氯胺酮对荷包牡丹碱诱导PC12细胞内Ca2+浓度波动方式的影响

目的 研究氯胺酮对荷包牡丹碱诱导PC12细胞内Ca2 浓度波动方式的影响.方法 使用含25 ng/L NGF的DMED培养基在多聚赖氨酸包被的培养皿中培养PC12细胞;与终浓度10μmol/L的Ca2 指示剂Fluo-3 AM ester共孵育30 min洗涤后,加入终浓度50 μmol/L荷包牡丹碱;在激光共聚焦显微镜选定多个细胞分别测定荧光强度的变化;随后加入氯胺酮,记录细胞荧光强度的改变.在试验结束前依次加入Triton X-100和EGTA分别记录单个细胞最大荧光强度(Fmax)和最小荧光强度(Fmin),以计算细胞内Ca2 的相对强度.结果 氯胺酮不改变荷包牡丹碱诱导PC12细胞内Ca2 浓度波动的基线,但抑制细胞内Ca2 浓度升高的幅度(P＜0.05),缩短相邻波峰间的时间间隙(P＜0.05).结论 氯胺酮不仅改变荷包牡丹碱诱导PC12细胞内Ca2 浓度升高的幅度,而且改变Ca2 浓度波动的周期.     

组织血液灌注与微循环的病理生理(1)——氧的利用障碍

2．细胞钙稳态紊乱：静息状态下，细胞胞浆Ca^2＋浓度约为10^-7mol／L，而细胞外液Ca^2＋浓度约为10-3mol/L，细胞内外Ca^2＋浓度相差10000倍左右。细胞内Ca^2＋浓度的变动可作为细胞内信使影响多种钙依赖性酶的活性而改变细胞的功能状态。细胞一系列的Ca^2＋运转机制失调使细胞内Ca^2＋浓度出现非控制性增高时，则出现细胞钙稳态紊乱。从理论上判断这种钙稳态紊乱是由于①Ca^2＋ -Mg^2＋ -ATP酶（钙泵）活性降低，或Na^2＋／Ca^2＋交换、H^＋／Ca^2＋交换逆转，以致胞内Ca^2＋外流减少；     

邻-氨基酚去甲表鬼臼毒素抗骨肉瘤SOSP-9607细胞作用及机理研究

目的：研究邻-氨基酚去甲表鬼臼毒素（ODE）抗骨肉瘤SOSP-9607细胞作用及机理。方法：采用MTT比色法测定体外抗骨肉瘤SOSP-9607细胞作用,透射电子显微镜观察细胞凋亡形态学;采用激光共聚焦显微镜测定SOSP-9607细胞内Ca^2＋、Mg^2＋．pH值和线粒体膜电位（MMP）的荧光强度;免疫细胞化学技术检测细胞内Bcl-2和Bax表达。结果：ODE时间、浓度依赖性地抑制SOSP-9607细胞生长,诱导细胞凋亡具有典型的凋亡形态特征如细胞膜表面微绒毛消失、核固缩、核碎裂等;剂量依赖性地增加SOSP-9607细胞内Ca^2＋,Mg^2＋浓度而降低细胞内pH值和线粒体膜电位;使SOSP-9607细胞内Bcl-2蛋白表达下降而Bax蛋白表达增加。结论：邻-氨基酚去甲表鬼臼毒素在体外实验中能明显抑制骨肉瘤SOSP-9607细胞生长,其作用机制可能与改变细胞内环境稳态及Bcl-2和Bax蛋白表达而诱导细胞凋亡有关。     

异丙酚对N-甲基-D-天冬氨酸诱发大鼠海马神经元内游离钙离子浓度的影响

目的观察异丙酚对N-甲基-D-天冬氨酸（NMDA）诱发大鼠海马神经元内游离钙离子浓度（[Ca^2＋]i）的影响。方法取当天新生的Wistar大鼠海马神经元，培养12d随机分为5组，对照组（C组）、NMDA组、异丙酚10μmol／L＋NMDA组（P1组）、异丙酚100μmol／L＋NMDA组（P2组）、异丙酚400μmol／L＋NMDA组（P3组）。NMDA组培养液中加入NMDA至终浓度20μmol／L，P1组、P2组及P3组加入NMDA前即刻分别加入异丙酚至终浓度为10、100、400μmol／L，加入异丙酚后11min用激光共轭聚焦显微技术测定[Ca^2＋]。结果NMDA可诱发海马神经元[Ca^2＋]．升高，预先加入异丙酚100、400μmol／L可抑制这种改变，异丙酚10μmol／L对NDMA诱发的上述改变无影响。结论高浓度异丙酚可抑制NMDA诱发的大鼠海马神经元细胞[Ca^2＋]．的升高，这可能是其神经保护作用的机制之一。     

生长抑素对人胰腺癌细胞株HS766T的生长调控

目的 观察生长幔地人胰腺癌细胞株HT766T的生长抑制作用并探讨其作用机制。方法 细胞培养，分别加入不同浓度的生长抑素，应用四甲基偶氮唑盐法观察细胞增殖程度；放射免疫法测定细胞内cAMP含量；Fura-2/AM测定细胞内Ca^2 浓度。结果 不同浓度的生长抑素（10^-6-10^-12M）均能有效地抑制HS766T的生长，能抑制HS766T细胞内cAMP生成和Ca^2＋水平，分别在5min时和3min时作用最大，cAMP生成量和Ca^2 水平与生长抑素浓度呈负相关。它能使垂体腺苷酸环化酶激活多肽（PACAP）诱导的细胞内cAMP生成量和Ca^2 减少。结论 生长抑素能抑制人胰腺癌HS766T细胞的生长，可明显抑制PACAP诱导的细胞的生长。     

铁调素及铁离子对人成骨细胞(hFOB 1.19)内钙离子转运的影响

目的研究铁调素（Hepcidin）及铁离子对人成骨细胞（hFOB1．19）内Ca^2＋转运的影响。方法成骨细胞34℃培养3—4天至细胞密度为90％，胰蛋白酶消化后分种于12孔培养板（每孔内置一圆形盖玻片）。（1）空白组加入双蒸水，实验组加入不同浓度Hepcidin（双蒸水配制），干预24h后用激光共聚焦扫描显微镜（cLSM）检测；（2）空白组加入双蒸水，实验组加入不同浓度的DFO和FAC，分别干预后立即用激光共聚焦扫描显微镜检测。结果经激光共聚焦扫描显微镜（CLSM）检测发现：（1）随着成骨细胞外Hepcidin浓度的升高，成骨细胞内钙离子的绿色荧光强度增强；（2）随着成骨细胞外DFO浓度的升高，成骨细胞内钙离子的绿色荧光强度增强；相反，随着成骨细胞外FAC浓度的升高，成骨细胞内钙离子的绿色荧光强度减弱。结论（1）Hepcidin可促进成骨细胞内Ca^2＋增加。（2）成骨细胞外Fe^3＋浓度的减少可以增加细胞内的Ca^2＋，而胞外Fe^3＋浓度增加则减少细胞内的Ca^2＋。     

异丙酚对大鼠内脏抗伤害作用与中枢γ-氨基丁酸受体A受体的关系

目的探讨异丙酚对大鼠内脏抗伤害作用与中枢γ-氨基丁酸受体A（BABAA）的关系。方法49只雄性SD大鼠，体重180～240g，随机均分为7组：腹腔异丙酚10mg／kg体重组（Pi．P．）、侧脑室荷包牡丹碱0．25μg组（Bici．c-v．）、脊髓蛛网膜下腔荷包牡丹碱0．25μg组（Bici．t．）、侧脑室与脊髓蛛网膜下腔荷包牡丹碱各0．125μg组（Bici．c．v．／i．t．）、侧脑室预注荷包牡丹碱0．25μg＋腹腔异丙酚10mg／kg体重组（Bici．c．v．＋Pi．P．）、脊髓蛛网膜下腔预注荷包牡丹碱0．25μg＋腹腔异丙酚10mg／kg体重组（Bici．t．＋Pi．P．）、侧脑室与脊髓蛛网膜下腔预注荷包牡丹碱各0．125μg＋腹腔异丙酚10mg／kg体重组（Bici．c．v．／i．t．＋Pi．P．）。侧脑室或／和脊髓蛛网膜下腔预注荷包牡丹碱后10min腹腔给药。采用结直肠扩张内脏痛模型，以腹壁明显收缩变平的最小扩张压力值为痛阈，观察给药前及给药后各时间点的大鼠痛阈变化。结果腹腔注射异丙酚10mg／kg体重，5min后结直肠扩张痛阈显著提高（P〈0．05，P〈0．01），10～15min达高峰，持续20min；侧脑室、脊髓蛛网膜下腔或侧脑室＋脊髓蛛网膜下腔预注荷包牡丹碱后结直肠扩张痛阈均无明显变化（P〉0．05）；侧脑室、脊髓蛛网膜下腔或侧脑室＋脊髓蛛网膜下腔预注荷包牡丹碱后10min腹腔注射异丙酚10mg／kg体重，3组给药后5～20min内结直肠扩张痛阈也均有提高，但其增高值均明显低于Pi．p．组（P〈0．05，P〈0．01）；且这3组之间最大镇痛效应差异无统计学意义（P〉0．05）。结论侧脑室、脊髓蛛网膜下腔、侧脑室＋脊髓蛛网膜下腔预注荷包牡丹碱，均可部分拮抗异丙酚的内脏抗伤害作用，因而异丙酚的内脏抗伤害作用受脊髓与脊髓上中枢γ-氨基丁酸A受体介导。     

氯胺酮对大鼠脊髓背角星形胶质细胞的保护机制

目的 探讨氯胺酮对N-甲基-D天冬氨酸（NMDA）诱导的大鼠脊髓背角星形胶质细胞损伤的保护机制。方法 取新生2～3dWistar大鼠40只T12～L5脊髓背角星形胶质细胞,原代纯化培养3周。将细胞随机分六组：NMDA组（N组）,氯胺酮组（K组）、NMDA加不同浓度氯胺酮组（标记为NK1～NK3组）,对照组（C组）。加药后培养30min或24h取各组细胞检测超氧化物岐化酶（SOD）活性和丙二醛（MDA）含量,免疫细胞化学观察Bcl-2／Bax表达,流式细胞仪检测星形胶质细胞凋亡率和胞内游离钙浓度（[Ca^2＋]i）。结果 与C组比较,N组细胞发生大量凋亡（P〈0．01）,Bax强阳性表达,Bcl-2阴性表达,SOD活性显著降低（P〈0．01）,MDA含量明显增加（P〈0．01）,[Ca^2＋]i显著升高（P〈0．01）。与N组比较,NK2、NK3组细胞凋亡明显减少（P〈0．05或P〈0．01）,Bcl-2阳性表达,Bax阴性表达,[Ca^2＋]i低（P〈0．05或P〈0．01）,SOD活性增加（P〈0．01）,MDA含量低（P〈0．01）。结论 氯胺酮抑制激活的背角星形胶质细胞内Ca^2＋超载,增强Bcl-2蛋白表达,抑制NMDA诱导的细胞凋亡,并增强抗氧化酶活性,抑制脂质过氧化反应引起的细胞损伤。     

氯胺酮对大鼠心肌细胞内游离钙的影响

目的　探讨氯胺酮对大鼠心肌细胞内游离钙的影响及其作用机制。方法　原代培养的SD大鼠心室肌细胞 ,用钙敏荧光探针Fluo 3/AM负载染色后 ,根据实验中加入氯胺酮终浓度不同分为六组 ,采用激光扫描共聚焦显微镜 ,测定心肌细胞内钙荧光强度的基础值及加入氯胺酮后 5min以及后续加入 4 0mM氯化钾 (KCl)或 1 0mM咖啡因后细胞内钙荧光强度值。结果　 (1 )≤ 1 0 0 μM的氯胺酮对静息心肌细胞内钙荧光强度无明显影响 ,而 30 0 μM的氯胺酮降低钙荧光强度 (P <0 0 1 ) ;(2 )KCl和咖啡因使细胞内钙荧光强度较基础值均明显升高 (P <0 0 1 ) ;氯胺酮剂量依赖性地抑制KCl诱发胞内钙荧光强度升高的幅度 ,尤以 1 0 0和 30 0 μM氯胺酮组明显 ;而各浓度的氯胺酮不抑制咖啡因诱发胞内钙荧光强度的升高 (P >0 0 5 )。结论　 1、1 0和 6 0 μM的氯胺酮可能不抑制整体状态下的心肌收缩 ;而 1 0 0和 30 0 μM的氯胺酮对心肌有剂量依赖性的负性肌力效应 ,其机制可能是氯胺酮抑制了胞外Ca2 + 经膜电压依赖性钙通道内流 ,胞内游离钙浓度降低所致 ,但不影响肌浆网释钙功能。     

异丙酚对肿瘤坏死因子-α诱导小鼠脊髓神经元凋亡的影响

目的研究异丙酚对肿瘤坏死因子-α（TNF-α）诱导小鼠脊髓神经元凋亡的影响。方法脊髓神经元取自孕14d胎龄小鼠的胎鼠，于含B27的神经细胞培养基中培养7d后，随机分为6组：对照组（Con组）；50μmol／L异丙酚组（P50组）；TNF-α组（TNF-α组）；25μmol／L异丙酚＋TNF-α组（P25＋TNF-α组）；50μmol／L异丙酚＋TNF-α组（P50＋TNF-α组）；100μmol／L异丙酚＋TNF-α组（P100＋TNF-α组），各组中加入相应终浓度的异丙酚孵育30min，再加入TNF-α至终末浓度为2000U／ml，培养24h后，采用碘化丙锭／Hoechst 33342双染法检测细胞凋亡，计算细胞凋亡率，采用免疫细胞化学方法测定Bcl-2表达。结果与Con组比较，TNF-α组神经元凋亡率升高，Bcl-2表达降低（P〈0．01），不同浓度异丙酚预先给药可减弱TNF-α诱导的上述改变（P〈0．05）。结论异丙酚可抑制TNF-α诱导小鼠脊髓神经元的凋亡，其机制与上调Bcl-2表达有关。     

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.     

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.     

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.