阴茎微循环检测在阳痿诊断中的价值

目的：探讨阴茎头微循环检测在阳痿诊断中的意义。方法：检测２２例勃起功能障碍病人的阴茎微循环,与１７例健康志愿者进行比较。结果：血管性阳痿病人阴茎头微血管密度（２６．８±６．３ｖｓ４７．８±６．２,Ｐ＜０．０１）和异常微血管百分率（３３．２±３．６ｖｓ１２．８±１．３,Ｐ＜０．０１）与对照组相比有显著性差异;心理性阳痿病人的两项指标（微血管密度４７．２±６．８ｖｓ４７．８±６．２,Ｐ＞０．０５;异常微血管百分率１３．１±１．１ｖｓ１２．８±１．３,Ｐ＞０．０５）与对照组相比没有统计学差异。结论：阴茎头微循环障碍与阳痿病人的器质性改变有关,阴茎头微循环检测可用于血管性阳痿的辅助诊断。     

血管性阳痿阴茎血流动力学研究及微循环检测

目的：研究血管性阳痿病人阴茎头微循环及其血流动力学特点,并对二者相关性进行比较。　方法：分别检测１７ 例血管性阳痿病人和１１ 名健康志愿者的阴茎头微循环,同时用超声多普勒研究其血流动力学指标,并分析二者间的相关关系。　结果：血管性阳痿病人与健康志愿者阴茎头微血管密度为（２７．１±５．２）条／ｍ ｍ ２ ｖｓ （４７．８±６．２）条／ｍ ｍ ２ （ Ｐ＜ ０．０１）,异常微血管百分率为（３２．１±３．４）％ ｖｓ （１２．８±１．３）％ （ Ｐ＜ ０．０１）及阴茎 臂指数（ Ｐ Ｂ Ｉ）值与对照组相比差异显著;阴茎血流动力学指标中 Ｐ Ｂ Ｉ值与微循环检测的两项指标均显著相关;阴茎血流动力学指标中阴茎各动脉的血流速度与微循环指标相关不明显。　结论：血管性阳痿病人的阴茎头微循环有器质性改变,这种改变与阴茎血流动力学之间相关不明显,阴茎血流动力学指标的检测易受各种因素的干扰。     

药物性阴茎双功能超声对静脉性勃起功能障碍血流循环阻力的评估

本文自１９９５年５月￣１９９６年６月对１６例静脉性勃起功能障碍（ＶＥＤ组）应用药物性阴茎双功能超声检测（ＰＰＤＵ）来观察静脉关闭机制受损所致阴茎血流循环阻力变化。阴茎血流循环阻力监测指标（１）阻力指数（ＲＩ），（２）Ａ／Ｂ比值，（３）搏动指数（ＰＩ）。并以３２例心理性勃起功能障碍（ＰＥＤ组）作对照。研究结果提示ＶＥＤ组ＲＩ〈１，Ａ／Ｂ值〉０。ＰＥＤ组Ｒ１≥１，Ａ／Ｂ比值≤０。ＶＥＤ组ＰＩ平均数低于     

药物性阴茎双功能超声对静脉性勃起功能障碍血流循环阻力的评估

本文自１９９５年５月～１９９６年６月对１６例静脉性勃起功能障碍（ＶＥＤ组）应用药物性阴茎双功能超声检测（ＰＰＤＵ）来观察静脉关闭机制受损所致阴茎血流循环阻力变化。阴茎血流循环阻力监测指标（１）阻力指数（ＲＩ），（２）Ａ／Ｂ比值，（３）搏动指数（ＰＩ）。并以３２例心理性勃起功能障碍（ＰＥＤ组）作对照。研究结果提示ＶＥＤ组ＲＩ＜１，Ａ／Ｂ比值＞０。ＰＥＤ组ＲＩ≥１，Ａ／Ｂ比值≤０。ＶＥＤ组ＰＩ平均数低于ＰＥＤ组，但参数有重叠现象，两组３项阻力指标参数有非常显著性差异（Ｐ＜０．０１）。我们认为静脉关闭机制障碍使海绵体内压下降，并引起阴茎血流循环阻力改变，阻力指标ＲＩ＜１和Ａ／Ｂ比值＞０可作为静脉关闭机制障碍判断标准，而ＰＩ的价值有待进一步探讨。     

主动脉瓣替换术后近期及晚期左心室功能随访

目的：评价主动脉瓣替换（ＡＶＲ）术后左心功能的近期及其远期效果。方法：对１９７８年１２月至１９９６年１２月期间连续１２９例单纯行ＡＶＲ的病人进行分析。结果：术前Ｂ超示左心室舒张末期内径（ＬＶＥＤＤ）、收缩末期内径（ＬＶＥＳＤ）分别为（６４．５±９．３）ｍｍ、（４４．７±９．９）ｍｍ,术后１４天至３个月分别为（５１．９±７．２）ｍｍ、（３１．５±４．５）ｍｍ（Ｐ＜０．０１）;术后１～２年分别为（４７．６±６．１）ｍｍ、（２９．５±５．４）ｍｍ（Ｐ＜０．０１）。手术死亡率３．９％。术后随访６个月至１６年,平均４．４年,累计随访５０１病人·年。晚期死亡６例（１．２％病人·年）,５年及１０年生存率分别为８９．３％、７７．３％。血栓栓塞及与抗凝有关的出血率分别为０．８％病人·年、１．０％病人·年。结论：ＡＶＲ术后９５％病人的心功能恢复至Ｉ或Ｉ级,长期效果满意。故主动脉瓣病变、ＬＶＥＤＤ扩大并出现症状的病人,应行主动脉瓣替换术。     

高血压患者红细胞镁含量、Mg2+/Na+交换速率的研究

目的探讨原发性高血压（ＥＨ）、肾实质性高血压（ＲＨ）和肾血管性高血压（ＲＶＨ）患者红细胞镁含量（ＥＭＣ）、Ｍｇ２＋／Ｎａ＋交换速率（ＶＮＤｍａｘ）及其与血压的关系。方法原子吸收光谱火焰法。结果（１）ＥＨ组的ＥＭＣ［（２．０３±０．０６）ｍｍｏｌ／Ｌ］显著较正常对照组（２．１６±０．０４）、ＲＨ（２．１７±０．０５）和ＲＶＨ（２．１５±０．０４）组低,而ＶＮＤｍａｘ［（１５５．３±１５．２）μｍｏｌ·Ｌ－１·ｈ－１］显著较另外三组高（分别为９６．８±１３．２、９４．３±１４．２和９７．３±１２．５）。（２）ＥＨ组ＶＮＤｍａｘ与舒张压显著相关（ｒ＝０４８７２,Ｐ＜００５）。结论（１）ＥＨ患者ＶＮＤｍａｘ明显升高,是造成ＥＭＣ低下的原因,可能在疾病的发生发展中起一定作用。（２）ＲＨ、ＲＶＨ患者细胞镁代谢状况无异常。     

男子勃起功能障碍病人阴茎微循环检测

检测26例勃起功能障碍（ED）病人的阴茎微循环，与17例健康志愿者进行比较，器质性ED病人阴茎头微血管密度为271±5．2，健康者为47．8±6．2（P＜0．01）；异常微血管百分率则分别为32．1±3．4与12．8±1．3（P＜0．01）；心理性ED病人该两项指标与对照组相比没有统计学差异（血管密度47．2±6.8vs47．8±6．2．P＞0．05；异常血管百分率13．1±1．1vs12．8±1．3．P＞0．05）。以上结果揭示，阴茎头微循环障碍与ED病人的器质性改变有关，可用于器质性ED的辅助诊断。     

无支架异种生物瓣膜主动脉瓣替换术后左室功能变化

评价无支架异种生物瓣膜主动脉瓣替换术后２年左室功能的变化。将８０例同期施行主动脉瓣替换病人分为２组，５０例（年龄６９．３±９．３岁）应用ＴｏｒｏｎｔｏＳＰＶＴＭ瓣；３０例（年龄７１．６±７．７岁）作为对照组接受支架人工瓣膜替换。术前、术后１、６、１２及２４个月间记录Ｍ型及Ｄｏｐｐｌｅｒ超声心动图，采用计算机图像数字分析，定量测定左室功能的变化。随访期间，Ｔｏｒｏｎｔｏ组主动脉瓣跨瓣压差为０．８±０．６ｋＰａ（６．０±４．５ｍｍＨｇ），明显低于对照组２．３±０．９ｋＰａ（１７．３±６．８ｍｍＨｇ）；术后１个月，左室心肌质量下降２５％，左室＋Ｖｃｆ及－Ｖｃｆ明显增加（２．０±０．８／１．４±０．３ｓ－１，Ｐ＜０．０１；２．８±１．２／１．８±０．７ｓ－１，Ｐ＜０．０１）。术后６个月，左室功能进一步改善，心室肥厚的消退更趋完全，该变化在其后的随访期间保持稳定。结论：与支架瓣膜相比，无支架异种生物瓣膜具有较大瓣口开放面积及低跨瓣压差，这促进了术后左室功能的恢复及病理性肥厚的逆转     

急症腹部手术后并发急性肺损伤的防治

目的：探讨腹部急症手术后肺损伤的预防和治疗。方法：回顾性分析４０例外科危重病人（ＡＰＡＣＨＥⅡ＞８分）首次手术后２４小时内的ＰａＯ２／ＦｉＯ２、ＡａＤＯ２和呼吸频率（ＢＲ）与急性肺损伤（ＡＬＩ）的关系,分为ＡＲＤＳ组（ Ⅰ组,１２例）和急性肺功能不全组（Ⅱ组,２８例）,同时分析液体治疗和机械通气模式在防治ＡＲＤＳ中的作用,并计算死亡率。结果： Ⅰ组的ＰａＯ２／ＦｉＯ２、ＡａＤＯ２、ＢＲ和死亡率分别为１８．２±４．5ｋＰａ、２６８．７±４１．３ｍｍＨｇ、３３．７±６．９次／分和４１．７％（５／１２）;Ⅱ组则分别为２３．０±５．9ｋｐａ、２４３．８±５３．１ｍｍＨｇ、２６．９±７．６次/分和３．６％（１／２８）。结论：外科危重病人术后２４小时内往往伴有不同程度的急性肺损伤,极易发生ＡＲＤＳ;ＰａＯ２／ＦＩＯ２和呼吸频率是早期发现ＡＲＤＳ的临床指标;控制补液量、早期给予激素和尽早加用ＰＥＥＰ（呼气末正压）是防治ＡＲＤＳ的三大重要措施。     

间断冷血与持续温血灌注心肌保护的对比研究

目的为探索临床上更为安全实用的心肌保护方法，对４０例心脏手术患者用含钾冷氧合血间断灌注与含钾温氧合血持续灌注进行对比研究。方法应用含钾温血持续灌注与含钾冷血间断灌注心肌保护法行心内直视手术各２０例，分别对复跳情况、心肌酶谱（ＡＳＴ，ＣＫ，ＣＫ－ＭＢ，ＬＤＨ）及手术前后心功能变化进行对照分析。结果持续温血组与间断冷血组自动复跳率分别为１８／２０和７／２０（Ｐ＜０．０５），超声心动图测得左心功能参数（手术前ＴＴＥ结果与停机拔管后ＴＥＥ结果之差）：射血分数（ＥＦ）分别为８．６９±６．２％和－１．３０±１２．７３％（Ｐ＜０．０５）；短轴缩短率（ＦＳ）分别为７．６±１０．７％和－１．７３±６．８％（Ｐ＜０．０５）；左心室舒张末内径（ＬＶＥＤＤ）分别为１．３７±０．３１ｃｍ和０．６±０．８８ｃｍ（Ｐ＜０．０５）。两组心肌酶谱无差异（Ｐ＞０．０５）。结论间断冷血灌注心肌保护法在临床上更为安全     

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.