SLIPA喉罩在老年膝关节镜全麻手术中的应用

目的：探讨喉罩在老年膝关节镜手术中应用的可行性和安全性。方法择期膝关节镜手术老年患者50例,美国麻醉医师协会（ASA）Ⅰ～Ⅲ级,随机分为两组,实验组和对照组,实验组采用喉罩通气全麻（S组）,对照组采用气管插管全麻（T组）。观察并记录诱导时（T0）、置入SLIPA喉罩/插气管导管即刻（T1）、置入喉罩/插入导管2分钟（ T2）、移开喉罩/拔气管导管即刻（ T3）、移开喉罩/拔气管导管2分钟（T4）患者的SBP、DBP、MAP、HR,记录各时相PETCO2、Ppeak以及术后两组患者移开喉罩/拔管期并发症,烦躁和呛咳、术后咽痛、术后声嘶的发生率。结果 T组与S组比较,插管或喉罩置入后T2时相T组心率、血压明显增加,差异有统计学意义（P0.05）;术毕拔管或移开喉罩时及拔管或移开喉罩后,T组血流动力学波动情况明显大于S组,差异有统计学意义（P〈0.05）;术后并发症组患者术后不良反应及并发症S组明显少于T组（P〈0.05）。结论与气管插管全麻比较,喉罩通气全麻对老年患者心率血压影响小,术后并发症少,能安全运用在老年膝关节镜手术。     

SLIPA喉罩和气管插管全麻在腹腔镜胆囊手术中的应用比较

目的 观察SLIPA喉罩与气管插管对患者血流动力学和气道阻力的影响.方法 择期全麻下腹腔镜胆囊手术患者60例,随机均分为SLIPA喉罩组(A组)和气管插管组(B组),记录插入喉罩/气管导管前(T0)、插入喉罩/气管导管后1 min(T1)、3 min(T2)和拔喉罩/气管导管前(T3)、拔喉罩/气管导管后1 min(T4)、3 min(T5)的SBP、DBP、HR和SpO2,同时在8 ml/kg潮气量下监测T1～T3时的平均气道压(Pmean)、气道峰压(Ppeak)和PETCO2,并观察有无反流误吸情况及术后咽喉部并发症.结果 与T0时相比,B组T1、T3、T4时SBP、DBP明显升高,HR明显增快,且相应时点均高于A组(P＜0.05);A组在T1、T2时的Pmean、Ppeak低于B组(P＜0.05);术后咽部不适患者B组(9例)明显多于A组(2例)(P＜0.05).结论 SLIPA喉罩通气用于腹腔镜胆囊手术时,患者应激反应小,术后咽喉部并发症少.     

Supreme喉罩在老年病人麻醉中的应用

目的 探讨Supreme喉罩在老年病人麻醉中使用的安全性及有效性.方法 择期腹部手术全麻患者100例,年龄65～93岁,随机均分为喉罩组(S组)及气管插管组(T组).全麻诱导后插入Supreme喉罩/气管导管.记录一次插入成功率及所需时间;记录两组患者麻醉诱导前(T1)、插入前(T2)、插入时(T3)、拔除喉罩/气管导管前(T4)及拔除喉罩/气管导管时(T5)的SBP、DBP及HR;术中SpO2、PETCO2和气道峰压(Ppeak);观察术中误吸、拔除喉罩/气管导管时呛咳及拔除喉罩/气管导管后低氧血症、咽喉疼痛情况.结果 与T组比较,S组喉罩一次插入成功率较高(P<0.05)、插入时间明显缩短(P<0.01);T3、T5时SBP、DBP、HR波动不明显;拔除喉罩后低氧血症及咽喉痛发生率减少(P<0.01),且无呛咳病例.两组术中SpO2、PETCO2和Ppeak均在正常范围内,均无误吸发生.结论 Supreme喉罩操作简便易行,插入/拔除操作对血流动力学无明显影响,不引起呛咳,术后不良反应少,可安全有效地用于老年患者全麻气道管理.     

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。     

喉罩通气全麻应用于老年人腹部手术的临床观察

目的 探讨气管捕管和喉罩通气道用于老年全身麻醉对血液动力学的影响.方法 将40例老年全麻腹部手术患者随机分为2组.喉罩组(L组):全麻诱导后置入喉罩;插管组(M组):全麻后喉镜下气管插管维持通气.分别记录诱导前(T0)、簧喉罩或气管导管前(T1).喉罩置人或气插管即刻(T2),之后2min(T3),4min(T4),6...     

脑电双频指数用于七氟醚全麻喉罩自主通气实施乳腺癌根治术的临床意义

目的 探讨腩电双频指数(BIS)对七氟醚全麻喉罩自主通气下实施乳腺癌根治术的指导意义.方法 40例ASA Ⅰ或Ⅱ级择期乳腺癌根治术患者,随机均均分为BIS组和对照组.记录麻醉期间不同时点吸气末七氟醚浓度(CINSev)、呼气末七氟醚浓度(CETSev)、SBP、DBP、HR、SpO2、PETCO2、VT、每分钟通气量(VE)、RR、气道峰压(PPEAK),并取外周动脉血行血气分析.结果 两组均可获得满意的插管条件,BIS组置入喉罩前CETSev显著低于对照组(P<0.01),诱导时间显著长于对照组(P<0.05),诱导期间自主呼吸抑制发生率显著低于对照组(P<0.05),清醒时间和拔除喉罩时间均显著短于对照组(P<0.05).BIS组麻醉期间CETSev和CINSev均显著低于对照组(P<0.01).两组的SBP、DBP、HR及VT、VE、RR、PPEAK各时点变化差异无统计学意义.两组PaO2、PaCO2、碳酸氰根浓度(HCO3)、SaO2均维持正常;BIS组pH及PaCO2于插入喉罩后15 min及切皮时均显著低于对照组(P<0.01).结论 BIS指导七氟醚全麻喉罩自主通气,可减少七氟醚用量,自主呼吸维持较平稳.血流动力学稳定,呼吸功能及血气指标接近正常,全麻苏醒迅速.     

食管引流型喉罩用于乳房悬吊术中的临床观察

目的比较食管引流型喉罩和气管插管用于乳房悬吊术对患者的血流动力学和应激激素的影响。方法60例ASAI或Ⅱ级,择期在全麻下实施乳房悬吊术的患者,随机均分为喉罩组和气管插管组。在麻醉诱导前(T0)、插入喉罩/气管导管前(T1)、插入喉罩/气管导管后(T2)及其后5min(T3)、10min(T4)、15min(T5)和手术开始时(T6)、拔管后(T7)。记录SBP、DBP、HR。同时在T0、T1、T2、T6、T7时点抽取患者的外周静脉血,应用高效液相色谱分析法测定血浆肾上腺素(AE)、去甲肾上腺素(NE)、多巴胺(DA)水平。结果气管插管组T2时点SBP、DBP、HR显著高于喉罩组(P<0.05),AE、NE、DA在T2、T7时点均显著高于喉罩组(P<0.05)。结论全麻喉罩通气用于乳房悬吊术患者优于气管插管,易于维持血流动力学稳定,应激反应轻,手术后恢复迅速。     

喉罩用于隆胸手术患者气道管理的效果

[摘要]目的观察喉罩通气全凭静脉麻醉用于隆胸术的临床效果。方法选择ASAI～Ⅱ级女性隆胸手术患者40例,年龄23—42岁;体重45—67kg;随机分为气管内插管组（A组,n=20）与喉罩组（B组,n=20）两组,A组静脉注射芬太尼0．2mg、丙泊酚2．0—2．5mg／kg、阿曲库铵0．15mg／kg诱导,插入气管导管;B组静脉注射芬太尼0．1mg、丙泊酚2．0～2．5mg／kg诱导,插入普通型喉罩,两组均接麻醉机行IPPV模式控制呼吸,两组均以微量泵持续泵入丙泊酚6～9tLg／（kg·min）,瑞芬太尼0．1—0．15μg/（kg·min）维持麻醉,A组间断静脉注射阿曲库铵,手术结束前10min停止用药,待受术者呼之能应,呼吸良好时拔除气管导管或喉罩。观察记录两组患者气管内插管和喉罩置入时间及置人情况、监测病人麻醉前（11D）、插管（插喉罩）后即刻（T1）、分离胸部肌肉时（他）、植入假体时（T3）、喉罩和气管导管拔除后即刻（T4）时的MAP、HR及SpO：的变化、通气状态以及操作时及术后的相关不良反应。结果A组1次成功完成气管内插管率与B组1次成功置入喉罩率无显著性差异（P〉0．05）;A组诱导时芬太尼用量显著多于B组（P〈0．05）;A组气管内插管后即刻（T1）以及拔管后即刻（rr4）的MAP及HR较诱导前显著升高（P〈0．05）,分离胸部肌肉时（T2）与植入假体时（T3）SBP、DBP、MAP和HR值均低于麻醉前,而B组T1、T2、T3时均较诱导前低（P〈0．05）;T4与诱导前相比无明显差异（P〉0．05）。A组插管时发生口腔粘膜出血及术后发生咽喉疼痛及呛咳的患者明显多于B组（P〈0．05）。结论与气管内插管全麻相比,喉罩通气全凭静脉麻醉施行隆胸手术,麻醉效果更满意、循环更稳定、并发症更少,术后恢复更舒适。     

喉罩通气全麻在脑血管动脉瘤介入栓塞治疗中的应用

目的 评价喉罩通气全麻应用于脑血管动脉瘤介入栓塞治疗的可行性和安全性,并与气管插管全麻作比较.方法 选择择期行颅内动脉瘤介入栓塞术患者80例,年龄25岁～65岁,ASA Ⅰ～Ⅱ级,采用随机数字表法分为喉罩组(L组)和气管插管组(T组),每组40例.记录患者诱导前、诱导后(插入气管导管或喉罩前)、插管即刻、插管后1、3 ...     

SLIPA喉罩与气管插管在老年全麻手术中的应用比较

目的 比较应用SLIPA喉罩与气管插管对老年患者全麻手术中血流动力学的影响.方法 腹腔镜胆囊手术96例,年龄65～81岁.随机均分为喉罩组(S组)和气管插管组(G组).记录入室后(T0)、麻醉诱导时(T1)、置入喉罩或气管导管即刎(T2)、置入喉罩或气管导管后3 min(T3)、气腹后20 min(T4)、拔除喉罩或气管导管前(T5)、拔除喉罩或气管导管后即刻(T6)的SBP、DBP、HR、SpO2、气道峰压(Paw);观察拔除喉罩(导管)后并发症的发生情况.结果 与T0时比较,两组T1时SBP、DBP均下降,HR减慢(P＜0.05);与T1时比较,G组T2时SBP、DBP明显升高,HR增快(P＜0.05);与T5时比较,G组T6时SBP、DBP明显升高,HR增快(P＜0.05).G组发生呛咳、躁动、喉痛及声嘶的患者明显多于S组.结论 全麻腹腔镜胆囊手术中使用SLIPA喉罩控制血流动力学平稳、安全性好、并发症少.     

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.