三种插管型喉罩在预测重度困难气道管理中的应用

目的回顾性评价Cookgas、Fastrach和CTrach三种插管型喉罩在预测重度困难气道管理中应用的临床效果。方法 21例择期在全身麻醉下行整形外科手术的预测重度困难气管插管患者,Mallampati分级Ⅲ或Ⅳ级。麻醉医师通过个人判断自行决定插管型喉罩使用类型。收集、整理气管插管过程的全部信息。在21例患者中,7例患者采用Cookgas喉罩联合纤维光导支气管镜(Fibreoptic Bronchoscope,FOB)引导气管插管(Cookgas组),8例患者采用Fastrach喉罩联合FOB(Fastrach组)以及6例患者采用CTrach喉罩(CTrach组)完成气管插管。结果除Fastrach组1例喉罩置入失败,其余患者均成功置入插管型喉罩。Cookgas组7例患者均在两次内获得FOB引导气管插管成功;7例置入Fastrach喉罩的患者,有6例在FOB引导下成功完成气管插管,1例失败;CTrach组6例患者均获得首次气管插管成功。三组患者喉罩首次置入成功率差异无统计学意义,但Fastrach组和CTrach组喉罩置入时间分别为(33.3±15.5)s和(41.7±22.3)s,明显长于Cookgas组的(23.9±16.2)s(P0.05)。结论 Cookgas、Fastrach和CTrach三种插管型喉罩均可安全、有效地应用于预测重度困难气管插管患者,但对于张口度小于15mm和/或颈部瘢痕重度挛缩或颈部置有巨大扩张器的患者,Cookgas喉罩具有明显优势。     

颈椎手术患者喉罩辅助纤维支气管镜引导气管插管的效果

目的 评价颈椎手术患者喉罩辅助纤维支气管镜引导气管插管的效果.方法 择期行前路颈椎手术患者40例,性别不限,年龄18～55岁,体重50～75 kg,ASA分级Ⅰ或Ⅱ级,Mallampatis分级Ⅰ或Ⅱ级.采用随机数字表法,将患者随机分为2组(n=20):纤维支气管镜引导气管插管组(FOB组)和喉罩辅助纤维支气管镜引导气管插管组(LMA组).麻醉诱导后,进行气管插管.记录气管插管时间和气管导管置入情况;记录气管插管期间高血压、心动过速和低氧血症的发生情况;记录LMA组喉罩置入情况、置入时间和拔除气管导管时喉罩移位情况.记录拔除喉罩带血和术后咽喉部不良反应的发生情况.结果 喉罩1次置入成功率为90％,置入时间为(13±3)s.两组气管插管成功率均为100％.与FOB组比较,LMA组气管插管时间缩短,1次气管插管成功率升高(P＜0.05).两组气管插管期间血液动力学稳定,均未发生高血压、心动过速和低氧血症.LMA组气管导管拔除时有8例(40％)发生喉罩移位;拔除喉罩时1例发生喉罩带血;术后1例发生咽部轻微疼痛;两组均未见其它不良反应的发生.结论 颈椎手术患者喉罩辅助纤维支气管镜引导气管插管不仅可确保有效通气,还可提高引导气管插管成功率,明显缩短气管插管时间.     

颈椎手术患者i-gel喉罩辅助纤维支气管镜引导气管插管的效果

目的 评价颈椎手术患者i-gel喉罩辅助纤维支气管镜引导气管插管的效果.方法 择期全麻气管插管的颈椎手术患者40例,ASA分级Ⅰ或Ⅱ级,性别不限,年龄36～62岁,体重57～78 kg,身高165～177 cm,Mallampati分级Ⅰ～Ⅲ级,随机分为2组(n=20):口咽通气道辅助FOB引导气管插管组(O组)和i-gel喉罩辅助FOB引导气管插管组(I组).麻醉诱导后,进行气管插管.记录气管插管时间、纤维支气管镜咽部解剖结构显露分级、气管插管置人情况;记录气管插管期间高血压、心动过速和低氧血症的发生情况;记录拔除喉罩带血和术后咽喉部不良反应的发生情况.结果 i-gel喉罩均1次置入成功,置入时间为(10±3)s,两组气管插管成功率均为100%;与O组比较,I组气管插管时间缩短,1次气管插管成功率升高,纤维支气管镜咽部解剖结构显露分级升高(P＜0.05).两组气管插管期间血液动力学稳定,均未发生高血压和心动过速和低氧血症,I组仅1例喉罩粘血,两组均未见其他不良反应发生.结论 颈椎手术患者i-gel喉罩辅助纤维支气管镜引导气管插管不仅可确保有效的通气,而且可提高引导气管插管成功机率,缩短操作时间.     

插管型喉罩LMA-Fastrach与I-gel引导盲探气管插管的比较

目的比较插管型喉罩LMA-Fastrach和I-gel喉罩引导盲探气管插管的临床效果。方法择期全麻手术患者60例,随机分为两组,分别采用LMA-Fastrach(L组)和I-gel(I组)行盲探气管插管。记录喉罩和气管导管插入时间、盲探插管总时间,及喉罩和气管导管尝试插入次数。结果I组喉罩插入时间[(20±3)s vs.(27±5)s]、盲探插管总时间[(85±4)s vs.(95±6)s]明显短于L组(P0.05)。两组气管导管插入时间以及喉罩、气管导管插入次数差异无统计学意义。结论LMA-Fastrach和I-gel喉罩均可用于引导盲探气管插管。     

CTrach喉罩改进导入法引导气管插管的效果

CTrach 光导纤维可视性气管插管型喉罩(CTrach喉罩)是一种具有光导纤维束和可拆卸显示器的气管插管型喉罩,可在直视下暴露声门,观察气管导管的置入方向、角度、与声门的位置关系以及是否进入声门,弥补了盲探技术的不足,从而减少了损伤勺状软骨、误入食管等情况的发生[1-2].     

全身麻醉诱导后经多功能插管型喉罩盲探气管插管的临床观察

目的 观察全身麻醉患者经多功能插管型喉罩盲探行气管插管的可行性及安全性. 方法 选择ASA分级Ⅰ、Ⅱ级,年龄18～77岁择期行全身麻醉下手术的患者100例.麻醉诱导使用芬太尼4μg/kg、丙泊酚1.5～2.0 mg/kg、罗库溴铵0.6 mg/kg,诱导后先置入多功能插管型喉罩,通气行纤维支气管镜检查并定位后,经喉罩盲探插入配套的鹰嘴气管导管,观察放置喉罩及气管插管的次数和时间,记录诱导前、放置喉罩前后、气管插管前后的BP和HR.结果 置入喉罩和气管插管均1～2次成功,置入喉罩时间平均(11.0±3.2)s,气管插管时间平均(10.5±6.2)s,插管成功退出喉罩后即刻SBP、DBP和HR与诱导前比较,差异均无统计学意义(P＞0.05). 结论 经多功能插管型喉罩盲探气管插管,安全、快捷、有效,患者舒适、刺激小,比经典的插管型喉罩盲探插管更具有优势.     

i-gel喉罩用于肥胖患者的气道管理

目的评估i-gel喉罩用于肥胖患者气道管理的安全性。方法择期全麻手术患者60例,BMI30kg/m2,年龄18～65岁。随机均分为i-gel喉罩组(I组)和气管插管组(E组)。记录插入气管导管或喉罩所需时间、插入次数、成功率、拔管时间、苏醒时间;测量喉罩气道密封压(OLP),纤维支气管镜检查喉罩对位情况;记录入室后、插管前、插管即刻、拔除前、拔管即刻的HR、SBP、DBP及术后不良反应发生情况。结果 I组插入时间明显短于E组(P0.01),喉罩首次置入成功率明显高于E组(P0.05);I组插管(喉罩)即刻、拔管(喉罩)即刻HR明显慢于E组,SBP、DBP明显低于E组(P0.05)。I组拔管(喉罩)时间、苏醒时间短于E组(P0.05)。OLP为(28.7±6.5)cm H2O,所有患者OLP均大于Ppeak,喉罩对位良好。I组呛咳、咽痛明显低于E组(P0.01),两组均未发生反流。结论肥胖患者全麻手术中i-gel喉罩与气管插管通气效果相同,但插管期和拔管期应激反应更小,不良反应更少,且简便快捷。     

Proseal喉罩与支纤镜联合Aintree导管用于颈椎不稳患者气管插管的临床研究

目的 通过与清醒经鼻支纤镜插管对比,研究Proseal喉罩与支纤镜联合Aintree导管用于颈椎不稳患者气管插管的有效性和安全性。方法 因颈椎骨折或严重颈椎间盘突出拟行颈椎减压内固定手术的患者40例,随机分配至以下两组：A组20例,清醒表麻后行经鼻支纤镜引导插管,然后麻醉诱导;B组20例,常规麻醉诱导后置入Proseal喉罩,沿喉罩在支纤镜引导下将Aintree导管插入气管内,退出喉罩后经Aintree导管置入气管插管。监测插管前（T0）、开始插管（T1）、插管成功时（T2）、插管成功后1min（T3）、插管成功后3min（T4）的平均动脉压（MAP）和心率（HR）;记录支纤镜插管时间、插管总时间（表麻时间或置喉罩时间加支纤镜插管时间）和插管相关并发症。结果 A组有1例因不能配合改为诱导后支纤镜插管,B组所有病例插管成功。T2和T3两时点,A组HR（92±17次/分,95±18次/分）显著高于B组（78±13次/分,83±17次/分）;T3时点A组MAP（93±28mmHg）显著高于B组（80±24mmHg）（P<0.05）;A组在T2、T3两时点的HR、MAP均显著高于各自的T0时点基础值（P<0.05）。插管的总时间两组相当（A组184±55s,B组179±27s,P>0.1）,而B组支纤镜插管时间较短（A组62±32s,B组39±18s,P<0.05）。两组患者术后无任何插管相关并发症。结论 Proseal喉罩与支纤镜联合Aintree导管用于颈椎不稳患者气管插管与传统支纤镜清醒插管效果相当,但血流动力学更平稳,是安全有效的困难气道处理新技术。     

喉罩用于幼猪动物实验中气道管理的效果

目的 评价喉罩用于幼猪动物实验中气道管理的效果.方法 雄性幼猪72头,2～3月龄,体重22 ～ 32 kg,采用随机数字表法,将其分为2组(n=36):气管插管组(TI组)和喉罩组(LMA组).LMA组置入4#ProSeal喉罩,TI组插入7.0#气管导管.插管成功后,进行间歇正压通气,潮气量8 ～ 10 ml/kg,通气频率16次/min,吸呼比1.0∶1.5,吸入氧浓度50％,氧流量3L/min,维持PETCO2 35 ～ 45mm Hg.麻醉维持:静脉输注丙白酚15 mg·kg-1 ·h-1和瑞芬太尼40 μg·kg-1·h-1,间断静脉注射维库溴铵0.1 mg/kg,通气时间1.5 h.记录插管时间和一次插管成功情况.分别于气管插管或喉罩置入前、气管插管和喉罩置入成功和拔除气管导管或喉罩后即刻记录SpO2,并于上述时点采集动脉血样,进行血气分析.记录咽喉损伤和胃胀气的发生情况.结果 与TI组比较,LMA组插管时间缩短,一次插管成功率、气管插管和喉罩置入成功时SpO2和PaO2升高,咽喉损伤发生率和PaCO2降低(P＜0.05),胃胀气发生率差异无统计学意义(P＞0.05).2组幼猪在机械通气期间,SpO2均＞95％,PaO2均＞ 150 mm Hg.结论 喉罩通气用于幼猪动物实验气道管理是便捷、有效和安全的方法.     

喉罩在颅内动脉瘤介入手术麻醉中的效果观察

目的观察20例喉罩在颅内动脉瘤介入手术麻醉中的应用效果。方法将40例行颅内动脉瘤介入手术患者依据麻醉给药途径分为喉罩组(置入普通型喉罩)和插管组(喉镜引导下经口明视插入内径7.5 mm气管导管),各20例。记录两组患者麻醉诱导前,插管(罩)即刻、插管(罩)后3 min、拔管(罩)即刻、拔管(罩)后3 min的MAP、HR,同时记录术中丙泊酚和瑞芬太尼的用量以及苏醒时间。结果插管组(除麻醉诱导前)各时间点的HR、MAP均较喉罩组明显升高(P0.05)。插管组术中丙泊酚、瑞芬太尼用量明显多于喉罩组。插管组术后苏醒时间明显长于喉罩组,差异具有统计学意义(P0.05)。结论喉罩用于全麻下颅内动脉瘤介入手术通气效果好、安全可靠,且较气管插管有血流动力学平稳、用药少、苏醒快等优点。     

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.     

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.     

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.