甲基强的松龙对脊髓损伤后伤段脊髓线粒体功能的影响

目的：探讨脊髓损伤后伤段脊髓线粒体呼吸功能和线粒体内游离钙的变化和早期使用甲基强的松龙（MP）对其的影响。方法：54只SD大鼠，随机分组为假手术组（对照组）、脊髓损伤组（SCI组，采用Allen’s打击法造成大鼠脊髓损伤模型）和脊髓损伤后应用MP治疗组（MP组），每组又分为处理后6h、12h、24h三个时间相，每个时间相6只。在各时间相处死动物后提取伤段脊髓线粒体，测定线粒体呼吸Ⅲ态（R3）、呼吸Ⅳ态（R4）、呼吸控制率（RCR）、磷氧比（P／0）和线粒体内游离Ca^2＋浓度。结果：SCI组在伤后6h、12h和24hR3、RCR和P／0显著低于对照组，R4和线粒体内游离Ca^2＋浓度显著高于对照组。差异有显著性（P〈0．01）；伤后6h和12h MP组R3、RCR和P／0高于SCI组，R4和线粒体内游离Ca^2＋浓度低于SCI组，差异有显著性（P〈0．01）；MP组R3、R4和RCR在6h和12h时与对照组之间无显著性差异，24h时R3、RCR和P／0低于正常对照组，有显著性差异（P〈0．05）。结论：脊髓损伤后伤段脊髓线粒体呼吸功能和线粒体内游离Ca^2＋浓度明显受到影响，线粒体内膜通透性增加，线粒体氧化磷酸化的偶联程度明显受到抑制。早期使用甲基强的松龙可明显改善线粒体的呼吸功能，抑制Ca^2＋内流，保护伤段脊髓线粒体的稳定性。     

低剂量他克莫司治疗大鼠急性脊髓损伤的实验研究

目的：探讨低剂量他克莫司（tacrolimus，又名FK506）对大鼠急性脊髓损伤是否具有神经保护作用。方法：雄性Wistar大鼠72只，随机分为假手术组（12只）、损伤组（30只）和FK506治疗组（30只）。采用Allen’s打击法致伤大鼠T10脊髓，假手术组仅做椎板切除术。FK506治疗组在脊髓损伤后5min一次性经尾静脉注射FK5060．3mg／kg，其余两组以相同方法给予等量生理盐水。致伤后30min、6h、24h、48h、72h取伤段脊髓组织行病理观察及原位末端标记法（TUNEL）检测神经细胞凋亡，伤后1、3、7、14、21d行脊髓功能BBB评分和斜板实验。结果：伤后3、7、14、21d，FK506治疗组斜板实验和BBB评分明显优于损伤组，两组间比较差异有显著性（P〈0．05）；伤后各时间点FK506治疗组脊髓损伤区出血坏死较损伤组轻；伤后6、24、48、72h神经细胞凋亡FK506治疗组较损伤组明显减少，两组间比较差异有显著性（P〈0．05）。结论：在大鼠急性脊髓损伤后早期应用低剂量他克莫司（0．3mg/kg）治疗对神经具有保护作用，可减少神经细胞凋亡，减轻脊髓继发性损伤，促进脊髓功能恢复。     

同种异体骨髓间充质干细胞移植治疗大鼠脊髓损伤的时效性分析

目的：观察脊髓损伤后不同时间点骨髓间充质干细胞（bone mesenchymal stem cells,BMSCs）移植治疗后大鼠行为学变化、脊髓的病理改变及脑源性神经营养因子（brain—derived neurotrophic factor,BDNF）和神经生长因子（nervegrowthfactor,NGF）表达变化,探讨BMSCs的最佳移植时间。方法：80只健康成年SD大鼠随机分为8组,每组10只。A组为假损伤组,暴露胸10段脊髓但不造成冲击伤,B、C、D、E、F、G、H组以改良Allen法建立脊髓损伤模型。造模成功后,C、D、E、F、G、H组分别于损伤后0h、6h、24h、3d、5d和7d,将lxl0。体外培养的BMSCs用微量注射器注入于脊髓损伤局部,B组为单纯造模组,用等量细胞培养液代替。各组分别于损伤后1、2、4周进行脊髓运动功能BBB（Basso,Beattie,Bresnahan）运动学评分;分别取各组脊髓损伤组织0．5cm,制作HE染色病理切片,观察其形态学改变;Elisa法检测各组大鼠脊髓BDNF和NGF表达情况。结果：假手术组1、2、4周大鼠脊髓功能BBB评分均明显高于其余7组（P〈0．01）;术后l周细胞移植各组评分与单纯造模组相比差异无统计学意义（P〉0．05）;术后2周和4周细胞移植各组评分高于单纯造模组（P〈0．05）;损伤后2周BBB评分从高到低依次为F、E、G、D、H、C组,但6组组间比较差异无统计学意义（P〉0．05）;损伤后4周BBB评分,F组与其余5组（C,D,E,G,H组）比较差异有统计学意义（P〈0．05）,但其余5组组间差异无统计学意义（P〉O．05）。EUSA检测结果显示,F组BDNF和NGF含量均高于其他7组（P〈0．05）。大鼠脊髓标本切片HE染色,假手术组脊髓组织结构完整清楚,无中性粒细胞浸润;其余7组局部组织水肿明显,灰白质交界处模糊,周围可见不同程度胶质细胞增生及炎细胞浸润。结论：大鼠脊髓损伤后同种异体BMSCs移植对脊髓功能恢复有一定疗效,损伤后3d可能是BMSCs最佳移植时间。     

汉防己甲素对大鼠急性脊髓损伤的作用及意义

目的：探讨汉防己甲素（Tet）对急性脊髓损伤（ASCI）的保护作用及作用机制。方法：81只大鼠随机分为三组：生盐水对照组（NS组）、汉防己甲素治疗组（Tet组）和甲基强松龙治疗组（MP组），每组27只，用加速型Allen′s打击法制成脊髓急性损伤模型，监测大鼠ASCI后及用药后的血压变化，测定损伤区脊髓Ca^2 、MDA含量；采用氢清除法测定脊髓伤区血流量（SCBF）的变化；连续观测6周ASCI后运动功能评分情况，ASCI后4h,8h、6周取伤区标本进行组织病理检查，结果：ASCI后10s各组动物的MABP显著升高，1min内迅速降至正常水平，之后Tet组舒张压，平均动脉明显降低（P＜0．05），而收缩压降低不明显（P＞0．05）；ASCI后SCBF下降，但Tet组和MP组的SCBF较NS组高（P＜0．05）；损伤区Ca^2 及MDA含量Tet组和MP组均较NS组低，神经功能评分均较NS组高。结论：Tet能改善微循环，防止SCBF的减少；抗脂质过氧化损伤，减少脂质过氧化物MDA的生成；减轻Ca^2 的局部积聚，防止钙超载，阻断继发性损伤的链式反应，减轻组织继发性损伤。对实验性急性脊髓损伤有保护作用。     

小鼠脊髓损伤标准化重物打击模型的制备及评价

目的以小鼠作为实验动物，采用改良垂直打击脊髓（weight dropping，WD）建立脊髓损伤（spinal cord iniury，SCI）动物模型，为进一步研究SCI机制奠定基础。方法将健康雌性昆明种小鼠180只随机分为4组，每组45只，采用改良WD法应用Impactor model-Ⅱ脊髓致伤仪分别以2．0×2．5g·cm（A组）、2．5×3．0g·cm（B组）、3．0×5．0g·cm（C组）致伤力致伤脊髓；对照组（D组）仅打开椎板，暴露脊髓，不造成SCI。于打击后即刻，6、12h，1、3d，1、2、4、8周对各组小鼠行运动诱发电位（motor evoked potentials，MEP）检测，并行后肢运动功能（Basso mousescale，BMS）评分，HE染色和甲苯胺蓝染色组织学观察。结果神经电生理检查示B组于伤后6h，C组于伤后12h出现N1潜伏期延长，随着时间延长，A、B、C3组潜伏期开始缩短，A组4周趋于正常为（2．40±0．12）ms，与D组比较差异无统计学意义（P〉0．05）；B组8周逐渐趋于正常为（2．96±0．15）ms，与D组比较差异无统计学意义（P〉0．05），而C组8周仍维持在较高水平（3．76±0．13）ms，与D组比较差异有统计学意义（P〈0．05）。SCI伤后即刻小鼠均呈现双后肢瘫痪，BMS主评分为0分；伤后前3dBMS主评分接近0分；随后各组BMS评分逐渐上升，A组伤后1周BMS主评分（5．45±0．12）分，B组伤后2周BMS主评分为（5．45±0．15）分，与D组比较差异均有统计学意义（P〈0．05）；伤后8周A组主评分（8．004±0．13）分，B组达（7．50±0.31）分；1周后各实验组组间比较差异均有统计学意义（P〈0．05），其中C组低于其余各组（P〈0．01）。伤后2周A组BMS副评分为（10．12±0．76）分，伤后8周B组BMS副评分为（9．85±0．55）分，与同时间点D组比较差异均无统计学意义（P〉0．05）。组织学检查可见C组伤后12h，损伤节段灰质内大片出血灶，炎性细胞浸润，神经元细胞肿胀明显，并出现中央性尼氏小体溶解；随时间推移，神经元细胞数量减少，胶质细胞增生，尼氏小体消失；伤后2周，可见大量胶质细胞增生及空洞形成。B组神经元细胞减少程度及空洞形成均轻于C组，A组最轻，D组除早期可见轻度细胞水肿外，整个观察期内细胞数量无明显改变。结论该模型准确地反映了小鼠脊髓不同程度损伤后的病理生理特点及变化规律，重复性好；可采用重物打击法制作标准小鼠SCI动物模型。     

17β-雌二醇对大鼠脊髓损伤后神经保护作用的研究

目的：探讨17β-雌二醇（E2）对大鼠脊髓损伤（SCI）后的神经保护作用及其机制。方法：应用改良的Allen′s重物打击法建立大鼠急性脊髓损伤模型,将大鼠随机分为两组：A组（PBS对照组）和B组（E2治疗组）,每组42只,B组造模成功后15min及24h腹腔注射E2（4.0mg/kg,以PBS溶解）,A组在相同时间给予等量无菌PBS。分别于伤后7d、14d、21d及28d,应用改良Tarlov评分法和Rivlin斜板试验评价大鼠脊髓神经功能恢复情况。于伤后6h、24h、3d、7d、14d及28d时处死动物,以损伤部位为中心取材,HE染色观察脊髓组织病理变化,TUNEL法染色检测细胞凋亡,免疫组化染色检测caspase-3、Bcl-2的表达情况。结果：从伤后14d起,B组Tarlov评分和斜板试验角度与A组相比差异有显著性（P〈0.01）。TUNEL法检测表明,大鼠SCI后存在细胞凋亡,3d时达高峰,与caspase-3的表达基本一致,B组伤后24h、3d及7d时凋亡细胞比率显著低于A组（P〈0.01或P〈0.05）。免疫组化结果显示B组伤后24h、3d、7d、14d及28d时caspase-3表达低于A组（P〈0.01或P〈0.05）,而Bcl-2表达高于A组（P〈0.01或P〈0.05）。结论：E2能促进大鼠SCI后的神经功能恢复,具有一定的神经保护作用;E2可能是通过减少SCI后继发性细胞凋亡的机制发挥作用的。     

大鼠锥体束损伤后多唾液酸神经细胞黏附分子的表达

目的 探讨大鼠脊髓锥体束损伤后多唾液酸神经细胞黏附分子（PSA-NCAM）的表达及意义。方法 Wistar大鼠60只，实验组（30只）毁损胸髓T10左侧锥体束，对照组（30只）未损伤脊髓。应用免疫组织化学和Western blot检测5-溴脱氧尿嘧啶（BrdU）、PSA-NCAM的表达。结果免疫组织化学染色：BrdU阳性细胞数，对照组（23．4±6．3），实验组在伤后第3天（93．1±7．6），第7天（65．1±8．6），组间差异有统计学意义（P〈0．05）；PSA-NCAM阳性细胞数，对照组（2．5±1．5），实验组在伤后第3天（82．1±11．4），第7天（31．1±5．2），组间差异有统计学意义（P〈0．05）；Western blot：蛋白表达组间差异有统计学意义（P〈0．01）。结论 锥体束损伤可激活自体室管膜细胞的增殖及迁移，后者具有一定的可塑性，参与脊髓的结构修复。     

大鼠脊髓损伤后室管膜细胞增殖迁移及可塑性研究

[目的]研究大鼠脊髓损伤后室管膜细胞的原位增殖、迁移及其可塑性。[方法]Wistar大鼠60只，制作大鼠脊髓全横断损伤模型，根据伤后不同时间点分组，应用免疫组织化学方法动态检测脊髓内5-溴脱氧尿嘧啶（Brdu）、多唾液酸神经细胞黏附分子（PSA—NCAM）的表达。[结果]与对照组相比，Brdu阳性细胞在脊髓损伤后1d开始增加（P〈0．05），7d达到高峰，14d后开始下降，但仍高于对照组（P〈0．05）；PSA—NCAM阳性细胞在脊髓损伤后3d开始增加（P〈0．05），7d达到高峰，14d后开始下降，但仍高于对照组（P〈0．05）；两者在时间上均呈一过性增高表达，空间上自中心向周围迁移。[结论]脊髓损伤可激活自体室管膜细胞的原位增殖及迁移．后者具有一定的可甥性．参与伤后脊髓的结构修复。     

基因重组可溶性补体受体Ⅰ型对大鼠脊髓损伤组织C9和Clusterin表达的影响

目的 探讨基因重组可溶性补体受体Ⅰ型(sCR1)对大鼠急性脊髓损伤组织补体固有成分C9及补体调节因子Clusterin表达的影响。方法 采用改良Allen重物打击法制成SD大鼠急性脊髓损伤模型，观察sCR1组与生理盐水(NS)组在伤后12h、1、3、7、14d时间点脊髓损伤组织中C9和Clusterin表达的部位及时程，并采用斜板实验评定两组大鼠的下肢运动功能，比较组间差异。结果 sCR1组及NS组在伤后各个时间点脊髓损伤组织中C9、CLusterin表达增强，并存在动态变化过程。sCR1组在伤后各个时间点C9表达均明显轻于NS组(P＜0，01)；sCR1组在伤后12h、1、3d时间点Clusterin表达明显轻于NS组(分别为P＜0．01、P＜0．01、P＜0，05)，伤后7、14d两组间差异无统计学意义。sCR1组在伤后3、7、14d时间点大鼠下肢运动功能明显优于NS组(分别为P＜O．05、P＜O，01、P＜O，01)。结论 基因重组sCR1可显著抑制大鼠急性脊髓损伤组织C9和Clusterin的表达，可通过抑制补体系统激活机制减轻继发性脊髓损伤。     

rhGDNF对大鼠脊髓损伤后Ntyr表达影响的研究

目的研究大鼠脊髓损伤（spinal cord injury,SCI）后应用人重组胶质细胞源性神经营养因子（recombinated human glial cell line derived neurotrophic factor,rhGDNF）对酪氨酸硝基化蛋白（nitrotyrosine,Ntyr）表达情况的影响。方法48只雄性SD大鼠随机分为正常组、假手术组、生理盐水对照组和rhGDNF实验组,改良Allen法致脊髓中等程度损伤,伤后1d、3d、7d、14d用免疫荧光染色法测定Ntyr的表达情况,同时评定下肢运动功能（Tarlov评分和改良Rivlin斜板）。结果伤后1d rhGDNF组Ntyr阳性神经元数量多于生理盐水对照组（P〈0．05）,伤后3d、7d、14d时较同时程生理盐水对照组明显减少（P〈0．05）。2组的运动功能评分比较：伤后1d无明显差异,伤后3d、7d、14d时rhGDNF治疗组较生理盐水对照组明显提高（P〈0．05）。结论SCI后应用rhGDNF可减少大鼠脊髓Ntyr的表达,促进其运动功能恢复。     

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.