大鼠脊髓慢性压迫性损伤动物模型的建立

目的 建立一种大鼠脊髓慢性压迫性损伤模型。方法 应用平头不锈钢螺钉从大鼠C4椎体前侧钻入压迫脊髓腹侧，术后保留螺钉30d，并用联合行为评分(CBS)、神经电生理、光镜、电镜检查进行综合评判。结果 模型动物脊髓慢性压迫随着螺钉轻、中、重程度的不同，其术后行为学、运动诱发电位(MEP)及组织学观察符合脊髓慢性压迫症病理改变的特点。结论 建立了大鼠脊髓慢性压迫性损伤模型，此模型制作简便，可重复性强，脊髓损伤能表现出不同的压迫深度，为进一步研究脊髓慢性压迫损伤病理机制奠定了基础。     

蛛网膜下腔灌注胶质细胞源性神经营养因子对损伤脊髓再生及功能恢复的影响

目的：探讨胶质细胞源性神经营养因子（GDNF）对大鼠脊髓完全性横断后脊髓再生及功能恢复的影响。方法：采用大鼠胸段（T7-T8）脊髓完全横切损伤模型，将SD雌性大鼠随机分为正常组（n=6）、假手术组（n=6）、单纯横断组（n=10）、GDNF治疗组（n=10）。于大鼠脊髓损伤术后不同时间点进行行为学评估。24周时行生物素葡聚糖胺（BDA）顺行示踪处理，取材前行电生理检测。所取脊髓标本作神经中丝（NF-200）、生长相关肽-43（GAP-43）、胶质原纤维生长蛋白（GFAP）免疫组化检查，并应用图像分析系统进行定量分析。结果：行为学评分表明，3周后，GDNF组好于单纯横断组（P〈O．05），术后24周，GDNF组和单纯脊髓横断组中均未记录到SEP波形，BDA示踪也未见伤区及远段蓝染的神经纤维，但GDNF组空泡样变较单纯横断组轻。免疫组化图像分析GDNF组的NF-200和GAP-43染色结果与单纯横断组间无统计学差异（P〉0．05）：但GDNF组GFAP染色明显弱于单纯横断组（P〈0．05）。结论：GDNF能一定程度上改善脊髓损伤区及两端的神经细胞功能，但没有功能意义上的神经纤维再生。     

常压及控制性降压下脊髓急性牵拉损伤比较研究

目的 评价控制性降压是否增加脊髓对牵拉损伤的易感性。材料与方法健康成年杂种犬6只，随机分为常压和控制性降压脊髓牵拉损伤组。观察常压及控制性降压水平下相同程度牵拉损伤后脊髓血流(SCBF)、体感诱发电位(SEP)、神经源性运动诱发电位(NMEP)改变的差异。结果 外周血有创动脉压(MABP)平均下降幅度为40．5％。经SSPS统计软件独立样本t检验，不同牵拉水平下，常压组及低压组的SCBF(％)、SEP波幅(Asep)(％)及NMEP波幅(％)无显著差异。结论 尼卡地平控制性降压不增加脊髓对牵拉损伤的易感性。     

周围神经移植修复大鼠陈旧性脊髓损伤的实验研究

目的：探讨利用自体周围神经组织游离移植修复大鼠陈旧性脊髓损伤病理机制。方法：利用改良Allen撞击方法建立脊髓打击损伤模型后，将大鼠分为2组，各20只。神经移植组切取后肢腓肠神经，利用显微外科技术去除神经外膜，将其修剪成小段，游离移植于脊髓损伤处，对照组不作处理。分别于术后4、12周，在光镜下观察脊髓损伤段及移植周围神经再生情况，并应用辣根过氧化物酶神经逆行示踪技术进行脊髓神经束的再生评价。分3个时点（1、2、3个月）观察大鼠后肢运动功能恢复情况。结果：对照组脊髓变性，可见瘢痕和空洞，移植组术后12周，损伤区脊髓与周围神经融合良好，可见再生轴突，跨越损伤段脊髓，周围神经无变性。12周时脊髓神经束的再生评价结果提示：神经移植组优于对照组．移植组大鼠后肢运动功能明显恢复。结论：周围神经组织游离移植修复大鼠陈旧性脊髓损伤后，存活良好并可促进大鼠脊髓结构和功能的恢复。     

胚胎脊髓移植后大鼠损伤脊髓c-Jun免疫反应的变化及其意义

目的：研究大鼠胚胎脊髓移植后能否影响,c-Hun免疫反应的表达和脊髓损伤后大鼠功能的恢复,方法;将动物分为脊髓半切洞损伤加胚胎脊髓移植组（A组）和单纯脊髓板切洞损伤加明胶海绵填塞组（B组）,每个时相点每组6只动物,术只1,3,7,14和28天,应用行为学和电生理检查观察大鼠功能恢复情况,应用免疫细胞化学方法,c-Jun免疫反应的表达,采用计算机图像分析技术,进行定量分析。结果：大鼠脊髓损伤后c-Jun免疫反应的表达A组明显高于B组,胚胎脊髓抑制后可使损伤脊髓高表达c-Jun 免疫反应持续到术后7天,增加的c-Jun免疫反应阳性细胞数目与神经功能的改善相平行。结论：胚胎脊髓移植后可使损伤脊髓高表达c-Jun,并促进大鼠功能恢复。     

肋间神经转位脊髓神经根桥接联合应用GDNF促进大鼠脊髓损伤后功能恢复

目的：肋间神经转位脊髓神经根桥接联合应用胶质源性神经营养因子(GDNF)恢复大鼠脊髓损伤的功能。方法：将成年大鼠分为脊髓半切洞损伤组(A组)、脊髓半切洞损伤 肋间神经转位脊髓神经根桥接组(B组)、脊髓半切洞 肋间神经转位脊髓神经根桥接 胶质源性神经营养因子(C组)。手术后应用联合行为评分(CBS)。感觉诱发电位(SEP)和运动诱发电位(MEP)检查，测定脊髓功能恢复情况。结果：3组CBS得分A组＞B组＞C组，SEP和MEP潜峰时，均A组＞B组＞C组，统计分析均有显著差异性(P＜0.05)。结论：肋间神经转位脊髓神经根桥接联合应用胶质源性神经营养因子能促进损伤脊髓功能的恢复。     

体外转基因成肌细胞移植对大鼠损伤脊髓细胞凋亡的影响

目的：探讨大鼠脊髓损伤后胚胎脊髓和腺病毒介导的脑源性神经生长因子（AxCA-BDNF)体外转基因成肌细胞移植对大鼠脊髓细胞凋亡的影响。方法：将动物分为：大鼠脊髓半切洞损伤明胶海绵填充组（A组）,大鼠脊髓半切洞损伤应用胚胎脊髓移植组（B组）,脊髓半切洞损伤损伤AxCA-BDNF基因转染的成肌细胞移植组（C组）大鼠脊髓半切洞损伤后应用胚胎脊髓和AxCA-BDNF基因转染的成肌细胞移植组（D组）。手术后1、3、7、14、28d应用行为学和电生理检查观察大鼠功能恢复情况,对脊髓损伤区进行细胞凋亡的检测（TUNEL）以及Bcl-2蛋白表达的测定（免疫组化法）。采用计算机图像分析技术,进行定量分析。结果：A、B、C、D四组中均发现凋亡细胞及Bcl-2蛋白阳性表达细胞,图像分析发现,各组凋亡细胞核为A＞B＞C＞D;Bcl-2免疫反应阳性细胞表达顺序为D＞C＞B＞A,Bcl-2免疫反应阳性细胞的表达与大鼠后肢功能恢复有同样的变化趋势。结论：大鼠胚胎脊髓和体外转基因成肌细胞移植能抑制脊髓损伤后的细胞凋亡。     

脑源性神经生长因子转基因细胞移植和大剂量甲基强的松龙对脊髓损伤后细胞凋亡的影响

目的：探讨大鼠脊髓损伤后腺病毒介导的脑源性神经生长因子（AxCA-BDNF）体外转基因成肌细胞移植和静脉内注射大剂量甲基强的松龙（MP）对大鼠脊髓损伤后细胞凋亡的影响。方法：120只Wistar大鼠分为：脊髓挫伤组（A组），脊髓挫伤后AxCA-BDNF基因转染的成肌细胞移植组（B组），脊髓挫伤后静脉内注射大剂量MP治疗组（C组），脊髓挫伤后同时应用AxCA-BDNF和MP组（D组）。手术后1、3、7、14、28d用行为学和电生理检查观察大鼠功能恢复情况，并用计算机图像分析技术对脊髓损伤区细胞凋亡（TUNEL法）和Bcl-2蛋白表达（免疫组化法）进行定量分析。结果：四组中均发现凋亡细胞及Bcl-2蛋白阳性表达细胞．图像分析发现四组凋亡细胞核数为A组〉B组〉C组〉D组；Bcl-2免疫反应阳性细胞表达顺序为D组〉C组〉B组〉A组。大鼠后肢功能恢复和电生理检查也有类似的变化趋势。结论：体外转基因成肌细胞移植和大剂量MP都能抑制大鼠脊髓损伤后的细胞凋亡，促进大鼠后肢功能恢复，两者联合应用具有协同作用。     

神经干细胞移植对大鼠脊髓损伤后BDNF与GAP-43基因表达的影响

目的：研究海马源性神经干细胞(NSCs)移植对大鼠脊髓损伤(SCI)后生长相关蛋白43(GAP-43)及脑源性神经营养因子(BDNF)基因表达的影响，探讨神经干细胞移植修复大鼠脊髓损伤的机制。方法：NSCs提取自新生胎鼠的海马区，经过培养及鉴定。实验分为3组：NSCs移植组、DMEM填充组、正常对照组。大鼠SCI后第7d移植NSCs，应用RT-PCR法观察NSCs移植后，大鼠脊髓损伤区GAP-43和BDNF基因表达的变化。结果：NSCs移植组较单纯损伤组明显增强了GAP-43mRNA与BDNFmRNA的表达。结论：NSCs移植后改变脊髓损伤区的微环境，上调BDNFmRNA，促进GAP-43mRNA的表达，是修复脊髓损伤的机制之一。     

胚胎脊髓不同移植方法对成年大鼠损伤脊髓神经元的影响

目的：探讨胚胎脊髓不同移植方法防止成年鼠脊髓轴突损伤后引起的神经元萎缩的作用。方法：采用Wistar成年大鼠腰脊髓半切洞损伤模型。将实验动物分为五组：A组为正常对照组,B组为损伤组;C组为损伤＋移植组;D组为损伤＋移植＋椎旁肌组;E组为损伤＋移植＋大网膜组,手术后应用行为学和电生理检查观察大鼠神经功能恢复情况,应用尼氏染色方法观察神经元的大小,采用计算机图像分析技术,进行定量分析。结果 胚胎脊髓不同移植方法均可以防止老年鼠脊髓轴突损伤引起的神经元萎缩,图像分析发现其作用为E组＞D组＞C组＞B组＞A组,尤以E组效果最好,可以完全恢复损伤神经元的形态,大鼠神经功能的恢复也出现了相同的变化趋势。结论 鼠胚胎脊髓不同移植方法能维持神经元的细胞形态,对成年大鼠损伤脊髓功能恢复有促进作用。     

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.