控制性再灌注防止肺再灌注损伤的研究

目的　探讨控制性再灌注在预防肺缺血再灌注 (I/R)损伤中的作用及其机制。方法将猪分为 2组 ,10只猪切取左肺作供体 ,4℃改良的E C液灌洗和保存 ,4h后进行左肺移植。对照组常规操作 ,实验组采用控制性再灌注 :灌注液 (去白细胞血 :改良Buckberg液 =4∶1) ;灌注压 2 0mmHg ;灌注时间 10min。 0 .5、1和 2h后测血氧分压、肺血管阻力、肺顺应性、一氧化氮 (NO)含量、丙二醛 (MDA)含量、肺干 /湿重比。结果　实验组的左肺氧合功能 ,肺顺应性明显好于对照组 ,肺循环阻力、MDA值及肺含水量均低于对照组 (P <0 .0 1) ;实验组肺中NO含量较对照组明显升高 (P <0 .0 1)。结论　控制性再灌注能明显降低肺I/R损伤 ,起到了较好的移植肺保护效果。     

参附注射液对兔移植肺缺血-再灌注损伤的保护作用

目的观察参附注射液对供肺缺血-再灌注损伤的保护作用。方法将20只新西兰白兔随机分为实验组和对照组,每组各10只,建立兔左肺自体原位移植模型,分别用参附注射液和生理盐水对兔肺进行预处理和供肺灌注。于主动脉阻断前、再灌注后15min、30min和60min各时点检测左肺静脉血中丙二醛(MDA)含量、总超氧化物歧化酶(SOD)的活力,于再灌注60min后称左肺组织的干湿比重(D/W),并观察其病理变化。结果主动脉阻断前两组MDA含量差异无统计学意义(P0.05);再灌注15min后实验组MDA含量较主动脉阻断前下降;再灌注30min和60min时,两组MDA含量均呈上升趋势,但实验组明显低于对照组(P0.05)。主动脉阻断前实验组SOD活力明显高于对照组(P0.05),再灌注后两组SOD活力均呈下降趋势,以对照组下降幅度明显(P0.05)。实验组的D/W显著高于对照组(0.23±0.01vs.0.19±0.02,P0.05)。对照组肺组织水肿明显,大量的炎性细胞浸润,肺泡腔内有片状渗出;而实验组表现为肺泡间隔水肿轻微,少量炎细胞浸润,渗出不明显。结论参附注射液对供肺的缺血-再灌注损伤有较好的保护作用。     

低钾右旋糖苷液加硝普钠在肺缺血再灌注损伤中的作用

临床肺移植实践中,肺缺血再灌注损伤(IRI)不可避免.预防和减轻IRI的发生一直成为肺移植领域的研究焦点.研究证实,一氧化氮(N0)能预防肺的缺血再灌注损伤.在各种供肺灌洗液中加入硝普钠(SNP)几乎是临床常用的方法.研究表明,硝普钠作为NO的提供者可有效预防肺的IRI.也有研究结果显示,硝普钠对肺移植中供肺保护没有特殊意义,并会加重损伤.     

肺外科中单侧肺缺血-再灌注损伤的研究

目的 通过建立新西兰白兔肺外科单侧肺缺血-再灌注损伤动物模型,观察其缺血-再灌注损伤特点.方法 将96只健康新西兰兔随机分成3组:Ⅰ组为对照组(n=36);Ⅱ组为单纯阻断肺动脉组(n=30);Ⅲ组为阻断肺循环组(n=30).术中监测动物血流动力学指标;分别于开胸时(Ⅰ组)、缺血1小时和再灌注1、2、4、6 h(Ⅰ、Ⅱ、Ⅲ组)取肺组织检测MDA;取肺组织作病理学观察,并测定手术侧肺湿/干比.结果 各组动物术中血流动力学指标平稳;在缺血1 h和再灌注1、2、4、6 h,Ⅲ组与Ⅱ组比较,肺湿/干比及肺组织中MDA含量的差异均无统计学意义(P＞0.05),Ⅰ组与Ⅱ、Ⅲ组比较差异有统计学意义(P＜0.05).在相同的时间点,Ⅱ、Ⅲ组呈现相似的肺损伤病理改变,且较为明显的肺损伤均出现在再灌注4h,再灌注6h肺损伤均呈恢复趋势.结论 肺外科中肺动脉阻断和肺循环阻断所致肺缺血一再灌注损伤特点相似,肺外科中肺血管阻断1h是安全的.     

西地那非在犬肺移植缺血再灌注损伤中的作用

目的 观察5型磷酸二酯酶抑制剂西地那非在肺移植缺血再灌注损伤中的作用.方法 12对体重匹配杂种犬随机分为对照组(n=6)和实验组(n=6),利用同种异体犬左单肺移植模型,实验组供肺肺动脉阻断前经主肺动脉注射西地那非1.0 mg/kg体重,移植后持续泵入西地那非每小时0.3 mg/kg体重,对照组给予等容量生理盐水.观察移植前及移植后30、60、120、180min移植肺上叶静脉血氧分压(PO2)变化,于移植后120 min取肺组织,测丙二醛(MDA)、髓过氧化物酶(MPO)及组织含水量(H)并观察组织形态学变化.结果 实验组PO2明显高于对照组(293±52比160±45,P＜0.05);供肺组织MDA(0.25±0.09比0.50±0.09)、MPO含量(0.13±0.06比0.25±0.09)及含水量(71.59±4.63比78.04±3.73)明显低于对照组(P＜0.05);组织形态学显示实验组损伤程度较对照组轻.结论 西地那非在供肺保存及再灌注损伤中具有肺保护作用.     

卡托普利在肺保存中的作用

目的 研究卡托普利在肺保存中的作用及可能的作用机制。方法 将猪分为2组，对照组用4℃改良的Euro-Colling液（E－C液）对供肺进行灌洗和保存，实验组用4℃含卡托普利（500μmol/L)的E－C液对供肺进行灌洗和保存，然后进行左肺移植。在再灌注后0．5、1和2h采血及肺组织，测定血氧分压、肺血管阻力、NO2^-/NO3^－含量、超氧化物歧化酶（SOD）的活性以及脂质过氧化产物丙二醛（MDA）的含量。结果 实验组的左肺氧合功能明显好于对照组，肺循环阻力及肺含水量也较对照组相应时间低，差异均有显著性；实验组在此期间的NO2^-/NO3^-含量较对照组有明显高（P＜0．01），但肺组织中的SOD活性及MDA含量变化不大。结论 卡托普利对供肺有较好的保护作用，能降低移植后肺循环阻力及肺含水量，对NO升高有一定作用，但对氧自由基的形成及消除效果不理想。     

腺苷对犬心肺联合移植供肺缺血-再灌注损伤的保护作用

目的 研究腺苷(ADO)对犬心肺联合移植供肺缺血-再灌注(I/R)损伤的保护作用.方法 建立犬心肺联合移植模型,将实验分为心肺联合移植对照组(对照组)和腺苷组,观察恢复血流灌注后30、60、90和120 min时两组犬动脉血氧分压(PaO2)的变化;测定缺血前10 min、缺血后10 min、120 min、再灌注后10 min、60 min供肺组织一氧化氮(NO)含量;在恢复血流灌注60 min后,取供肺组织为标本,检测肺组织中髓过氧化物酶(MPO)活力、丙二醛(MDA)含量、超氧化物歧化酶(SOD)含量以及肺组织湿干重比(W/D);HE染色光学显微镜下观察病理变化.结果 (1)在各时间点腺苷组PaO2值较对照组明显升高(P＜0.05);(2)与缺血前比较,缺血后120min、再灌注后10min和60min的肺组织NO含量均显著降低(P＜0.05),而腺苷组缺血后120 min、再灌注后10 min和60 min肺组织NO含量显著高于对照组(P＜0.05);(3)腺苷组肺组织中MPO活力、MDA含量、肺组织W/D显著低于对照组,SOD含量显著高于对照组(P＜0.05);(4)病理切片观察显示对照组的肺组织呈严重的炎性细胞浸润及肺水肿形成,而腺苷组的病变程度较对照组轻微.结论 在心肺联合移植过程中应用ADO,对供肺的缺血-再灌注损伤有保护作用.     

门静脉高压犬肝缺血再灌注时肺循环血液动力学及NO/ET和PGI2/TXA2的变化

目的 评价门静脉高压犬肝缺血再灌注时肺循环血液动力学及肺循环一氧化氮(NO)/内皮素(ET)和前列腺素I2(PGI2)/血栓素A2(TXA2)的变化.方法 健康家犬12只,雌雄不拘,体重10～18 kg,随机分为2组(n=6):对照组和模型组.模型组采用部分结扎门静脉的方法 建立犬门静脉高压模型,12周后完全阻断门静脉、肝后下腔静脉30 min,再灌注60 min制备肝缺血再灌注模型.于第2次麻醉后即刻、肝缺血前即刻、缺血5、30 min、再灌注前即刻、再灌注5、10、15、30和60 min(T1-10)时记录心率(HR)、心输出量(CO)、中心静脉压(CVP)、肺动脉楔压(PAWP)和平均肺动脉压(MPAP),计算心脏指数(CI)、肺血管阻力(PVR)和肺血管阻力指数(PVRI),并计算T2-10时CI、CVP、MPAP、PAWP和PVRI相对于T1的变化幅度;于T2、T4和T9时测定肺动脉血浆NO、ET、TXA2和PGI2的浓度,并计算NO/ET和PCI2/TXA2比值.结果 两组肝缺血时CI、CVP、PVRI、PAWP和MPAP均降低,且模型组CI、CVP、PAWP、MPAP降低幅度低于对照组,两组再灌注时CVP、PAWP、MPAP和PVRI均升高,且模型组PAWP和PVRI升高幅度高于对照组(P<0.05或0.01);模型组肝缺血再灌注时肺动脉血浆NO浓度、NO/ET比值和肝缺血时肺动脉血浆TXA2浓度、PGI2/TXA2比值均低于对照组(P<0.01).模型组PVR与肺动脉血浆NO浓度呈负相关(r=-0.567,P<0.05).结论 门静脉高压犬肝缺血再灌注时肺动脉压升高,可能与肺循环NO水平降低、NO与ET失衡有关.     

川芎嗪在骨骼肌缺血再灌注损伤中的作用

目的　探讨中药川芎嗪在骨骼肌缺血再灌注损伤中有无保护作用。方法　健康成年家兔14只 ,随机分对照组、实验组 ,每组 7只。应用家兔肢体缺血再灌注损伤动物模型 ,在恢复血流再灌注当时 ,实验组静脉输注川芎嗪注射液 ,对照组静脉输注 0 9%生理盐水。测定缺血前、缺血后、再灌注后血浆丙二醛 (MDA)、乳酸脱氢酶 (LDH)及超氧化物歧化酶 (SOD)的含量。制备骨骼肌标本进行光镜及透射电镜观察。结果　实验组在恢复血流并注射川芎嗪后 1小时 ,其血浆MDA、LDH的含量较对照组明显降低 (P <0 0 1) ,而SOD较对照组明显升高 (P <0 0 1)。光镜及电镜下观察可见实验组骨骼肌损害轻于对照组。结论　实验表明中药川芎嗪对骨骼肌缺血再灌注损伤有保护作用     

自体肺氧合体外循环防止炎症反应性肺损伤

目的 探讨采用自体肺代替人工氧合器的体外循环技术是否比常规体外循环对肺组织有更好的保护作用。方法12只小猪随机分为实验组和对照组。实验组用自体肺代替人工氧合器，对照组按常规体外循环方法，分别转流135min，主动脉阻断60min，测定实验前、后肺静态顺应性、肺动-静脉氧差，检测灌注液中肿瘤坏死因子（TNF）-α、白细胞介素（IL）-6变化，测定肺组织湿，干比和观察肺病理学改变。结果两组体外循环后的肺静态顺应性均下降、肺动-静脉氧分压差增大，灌注液中TNF-α和IL-6含量增加，但两组相比，实验组的改变显著轻于对照组。肺组织标本显示，实验组的肺湿，干比明显低于对照组，光镜和电镜观察肺损伤程度也较轻。结论自体肺能够耐受非搏动性灌注而代替人工氧合器进行体外循环且可显著减轻因肺的缺血再灌注以及因采用人工氧合器所引起的炎症反应性肺损伤，对肺组织有较好的保护作用。     

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.