脾切除术对大鼠海马tau表达的影响

目的 评价脾切除术对大鼠海马tau表达的影响.方法 SD大鼠105只,随机分为3组,正常对照组(A组,n=15)不给予任何处理,麻醉组(B组,n=45)仅吸入1.5%异氟醚2 h,手术+麻醉组(C组,n=45)吸入1.5%异氟醚(吸入2 h)麻醉下实施脾切除术.B组和C组分别于麻醉后或术后1、3、7 d时处死15只大鼠,取海马组织,测定海马IL-1β mRNA、TNF-α mRNA、IL-1β、TNF-α、总tau、苏氨酸第205位点磷酸化tau(pT205 tau)、丝氨酸第396位点磷酸化tau(pS396 tau)、总糖原合成酶-3β(GSK-3β)和磷酸化GSK-3β(p-GSK-3β)的表达水平.结果 与A组比较,B组各时点IL-1β mRNA、TNF-α mRNA、IL-1β、TNF-α、总tau、pT205 tau、pS396 tau、GSK-3β和p-GSK-3β的表达水平差异无统计学意义(P＞0.05),C组术后IL-1βmRNA、TNF-α mRNA、IL-1β、pT205 tau和pS396 tau的表达上调,p-GSK-3β表达下调(P＜0.05或0.01).结论 手术创伤可导致大鼠海马tau磷酸化,其机制与手术创伤诱发炎性反应,从而激活GSK-3β有关.     

手术创伤对大鼠空间学习记忆能力及海马Bcl-2和Bax基因表达的影响

目的探讨手术创伤对大鼠空间学习记忆能力及海马内抗凋亡基因Bcl2和促凋亡基因Bax蛋白表达的影响。方法SD大鼠98只随机分为三组:麻醉组(A组,n=42)、手术组(B组,n=42)、正常对照组(C组,n=14)。A、B组各分3个亚组A1、A3、A7组和B1、B3、B7组(每组14只),分别在麻醉或手术后1d或3d或7d用Y型电迷宫测试大鼠的学习记忆能力,同时用免疫组织化学方法观察海马内Bcl2和Bax蛋白的表达。结果(1)学习记忆能力测试表明:B1组的刺激电压明显高于其余各组(P<0.01)。B1、B3组大鼠Y迷宫的学习记忆成绩明显下降(P<0.01)。B7组学习记忆能力与A组相似。(2)A组、C组海马内无Bax、Bcl2表达,B组Bax、Bcl2的表达均增多,B1组Bax/Bcl2比值明显增高(P<0.05)。结论手术创伤可暂时影响大鼠的空间学习记忆能力,与海马Bax、Bcl2表达增多、Bax/Bcl2升高有关。     

肝部分切除术后大鼠认知功能及β淀粉样蛋白的变化

目的 评价大鼠肝部分切除术后认知功能及β淀粉样蛋白(Ap)的变化.方法 健康雄性sD大鼠70只,体重200～250 g,随机分为3组:对照组(C组,n=12)、麻醉组(A组,n=29)和肝部分切除术组(PH组,n=29).A组和PH组于术后1 d(T1)和7 d(T3)时各取7只大鼠,采用Y型迷宫检测术后第1、2、3、7、8、9天时学习记忆能力;于术后1 d(T1)、3 d(T2)和7 d(T3)时取5只大鼠,取左侧海马,并断尾取血,测定Aβ表达;取右侧海马采用荧光定量PCR测定App mRNA表达.结果 与C组相比,PH组术后学习记忆能力下降,T1,3时血清Aβ浓度降低,T1-3,时海马Aβ含量升高,TI时App770mRNA含量升高(P＜0.05);与A组相比,PH组术后学习记忆能力下降,T1,3时血清Aβ浓度降低,T1-3时海马Aβ含量升高,T1时App770 mRNA含量升高(P＜0.05).结论 肝部分切除术后大鼠发生短期认知功能减退,可能与海马Aβ含量升高有关.     

异氟烷对发育期大鼠海马IL-1β mRNA、IL-6 mRNA和TNF-α mRNA表达的影响

目的 探讨异氟烷对发育期大鼠海马IL-1β mRNA、IL-6 mRNA和TNF-α mRNA表达的影响.方法 出生7 d的SD大鼠64只,随机分为2组(n=32):对照组(C组)和异氟烷麻醉组(I组).I组大鼠吸入1.5%异氟烷麻醉6 h,C组吸入空气.I组于麻醉前(T0,基础状态)、麻醉2 h(T1)、4 h(T2)、6 h(T3)、麻醉停止后4 h(L)、6 h(T5)、12 h(T6)、24 h(T7)时,C组在对应时点各取4只大鼠,测定海马IL-1β mRNA、IL-6 mRNA及TNF-α mRNA的表达水平.结果 C组各时点海马IL-1β mRNA、IL-6 mRNA和TNF-α mRNA比较差异无统计学意义(P＞0.05);与C组比较,I组海马T1～5 时IL-1βmRNA表达上调,T2,3 时IL-6 mRNA表达上调,T1～6时TNF-α mRNA表达上调(P＜ 0.05).结论 1.5%异氟烷麻醉可短暂上调发育期大鼠海马IL-1β mRNA、IL-6 mRNA和TNF-α mRNA的表达.     

乌司他丁后处理对肝切除老年大鼠学习记忆功能的影响及机制研究

目的观察乌司他丁（UTI）后处理对肝部分切除术（PH）老年大鼠学习记忆能力的影响并探讨其作用机制。 方法选择健康雄性无特定病原体SPF级C57BL/6J大鼠36只,18月龄,体质量27~36 g。按照随机数字表法将大鼠分为3组：对照组（C组）、肝部分切除术组（PH组）和UTI后处理组（UTI组）,每组12只。UTI组大鼠术毕苏醒即刻经腹腔注射UTI 50 000 U/kg,连续注射7 d,C组和PH组大鼠连续7 d每日腹腔注射等量0.9%氯化钠溶液。3组大鼠于末次给药结束后24 h均进行Morris水迷宫试验和旷场实验等行为学测试,测试完毕后处死大鼠,立即取海马组织冻存备用,采用ELISA法检测海马组织炎性因子IL-1、IL-6、TNF-α水平,Western blotting法检测海马组织Amlyoid-β蛋白、tau蛋白、磷酸化tau-Ser396蛋白的表达。 结果与C组和UTI组比较,PH组大鼠第3、4天的逃避潜伏期、游泳距离均延长（F=11.783、72.141、70.807,均P<0.001）,探索时间、穿越次数均缩短（F=143.244、32.428,均P<0.001）,中央区探索时间、跨格次数、旷场直立次数均缩短（F=76.232、105.990、17.477,均P<0.001）;海马组织炎症因子TNF-α、IL-6、IL-1的浓度均增加（F=395.545、1 124.503、474.526,均P<0.001）,海马组织tau蛋白、磷酸化tau-Ser396蛋白、Amlyoid-β蛋白表达均增加（F=285.764、307.440、557.347,均P<0.001）。 结论UTI可改善PH后老年大鼠的学习记忆能力,其机制可能与UTI抑制海马细胞炎症及Amlyoid-β蛋白、tau蛋白、磷酸化tau-Ser396蛋白的表达有关。     

氯化锂预先给药对异氟醚麻醉诱发老龄大鼠认知功能障碍及海马炎性反应的影响

目的 评价氯化锂(LiCl)预先给药对异氟醚麻醉诱发老龄大鼠认知功能障碍及海马炎性反应的影响.方法 老龄雄性SD大鼠80只,20月龄,体重350 ～400g,采用随机数字表法,将大鼠随机分为4组(n=20):对照组(C组)吸入30％O2-70％ N26h;异氟醚麻醉组(I组)吸入1.4％异氟醚6h,以30％O2-70％N2作为载气;LiCl+异氟醚麻醉组(L+I组)腹腔注射LiC1 100 mg/kg,1次/d,连续3d,第4d行异氟醚麻醉;LiCl组(L组)腹腔注射LiCl 100 mg/kg,1次/d,连续3d,第4d吸入30％ O2-70％ N26h.麻醉结束即刻行动脉血气分析,麻醉结束后24h取海马组织,采用Western blot法测定海马糖原合成酶激酶-3β(GSK-3β)和核因子κB第310赖氨酸乙酰化蛋白[acetyl-NF-κB (Lys310)]的表达,采用实时定量PCR和ELISA法分别检测海马TNF-α、IL1β和IL-6的mRNA表达及其含量;麻醉结束后第2d评估认知功能.结果 与C组比较,I组GSK-3β和acetyl-NF-κB (Lys310)表达上调,TNF-α、IL-1β及IL-6含量及其mRNA表达水平升高,逃避潜伏期延长,探索时间缩短(P＜0.05),L+I组和L组上述指标差异无统计学意义(P＞0.05);与I组比较,L+I组GSK-3β、acetyl-NF-κB (Lys310)表达下调,TNF-α、IL-1β、IL-6含量及其mRNA表达水平降低,逃避潜伏期缩短,探索时间延长(P＜0.05).结论 氯化锂预先给药可改善异氟醚麻醉诱发老龄大鼠认知功能障碍,其机制与抑制海马炎性反应有关.     

毒扁豆碱对异氟醚麻醉大鼠炎性反应和认知功能的影响

目的探讨毒扁豆碱对异氟醚麻醉大鼠认知功能的影响及其机制。方法 2月龄SD大鼠80只,随机分为四组,每组20只。对照组(C组)吸入含有30%氧气的空氧混合气体6h;异氟醚组(I组)吸入1.4%的异氟醚6h;毒扁豆碱+异氟醚组(PI组)与毒扁豆碱组(P组)腹腔注射毒扁豆碱100μg/kg,每8小时一次,共3次。首次给药后,PI组吸入1.4%异氟醚6h;P组吸入同浓度载气6h。麻醉结束行动脉血气分析,12h后取海马组织,ELISA法检测TNF-α、IL-1β、IL-6含量,RTPCR法检测capase-3mRNA的表达。光镜下观察海马CA1区锥体细胞形态学变化。麻醉后第2~7天评估认知功能。结果四组大鼠动脉血气指标、血糖和海马TNF-α含量差异均无统计学意义。与C组和P组比较,I组和PI组大鼠海马IL-1β、IL-6含量、capase-3mRNA明显升高,第4~6天逃避潜伏期明显延长,探索时间明显缩短(P0.05)。与I组比较,PI组大鼠海马IL-1β、IL-6含量、caspase-3mRNA表达明显降低,第4~6天逃避潜伏期明显缩短,探索时间明显延长(P0.05)。结论毒扁豆碱改善了异氟醚麻醉引起的大鼠认知功能损害,其机制可能与抑制海马炎性反应及神经元凋亡有关。     

地塞米松对老龄大鼠术后认知功能的影响

目的 评价地塞米松对老龄大鼠术后认知功能的影响.方法 雄性SD大鼠180只,18 ～ 20月龄,体重400 ～ 600 g,采用随机数字表法,将大鼠随机分为3组(n=60)∶对照组(C组)、手术组(S组)和地塞米松组(D组).采用大鼠剖腹探查手术模型.D组于麻醉开始时腹腔注射地塞米松10 mg/kg.C组不进行手术,腹腔注射生理盐水2 ml/kg.于术后3h、7d时测定海马OX42(小胶质细胞激活特异性标志物)的表达水平；于术后3h、1d、3d和7d时测定海马IL-1β mRNA和TNF-α mRNA的表达水平.采用Morris水迷宫实验和条件恐怖适应实验检测大鼠术后认知功能.结果 与C组比较,S组和D组逃逸潜伏期延长,穿越原平台次数减少,术后僵直时间缩短,海马OX42表达、IL-1β mR-NA和TNF-α mRNA表达上调(P＜0.05或0.01)；与S组比较,D组逃逸潜伏期缩短,穿越原平台次数增多,术后僵直时间延长,海马OX42、IL-1β mRNA和TNF-α mRNA表达下调(P＜0.05或0.01).结论 地塞米松可抑制海马小胶质细胞过度激活,减轻炎性反应,从而改善老龄大鼠术后认知功能.     

手术创伤对老龄大鼠海马环氧化酶-2和前列腺素E2的影响

目的 探讨手术创伤对老龄大鼠海马环氧化酶-2(COX-2)和前列腺素E2(PGE2)的影响.方法 健康雄性SD大鼠45只,月龄18月,体重500～600 g,随机分为3组(n=15):对照组(C组)腹腔注射生理盐水3 ml;麻醉组(A组)和手术组(S组)腹腔注射1%戊巴比妥钠50 mg/kg(稀释至3 ml)麻醉,S组麻醉下行腹腔探查+阑尾切除术+脾切除术.于麻醉或术后1、3、7 d(T1～3)时测定认知功能、海马COX-2 mRNA表达和PGE2含量.结果 与C组和A组比较,S组中央格时间延长,跨格及站立次数和正确反应次数减少,全天总反应时间延长,海马COX-2 mRNA表达上调,PGE2含量增加(P＜0.05),C组和A组上述指标差异无统计学意义(P＞0.05).结论手术创伤导致老龄大鼠术后认知功能障碍的机制可能与上调海马COX-2 mRNA表达和增加PGE2含量有关.     

七氟醚预处理对急性心肌缺血再灌注损伤大鼠认知功能的影响

目的 探讨七氟醚预处理对急性心肌缺血再灌注损伤大鼠认知功能的影响.方法 健康SD大鼠60只,雌雄各半,体重300～350 g,随机分为4组:正常对照组(C组,n=6),假手术组(S组,n=18)仅挂线不结扎左冠状动脉;急性心肌缺血再灌注组(IR组,n=18)结扎左冠状动脉30 min后恢复再灌注;七氟醚预处理组(SP组,n=18)吸入七氟醚1.0 MAC 60 min,停止吸入七氟醚后60 min结扎左冠状动脉,缺血30 min后恢复再灌注.分别于左冠状动脉结扎前(T1)、缺血30 min(T2)及再灌注120 min(T3)时抽取股动脉血1 ml,测定血浆丙二醛(MDA)浓度和超氧化物歧化酶(SOD)活性.C组随机取3只大鼠,其余各组于再灌注1、3、7 d各随机取3只大鼠测定海马长时程增强(LTP),C组取另外3只大鼠,其余各组于上述时点随机取3只大鼠,测定海马肿瘤坏死因子α(TNF-α)、TNF-α mRNA、白细胞介素1β(IL-1β)、IL-1β mRNA、血红素氧合酶(HO)-1的表达水平.结果 与C组和S组比较,IR组和SP组LTP降低;与IR组比较,SP组LTP升高(P＜0.05).与C组比较,IR组和SP组HO-1、IL-1β mRNA、IL-1β、TNF-α mRNA表达上调;与S组比较,IR组和SP组IL-1β mRNA及IL-1β表达上调;与IR组比较,SP组TNF-α mRNA、HO-1、IL-1β mRNA及IL-1β表达下调,血浆MDA浓度降低,SOD活性升高(P＜0.05).结论 七氟醚预处理可改善急性心肌缺血再灌注损伤大鼠认知功能,其机制可能与下调TNF-α、IL-1β表达有关.     

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.     

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.