七氟醚和地氟醚低流量麻醉对酶诱导大鼠的肝毒性作用

地氟醚被认为肝毒性小 ,但临床仍有报道与其有关的肝损害可能性。联合肝细胞凋亡、谷胱甘肽 Ｓ 转移酶 (ＧＳＴ)、丙二醛 (ＭＤＡ)、病理等指标全面、客观地研究地氟醚低流量麻醉对异烟肼酶诱导大鼠的肝毒性作用及其对脂质过氧化反应的影响 ,并与七氟醚相比较 ,现报道如下。材料与方法实验方法　成年雄性ＳＤ大鼠 40只 ,随机分成 4组 ,每组 10只。Ｃ :正常对照组 ;Ｉ :异烟肼酶诱导组 ;ＳＩ:酶诱导七氟醚组 ;ＤＩ:酶诱导地氟醚组。将后三组动物异烟肼酶诱导处理后置入与麻醉机 (使用标准、新鲜钠石灰 )回路相连的小室内 ;分别吸入氧气、1 1…     

七氟醚预处理对肝脏缺血-再灌注损伤及PI3K/Akt信号通路的影响

目的 探讨七氟醚预处理对肝脏缺血-再灌注损伤及磷脂酰肌醇3激酶/蛋白激酶B(PI3K/Akt)信号通路的影响.方法 48只成年SD大鼠随机分为假手术组(SH组)、缺血-再灌注组(IR组)、七氟醚预处理组(SI组)和七氟醚Wortmannin组(SW组),每组12只.除SH组外,IR组、SI组和SW组建立70％肝脏缺血-再灌注模型.检测大鼠血清谷草转氨酶(AST)和谷丙转氨酶( ALT)含量,并取再灌注的肝组织用ELISA法测IL-1β浓度,用Western Blot法测定肝组织的p-PI3K、p-Akt(ser473)、Akt等表达量;用HE染色进行病理学检查,观察肝细胞损伤及坏死情况.结果 与SW组比较,SI组ALT、AST和IL-1β浓度明显降低(P＜0.05),且p-PI3K、p-Akt(ser473)表达量明显增加(P＜0.05),肝组织损伤减轻.结论 七氟醚对肝脏缺血-再灌注损伤有保护作用,可能通过激活PI3K/Akt信号通路起作用.     

ATP敏感性钾通道在七氟醚预处理延迟相减轻大鼠心肌缺血-再灌注损伤中的作用

目的 探讨线粒体ATP敏感性钾通道(mito-KAar)在七氟醚预处理延迟相减轻大鼠心肌缺血-再灌注(I-R)损伤中的作用.方法 雄性SD大鼠80只随机均分为五组:假手术组(A组);I-R组(B组),左冠状动脉前降支结扎30 min后再灌注120 min;七氟醚预处理组(C组),I-R前24 h吸人2.5%七氟醚1 h;七氟醚预处理+mito-K<,ATP>抑制剂5-羟基癸酸(5-HD)组(D组),七氟醚预处理前尾静脉注射5-HD 5 mg/kg;单纯5-HD组(E组).再灌注120 min后各组取10只大鼠测定心肌缺血危险面积与梗死面积,酶联免疫吸附(ELISA)法检测血清肌钙蛋白I(cTnI)浓度,各组另取6只大鼠采用免疫印迹检测左室心肌Bc1-2及Bax蛋白表达.结果 七氟醚预处理可减少I-R引起的心肌梗死面积、降低血清cTnI水平,上调心肌Bc1-2表达、下调Bax表达(P<0.05).而这种效应可以被5-HD所抑制.结论 七氟醚预处理延迟相可减轻大鼠心肌I-R损伤,可能与mito-K<,ATP>开放引起的Bc1-2及Bax表达变化有关.     

七氟醚不同吸入方式对瓣膜置换术患者血清肌钙蛋白-T及炎性细胞因子的影响

目的观察七氟醚不同吸入方式对心肺转流(CPB)下心脏瓣膜置换术中血清肌钙蛋白T(cTnT)和炎性细胞因子IL-6、IL-8浓度的影响,探讨不同七氟醚处理方法的心肌保护作用及其机制。方法 52例拟行全身麻醉下CPB心脏瓣膜置换术的患者,随机均分为:七氟醚预处理组(S1组)、七氟醚后处理组(S2组)和七氟醚预处理联合后处理组(S3组)和对照组(C组)。S1组:麻醉诱导后连续吸入1%七氟醚至主动脉阻断;S2组:主动脉、腔静脉开放后连续吸入1%七氟醚至手术结束;S3组:麻醉诱导后连续吸入1%七氟醚至主动脉阻断时停止,主动脉、腔静脉开放后再连续吸入1%七氟醚至手术结束;C组在整个麻醉手术期间不吸入七氟醚。于麻醉诱导后即刻(T0)、主动脉开放后2h(T1)、6h(T2)、12h(T3)和24h(T4)分别采集桡动脉血3ml,测定cTnT、IL-6和IL-8浓度。结果与T0时比较,T1~T3时S1组、S2组和S3组血清cTnT、IL-6和IL-8浓度明显升高(P0.05)。与C组比较,T1~T3时S1组、S2组和S3组血清cTnT、IL-6和IL-8浓度明显降低(P0.05);而T4时S1组、S3组血清cTnT浓度和S1组、S2组和S3组血清IL-6、IL-8浓度明显降低(P0.05)。结论七氟醚预处理、七氟醚后处理和七氟醚预处理联合后处理三种方式均可有效显减轻瓣膜置换术中心肌缺血-再灌注损伤,心肌保护作用相近,机制可能与抑制全身炎症反应有关。     

异氟醚和七氟醚麻醉期间尿氧分压的变化

作者将尿氧分压(PuO_2)作为反映肾髓质循环的指标。观察了异氟醚,七氟醚麻醉对肾循环的影响。对象及方法:排除心、肾疾患,ASAⅠ～Ⅱ级,择期非剖腹手术(不输血)的成年病人20例。随机分为异氟醚(Ⅰ)组,七氟醚(S)组各10例。芬太尼,咪唑安定,维库溴铵快速诱导气管内插管后于吸入O_2-N_2O10min后(C值),在此基础上复合异氟醚或七氟醚麻醉。手术开始后30min(30值),60min(60值),120min(120值)以及停吸麻醉剂后10min(OFF值)分别测定PaO_2、     

七氟醚不同吸入时间对老年大鼠认知功能的影响

目的 评价七氟醚不同吸入时间对老年大鼠认知功能的影响.方法 健康SD雄性大鼠40只,月龄18月,体重(600±50)g,采用完全随机法分为5组(每组8只):对照组(C组)、吸入3％七氟醚0.5 h组(S1组)、吸入3％七氟醚1h组(S2组)、吸入3％七氟醚2h组(S3组)、吸入3％七氟醚4h组(S4组).所有组于干预结束后第2天行水迷宫实验,于水迷宫实验结束后15 min处死大鼠,取海马组织,采用Western blot法测定海马N-甲基-D-天门冬胺酸受体2B亚基(N-methyl-D-aspartatereceptor type 2B,NR2B)的表达.结果 与C组平台穿越次数[(5.5±1.2)次]比较,S1组[(7.3±1.7)次]明显增多(P＜0.05),S3组[(3.8±1.0)次]和S4组[(1.9±1.0)次]均明显减少(P＜0.05);与S3组比较,S4组减少较为明显(P＜0.05).与C组目标象限停留时间[(48.2±6.2)s]比较,S1组[(56.8±5.1)s]明显延长(P＜0.05),S3组[(39.1±4.0)s]和S4组[(31.6±3.2)s]均明显缩短(P＜0.05);与S3组比较,S4组缩短较为明显(P＜0.05).与C组(1.00)比较,S1组(0.69±0.88)NR2B蛋白相对密度减少(P＜0.05),S3组(1.47±0.17)和S4组(2.17±0.10)NR2B蛋白相对密度均增多(P＜0.05),与S3组比较,S4组增多更为明显(P＜0.05).结论 吸入3％七氟醚2h或4h均可导致老年大鼠认知功能下降,吸入3％七氟醚4h更为明显,其机制可能与海马中过度表达NR2B蛋白有关.     

石杉碱甲预处理对七氟醚麻醉新生大鼠学习记忆的影响

目的探讨石杉碱甲预处理对七氟醚麻醉新生大鼠学习记忆的影响。方法 7日龄SD大鼠80只,雌雄不拘,体重15~20g,采用随机数字表法分为五组(n=16):对照组(C组)吸入30%的氧气6h,3%七氟醚麻醉2h组(S1组),预处理3%七氟醚麻醉2h组(AS1组),3%七氟醚麻醉6h组(S2组),预处理3%七氟醚麻醉6h组(AS2组),AS1组和AS2组麻醉前30min给予石杉碱甲0.2mg/kg腹腔注射。麻醉结束24h后,每组随机取8只大鼠断头取血,ELISA法检测血清S100β蛋白和神经元特异性烯醇化酶(NSE)浓度。五组余大鼠14日龄行Morris水迷宫实验。结果与C组比较,AS1组第1~6天逃避潜伏期、平台象限滞留时间、穿越平台次数无明显变化;AS2组第1~6天逃避潜伏期明显延长(P0.05),平台象限滞留时间、穿越平台次数无明显变化;余四组大鼠血清S100β及NSE浓度明显升高(P0.05)。与S1组比较,AS1组第1~6天逃避潜伏期无明显变化,平台象限滞留时间、穿越平台次数明显增加(P0.05),血清S100β和NSE浓度均明显降低(P0.05)。与S2组比较,AS2组第1~6天逃避潜伏期明显缩短、平台象限滞留时间、平台穿越次数明显增加(P0.05),血清S100β和NSE浓度均降低(P0.05)。结论石杉碱甲预处理能有效改善七氟醚麻醉新生大鼠学习记忆,对大脑神经细胞有一定的保护作用。     

七氟醚对心肌缺血-再灌注幼兔心肌细胞凋亡及Fas/FasL蛋白表达的影响

目的探讨七氟醚对幼兔缺血-再灌注心肌细胞凋亡及Fas、FasL蛋白表达的影响。方法取30只日本大耳白幼兔随机均分为三组,缺血-再灌注组(IR组):结扎30min,再灌注120min;七氟醚预处理组(S组):缺血前吸入2.5%七氟醚30min,洗脱15min后处理同IR组;假手术组(C组):只穿线不结扎。观察三组兔心肌细胞凋亡和Fas、FasL蛋白表达情况,电镜观察细胞超微结构。结果心肌细胞凋亡率S组(13.71±6.01)%明显低于IR组(31.33±7.04)%(P<0.05),而C组(3.3±0.5)%明显低于IR组和S组(P<0.05)。S、C组Fas、FasL蛋白表达的平均灰度高于IR组(P<0.05)。电镜显示S组细胞损伤程度小于IR组。结论七氟醚能明显降低幼兔缺血-再灌注心肌细胞的凋亡。     

七氟醚预处理中核因子-κB的激活对大鼠心肌缺血/再灌注损伤的保护作用

目的 研究七氟醚预处理中NF-κB的激活对大鼠在体心肌缺血/再灌注损伤的保护作用.方法 48只雄性SD大鼠,阻断左冠状动脉前降支缺血30 min,开放再灌注120 min,随机分为6组.①对照组进行单纯心肌缺血/再灌注;②DMSO组于心肌缺血前15 min腹腔内注射二甲亚砜(DMSO);③PTN组于缺血前15 min腹腔内注射核转录因子-κB(NF-κB)特异性阻断剂小白菊内酯(PTN)500 μg/kg;④七氟醚组于吸入2.5%七氟醚30 min,继之15 min药物排出;⑤PTN+七氟醚组于七氟醚预处理前15 min腹腔内注射PTN;⑥七氟醚+FTN组于七氟醚预处理后即刻腹腔内注射PTN.实验中监测血液动力学变化,实验结束用氯化三苯四氮唑染色法(TPT)测定心肌梗死范嗣.结果 平衡期,各组间心率(HR),平均动脉压(MAP)和心率-收缩压乘积(RPP)无统计学意义(P>0.05).七氟醚组、PTN+七氟醚组和七氟醚+PTN组在吸入七氟醚期间HR、MAP和RPP明显降低,再灌注1 h和2 h引起各组MAP和RPP明显降低(P<0.05).与对照组(52.48±6.04)%相比,七氟醚组的心肌梗死范围显著减少(33.73±5.72)%,而PTN+七氟醚组(52.60±5.01)%和七氟醚+PTN组(52.39±7.00)%的心肌梗死范围明显高于七氟醚组(33.73±5.72)%(P<0.05).结论 七氟醚预处理缩小了大鼠心肌梗死范围,而PTN阻断了七氟醚的心肌保护作用,NF-κB可能参与了七氟醚预处理的心肌保护机制.     

孕晚期七氟醚麻醉对子代大鼠认知功能和海马神经元树突棘发育的影响

目的 探讨孕晚期不同浓度七氟醚麻醉对子代大鼠认知功能及树突棘发育的影响.方法 取SD孕鼠16只,用随机数字表法将其分为4组(每组4只):对照组(C组)、1.5％七氟醚麻醉组(S1组)、2.8％七氟醚麻醉组(S2组)和3.3％七氟醚麻醉组(S3组).七氟醚麻醉组母鼠于孕18～20 d进行每天1次的七氟醚麻醉,S1组、S2组和S3组孕鼠分别使用1.5％、2.8％和3.3％的七氟醚吸入4h并保持0.5、1.0、1.5 MAC;C组仅置于麻醉箱内,通入相同流量氧气暴露4h.于出生后21 d对各组子代大鼠水迷宫测定其认知功能,出生后28 d完成水迷宫测试后处死子代大鼠,采用高尔基染色法进行海马树突棘密度测定,采用RT-PCR法测定caspase-3 mRNA表达.结果 各组子代大鼠游泳路程、逃避潜伏期、穿越平台次数及平台所在象限停留时间比较差异无统计学意义(P＞0.05).与C组[(12±3)/10 μm]比较,S3组大鼠海马神经细胞树突棘密度降低[(9±3)/10μm](P＜0.05).各组子代大鼠海马内caspase-3 mRNA表达变化差异无统计意义(P＞0.05).结论 1.5 MAC七氟醚麻醉4h可降低子代大鼠海马内神经细胞树突棘密度,但未对子代大鼠认知功能及caspase-3 mRNA表达产生影响.     

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.