椎管内麻醉不同穿刺入路对膝关节镜手术的影响

目的：观察直入穿刺法与旁入穿刺法2种不同椎管内麻醉穿刺方法对膝关节镜手术患者的影响。方法：择期行膝关节镜手术120例,ASA Ⅰ～Ⅱ级,按随机数字表法随机分为直入法穿刺组和旁入法穿刺组。均采用一点法即针内针单间隙穿刺技术。观察每组患者的麻醉起效时间、穿刺成功率、神经异感、硬膜外置管困难发生率、硬膜外导管误入血管发生率、术后腰背痛发生情况,麻醉后1、5、10、30min无创血压、心率、脉搏血氧饱和度。结果：直法与旁入法腰麻硬膜外联合穿刺在麻醉起效时间（5．24±0．4）min vs（5．14±0．6）min、硬膜外置管困难发生率1．7％ vs 1．7％、硬膜外导管误入血管发生率3．4％ vs 1．7％、神经异感发生率3．4％ vs 3．4％无显著性差异（P〉0．05）。麻醉后1、5、10、30min SBP、DBP、HR、SpO2,2组间差异无统计学意义（P〉0．05）。旁入法术后腰背痛的发生率75．0％（45／60） vs 23．3％（14／60）及持续时间（2．44±0．8）d vs（2．04±0．7）d明显低于直入法组（x^2=32．042,P=0．000;t=2．195,P=0．004）。结论：2种麻醉穿刺方法均可安全有效地应用于膝关节镜手术;与直入法相比,旁入法腰麻硬膜外联合麻醉术后腰痛发生率低。     

氯普鲁卡因硬膜外阻滞时的药效学和药代动力学

目的通过对氯普鲁卡因（2-CP）在硬膜外阻滞时药效学和药代动力学的研究,探讨不同年龄因素及加入肾上腺素的2-CP进入硬膜外腔后在人体的吸收、分布和消除规律。方法选择ASAⅠ或Ⅱ级、在连续硬膜外阻滞下行择期下腹部手术患者30例,根据年龄和用药的不同随机分为三组,每组10例。青壮年组（C组）,年龄为30-55岁,以3％2-CP 6mg／kg行硬膜外阻滞;肾上腺素组（CE组）,青壮年患者,以3％2-CP6mg／kg加入1：200000肾上腺素行硬膜外阻滞;老年组（CO组）,年龄65岁以上,以3％2-CP6mg／kg行硬膜外阻滞。分别观察局麻药起效时间、运动阻滞起始时间和运动阻滞程度;用高效液相色谱仪测定注药后3、6、9、11、13、15、17、20、30、45、60、90min血浆2-CP浓度。用药代动力学计算程序（3p97）进行血药浓度数据处理,计算药代动力学参数。结果三组的局麻药起效时间、运动阻滞起始时间和运动阻滞程度差异均无统计学意义。三组的血浆药物浓度峰值（Cmax）分别为：（0．47±0．31）、（0．32±0．22）、（0．58±0．39）mg／L;血药浓度达峰时间（Tmax）分别为：（8．71±3．45）、（7．84±3．42）、（6．42±4．84）min;血浆药物浓度-时间曲线下面积（AUC）分别为：（9．16±4．09）、（8．66±3．47）、（7．71±3．82）μg·min^-1·ml^-1;清除速率常数（K）分别为：（0．53±0．48）、（0．45±0．42）、（0．52±0．42）／min。以上参数三组间比较差异均无统计学意义。结论1：200000肾上腺素和年龄对3％2-CP行硬膜外阻滞的药代动力学和药效学无明显影响。     

罗哌卡因、左旋布比卡因与布比卡因低位硬膜外麻醉的比较

目的比较罗哌卡因、左旋布比卡因与布比卡因低位硬膜外麻醉的临床效果。方法60例行下腹部手术病人。随机分成三组,每组20例。Ⅰ组：0．5％罗哌卡因;Ⅱ组：0．5％左旋布比卡因;Ⅲ组：0．5％布比卡因。行连续低位硬膜外麻醉。观察感觉阻滞起效时间、感觉阻滞平面上界、运动阻滞起效时间、运动阻滞程度及麻醉质量。结果Ⅰ、Ⅱ和Ⅲ组首次局麻药用量分别为（14．38±1．57）、（14．75±0．50）和（13．80±1．30）ml。Ⅰ组运动阻滞起效时间比Ⅲ组长（P〈0．05）,Ⅰ组Bromage评分为1分的例数多于Ⅲ组（P〈0．05）。与Ⅲ组比较,Ⅰ、Ⅱ组感觉阻滞起效时间、感觉阻滞平面上界差异均无统计学意义。Ⅲ组SBP在感觉阻滞平面达上界及运动阻滞起效时有明显降低（P〈0．05）。结论0．5％罗哌旨因、左旋布比卡因或布比卡因连续硬膜外麻醉均可产生良好的感觉和运动阻滞,三种药物药效学相似。     

光选择性汽化治疗良性前列腺增生的经验

2002年至2005年采用光选择性汽化（PVP，绿激光）治疗良性前列腺增生201例。按前列腺体积分为2组，A组体积≤80ml 150例，B组体积〉80ml 51例。B组平均年龄73岁，其中美国麻醉学会分级3～4级者14例（32．6％）。结果：A组手术时间（59±26）min，B组（79±31）min（P〈0．001）。A组激光功率（189±89）kJ／m^2，B组（268±105）kJ／m^2（P〈0．001）。A组留置导尿管时间（1．7±1．3）d，B组（1．8±1．9）d（P=0．397）。A组住院时间（5．2±2．2）d，B组（5．6±2．6）d（P=0．394）。2组术中均无TUR综合征、穿孔，均未输血。术后并发症：①排尿困难〉10d：A组11例（7．3％），B组3例（5．9％）（P=0．506），抗胆碱能和非类甾醇抗风湿药疗效良好。②尿路感染（〈4周尿培养阳性）：A组10例（6．7％），B组4例（7．8％）（P=0．756）。     

心区交感神经阻滞治疗急性心肌梗死支架置入术后重度心力衰竭的观察

目的观察高位硬膜外阻滞（心区交感神经阻滞）对急性心肌梗死冠状动脉内支架置入术后重度心力衰竭（心衰）的疗效。方法高位硬膜外阻滞T1～T5交感神经,间隔2h于管内注射0．5％利多卡因3～5ml,并辅助常规药物治疗,疗程4周,观察8例患者治疗前后的症状、Killip分级及心脏彩超检查心功能参数的变化,测量左心房收缩末期内径（LAD）、左心室舒张末期内径（LVEDd）、左心室射血分数（LVEF）及短轴缩短率（FS）。结果治疗后呼吸困难明显减轻,治疗前后的心功能Killip分级分别为（3．7±0.4）和（2．0±0．5）（P〈0．01）,LVEDd分别为（64．7±4．2）和（56．7±4．3）mm（P〈0．01）,LVEF分别为（40．4±2．1）％和（56．5±5．2）％（P〈0．01）。结论心区交感神经阻滞对常规方法治疗无效或疗效欠佳的急性心肌梗死冠状动脉内支架置入术后心衰疗效好,可改善心功能。     

利多卡因加布比卡因局部麻醉在前列腺穿刺活检术中的应用

目的探讨经直肠前列腺穿刺活检引起的疼痛规律，评价利多卡因加布比卡因局部麻醉的镇痛效果及安全性。方法经直肠行前列腺10针穿刺活检患者150例，随机分3组，每组50例，A组在尖部、两侧的前列腺体部与直肠壁间注入利多卡因加布比卡因复合剂（质量浓度为1％利多卡因、0．2％布比卡因、1：20万单位肾上腺素）各3ml，B组在相同位置注射1％利多卡因，C组直接行穿刺活检。对患者术中及术后1周内的疼痛行视觉模拟评分尺评分。结果A、B、C组术中疼痛评分分别为2．2±1．5、2．0±1．5、3．5±1．9，P〈0.01；术后1h疼痛评分分别为2．2土1．3、3．1±1.1、2．8±1．4，P〈0．01；术后1d分别为1．7±1.1、1.8±1．1、1．7±1．3，P〉0.05；术后6d均为0．2土0．5，P〉0.05。A组2例患者出现术后寒战高热，C组1例术后当晚出现低热。术后A、B、C组分别有1、3、4例患者需口服止痛药。结论经直肠前列腺穿刺活检引起的疼痛主要在术中及术后1d之内。联合应用利多卡因加布比卡因局部麻醉能显著降低患者术中、术后的疼痛程度，并能消除单用利多卡因麻醉引起的术后疼痛反弹现象。     

胰岛素强化治疗对烫伤大鼠心肌保护作用的研究

目的 了解胰岛素强化治疗对重度烫伤大鼠心肌的保护作用，并探讨其作用机制。方法 将18只SD大鼠分为3组，每组6只。强化组及烫伤组大鼠背部脱毛造成30％TBSA的Ⅲ度烫伤。强化组伤后即输注胰岛素等渗盐水（含胰岛素0．12U／m1）及100g／L葡萄糖，使大鼠血糖水平控制在4．0～6．6 mmol／L之间，补液总量为2ml·kg^-1。·％TBSA^-1·8h^-1；烫伤组伤后仅给予等渗盐水，总量同前。假伤组模拟烫伤，伤后补充生理量的液体。于伤前及伤后1、2、3、4、5、6 h 抽取大鼠静脉血测定其血糖值。各组大鼠伤后均经右颈动脉插管人左心室并连接生理记录仪，观察左心室收缩压（LVSP）及左心室舒张末期压（LVEDP）。伤后6h，处死各组大鼠，留取左心室组织标本用于心肌细胞肌钙蛋白T的检测。结果 烫伤组大鼠伤后1～6h的血糖值为（7．6±1．7）～（8．4±4．7）mmol／L，均高于强化组[（4．5±0．9）～（5．2±1．3）mmol／L，P〈0．01]。伤后1h，烫伤组LVSP[（60±11）mmHg（1mmHg=0．133kPa）]降低、LVEDP[（21．3±11．3）mmHg]升高，与强化组[（72±8）、（11．7±5．2）mmHg]比较，差异有统计学意义（P〈0．05）。烫伤后各组大鼠肌钙蛋白T在心肌细胞内大量缺失，而强化组缺失程度明显低于烫伤组（P〈0．05）。结论 胰岛素强化治疗对重度烫伤大鼠左心室功能具有明显的保护作用，此作用可能与抑制心肌细胞蛋白的缺失有关。     

倍他洛克用于气管插管期对BIS，ICP和血流动力学的影响

目的：观察长效选择性β受体阻滞剂—倍他洛克（metoprolol．美托洛尔）对丙泊酚麻醉诱导气管内插管期的BIS、ICP和血流动力学影响。方法：随机选择鼻蝶入路垂体瘤切除术病人100例，ASAⅠ-Ⅱ级，分为倍他洛克组（工组）和对照组（Ⅱ组），每组50例。工组於麻醉诱导期静脉注射倍他洛克60μg／kg；Ⅱ组静脉注射等容量生理盐水。麻醉诱导采用丙泊酚2mg/kg、芬太尼3μg／kg、罗库溴铵1mg／kg，OSS／A评分0级施行气管内插管．术中持续监测平均动脉压（MAP），心率（HR），颅内压（ICP）和脑电双频谱指数（BIS）。结果：倍他洛克组与对照组在气管插管后1min时的BIS分别为39±11和58±8，前者与插管前相比无显着性改变，而后者则较插管前有明显增高并延续至插管后5min（P〈0.05，P〈0.01），且其组间的显着性差异延续至插管后15min（P〈0.01）．倍他洛克组与对照组的MAP和HR在插管后3min和5min，均较插管前明显上升，对照组HR分别为89±11bpm和76±12bpm，MAP分别为122±16mmHg和106±18mmhg，倍他洛克组HR分别为81±12bpm和74±8bpm，MAP分别为111±18mmHg和97±17mmHg。两组相比，对照组的血流动力学显着性上升（P〈0.01），且其组间的显着性差异延续至插管后30min（P〈0.05，P〈0，01）。对照组的ICP於插管后3min上升为14．0±2.3mmHg，舆插管前相比有显着性差异（P〈0．05）；插管后5min，15min和30min的ICP分别为14.9±．0mmHg，15．5±2．6mmHg和14.4±2.7mmHg，显着性高於倍他洛克组（P〈0．05，P〈0．01）．两组插管后的ICP舆麻醉前比较均有显着性升高（P〈0。01）。结论：倍他洛克能减低麻醉诱导气管插管期的血流动力学波动和ICP升高，并抑制DIS反跳．     

奥美拉唑对大鼠减体积肝移植后肝再生的影响

目的观察奥美拉唑对大鼠减体积肝移植肝细胞再生的影响。方法建立大鼠减体积肝移植模型，实验组移植后即时给予奥美拉唑，对照组予生理盐水。两组分别于肝移植术后分为5组（n=8），观察术后3、5、7、10、14d血清丙氨酸转氨酶、天冬氨酸转氨酶值、移植肝重／供肝减体积前全肝重比值、移植肝细胞有丝分裂指数（MI）、增殖细胞核抗原（PCNA）表达指数、溴脱氧尿嘧啶核苷（BrdU）掺入指数及血清胃泌素值。结果大鼠减体积肝移植术后5d肝细胞再生达高峰，实验组的再生活性显著高于对照组，MI为（2．54±0．24）％和（1．71±0．16）％（P〈0．01）、PC—NA指数为（26．96±2．09）％和（18．73±1．94）％（P〈0．01）、BrdU指数为（10．24±1．11）％和（5．75±0．88）％（P〈0．01）。术后7d，实验组和对照组移植肝重／全肝重比值分别为（76．3±1．6）％和（71．2±1．0）％（P〈0．05），血清胃泌素水平分别为（441．9±25．9）ng／L和（292．9±14．2）ng／L（P〈0．05）。术后14d，实验组和对照组移植肝重／全肝重比值分别为（94．5±1．7）％和（86．9±1．5）％（P〈0．01），血清胃泌素水平分别为（487．8±29．4）ng／L和（291．7±21．6）ng／L（P〈0．01）。实验组和对照组血清ALT、AST值差异无统计学意义。结论奥美拉唑能促进减体积肝移植术后的肝细胞再生，其作用可能与胃泌素分泌增高有关。     

全反式维甲酸和三氧化二砷协同诱导胰腺癌细胞凋亡

目的研究与三氧化二砷（As2O2）具有协同效应治疗胰腺癌的药物。方法以胰腺癌细胞系SWl990为研究对象，观察5-氟尿嘧啶（5-Fu）、健择（Gemcitabine）和全反式维甲酸（AT—RA）与As2O3共同作用对细胞的影响。通过台盼蓝拒染法检测细胞生长和细胞活力，流式细胞仪检测AnnexinV或PI阳性细胞的含量，评价以上药物对细胞增殖和凋亡的作用。结果5-Fu和Gemcitabine与As2O3无协同效应。单独应用As2O3或ATRA均抑制SWl990细胞生长，不诱导细胞凋亡。其中，对照组活细胞密度为（8．5±0．3）×10^5个／ml，As2O3组为（4．4±0．1）×10^5个／ml，ATRA组为（6．7±0．2）×10^5个／ml。但是，As203和ATRA共同处理SWl990细胞后，细胞生长明显抑制，并诱导细胞凋亡。对照组活细胞密度为（8．5±0．3）×10^5个／ml，As2O3＋ATRA组为（3．3±0．1）×10^5个／ml；对照组细胞活力为（92，0±1．2）％，As2O3组为（90．0±1．3）％，ATRA组为（93．0±1．4）％，As2O3＋ATRA组为（65．0±2．1）％；对照组Annexin V和PI阳性细胞的含量为（6．0±1．2）％，As2O3组为（11．0±3．3）％，ATRA组为（5．0±1．4）％，As2O3＋ATRA组为（37．0±5．3）％。结论As2O3和ATRA可协同诱导胰腺癌细胞凋亡，两者联合应用可能作为胰腺癌辅助治疗的另一选择。     

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.