氯胺酮预先给药对缺氧复氧诱导大鼠小脑颗粒神经元凋亡的影响

目的 研究氯胺酮预先给药对缺氧复氧诱导大鼠小脑颗粒神经元（CGNs）凋亡的影响，及磷脂酰肌醇-3-激酶（PI3K）／Akt通路在其中的作用。方法 出生7-8d的清洁级SD大鼠，雌雄不拘，体重15～20g；制备CGNs，培养的8d的CGNs随机分为5组，对照组（A组）、缺氧复氧组（B组）、氯胺酮预先给药组（C组）、PDK／Akt通路的特异性抑制剂Ly294002-氯胺酮预先给药组（D组）、Ly294002组（E组）。B组将CGNs放入特制缺氧盒中，缺氧3h后复氧；C组缺氧前1h加入200μmol／L氯胺酮；D组加入氯胺酮前30min加入20μmol／LLy294002；E组加入20μmol／LLy294002。复氧16h后进行下述指标的观察。二乙酸荧光素染色法测定CGNs存活率，Hoechst33258核染色检测CGNs凋亡细胞核，琼脂糖凝胶电泳检测DNA片断化水平，蛋白免疫印迹法（Western blot法）检测CGNs磷酸化Akt、磷酸化GSK3β及总Akt水平。结果缺氧复氧可诱导CGNs的凋亡，降低CGNs磷酸化Akt和磷酸化GSK3β水平（P〈0．05），氯胺酮预先给药可减轻缺氧复氧诱导的上述改变，氯胺酮对CGNs的这种保护作用可被Ly294002部分抑制。结论 氯胺酮预先给药可减轻缺氧复氧诱导大鼠CGNs凋亡，其机制与激活PI3K／Akt通路有关。     

不同浓度氯胺酮对谷氨酸诱导大鼠脊髓背角神经元和星形胶质细胞凋亡的影响

目的观察不同浓度氯胺酮对谷氨酸诱导的大鼠脊髓背角神经元和星形胶质细胞凋亡的影响。方法取出生1-3 d Wistar大鼠T11-L5脊髓背角神经元和星形胶质细胞,原代混合培养2 周。将细胞随机分为6组(n=8):对照组(C组)加入Hanks液;谷氨酸组(G组)加入谷氨酸至终浓度100μmol/L;氯胺酮组(K组)加入氯胺酮至终浓度1 mmol/L;GK1、GK2、GK3组先加入谷氨酸至终浓度100μmol/L,30min后分别加入氯胺酮至终浓度0.1、1、10mmol/L。培养48 h后取各组细胞上清液检测白细胞介素-1β(IL-1β)、肿瘤坏死因子α(TNF-α)浓度,瑞氏染色观察细胞形态变化,流式细胞仪检测神经元和星形胶质细胞凋亡。结果与C组比较,G、GK1、GK2组神经元和星形胶质细胞凋亡峰值增加,GK3组细胞几乎全部死亡,未能上机检测细胞凋亡,G、GK1、GK2、GK3组IL-1β和TNF-α浓度升高(P<0.01)。与G组比较,GK2组各指标均降低,GK,组IL-1β和TNF-α浓度升高(P<0.01)。结论1 mmol/L氯胺酮可降低谷氨酸引起大鼠脊髓背角神经元和星形胶质细胞的凋亡。     

氯胺酮复合咪达唑仑对谷氨酸诱导PC12细胞凋亡的影响

目的 探讨氯胺酮复合咪达唑仑对谷氨酸诱导PC12细胞凋亡的影响.方法 诱导分化4 d的神经元样PC12细胞随机分为5组:对照组(c组);谷氨酸组(Glu组)加入20 mmol/L谷氨酸;氯胺酮组(K组)、咪达唑仑组(M组)、氯胺酮+咪达唑仑组(K+M组)均加入20 mmol/L谷氨酸后,分别加入50 μmol/L氯胺酮、1μmol/L咪达唑仑、50 μmol/L氯胺酮+1 μmol/L咪达唑仑.各组细胞继续培养24 h后采用MTT法检测细胞活力,Hoechst33258核染色法及Annexin V-FITC/PI双染流式细胞术检测凋亡细胞.结果 与C组比较,Glu组细胞活力降低,细胞凋亡率升高(P<0.01);与Glu组比较,K组和M组细胞活力升高,细胞凋亡率降低(P<0.05);与K组和M组比较,K+M组细胞活力升高,细胞凋亡率降低(P<0.05);K组和M组细胞活力及细胞凋亡率差异无统计学意义(P>0.05).结论 氯胺酮复合咪达唑仑可更有效地抑制谷氨酸诱导PC12细胞凋亡.     

NF-κB在氯胺酮诱导大鼠原代培养大脑皮层神经元凋亡中的作用

目的 评价NF-κB在氯胺酮诱导大鼠原代培养大脑皮层神经元凋亡中的作用.方法 体外培养6 d的大鼠大脑皮层神经元15孔,随机分为3组(n=5):对照组(C组)正常培养;氯胺酮组(K组)和氯胺酮+NF-κB抑制剂SN50组(KS组)分别加入1 mmol/L氯胺酮、1 mmol/L氯胺酮+2.5 μmol/L SN50,作用24 h.洗脱后24 h时采用凝胶迁移实验检测神经元NF-κB活性,采用Westernblot法测定凋亡相关蛋白Bcl-XL和Bax的表达,计算Bcl-XL/Bax,计数凋亡神经元,电镜下观察神经元的超微结构.结果 与C组相比,K组NF-κB活性、Bcl-XL/Bax、神经元凋亡率升高(P＜0.05),KS组上述指标差异无统计学意义(P＞0.05);与K组相比,KS组NF-κB活性、Bcl-XL/Bax、神经元凋亡率降低(P＜0.05).电镜结果显示:KS组神经元损伤较K组明显减轻.结论 NF-κB参与了氯胺酮诱导大鼠原代培养大脑皮层神经元凋亡的过程.     

异丙酚对谷氨酸诱导大鼠海马神经元损伤的影响

目的观察异丙酚对谷氨酸诱导体外培养大鼠海马神经元损伤的影响。方法酶消化法分离Wistar新生大鼠海马,培养12 d的海马神经元随机分为三组(n=5),正常对照组(Con组)、谷氨酸100 μmol/L孵育24 h组(Glu组)、谷氨酸100 μmol/L孵育24 h后异丙酚500 μmol/L再孵育24 h组 (Pro-Glu组)。四甲基氮唑蓝法测定细胞存活率,免疫细胞化学法测定c-fos蛋白表达,流式细胞仪测定细胞凋亡率。结果与Con组比较,Glu组及Pro-Glu组的细胞存活率下降,c-fos蛋白在细胞核内表达呈紫黑色且数量增加,细胞凋亡率增高(P<0．05或0．01);与Glu组比较,Pro-Glu组c-fos阳性蛋白减少,细胞凋亡率降低,细胞存活率增高(P<0．05)。结论异丙酚通过降低细胞凋亡率和c-fos阳性蛋白表达,提高细胞存活率,对谷氨酸诱导的海马神经元损伤起一定保护作用。     

NORAD在氯胺酮诱发小鼠海马神经元毒性中的作用：与内质网应激的关系

目的评价长链非编码RNA NORAD在氯胺酮诱发小鼠海马神经元毒性中的作用及其与内质网应激的关系。方法分离并培养原代小鼠海马神经元, 采用随机数字表法分为5组(n=36):对照组(C组)、氯胺酮组(K组)、氯胺酮+pcDNA3.1-NORAD质粒组(K+NORAD组)、氯胺酮+对照质粒组(K+NC组)和氯胺酮+NORAD+衣霉素组(K+NORAD+TM组)。C组使用正常培养基培养24 h;K组加入40 μmol/L氯胺酮孵育24 h;K+NORAD组先转染pcDNA3.1-NORAD质粒至神经元中, 48 h后加入氯胺酮40 μmol/L孵育24 h;K+NC组先转染pcDNA3.1(+)质粒至神经元中, 48 h后加入氯胺酮40 μmol/L孵育24 h;K+NORAD+TM组先转染pcDNA3.1-NORAD质粒, 24 h后加入内质网应激激活剂衣霉素1 μg/ml孵育24 h, 然后再加入氯胺酮40 μmol/L孵育24 h。采用CCK-8法检测神经元活力, 检测乳酸脱氢酶(LDH)释放量, 采用TUNEL法和流式细胞术检测细胞凋亡情况, Real-time PCR法测定NORA...     

异丙酚对β-淀粉样蛋白诱导大鼠皮层神经元损伤的影响

目的 探讨异丙酚对β-淀粉样蛋白(β-AP)诱导大鼠皮层神经元损伤的影响.方法 孕18 dSD大鼠,体外分离皮层神经元,5×104个/孔,每孔200μl接种于96孔培养板上,培养7 d.实验一:取15孔神经元随机分为5组(n=3):对照组;损伤组;异丙酚预防给药Ⅰ组加入β-AP 25μmol/L前24 h加入异丙酚50μmol/L,再孵育24h;异丙酚预防给药Ⅱ组同时加入异丙酚50 μmol/L和β-AP 25μmol/L,孵育24 h;异丙酚治疗给药组加入β-AP 25μmol/L后6 h,加入异丙酚50μmol/L,再孵育18 h.实验二:取18孔神经元随机分为6组(n=3):对照组;损伤组;脂肪乳剂组加入β-AP 25μmol/L后6 h,加入等容量10%脂肪乳剂,再孵育18 h;不同浓度异丙酚组加入β-AP 25μmol/L后6 h,分别加入异丙酚1、10、50 βmol/L,再孵育18 h.测定神经元乳酸脱氢酶(LDH)释放量和神经元活力.采用TUNEL法、Hoechst33342染色观察细胞凋亡情况,计算细胞凋亡率.结果 实验一:与损伤组比较,异丙酚预防给药组LDH释放量差异无统计学意义(P＞0.05),异丙酚治疗给药组神经元LDH释放量减少(P＜0.05).实验二:与损伤组比较,异丙酚50μmol/L组神经元LDH释放量减少,神经元活力升高,细胞凋亡率降低(P＜0.05).结论 异丙酚50 μmol/L治疗性给药可减轻β-淀粉样蛋白诱导大鼠皮层神经元损伤,预防性给药对其无影响.     

氯胺酮对大鼠海马神经元CREB磷酸化水平的影响

目的 探讨氯胺酮对大鼠海马神经元cAMP反应元件结合蛋白(CREB)磷酸化水平的影响.方法 原代培养1 d龄SD大鼠海马神经元5 d,随机分为对照组(C组)和氯胺酮组(K组),每组6孔.K组在终浓度为1 000 μmol/L氯胺酮的Neurobasel培养液中孵育3 h,C组不做任何处理.采用流式细胞仪Aanexin V-PI共染法检测凋亡神经元,计算神经元凋亡率;采用免疫组化法测定神经元Ser133位点磷酸化的CREB(pCREB)表达水平;采用RT-PCR法半定量测定CREB下游基因脑源性生长因子(BDNF)mRNA和抑凋亡基因Bcl-2 ndlNA的表达.结果 与C组相比,K组神经元凋亡率升高,pcREB、BDNFmRNA及Bcl-2 mRNA的表达均下调(P＜0.01).结论 氯胺酮可能通过抑制CREB磷酸化,下调BDNF及Bcl-2表达,诱导新生大鼠海马神经元凋亡.     

大剂量氯胺酮致原代培养皮层神经元凋亡

目的观察不同剂量氯胺酮对突触快速生长期大鼠神经元的损伤作用。方法 0.01、0.1、1和2mmol/L氯胺酮（K1、K2、K3和K4组）及单纯培养基（C组）作用于体外原代培养第6天的大鼠神经元24h。药物洗脱24h后,通过MTT细胞还原检测、原位荧光TUNEL染色、LDH释放检测及电镜观察神经元损伤程度。结果与C组相比,K3和K4组神经元MTT显著降低（P〈0.05）,TUNEL阳性细胞百分比显著增高（P〈0.05）,电镜检查显示凋亡细胞增多。结论大剂量氯胺酮可致体外原代培养大鼠皮层神经元凋亡。     

氯胺酮对新生大鼠海马CREB磷酸化水平的影响

目的 探讨氯胺酮对新生大鼠海马环磷腺苷反应元件结合蛋白(CREB)磷酸化水平的影响.方法 SD大鼠75只,日龄7 d,雌雄不拘,随机分为对照组(C组)、氯胺酮10 mg/kg组(K1组)和氯胺酮20 mg/kg组(K2组),每组25只.K1组和K2组分别皮下注射氯胺酮10、20 mg/kg,C组注射等容量生理盐水,每间隔90 min注射1次,共注射7次.于首次注射后24 h时断头取脑,分离海马,采用TUNEL法检测凋亡神经元,计算凋亡指数;免疫荧光双标法检测p-CREB表达水平;RT-PCR法半定量检测CREB下游基因BDNF mRNA及Bcl-2 mRNA表达水平;于首次注射后6周时采用Morris水迷宫实验测定各组大鼠认知功能.结果 与C组相比,K1组和K2组大鼠海马神经元凋亡指数升高,p-CREB、BDNF mRNA及Bcl-2 mRNA表达下调(P<0.05);与K1组相比,K2组大鼠海马神经元凋亡指数升高,p-CREB、BDNF mRNA及Bcl-2 mRNA表达下调(P<0.05);与C组和K1组相比,K2组逃避潜伏期延长(P<0.05).结论 氯胺酮10、20 mg/kg均可诱导发育期大鼠海马神经元凋亡,而氯胺酮20 mg/kg可导致大鼠发育成熟后认知功能降低,可能与其抑制CREB磷酸化后BDNF及Bcl-2表达下调,导致神经元凋亡,影响大鼠神经系统发育有关.     

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.