α1D与α1A受体亚型对大鼠不稳定逼尿肌收缩功能的影响

目的研究α1D及α1A受体亚型对大鼠膀胱出口梗阻（BOO）引起的不稳定逼尿肌（D1）收缩性、自律性的影响。方法建立Wistar大鼠BOO模型，充盈性膀胱测压确定D1模型，通过离体肌条牵拉实验，记录高选择性α1D及α1A受体亚型拮抗剂作用下，D1组和假手术对照组肌条自发性收缩频率及收缩力变化。结果35只BOO模型大鼠存活32只，D1发生率为71．9％。在一定张力前负荷下离体逼尿肌均产生自发性收缩，D1组肌条自发性收缩频率及收缩力均明显高于对照组；α1受体激动剂苯福林（PE）可使肌条自发性收缩频率及收缩力增加，选择性α1A受体拮抗剂5-MU能降低[（2．43±0．71）次／min，（0．14±0．03）g]对照组肌条的自发性收缩频率（2．64±0．72）次／min及收缩力（O．20±0．04）g，也能拮抗[（2．37±0．57）次／min，（0．19±0．02）g]PE所致的对照组肌条收缩频率（4．22±0．37）次／min和收缩力（0．31±0．03）g的增加（P〈O．01），而对D1逼尿肌作用不明显。选择性α1D受体拮抗剂BMY7378能降低[（2．32±0．56）次／min，（0．18±0．04）g]DI组肌条的自发性收缩频率（5．06±1．02）次／min及收缩力（0．42±0．08）g，并拮抗[（4．28±0．71）次／min，（0.48±0．04）g]PE所致的肌条收缩频率（6．73±0．61）次／min和收缩力（0.95±0．07）g的增加，但对正常逼尿肌作用不明显。结论 α1受体兴奋可使逼尿肌收缩频率及收缩力增加，正常逼尿肌中α1受体主要通过α1A亚型发挥作用，而梗阻性不稳定逼尿肌则主要通过α1D亚型发挥作用。     

NANC神经递质对膀胱下尿路梗阻逼尿肌稳定性的影响

目的　观察非肾上腺素能非胆碱能 (NANC)神经递质对下尿路梗阻逼尿肌肌条自发性收缩频率及收缩幅度的作用。　方法　建立Wistar大鼠膀胱下尿路梗阻动物模型 ,6周后以充盈性膀胱测压的变化检测逼尿肌不稳定的发生率。制备离体逼尿肌肌条 ,观察NANC神经递质血管活性肠肽 (VIP)、三磷酸腺苷 (ATP)对肌条自发性收缩频率及收缩幅度的影响。　结果　大鼠膀胱下尿路梗阻 6周后逼尿肌不稳定发生率为 6 2 % ;VIP、ATP能明显抑制逼尿肌的自发性收缩 ,降低逼尿肌肌条自发性收缩频率及收缩幅度 (P <0 .0 5 ) ;梗阻后逼尿肌不稳定组、逼尿肌稳定组及对照组之间差别无显著性意义 (P >0 .0 5 )。　结论　VIP、ATP能显著抑制正常和梗阻后逼尿肌自发性收缩的频率及收缩幅度     

肾上腺素β3受体与梗阻后逼尿肌不稳定关系的实验研究

目的　探讨肾上腺素β3 受体 (β3 AR)在膀胱出口梗阻 (BOO)型逼尿肌不稳定 (DI)中的作用。　方法　Wister大鼠 15只 ,建立BOO后DI模型 ,6周后行充盈性膀胱测压 ,根据是否有DI将下尿路梗阻大鼠分为DI组和逼尿肌稳定 (DS)组 ,正常大鼠 8只作为对照组。用离体逼尿肌条拉力实验观察BRL37344A(β3 AR激动剂 )对逼尿肌自律性和舒张功能的影响 ,RT PCR检测膀胱 β3 ARmRNA含量。　结果　BOO后DI发生率为 6 7% (10 / 15 )。BRL37344A能明显抑制正常及不稳定膀胱逼尿肌自发性收缩频率及收缩强度 ,作用呈浓度依赖性 ,对DI组的作用强度明显低于正常对照组及梗阻后DS组 (P <0 .0 5 ) ;梗阻后DI组、对照组及梗阻组 β3 ARmRNA相对含量分别为 10 .2 7± 1.17、19.84± 2 .6 2和 18.38± 3.4 5 ,DI组明显降低 (P <0 .0 5 )。　结论　β3 AR激动剂能降低正常及梗阻后逼尿肌条自律性及收缩力 ,β3 AR密度变化可能参与大鼠BOO后逼尿肌不稳定的发生。     

大鼠输尿管部分梗阻后平滑肌形态及功能改变

目的 探讨单侧输尿管部分梗阻后输尿管平滑肌超微结构、收缩功能和自律性的改变.方法 Wistar大鼠80只.随机分4组:8周实验组、8周对照组、16周实验组、16周对照组.每组20只.实验组大鼠左侧输尿管上1/2段腰大肌包埋造成单侧输尿管部分梗阻的动物模型,对照组仅分离左侧输尿管.成模后于不同实验点分离大鼠输尿管进行离体肌条实验,测定肌条的收缩幅度和频率的改变,并通过透射电镜观察梗阻后平滑肌超微结构的变化.结果 8周实验组输尿管收缩力和收缩频率分别为(0.62±0.38)g、(18.52±6.70)次/min,8周对照组分别为(0.38±0.36)g、(14.80±4.98)次/min,2组比较差异均有统计学意义(P＜0.05).16 周实验组输尿管收缩力和收缩频率分别为(0.15±0.10)g、(12.84±3.32)次/min,16周对照组分别为(0.41±0.38)g、(16.48±3.44)次/min.2组间比较差异均有统计学意义(P＜0.05).8周实验组均高于16周实验组(P＜0.05),8周对照组与16周对照组比较差异无统计学意义(P＞0.05).透射电镜观察到8周实验组平滑肌细胞胞质中线粒体数增多,而16周实验组平滑肌细胞胞质中线粒体数目减少、线粒体肿胀和空泡化、细胞间质中可见大量胶原纤维增生.结论 输尿管梗阻8周的大鼠输尿管肌条自律性和收缩力增加,输尿管平滑肌细胞胞质中线粒体增多,可能是机体代偿所致.输尿管梗阻16周后输尿管平滑肌自律性和收缩力均降低.平滑肌细胞胞质中线粒体数目减少,线粒体肿胀和空泡化,细胞间质中有大量胶原纤维增生,呈失代偿表现.     

前列腺增生患者逼尿肌肾上腺素α_(1a)/α_(1d)受体的表达及其作用

目的:初步研究前列腺增生患者逼尿肌肾上腺素能α1a/α1d受体亚型mRNA的表达及其作用.方法:选择前列腺增生膀胱出口无梗阻患者(对照组)9例和膀胱出口梗阻患者(实验组)21例,根据尿动力学将实验组分为逼尿肌稳定组和不稳定组,采用半定量RT-PCR方法检测三组逼尿肌α1a/α1d受体亚型mRNA的表达,采用离体逼尿肌拉力实验检测αl受体激动剂对三组逼尿肌收缩力的影响.结果:前列腺增生患者逼尿肌肾上腺素能受体α1d亚型约占a1受体2/3;对照组、逼尿肌稳定组和不稳定组α1d受体mRNA相对含量为7.53±1.08、7.77±1.50和11.64±3.80,不稳定组ald受体明显增加(P<0.05);αl受体激动剂诱导逼尿肌收缩力呈浓度依赖性,对不稳定组作用大于稳定组和对照组(P<0.05),对照组与稳定组没有差别.结论:αl受体激动剂能够显著增加膀胱出口梗阻患者逼尿肌收缩,逼尿肌肾上腺素能受体α1d亚型可能参与逼尿肌收缩力的变化.     

逼尿肌过度活动中ATP-敏感性钾通道的变化及意义

目的 研究ATP-敏感性钾(KATP)通道在逼尿肌过度活动(DO)中的作用及表达变化,探讨DO的发生机制及KATP通道作为治疗靶点的可行性.方法 雌性Wistar大鼠建立膀胱出口部分梗阻,6周后行膀胱测压获得DO模型.离体收缩实验观察KATP通道阻断剂及开放剂对逼尿肌肌条自发收缩功能的影响,RT-PCR技术检测逼尿肌中KATP通道mRNA的表达. 结果 KATP通道阻断剂格列本脲干预后,2组肌条收缩频率及幅度无显著变化.KATP通道开放剂克罗卡林干预后,2组肌条收缩频率均下降,对照组下降率为(46.8±14.8)%,DO组为(67.9±17.1)%,DO组下降率高于对照组(P＜0.05),而收缩幅度无显著变化.对照组逼尿肌中KATP通道亚型SUR2B、Kir6.2的相对含量分别为0.30±0.05、0.48±0.07,DO组分别为0.52±0.07、0.60±0.09,DO组均增加,其中SUR2B增加更明显(P＜0.01).结论 KATP通道开放剂对逼尿肌的自发性收缩活性有明显的抑制作用,此作用在DO组明显增强,这也许对控制DO的肌原性活性提供了独特的作用机制.这种变化可能和DO组逼尿肌中KATP通道亚型,特别是SUR2B的mRNA表达增加有关.SUR2B也许可以作为治疗DO的较好靶点.     

非胰岛素依赖型糖尿病大鼠逼尿肌兴奋性及自律性改变

目的　研究非胰岛素依赖型糖尿病(NIDDM)大鼠的逼尿肌兴奋性及自律性的变化。方法　制作NIDDM大鼠模型,以正 常大鼠为对照,采用离体逼尿肌条研究膀胱兴奋性和自律性变化。结果　NIDDM组引起逼尿肌肌条自发收缩的张力阈值 [(0.716±0.325)g]明显高于对照组[(0.323±0.177)g](F=59.63,P<0.0001),不同时间段NIDDM组引起逼尿肌收缩的张 力阈值也高于对照组。NIDDM组逼尿肌自发收缩的频率在第6～18周的变化较对照组增高,在第22、26周较对照组减低。 结论　膀胱逼尿肌兴奋性降低是糖尿病膀胱功能最早且最明显的改变。逼尿肌自主节律性改变也是糖尿病膀胱的早期变化之一。     

糖尿病大鼠膀胱重构中M3受体改变的实验研究

目的:研究病程24周的2型糖尿病大鼠膀胱重构时,逼尿肌收缩功能的改变和M3受体含量及其基因转录水平的改变情况,并探讨二者之间的相关性。方法:2d龄雌性Wistar大鼠随机分成实验组和正常对照组,应用链脲佐菌素腹腔注射并结合高糖高脂饮食进行2型糖尿病大鼠动物模型制备。于糖尿病病程24周时进行下列实验:应用离体膀胱灌注方法观察逼尿肌收缩功能的变化;应用RT-PCR和Western blotting方法观察逼尿肌M3受体mRNA和蛋白表达的变化。结果:2型糖尿病组大鼠逼尿肌收缩功能低于正常对照组,为(16.52±2.97)cmH2O/100mgVS(25.66±3.56)cmH2O/100mg;2型糖尿病组大鼠逼尿肌M3受体mRNA和蛋白的表达均高于正常对照组,分别为(65.27±4.61)%VS(37.53±4.02)%和(45.19±2.37)%VS(23.67±2.85)%。结论:本研究证实了2型糖尿病大鼠在病程24周时膀胱逼尿肌的收缩力降低,但M3受体的生物合成却上调,这种不平行现象可能是病变进展的表现,为深入研究糖尿病膀胱病的发病机制提供了有价值     

P2X受体与膀胱过度活动症

随着不稳定膀胱中阿托品抵抗性逼尿肌收缩的深入研究,学者们发现膀胱逼尿肌收缩和膀胱充盈两方面功能除了接受M受体支配外,还接受其他途径的支配。病理条件下,嘌呤受体（P2X受体）途径也参与逼尿肌感觉和运动功能的调节,P2X受体传导途径在泌尿系统病理生理中的作用越来越明显,P2X受体与膀胱过度活动症之间的关系越来越受到重视。本文就膀胱过度活动症时P2X各亚型在逼尿肌上的表达异常和功能异常与膀胱过度活动症之间可能的联系作综述。     

P2X受体与膀胱过度活动症

随着不稳定膀胱中阿托品抵抗性逼尿肌收缩的深入研究,学者们发现膀胱逼尿肌收缩和膀胱充盈两方面功能除了接受M受体支配外,嘌呤受体（P2X受体）传导途径也参与逼尿肌感觉和运动功能的调节。病理条件下,P2X受体传导途径在泌尿系统病理生理中的作用越来越明显,P2X受体与膀胱过度活动症之间的关系越来越受到重视。本文就膀胱过度活动症时P2X各亚型在逼尿肌上的表达异常和功能异常与膀胱过度活动症之间可能存在的联系作一综述。     

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.