椎间盘退变模型诱导方法。本研究观察16周，椎间盘退变未见缓解及自行修复，诱发的退变严重度与术后时间因素显著相关，而与椎间盘节段序列间无相关性。该模型在术后2周尚未出现明显组织学改变，或许是进行干预的良好时机。     

双侧小关节切除制作大鼠颈椎间盘退变模型的可行性

【摘要】 目的：探讨双侧小关节切除建立大鼠颈椎间盘退变模型的可行性。方法：16只3月龄雌性SD大鼠随机均分为实验组和对照组。实验组大鼠C4/5和C5/6双侧上、下关节突采用磨钻切除。术后12周时获取大鼠C4~C6标本。显微CT扫描C5/6节段,测量椎间高度及软骨终板的缺损率,并观测C5椎体微结构的变化;番红O快绿染色后观察髓核和纤维环的形态,并对椎间盘退变程度评分。采用RT-PCR法检测C4/5椎间盘组织中蛋白聚糖、Ⅱ型胶原以及基质金属蛋白酶（MMP）3和13的mRNA表达水平。组间定量指标行独立样本t检验,显著性水平为P<0.05。结果：术后12周,实验组椎间高度为0.51±0.04mm,显著低于对照组（0.55±0.02mm）（P<0.05）。实验组软骨终板出现明显的缺损,下终板缺损主要出现在腹侧,而上终板四周及中央均出现缺损;实验组的缺损率为（11.5±2.0）%,显著大于对照组的（6.9±1.0）%（P<0.05）。在椎体微结构中,实验组骨体积分数和骨小梁间隙分别为（53.0±6.0）%和170±2μm,而对照组分别为（46.4±3.0）%和195±1μm,两组间的差异均有统计学意义。实验组的骨小梁数目和厚度与对照组无统计学差异。组织学观察到实验组椎间盘的软骨终板形态不规则、出现缺损及少许钙化,髓核细胞出现聚集、数量减少,纤维环排列紊乱。实验组椎间盘退变评分为8.6±0.8分,显著高于对照组的5.8±0.5分。在实验组椎间盘组织中,蛋白聚糖和Ⅱ型胶原的mRNA表达水平明显低于对照组,MMP-13的mRNA表达水平显著高于对照组,MMP-3则呈现上升趋势。结论：大鼠颈椎双侧小关节切除可导致切除节段椎间盘在形态学、组织学和分子生物学上的退变,是建立椎间盘退变模型的一种可行方法。     

动静力失衡性大鼠颈椎间盘组织形态学及超微结构

[目的]动态观察大鼠颈部动、静力失去平衡后颈椎间盘组织形态学及超微结构的改变。[方法]SD大鼠60只，随机分为3、5、7个月模型组和对照假手术组，每组10只，通过破坏大鼠颈部肌肉、韧带诱导颈椎间盘退变，按月取材。各组椎间盘HE、Toluidine blue染色，在光镜下观察用体视学分析软件、Dissector自动计数法分析软骨终板内血管芽的数量、面积和软骨终板的厚度，Miyamoto分级法综合评判颈椎间盘退变的程度；透射电镜观察椎间盘细胞凋亡的超微结构。[结果]与对照假手术组比较，3个月造模组动物颈椎间盘已开始退行性变化，纤维环板层结构紊乱，关节软骨钙化层增厚，软骨下血管明显减少；5个月模型组髓核完全纤维化，纤维环板层状结构消失，血管芽稀少，血管壁充血曲张；7个月模型组椎间盘内部结构与5个月模型组相似，部分椎体边缘骨赘形成。在电镜下，3个月造模组椎间盘细胞，细胞表面突起减少，细胞器稀少，胞质内有脂滴，可见到凋亡细胞形成的凋亡小体。5个月和7个月模型组椎间盘组织中细胞较少，基质中胶原纤维断裂，可见到许多坏死空化的细胞。[结论]模型组大鼠颈椎间盘都出现典型的退变形态学变化，随着造模月份的延长退变程度越严重；早期和中期退变椎间盘中可观察到凋亡细胞，在退变的晚期可观察到坏死细胞。     

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.