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.     

七氟醚对罗库溴铵肌松效应的影响

目的 观察七氟醚对罗库溴铵肌松作用的影响.方法 成人全麻手术患者60例随机均分为三组.每组20例.Ⅰ组丙泊酚静脉麻醉,Ⅱ组吸入七氟醚(1 MAC)15 min,Ⅲ组吸入七氟醚(1 MAC)45 min.在麻醉平稳(Ⅱ、Ⅲ组在呼气末七氟醚浓度稳定在1 MAC)后静脉注射罗库溴铵0.6 mg/kg,记录TOFr的变化.结果 Ⅱ、Ⅲ组罗库溴铵的起效时间分别为97.60 s和94.50 s,明显短于Ⅰ组的119.90 s(P<0.05);Ⅱ和Ⅲ组完全肌松时间(T1消失)明显长于Ⅰ组(32.7 min和44,6 min vs.21.3 min)(P<0.05),Ⅲ组明显长于Ⅱ组(P<0.05);TOF的T2～T4出现的时间及TOFr恢复到25%、50%和75%的时间,Ⅱ、Ⅲ组均长于Ⅰ组,且Ⅲ组长于Ⅱ组(P<0.05).结论 持续吸入1 MAC七氟醚能随吸人时间延长而增强罗库溴铵的神经肌肉阻滞效应.     

肝硬化病人乌司他丁预处理对罗库溴铵肌松作用的影响

目的观察肝硬化病人乌司他丁预处理对罗库溴铵肌松作用的影响。方法选择30例患有肝硬化的成年手术病人,随机均分为两组:乌司他丁组(Ⅰ组),静注乌司他丁5000U/kg后1min,静脉给予罗库溴铵0.6mg/kg;生理盐水组(Ⅱ组),静脉给予生理盐水0.1ml/kg后1min,静脉给予罗库溴铵0.6mg/kg。另选15例无肝脏疾患的、ASAⅠ～Ⅱ级择期成年手术病人为对照组(Ⅲ组),处理同Ⅱ组。肌松监测仪检测四个成串刺激(TOF)的变化,记录三组注药后罗库溴铵的起效时间(注药到TOFr=0)、TOF无反应时间(T1=0持续时间)、T1最大抑制程度、临床时效(TOFr恢复至25%时间)、T1恢复至75%时间、恢复指数。结果与Ⅱ、Ⅲ组比较,Ⅰ组插管剂量罗库溴铵的起效时间明显延长(P<0.05)。Ⅱ、Ⅲ组罗库溴铵肌松的起效时间相似。与Ⅱ组比较,Ⅰ、Ⅲ组T1恢复25%时间和恢复指数明显缩短(P<0.05)。Ⅰ、Ⅲ组罗库溴铵肌松的恢复时间相似。结论肝硬化病人乌司他丁预处理延长罗库溴铵的起效时间,但缩短罗库溴铵肌松作用时间。     

不同浓度异氟醚对罗库溴铵肌松作用的影响

目的 观察不同浓度异氟醚对罗库溴铵肌松作用的影响。方法 60例ASA Ⅰ-Ⅱ择期手术患者,随机分为3组,每组20例。组Ⅰ静脉注射罗库溴铵0.6 mg·kg-1;组Ⅱ吸入0.6％异氟醚后静脉注入罗库溴铵0.6mg·kg-1;组Ⅲ吸入1.2％异氟醚后从静脉注入罗库溴铵0.6mg·kg-1。分别记录各组注药后肌松作用的起效时间、作用时间及T1恢复时间。结果 与组Ⅰ相比,组Ⅱ、Ⅲ起效时间明显缩短(P<0.05),TOF无反应期明显延长(P<0.01),T1恢复25％、50％、90％时间明显延长(P<0.01),且组Ⅲ较组Ⅱ延长(P<0.05),恢复指数明显延长,且组Ⅲ较组Ⅱ延长(P<0.05)。结论 吸人异氟醚能明显缩短罗库溴铵起效时间,延长罗库溴铵作用时间,临床合并使用时应注意减少用量。     

儿童七氟醚、异氟醚及全静脉麻醉中罗库溴铵的恢复时程

目的 比较罗库溴铵气管插管剂量在儿童七氟醚、异氟醚和全静脉麻醉中恢复时程的差异.方法 51例2～14岁儿童随机均分为七氟醚组(S组)、异氟醚组(I组)和全静脉麻醉组(P组).静脉给予罗库溴铵O.6 mg/kg,比较T1恢复至基础值10%、25%、75%的时间(T10、T25、T75)和恢复指数(RI=T75-T25)在不同麻醉方式下的差异.结果 三组儿童T10、T25差异无统计学意义.I组T75和RI长于P组(P＜0.05),S组与P组比较有延长趋势,但差异无统计学意义.S组与I组所有时点差异均无统计学意义.结论 儿童罗库溴铵气管插管剂量,在七氟醚、异氟醚和全静脉麻醉下的临床作用时间差异无统计学意义,异氟醚麻醉下肌松作用完全恢复时间较在全静脉麻醉下显著延长.     

七氟醚对不同性别患者罗库溴铵肌松作用的影响

目的 比较罗库溴铵肌松效应的性别差异和七氟醚对不同性别患者罗库溴铵肌松增效作用.方法 择期手术患者120例(男:女为1:1),年龄20～60岁.ASA Ⅰ或Ⅱ级,按性别随机分为丙泊酚组和七氟醚组:女性丙泊酚组(PF组).男性丙泊酚组(PM组),女性七氟醚组(SF组),男性七氟醚组(SM组),每组30例.所有患者静脉注射咪达唑仑、芬太尼和丙泊酚行麻醉诱导,意识消失后,置入喉罩,接麻醉机辅助通气并启动肌松监测.丙泊酚组静脉输注丙泊酚维持麻醉,设定血浆靶控浓度2～6 μg/ml,输注丙泊酚5 min后静脉注射罗库溴铵0.6 mg/kg,七氟醚组在呼气末七氟醚浓度稳定于1 MAC 5 min后静脉注射罗库溴铵0.6 mg/kg.记录肌松起效时间、完全肌松时间、T1恢复到25%和TOF恢复到25%的时间.结果 PM组较PF组起效时间长,完全肌松时间、T1恢复到25%和TOF恢复到25%的时间缩短(P＜0.05).SF组TOF恢复到25%的时间较PF组延长(P＜0.05),SM组较PM组起效时间缩短,完全肌松时间、T1恢复到25%和TOF恢复到25%的时间均延长(P＜0.05).SM组T1恢复到25%和TOF恢复到z5%的时间较SF组延长(P＜0.05).结论 女性罗库溴铵起效更快,作用时间长;而七氟醚对男性罗库溴铵的增效作用优于女性.     

七氟醚、异氟醚对阿曲库铵肌松恢复的影响

目的 观察七氟醚、异氟醚对阿曲库铵肌松恢复的影响.方法 选择75例Ⅰ或Ⅱ级成年择期全麻手术病人随机均分为三组.Ⅰ组丙泊酚4～10 mg·kg-1·h-1泵入;Ⅱ、Ⅲ组分别吸入呼气末浓度为1 MAC的七氟醚、异氟醚.诱导插管后阿曲库铵均以30μg·kg-1·min-1的速度静脉泵入.使用Biomter加速度仪监测肌松恢复情况,记录T1恢复至25%,75%及TOFr恢复至0.7的时间.结果 Ⅱ、Ⅲ组T1恢复至25%、75%的时间及TOFr恢复至0.7的时间均比Ⅰ组显著延长(P＜0.05).恢复指数(T1从25%至75%的时间)三组比较差异无统计学意义.结论 七氟醚、异氟醚均可增加阿曲库铵残余肌松作用.     

异氟醚吸入麻醉与异丙酚静脉麻醉下长时间持续输注罗库溴铵的肌松作用

目的比较异氟醚吸入麻醉与异丙酚静脉麻醉下长时间持续输注罗库溴铵的肌松作用。方法拟在全麻下行口腔-颌面肿瘤择期手术(手术时间达5 h左右)病人30例,ASAⅠ或Ⅱ级,年龄18～65岁,随机分为2组(n=15):异丙酚组(Ⅰ组)异氟醚组(Ⅱ组)。用TOF-Watch SX肌松监测仪进行拇内收肌肌松监测。静脉注射罗库溴铵初始剂量0．6 mg·kg-1后气管插管,持续输注罗库溴铵。调整罗库溴铵的输注速率,T1稳定在基础值的10％时(初始状态),Ⅰ组靶控输注异丙酚维持麻醉,Ⅱ组吸入1 MAC异氟醚维持麻醉,持续5 h,术中维持T1在基础值的10％。记录罗库溴铵输注速率、恢复指数(T1恢复25％至75％的时间,T25-75)以及罗库溴铵停止输注到TOFR为0．9的时间。结果与初始状态比较,Ⅰ、Ⅱ组持续给药30 min-5 h时罗库溴铵输注速率下降(P<0．05);Ⅱ组持续给药1～5 h时罗库溴铵输注速率低于Ⅰ组(P<0．05)。两组间恢复指数和罗库溴铵停止输注到TOFR为0．9的时间差异无统计学意义(P>0．05)。结论罗库溴铵可用于长时间持续输注以维持稳定的肌松。维持T1在基础值的10％的情况下,持续输注罗库溴铵5 h时异氟醚麻醉比异丙酚为主的全凭静脉麻醉罗库溴铵输注速率减少30％,但其恢复指数无差异。     

罗库溴铵预注和麻黄碱预处理对小儿罗库溴铵肌松起效的影响

目的 观察小儿在罗库溴铵预注、麻黄碱预处理和罗库溴铵预注复合麻黄碱预处理对罗库溴铵起效时间、插管条件和肌松时效的影响.方法 选择全麻下行择期手术的患儿80例,ASA Ⅰ或Ⅱ级,随机均分为四组.在麻醉诱导前预先静注:Ⅰ组生理盐水O.5 ml,Ⅱ组罗库溴铵0.06 mg/kg,Ⅲ组麻黄碱70 μg/kg,Ⅳ组罗库溴铵0.06 mg/kg和麻黄碱70 μg/kg.预注和预处理4min后,Ⅰ、Ⅲ组静注罗库溴铵0.6 mg/kg,Ⅱ、Ⅳ组静注罗库溴铵0.54 mg/kg.待四个成串刺激(TOF)第1个颤搐反应高度(Th)达最大阻滞程度后行气管插管.记录肌颤搐抑制75%、90%和达最大阻滞程度的时间,并评估气管插管条件,同时观察HR、BP变化.结果 Ⅰ、Ⅱ、Ⅲ、Ⅳ组的最大阻滞起效时间分别为(196±43)、(140±43)、(144±35)和(100±33)s,Ⅱ、Ⅲ、Ⅳ组的起效时间明显短于Ⅰ组(P＜0.05),Ⅳ组的起效时间较Ⅱ、Ⅲ组短(P＜0.05).各组气管插管条件均达到6～9分,优良率100%.各组麻醉诱导期间均无明显的心血管不良反应.各组的临床肌松作用时间和恢复指数差异均无统计学意义.结论 罗库溴铵预注和麻黄碱预处理分别使用均能缩短小儿罗库溴铵的肌松起效时间,而两种方法复合使用可进一步加快肌松起效,但该方法对罗库溴铵的肌松时效无明显的影响.     

罗库溴铵和阿曲库铵的预注量对相互起效的影响

目的　研究罗库溴铵和阿曲库铵的预注量对相互起效和插管条件的影响。方法　 6 0例患者随机平均分成六组。麻醉诱导用地西泮、硫喷妥钠和芬太尼。Ⅰ组和Ⅳ组分别静注罗库溴铵0 6mg/kg和阿曲库铵 0 5mg/kg ,Ⅱ组和Ⅴ组预注罗库溴铵 0 0 6mg/kg ,Ⅲ组和Ⅵ组阿曲库铵0 0 5mg/kg。 3分钟后Ⅱ组和Ⅲ组静注罗库溴铵 0 5 4mg/kg ,Ⅴ组和Ⅵ组阿曲库铵 0 4 5mg/kg。观察插管量后的起效时间和气管插管条件。结果　Ⅲ组的起效时间为 (6 7 6± 14 2 )秒稍短于Ⅰ组的(73 1± 13 4 )秒和Ⅱ组的 (76 3± 15 3)秒 (P >0 0 5 )。Ⅴ组和Ⅵ组的起效时间为 (93 8± 2 2 4 )秒和(115 8± 14 9)秒 ,比Ⅳ组 (15 6 0± 37 2 )秒的短 (P <0 0 5和P <0 0 1) ,Ⅴ组的起效时间也显著短于Ⅵ组。气管插管条件Ⅴ组较Ⅳ组明显改善。结论　预注罗库溴铵不能使罗库溴铵的起效增快。预注罗库溴铵使阿曲库铵的起效明显增快 ,插管条件改善 ;预注罗库溴铵比预注阿曲库铵对阿曲库铵起效的增快作用更明显     

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.     

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.     

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.     

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.