吸入和静脉应用盐酸戊乙奎醚对油酸诱导大鼠急性肺损伤的影响

目的观察雾化吸入和静脉应用盐酸戊乙奎醚对油酸诱导大鼠急性肺损伤(ALI)的影响。方法采用静脉注射油酸复制ALI大鼠模型。将40只SD大鼠随机均分为四组:空白对照组(Ⅰ组)、ALI组(Ⅱ组)、盐酸戊乙奎醚雾化吸入组(Ⅲ组)和盐酸戊乙奎醚静脉注射组(Ⅳ组)。每隔60分钟记录大鼠BP、肺动脉压(PAP),并检验动脉及混合静脉血气。注射油酸240min后检测支气管肺泡灌洗液(BALF)蛋白定量、肺髓过氧化物酶(MPO)活性。结果Ⅲ、Ⅳ组较之Ⅱ组能够缓解由注射油酸引起的PAP升高和PaO2/FiO2下降,Ⅲ组缓解更为明显(P<0.05)。Ⅲ、Ⅳ组BALF蛋白定量、白细胞计数和肺MPO活性均比Ⅱ组降低,Ⅲ组降低更为明显(P<0.05)。结论盐酸戊乙奎醚雾化吸入较静脉注射更能缓解油酸引起的ALI。     

盐酸戊乙奎醚预先给药对内毒素性急性肺损伤大鼠肺组织NF-κB mRNA表达及SOD活性的影响

目的 探讨盐酸戊乙奎醚预先给药对内毒素性急性肺损伤大鼠肺组织NF-κB mRNA表达及SOD活性的影响.方法 健康雄性SD大鼠32只,月龄2月,体重230～280 g,随机分为4组(n=8),对照组(C组)腹腔和尾静脉均注射生理盐水1 ml/kg;急性肺损伤组(ALI组):腹腔注射生理盐水1 ml/kg,30 min后经尾静脉注射LPS 5 mg/kg;盐酸戊乙奎醚低剂量组(LP组)、高剂量组(HP组)分别腹腔注射盐酸戊乙奎醚0.3和1 mg/kg,30 min后经尾静脉注射LPS 5 mg/kg.静脉注射生理盐水或LPS后6 h时,取肺组织,检测NF-κB mRNA的表达、TNF-α和MDA的含量和SOD活性,计算肺组织湿/干重比(W/D)及含水量,观察肺组织病理学结果.结果 与C组比较,ALI组、LP组和HP组肺组织NF-κB mRNA表达上调,TNF-α及MDA含量升高,SOD活性降低,W/D和肺组织含水量升高(P＜0.05);与ALI组比较,LP组和HP组肺组织NF-κB mRNA表达下调,TNF-α及MDA含量降低,SOD活性升高,W/D和肺组织含水量降低(P＜0.05);与LP组比较,HP组肺组织NF-κB mRNA表达下调,TNF-α及MDA含量降低,SOD活性升高,W/D和肺组织含水量降低(P＜0.05).LP组和HP组肺组织病理学损伤较ALI组减轻.结论 盐酸戊乙奎醚预先给药减轻大鼠内毒素性急性肺损伤的机制可能与下调肺组织NF-κB mRNA表达,降低肺局部炎性反应,增强机体抗氧化能力有关.     

盐酸戊乙奎醚预先给药对脓毒症小鼠急性肺损伤时肺组织β-arrestin-2表达的影响

目的 探讨盐酸戊乙奎醚预先给药对脓毒症小鼠急性肺损伤时肺组织p抑制蛋白-2(β-arrestin-2)表达的影响.方法 健康雌性昆明小鼠30只,6周龄,体重18～20 g,采用随机数字表法,将其随机分为3组(n=10):假手术组(S组)、脓毒症组(CLP组)和盐酸戊乙奎醚预先给药组(PHC组).CLP组和PHC组采用盲肠结扎并穿孔法制备脓毒症模型.PHC组于模型制备前1h时腹腔注射盐酸戊乙奎醚0.45 mg/kg,S组和CLP组于模型制备前1h时腹腔注射等容量生理盐水.模型制备后12h时,采血和收集肺泡灌洗液测定肺通透性指数,采用化学比色法测定肺组织MPO活性,采用ELISA法测定肺组织IL-6含量,采用Western blot法测定肺组织β-arrestin-2蛋白表达,采用RT-PCR法测定肺组织β-arrestin-2 mRNA表达.结果 与S组比较,CLP组肺通透性指数、肺组织MPO活性和IL-6含量均升高,肺组织β-arrestin-2蛋白表达下调,β-arrestin-2 mRNA表达上调(p＜0.05),PHC组肺通透性指数、肺组织MPO活性和IL-6含量均升高,肺组织β-arrestin-2蛋白表达上调,β-arrestin-2 mRNA表达下调(p＜0.05).与CLP组比较,PHC组肺通透性指数、肺组织MPO活件和IL-6含量均降低,肺组织β-arrestin-2蛋白表达上调,β-arrestin-2 mRNA表达下调(P＜0.05).结论 盐酸戊乙奎醚预先给药减轻脓毒症小鼠急性肺损伤的机制可能与上调肺组织β-arrestin-2的蛋白表达有关.     

盐酸戊乙奎醚对新生大鼠内毒素性急性肺损伤时肺氧化应激和细胞凋亡的影响

目的评价盐酸戊乙奎醚对新生大鼠内毒素性急性肺损伤(acute lung injury,ALI)时肺氧化应激和细胞凋亡的影响。方法清洁级健康雄性Wistar大鼠30只,7日龄,体重12~18g。采用随机数字表法分为三组:盐酸戊乙奎醚组(PHC组)、ALI组和生理盐水组(NS组),每组10只。PHC组和ALI组大鼠腹腔注射内毒素5.0mg/kg制备ALI模型。PHC组于内毒素注射前1h腹腔注射盐酸戊乙奎醚2.0mg/kg,NS组和ALI组给予等容量生理盐水。于注射内毒素4h后处死大鼠取肺组织标本,计算肺湿/干重比(W/D),采用硫代巴比妥酸法测定丙二醛(MDA)浓度,黄嘌呤氧化酶法测定大鼠超氧化物歧化酶(SOD)活性,免疫组织化学法测定细胞色素C(Cyt-C)、半胱氨酸天冬蛋白酶-3(Caspase-3)的含量,TUNEL法计数凋亡细胞,计算细胞凋亡指数(AI)。结果与NS组比较,ALI组和PHC组肺W/D和MDA浓度明显升高,SOD活性明显降低(P0.05);与ALI组比较,PHC组肺W/D和MDA浓度明显降低,SOD活性明显升高(P0.05)。与NS组比较,ALI组和PHC组Cyt-C、Caspase-3含量和AI明显升高;与ALI组比较,PHC组Cyt-C、Caspase-3含量和AI明显降低(P0.05)。结论盐酸戊乙奎醚可能通过抑制肺组织氧化应激和细胞凋亡,减轻新生大鼠内毒素性急性肺损伤。     

盐酸戊乙奎醚后处理对肢体缺血-再灌注大鼠肝损伤的影响

目的探讨盐酸戊乙奎醚对肢体缺血-再灌注大鼠肝损伤的影响。方法健康雄性Wistar大鼠108只,随机分为三组:对照组(C组)、肢体缺血-再灌注组(LIR组)及盐酸戊乙奎醚组(PHC组)。用弹力橡皮筋完全阻断大鼠双后肢血流3h,PHC组在缺血177min自尾静脉注射盐酸戊乙奎醚0.15mg/kg。三组分别在再灌注即刻(T0)、1h(T1)、3h(T2)、6h(T3)、12h(T4)、24h(T5)取血和肝组织,测定血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)的活性,肿瘤坏死因子α(TNF-α)、白细胞介素10(IL-10)的浓度;检测肝组织丙二醛(MDA)含量及超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)活性;光镜观察肝脏病理改变。结果 T3时LIR组及PHC组血清ALT、AST活性、肝脏组织MPO活性达到高峰;肝组织SOD活性最低,T1时血清TNF-α浓度达到高峰。与LIR组比较,T1～T3时PHC组血清ALT、AST活性下降,T1时血清TNF-α浓度下降,T1～T4时血清IL-10浓度升高,T1、T3时肝组织MDA含量降低,T1～T5时SOD活性升高,T1～T3时MPO活性下降(P<0.05)。光镜下,PHC组T3时肝组织病理学改变轻于LIR组。结论盐酸戊乙奎醚后处理对肢体缺血-再灌注大鼠肝脏具有一定保护作用,其机制可能与抑制活性氧生成及炎症反应有关。     

盐酸戊乙奎醚不同给药方式对大容量肺灌洗患者术后呼吸动力学的影响

目的 探讨盐酸戊乙奎醚不同给药方式对大容量肺灌洗患者术后呼吸动力学的影响.方法 择期行左全肺大容量肺灌洗术患者40例,采用完全随机分组法分成静脉注射盐酸戊乙奎醚组(A组)与雾化吸入盐酸戊乙奎醚组(B组),每组20例.灌洗开始前30 min A组静脉注射盐酸戊乙奎醚0.01 mg/kg,B组给予灌洗侧肺雾化吸入盐酸戊乙奎醚0.01 mg/kg(用生理盐水稀释至5 ml),15 min.记录插管后(T0)、灌洗开始前(T1)、灌洗结束(T2)及灌洗结束后30 min(T3)、60 min(T4)、90 min(T5)、120 min(T6)灌洗侧肺气道峰压(peak airway pressure,Ppeak)及肺动态顺应性(lung dynamic compliance,Cdyn).统计灌洗液总量、灌洗液残留量、灌洗时间,收集术中患者口腔分泌物.结果 与T0比较,两组患者T1时Cdyn[A组(30.3±1.9) ml/cmH2O,B组(30.5±1.8) ml/cmH2O(1 cmH2O=0.098 kPa)]均明显升高,Ppeak[A组(18.8±1.2) cmH2O,B组(17.9±1.4) cmH2O)]均明显降低(P＜0.05).T4、T5时与A组比较,B组Cdyn[(22.8±1.7)、(26.8± 1.7) ml/cmH2O)]明显升高,Ppeak[(25.2±1.5)、(20.2±1.2) cmH2O)]明显降低(P＜0.05).结论 大容量肺灌洗术患者灌洗侧肺术前雾化吸入戊乙奎醚有利于患者术后Cdyn的恢复,能改善患者通气,缩短术后呼吸力学指标的恢复时间.     

盐酸戊乙奎醚对心肺转流后肺损伤的保护作用

目的探讨盐酸戊乙奎醚对心肺转流(CPB)后肺损伤的保护作用。方法 40例二尖瓣置换手术患者随机均分为盐酸戊乙奎醚组(P组)和对照组(C组),两组麻醉方法相同。P组在麻醉诱导后和升主动脉开放前分别缓慢静注盐酸戊乙奎醚0.02mg/kg;C组在同时点给予等容量的生理盐水。手术开始前(T1)和升主动脉开放后30min(鱼精蛋白中和后,T2)分别进行右肺中叶灌洗。测定肺灌洗液(BALF)中细胞因子白细胞介素-8(IL-8)和肿瘤坏死因子α(TNF-α)浓度;行血气分析计算肺泡-动脉氧分压差(PA-aDO2)。结果 T2时C组BALF中IL-8、TNF-α和PA-aDO2明显高于T1时和P组(P0.05或P0.01)。结论盐酸戊乙奎醚通过抑制炎性细胞因子释放IL-8和TNF-α,减轻CPB后的肺损伤。     

盐酸戊乙奎醚对体外循环致大鼠急性肺损伤的影响

目的 评价盐酸戊乙奎醚对体外循环(CPB)致大鼠急性肺损伤的影响.方法 成年雄性SD大鼠40只,4～6月龄,体重330～420 g,采用随机数字表法,将其随机分为4组(n=10):假手术组(S组)仅进行动脉和静脉穿刺置管;急性肺损伤组(ALI组)、低剂量盐酸戊乙奎醚组(PL组)和高剂量盐酸戊乙奎醚组(PH组)建立CPB模型;PL组和PH组分别在预冲液中加入盐酸戊乙奎醚0.6和2.0 mg/kg,ALI组加入等容量生理盐水,进行CPB1h.于CPB前和CPB结束后2h采集动脉血样,进行血气分析;于CPB结束后2h时采集上腔静脉血样,测定血浆TNF-α和IL-6的浓度;取肺组织测定含水量、MDA含量和谷胱甘肽过氧化物酶(GSH-px)活性,光镜下观察病理学改变.结果 与S组比较,ALI组、PL组和PH组CPB结束后2h时PaO2降低,肺组织含水量、MDA含量和血浆TNF-α和IL-6的浓度升高,肺组织GSH-px活性降低(P＜0.05);与ALI组比较,PL组和PH组CPB结束后2h时PaO2升高,肺组织含水量、MDA含量和血浆TNF-α和IL-6的浓度降低,肺组织GSH-px活性升高(P＜0.05),病理学损伤减轻;与PL组比较,PH组CPB结束后2h时PaO2升高,肺组织含水量、MDA含量和血浆TNF-α和IL-6的浓度降低,肺组织GSH-px活性升高(P＜0.05),病理学损伤减轻更明显.结论 盐酸戊乙奎醚0.6和2.0 mg/kg可减轻CPB致大鼠急性肺损伤,且与剂量有关,其机制与抑制脂质过氧化反应和炎性反应有关.     

盐酸戊乙奎醚对体外循环大鼠肝脏损伤的影响

目的 探讨盐酸戊乙奎醚对体外循环大鼠肝脏损伤的影响.方法 健康清洁级成年雄性SD大鼠32只,随机分为4组(n=8),假手术组(Sham组)、模型组(Mod组)、盐酸戊乙奎醚低剂量组(L-PHC组)和高剂量组(H-PHC组).Sham组只置管不转流,Mod组体外循环预充液中不加入盐酸戊乙奎醚,L-PHC组和H-PHC组体外循环预充液中分别加入盐酸戊乙奎醚0.6mg/kg和2mg/kg.于停止体外循环即刻抽取左股动脉血2ml后处死,测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)活性,观察肝脏组织超微结构改变.结果 与Sham组比较,Mod组、L-PHC组、H-PHC组血清ALT,AST活性升高(P＜0.05);与Mod组比较,L-PHC组、H-PHC组血清ALT、AST活性降低(P＜0.01),病理损伤程度减轻;与L-PHC组比较,H-PHC组血清ALT、AST活性降低(P＜0.05),病理损伤程度减轻.结论 盐酸戊乙奎醚0.6mg/ks和2mg/kg可减轻体外循环诱发大鼠肝脏损伤的程度,2mg/kg的效果更明显.     

盐酸戊乙奎醚与阿托品用于婴幼儿支气管肺泡灌洗术的比较

目的比较盐酸戊乙奎醚与阿托品在婴幼儿支气管肺泡灌洗术术前用药的有效性及安全性。方法 80例接受支气管肺泡灌洗术患儿随机均分为P组与A组,分别静注盐酸戊乙奎醚0.01 mg/kg或阿托品0.01 mg/kg。记录给药前(T1)、给药后10 min(T2)、手术开始时(T3)、手术30min(T4)、手术结束(T5)与术后4 h(T6)时的HR、MAP、SpO2及唾液分泌量。结果 T2时唾液分泌量两组均明显低于T1时(P<0.05);T3后开始增加,P组增加缓慢,T6时恢复正常;而A组增加较快,至T6时明显多于T1时(P<0.05);A组唾液分泌总量明显多于P组(P<0.05)。血流动力学T2时P组HR减慢、MAP下降(P<0.05),T3后增快或升高;T2后A组HR即明显增快、MAP升高(P<0.05),T6时两组均恢复正常。A组HR明显快于、MAP明显高于P组(P<0.05)。结论婴幼儿支气管肺泡灌洗术前用盐酸戊乙奎醚临床效果优于阿托品。     

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.     

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.     

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.