透明质酸对创面胶原代谢的影响

目的:通过观察外源性透明质酸(HA)对兔耳创面胶原代谢的影响,探讨外源性透明质酸在伤口愈合中的作用.方法:18只日本大耳白兔,建立兔耳创伤愈合模型后,随机分成2％HA治疗组(A组),1％HA治疗组(B组)和生理盐水对照组(C组).观察创面愈合及瘢痕形成情况,术后第3、7、10、14、18天取标本匀浆后测定羟脯氨酸(HPr)含量,将数据进行统计学处理.结果:A、B两组羟脯氨酸含量明显低于C组(P＜0.01),A、B两组间也有统计学差异(P＜0.05).A、B两组创面愈合相对C组延迟,形成瘢痕小于C组.结论:外源性HA能够抑制成纤维细胞合成胶原,延迟创面愈合,减少瘢痕形成,其作用有剂量依赖性.     

外源性透明质酸对兔耳创面胶原代谢的影响

目的　通过观察外源性透明质酸(HA)对兔耳创面愈合前后胶原代谢的影响,探讨透明质酸抑制瘢痕增生的机理。方法　18只日本大耳白兔,建立兔耳创伤愈合模型后,随机分成2％HA治疗组（A组）,1％HA治疗组（B组）和生理盐水对照组（C组）。术后第3、7、10、14、18天取标本匀浆后测定羟脯氨酸（HPr）含量,将数据进行统计学处理。结果　A、B两组羟脯氨酸含量明显低于C组（P＜0.01）,A、B两组间也有统计学差异（P＜0.05）。结论　HA能够抑制成纤维细胞合成胶原,其作用有剂量依赖性。     

外源性透明质酸对兔耳创面胶原代谢的影响

目的　通过观察外源性透明质酸 (HA)对兔耳创面愈合前后胶原代谢的影响 ,探讨透明质酸抑制瘢痕增生的机理。方法　 18只日本大耳白兔 ,建立兔耳创伤愈合模型后 ,随机分成 2 %HA治疗组 (A组 ) ,1%HA治疗组 (B组 )和生理盐水对照组 (C组 )。术后第 3、7、10、14、18天取标本匀浆后测定羟脯氨酸 (HPr)含量 ,将数据进行统计学处理。结果　A、B两组羟脯氨酸含量明显低于C组 (P <0 .0 1) ,A、B两组间也有统计学差异 (P <0 .0 5 )。结论　HA能够抑制成纤维细胞合成胶原 ,其作用有剂量依赖性     

大鼠感染性创面肉芽组织胶原代谢的改变

目的：观察大肠杆菌诱导的大鼠感染性创面修复过程中创面肉芽组织中蛋白含量、羟脯氨酸含量及胶原合成的变化。方法：Wistar大鼠48只,随机分为感染组和对照组,切取大鼠背部2.0cm×2.0cm大小皮肤、皮下组织,形成开放性创面,感染组采用含9×108CFU/mL大肠杆菌1mL培养液涂擦创面,术后第3d、第7d、第15d和第22d分别处死感染组和对照组各6只,观察创面愈合时间和未愈合面积,测定创面肉芽组织中蛋白含量、羟脯氨酸含量和创面I、Ⅲ型胶原含量及比值。结果：大肠杆菌诱导的大鼠感染性创面愈合时间为（21.8±0.2）d,显著长于对照组（19.5±0.75）d（P〈0.01）。感染组在各时间点创面未愈合面积明显大于对照组（P〈0.05）。感染组在不同时间点的创面肉芽组织中蛋白、羟脯氨酸含量和创面I、Ⅲ型胶原含量及其比值明显低于对照组（P〈0.01）。结论：大肠杆菌可能通过影响创面肉芽组织中蛋白含量、羟脯氨酸含量及胶原合成,从而导致感染创面愈合延缓。     

皮肤源祖细胞-透明质酸复合物对糖尿病大鼠创面愈合的影响

目的研究皮肤源祖细胞（SKP）-透明质酸（HA）复合物的构建方法，观察其对糖尿病（DM）大鼠创面愈合的影响。方法分离培养SD大鼠SKP，以HA为载体构建复合物，观察复合物中SKP的分化特性。选取60只SD大鼠腹腔注射链脲菌素诱导成DM模型．背部对称制作2个直径1cm全层皮肤缺损创面，随机分为SKP-HA组，创面涂布100μl SKP-HA；HA组，创面涂布100μl HA；对照组，创面涂布DMEM／F12培养基。每组20只。各组大鼠于伤后1、2、3、4周检测创面愈合率，留取创面组织标本检测羟脯氨酸（Hyp）含量，并观察SKP在创面愈合过程中的迁移。结果大鼠SKP与HA共培养后生长良好，复合物中的SKP可保持其特性：向神经元细胞、神经胶质细胞、脂肪细胞分化。伤后2周SKP-HA组、HA组的创面愈合率分别为（72．1±2．8）％、（53．7±2．9）％，均明显高于对照组的（42．5±1．5）％（P＜0．05）；伤后3周SKP—HA组高于HA组及对照组（P＜0．05或0．01）；伤后4周SKP—HA组、HA组创面完全愈合，与对照组比较，差异有统计学意义（P＜0．01）。伤后1周各组Hyp含量差异无统计学意义（P＞0．05）；伤后2～4周，SKP-HA组、HA组Hyp含量均高于对照组（P＜0．01）；伤后3、4周SKP-HA组高于HA组（P＜0．01）。SKP在创面得以成活并随时间的延长逐渐向真皮层迁移。结论SKP-HA复合物可促进DM大鼠创面愈合。     

透明质酸对创面愈合胶原代谢影响的实验研究

目的　探讨外源性透明质酸 (HA)抑制瘢痕形成的作用机理及其浓度依赖性关系。方法　健康成年大鼠 4 5只 ,复制背部创伤模型 ,随机分成 2 %HA治疗组 (A组 )、1%HA治疗组 (B组 )、磷酸盐缓冲液 (PBS)对照组 (C组 ) ,观察大体形态和组织学改变 ,平均愈合时间和残留面积的大小 ,测定愈合部位组织蛋白、羟脯氨酸 (HPr)、Ⅲ型前胶原 (PCⅢ )的含量。结果　① 3组的平均愈合时间为 ( 15 2± 2 0 ) ,( 14 2± 1 6)和 ( 13 4± 1 4 )d ,A、B两组与C组比较差异有显著性意义 (P <0 0 5 )。A、B两组的残留面积与C组比较差异有显著性意义 ,3组间比较差异也有显著性意义 (P <0 0 5 )。②组织学上 ,A、B两组成纤维细胞增生明显 ,胶原纤维直径较为纤细、排列整齐。C组则显示出明显的炎性细胞浸润 ,新生血管数目增多。③HPr和PCⅢ含量的测定 :A、B两组HPr含量的均值低于C组 (P <0 0 1) ,而PCⅢ的含量却高于C组 (P <0 0 1)。结论　①HA通过对细胞的调控作用 ,可有效地抑制胶原的合成 ,提高Ⅲ型胶原含量 ,使得创面愈合过程中瘢痕形成减少。②HA在创面愈合中抑制瘢痕形成的生物学作用与其浓度成正比关系。     

海藻酸钙敷料对大鼠创面愈合影响的组织学研究

目的：探讨海藻酸钙敷料对大鼠创面愈合的影响。方法：48只雄性SD大鼠随机分为实验组和对照组,每组24只。制作大鼠背部全层皮肤缺损模型,在创面局部以海藻酸钙敷料（实验组）或干棉纱布（对照组）包扎,观察伤后3、7、14 d创面愈合率的变化;于伤后3、7、14 d取创面组织,石蜡包埋、切片、分别行HE和Masson染色,计算血管横断面面积与肉芽组织面积的比值、肉芽组织厚度和胶原蛋白含量（胶原面积与创面面积比值）。结果：术后第3天时实验组大鼠较对照组创面愈合率明显增加（P〈0.05）。术后第3天实验组与对照组肉芽组织厚度[分别为（1 540.0±118.5）μm和（1 504.6±131.8）μm,P〉0.05]和新生肉芽组织血管面积与肉芽组织面积之比[分别为0.118±0.007和0.113±0.007,P〉0.05）差异均无显著性,但术后3 d实验组胶原蛋白面积较对照组明显增多[分别为（45.7±5.3）%和（11.6±2.5）%,P〈0.05];术后第7天实验组以上指标均高于对照组（P〈0.05）,第14天时这种趋势依然存在（P〈0.05）。结论：海藻酸钙能提高伤口皮肤组织内的胶原蛋白含量,加速创面肉芽组织形成,促进伤口的愈合。     

静脉移植的脂肪来源干细胞在创伤鼠体内的分布

目的：研究脂肪组织来源干细胞（ADSCs）经尾静脉移植到软组织创面大鼠体内后的迁移和分布。方法：取第3代SD大鼠ADSCs,DiI标记后通过尾静脉移植到创伤鼠体内,术后3天、7天、11天、14天观察创口收缩率、愈合时间等,24天处死大鼠收集创面愈合组织标本行常规HE染色观察,48天收集创伤愈合组织及多个器官组织标本行快速冰冻切片,直接在荧光显微镜下观察拍照。结果：实验组较对照组创口收缩率大,创面完全愈合时间短,统计学上两组有显著性差异（P〈0．05）。组织学观察发现实验组创面较对照组的新生血管形成、成纤维细胞、腺样结构更为明显。荧光显微镜下实验组标本里可见标记细胞发出的荧光,肺、脾组织中滞留大量且较强的荧光,肝、心、肾组织内亦可见较多细弱荧光,远隔部位的正常皮肤软组织仅见少量荧光,创面愈合组织中所见的荧光要多于正常皮肤组织且分布相对有规律。对照组均未见有荧光。结论：静脉移植的大鼠ADSCs仅有少部分迁移到创伤部位,绝大部分细胞仍主要滞留于肺、脾等组织中,但ADSCs对于创伤愈合仍具有促进作用。     

VEGF165基因对大鼠软组织缺损修复及Ⅰ、Ⅲ型胶原mRNA表达的影响

目的 将pcDNA3.1-VEGF165质粒用于软组织缺损局部,观察其对软组织修复的作用和Ⅰ型、Ⅲ型胶原mRNA表达的影响.方法 SD大鼠32只于两侧臀部制备直径12 mm圆形全层皮肤、肌肉的复合软组织缺损;随机分为实验组,对侧为对照组.于实验组注射0.2 ml(含200 ng)质粒液,对照组以同量生理盐水代替.分别于术后3、5、7、14、30 d照相计算创面收缩率、取材.以RT-PCR法检测局部Ⅰ型、Ⅲ型胶原mRNA表达;制备常规切片观察局部组织血管形成(MVD)及修复情况.结果 所有动物术后无死亡、感染.实验组及对照组创面愈合时间分别为14.2 d及17.4 d,于1、2周时新生血管密度分别为63.38±9.20、52.72±7.06(P＜0.05)及76.64±12.27、66.84±9.82(P＜0.05),差别有统计学意义.RT-PCR示Ⅰ型及Ⅲ型胶原mRNA于术后3 d即开始有表达,2周达到高峰后减弱,实验组表达量较大.结论 pcDNA3.1-VEGF165质粒用于创面后,具有上调Ⅰ型及Ⅲ型胶原mRNA表达,促进软组织缺损区血管生成、加速创面愈合作用.     

血竭局部外用对兔耳缺血创面愈合的影响

目的:血竭为传统医学中生肌方剂的主要成分,曾长期应用于临床治疗多种难愈性创面,具有确切的疗效。本课题应用兔耳缺血创面模型,观测血竭对创面愈合的作用。方法:血竭用基质稀释为A1(0.3mg/ml),A2(3mg/ml),A3(30mg/ml),A4(100mg/ml)4种浓度,并以基质A5作对照,作用于兔耳缺血创面,于创面形成后第3、6、9、12天进行大体观察及显微测量,通过苏木精-伊红染色观测创面愈合组织病理变化,天狼猩红染色观察创面愈合过程中Ⅰ、Ⅲ型胶原比例。结果:血竭组A2(13.1±1.7)d、A3(12.3±0.9)d创面愈合速度快于对照组A5(15.7±0.9)d,两者差异具有显著性意义(P0.01);术后3d到术后12d创面愈合过程中,A2,A3组创面愈合面积与对照组差异具有统计学意义(P0.01);A3组新生肉芽组织体积与对照组相比差异有显著意义(P0.01);创面愈合第6天A3组天狼猩红染色Ⅰ、Ⅲ型胶原比值2.23/1大于对照组1.44/1(P0.01),而第15天Ⅰ、Ⅲ型胶原比例与对照组相比无明显差异(P0.05)。结论:血竭能够提高兔耳缺血创面愈合速度,改善创面愈合质量,具有显著促进缺血创面愈合的作用。     

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.     

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.