麻黄碱预处理对顺式阿曲库铵肌松时效的影响

目的 观察麻黄碱预处理对顺式阿曲库铵肌松时效的影响.方法 选择50例ASAⅠ或Ⅱ级择期手术患者,随机均分为两组:观察组麻黄碱70 μg/kg静注后4 min内给予顺式阿曲库铵;对照组静注相同剂量的生理盐水后给予顺式阿曲库铵.比较两绀的肌松起效时间、肌松恢复时间和插管期间的血流动力学变化.记录入室后安静≥10 min诱导前(T0基础值)、插管即刻(T1)、插管后1 min(T2)和插管后3 min(T3)的MAP和HR.结果 与对照组比较,观察组肌松起效时间显著缩短(P<0.01);95%恢复时间显著缩短(P<0.05).与T0时比较,T2时观察组MAP明显升高,HR明显增快(P<0.05);T1、T2时对照组MAP明显降低,HR明显减慢(P<0.05或P<0.01).结论 静注麻黄碱70 μg/kg预处理后≤4 min时.再给予顺式阿曲库铵可有效缩短肌松起效时间和95%恢复时间.     

不同剂量顺式阿曲库铵对患者拇内收肌与眼轮匝肌肌松效应的比较

目的 比较不同剂量顺式阿曲库铵对患者拇内收肌与眼轮匝肌的肌松效应.方法 全麻患者25例,ASA Ⅰ或Ⅱ级,年龄42～64岁,体重51～81 kg,随机分为2组,顺式阿曲库铵0.075ms/ks组(Ⅰ组,n=11)和顺式阿曲库铵0.15 mg/kg组(Ⅱ组,n=14).静脉注射咪达唑仑0.035～0.045mg/kg、异丙酚1.5～2 mg/kg、芬太尼0.1～0.2 mg、顺式阿曲库铵0.075 mg/kg或0.15 mg/kg行麻醉诱导,吸入50%氧化亚氮、间断静脉注射芬太尼维持麻醉.采用2台TOF-Watch SX加速度肌松监测仪同步监测眼轮匝肌和拇内收肌的神经肌肉阻滞情况,记录肌松起效时间、无反应期及T25%和T75%恢复时间.于眼轮匝肌肌颤搐抑制75%～80%时行气管插管,并评价气管插管条件.结果 2组气管插管条件良好且差异无统计学意义(P>0.05);与Ⅰ组比较,Ⅱ组拇内收肌和眼轮匝肌肌松起效时间缩短,T25%恢复时间、T75%恢复时间和无反应期延长(P<0.01);与拇内收肌比较,Ⅰ组眼轮匝肌T75%恢复时间缩短,Ⅱ组眼轮匝肌无反应期和T25%恢复时间缩短(P<0.05或0.01).结论 顺式阿曲库铵对拇内收肌和眼轮匝肌的肌松效应呈剂量依赖性,眼轮匝肌对顺式阿曲库铵的敏感性低于拇内收肌;监测顺式阿曲库铵对眼轮匝肌神经肌肉阻滞情况可有效指导气管插管.     

婴幼儿和成年患者活体肝移植术中顺阿曲库铵的药效学

目的 探讨婴幼儿和成年患者活体肝移植术中顺阿曲库铵的药效学.方法 选择2008年7月至2008年12月在本院拟行成人-成人,成人-小儿活体肝移植受体患者26例,年龄7个月～64岁,体重6～80 kg,性别不限,Child-Push评分7～10分,肝功能Child分级B或C级,ASAⅢ或Ⅳ级,按年龄分为成人组(A组,n=16),年龄≥18岁;婴幼儿组(B组,n=10),年龄≤2岁.麻醉诱导时顺阿曲库铵用量为0.1 mg/kg,T1达最大抑制时气管插管.于无肝前期吊式拉钩固定后、无肝期门静脉及腔静脉阻断后、新肝期胆道吻合后分别暂停使用顺阿曲库铵,待T1恢复至基础值的75%时重新开始使用.各期待T1恢复至基础值的25%或TOF出现4个反应时追加顺阿曲库铵0.03 mg/kg.记录麻醉诱导时肌松起效时间、给药间隔时间、临床肌松有效作用时间、恢复指数,并评价气管插管条件.结果 与A组比较,B组麻醉诱导时顺阿曲库铵肌松起效时间延长,各期恢复指数缩短(P<0.01),气管插管条件满意率、给药间隔时间和临床肌松有效作用时间差异无统计学意义(P>0.05).结论 顺阿曲库铵0.1 mg/kg可为行活体肝移植术的婴幼儿和成年患者提供满意的气管插管条件,肌松起效快,恢复迅速,无蓄积;婴幼儿较成年患者顺阿曲库铵肌松起效时间延长,肌松恢复加快.顺阿曲库铵可用于不同年龄和不同肝功能状态的患者.     

急性高容量血液稀释对全麻患者顺式阿曲库铵药效学的影响

目的 探讨急性高容量血液稀释(AHH)对全麻患者顺式阿曲库铵药效学的影响.方法 择期腹部手术患者印例,年龄18～60岁,ASAI或Ⅱ级,随机分为对照组(C组)和AHH组,每组30例,各组按顺式阿曲库铵首剂量(首剂量分别为30、40、50μg/kg,总用量100 μg/kg)分为3个亚组,每亚组10例.采用TOF-Wateh~(R)SX肌松监测仪监测神经肌肉阻滞情况.AHH组经30～40 min静脉输注6%羟乙基淀粉130/0.4 15 ml/kg行血液稀释,AHH后各亚组分别给予首剂量顺式阿曲库铵,当T_1达最大抑制后再注入余量.记录肌松起效时间、临床肌松作用时间、体内作用时间及恢复指数.采用概率单位法计算T_1抑制50%、90%、95%时顺式阿曲库铵的用量(ED_(50)、ED_(90)、ED_(95).结果 与C组比较,AHH组顺式阿曲库铵ED_(50)、ED_(90)、ED_(95)升高,肌松起效时间延长,临床肌松作用时间及体内作用时间缩短(P<0.05或0.01),恢复指数差异无统计学意义(P>0.05).结论 AHH可降低顺式阿曲库铵的肌松效应.     

小儿不同剂量顺式阿曲库铵的肌松作用

目的通过观察小儿不同剂量顺式阿曲库铵的肌松作用,评价是否存在封顶效应,探讨小儿合适的麻醉诱导剂量。方法45例择期手术的息儿,年龄15～50月,ASAⅠ或Ⅱ级,随机分为3组(n=15):顺式阿曲库铵0.1 mg/kg组(A组)、顺式阿曲库铵0.15 mg/kg组(B组)、顺式阿曲库铵0.2 mg/kg(C组)。采用TOF-Guard肌松监测仪对尺神经行连续四个成串(TOF)刺激,监测拇内收肌肌颤搐变化;静脉注射异丙酚2 mg/kg、芬太尼2μg/kg及相应剂量顺式阿曲库铵麻醉诱导,吸入O2-N2O和静脉持续输注异丙酚维持麻醉;评价气臂插管条件评估分级,监测诱导期间血液动力学变化,记录起效时间(肌松药注毕至T1达最大抑制的时间)、临床肌松维持时间(肌松药注毕至T1恢复5%的时间)、临床肌松有效作用时间(T1从最大抑制至恢复25%的时间)、恢复指数(T1恢复从25%至75%的时间)、体内肌松作用时间(肌松药注毕至T1恢复95%的时间)。结果3组气管插管条件评估分级比较差异无统计学意义;三组T1达最大抑制时心率、平均动脉压组间和组内比较差异均无统计学意义。与A组相比,B组、C组起效时间较短,临床肌松维持时间、临床肌松有效作用时间、体内肌松作用时间较长(P<0.01);三组恢复指数差异无统计学意义。与B组相比,C组起效时间差异无统计学意义,但临床肌松维持时间、临床肌松有效作用时间、体内肌松作用时间较长(P<0.05或0.01)。结论小儿芬太尼复合异丙酚时,顺式阿曲库铵0.15 mg/kg(3倍ED95)是麻醉诱导的适宜剂量。     

顺式阿曲库铵用于梗阻性黄疸手术患者的药效学研究

目的 观察梗阻性黄疸患者与肝功能正常患者行上腹部手术时顺式阿曲库铵肌松药效的变化.方法 选择无神经肌肉疾患,肾功能正常,在全麻下行择期手术的患者40例,分为两组:观察组(L组),20例,ASAⅢ级,有梗阻性黄疸;对照组(Ⅱ组),20例,ASAⅠ或Ⅱ级,肝功能正常.均采用静吸复合麻醉,顺式阿曲库铵首剂量为3×ED<,95>(0.15 mg/kg).术中用单刺激颤搐值/对照值(T/Tc)监测肌松,当其值达10%时追加肌松药顺式阿曲库铵1.5×ED<,95>(0.075 mg/kg).结果 与Ⅱ组相比,Ⅰ组患者顺式阿曲库铵的90%起效时间、临床时效、追加肌松药后90%恢复时间有延长趋势,但差异无统计学意义.结论 顺式阿曲库铵可以安全地用于梗阻性黄疽的患者,但应加强术中的肌松监测.     

年龄对顺式阿曲库铵靶控输注药效学的影响

目的探讨靶控输注(TCI)顺式阿曲库铵时年龄对其药效学的影响。方法接受丙泊酚-N2O/O2-芬太尼复合麻醉的患者40例均分为Ⅰ组(62～85岁)和Ⅱ组(20～59岁)。在四个成串刺激(TOF)监测下静注顺式阿曲库铵0.15mg/kg。待TOF的T1为0时行气管插管,并对插管条件进行评级。待T1恢复至5%时开始TCI阿曲库铵,保持T1<10%。记录神经肌肉阻滞的起效时间、无反应期、阻滞维持时间和停药后肌松恢复时间,并记录顺式阿曲库铵的用药量。结果两组起效时间及恢复指数差异无统计学意义;Ⅰ组无反应期、阻滞维持时间和停药后肌松恢复时间明显长于Ⅱ组(P<0.05);顺式阿曲库铵的平均用药量明显少于Ⅱ组(P<0.05)。结论老年患者TCI顺式阿曲库铵用药量虽然相应减少,但其恢复过程仍较青壮年延长。     

不同体温对兔不同剂量顺式阿曲库铵肌松效应的影响

目的 评价不同体温对兔不同剂量顺式阿曲库铵肌松效应的影响.方法 健康成年新西兰大白兔72只,体重2.0～2.2 kg,雌雄各半,随机分为低体温组(L组)、常温组(N组)和高体温组(H组),每组24只,各组直肠温度依次为34.5、38.5和41.8℃,各组随机分为4个亚组,L<1～4组、N1～4组和H1～4组,每组6只.各亚组分别于直肠温度稳定20 min后静脉注射顺式阿曲库铵0.33、0.66、0.99和1.32 mg/kg,于改变动物体温前5 min、给药前2 min、给药后5、10、30、60、90 min时监测平均动脉压(MAP)、心率(HR)及直肠温度,记录肌松起效时间、从注药毕到T1恢复至基础值5%、25%和95%的时间及恢复指数.结果 不同体温下相同剂量组间比较:与N组比较,H组肌松起效时间、从注药毕到T1恢复至基础值5%、25%和95%的时间及恢复指数缩短,L组延长(P<0.05或0.01);相同体温下不同剂量组间比较:随顺式阿曲库铵剂量增加,各组肌松起效时间缩短、从注药毕到T1恢复至基础值5%、25%和95%的时间延长(P<0.01);剂量与体温因素的交互作用对起效时间的影响差异有统计学意义(P<0.01);相同剂量不同体温下MAP、HR比较:与N组比较,H组各时点MAP降低、HR升高,L组各时点MAP、HR升高(P<0.05或0.01).结论 体温升高时顺式阿曲库铵的肌松效应降低,体温降低时顺式阿曲库铵的肌松效应升高;相同体温下顺式阿曲库铵(0.33～1.32 mg/kg)的肌松效应呈剂量依赖性;两因素间存在交互作用.     

顺式阿屈库铵与维库溴铵诱导期药效学研究

目的对比观察顺式阿屈库铵与维库溴铵单次静注的药效学及对循环系统的影响。方法择期行声带息肉摘除术ASAI-II级病人30例,随机分为2组,分别以顺式阿屈库铵0.15mg/kg(C组)与维库溴铵0.1mg/kg(V组)为肌松剂静注诱导,观察记录诱导期间患者血压、心率变化,应用肌松监测仪记录各组起效时间、最大阻滞程度、T1恢复到25%、75%、90%的时间及气管插管条件。结果2组患者诱导后血压、心率变化与临床常规诱导相似,组间对比无明显差异。肌松起效时间分别为5.2±1.9(C组)与3.1±0.8(V组),差别具有显著性(P0.05)。最大阻滞程度、T1恢复到25%、75%、90%的时间及气管插管条件无统计学差异。结论顺式阿屈库铵与维库溴铵在药效学及对循环系统的影响相似。     

性别因素对七氟醚增强顺阿曲库铵或罗库溴铵肌松效应的影响

目的 探讨性别因素对七氟醚增强顺阿曲库铵或罗库溴铵肌松效应的影响.方法 择期全麻手术患者240例,年龄20～60岁,ASA分级Ⅰ或Ⅱ级,BMI 20～30 kg/m2,随机分为2组(n=120):顺阿曲库铵组和罗库溴铵组,各组按性别和麻醉药再分4个亚组(n=30):女性异丙酚组、男性异丙酚组、女性七氟醚组和男性七氟醚组.各异丙酚组靶控输注异丙酚,血浆靶浓度2～6 μg/ml,各七氟醚组吸入七氟醚,于靶控输注或待呼气末七氟醚浓度稳定于1.71%5 min后,静脉注射顺阿曲库铵0.15 mg/kg或罗库溴铵0.6 mg/kg.记录肌松起效时间、肌松作用峰值时间、T1 25%恢复时间和TOFR25%恢复时间.结果 与异丙酚麻醉比较,女性患者七氟醚麻醉时,罗库溴铵TOFR 25%恢复时间延长,顺阿曲库铵肌松作用峰值时间、T1 25%恢复时间和TOFR 25%恢复时间延长,男性患者七氟醚麻醉时,罗库溴铵起效时间缩短,肌松作用峰值时间、T1 25%恢复时间和TOFR 25%恢复时间延长,顺阿曲库铵肌松作用峰值时间、T1 25%恢复时间和TOFR 25%恢复时间延长(P＜0.05或0.01);七氟醚麻醉时与男性患者比较,女性患者罗库溴铵T1 25%恢复时间和TOFR 25%恢复时间缩短,顺阿曲库铵起效时间缩短(P＜0.05或0.01).结论 七氟醚对罗库溴铵肌松的增强作用存在性别差异,男性强于女性;对顺阿曲库铵肌松的增强作用无明显性别差异.     

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.