瑞芬太尼复合艾司洛尔对全麻患者气管插管时心血管指标的影响

目的 评价瑞芬太尼复合艾司洛尔对全麻患者气管插管时心血管系统的影响.方法 选择择期上腹部手术患者60 例,ASAⅠ - Ⅱ级,随机分为3 组（n = 20）：瑞芬太尼2 μg/kg组（Ⅰ组）,芬太尼4 μg/kg ＋ 艾司洛尔1 mg/kg 组（Ⅱ组）和瑞芬太尼2 μg/kg ＋ 艾司洛尔1 mg/kg组（Ⅲ组）.分别注入上述药物、丙泊酚2 mg/kg 和阿曲库铵1.5 mg/kg 后行气管插管,机械通气.记录麻醉诱导前（T1）、麻醉诱导后1 min（T2）、气管插管后即刻（T3）、气管插管后1 min（T4）、3 min（T5）及10 min（T6）的HR、收缩压（SP）、舒张压（DP）,并于T1、T2、T4 时分别采集桡动脉血7 ml,测定血浆肾上腺素（Ad）和去甲肾上腺素（NA）的浓度.结果 与Ⅰ组比较,Ⅱ组和Ⅲ组HR、SP、DP 及血浆Ad 和NA 的浓度降低（P 〈 0.05）;与Ⅱ组比较,Ⅲ组HR、SP、DP 降低（P 〈 0.05）;与T1 比较,T2时3 组HR、SP、DP 及血浆Ad 和NA 的浓度降低（P 〈 0.05）;Ⅰ组T3 时HR、SP、DP 升高,Ⅱ组和Ⅲ组差异无统计学意义.结论 瑞芬太尼复合艾司洛尔可更好地预防全麻患者气管插管时的心血管副作用.     

不同给药方法对舒芬太尼咳嗽反应的影响

目的比较不同方法快诱导全麻对减轻舒芬太尼诱发咳嗽反应的影响。方法 200例ASAI或Ⅱ级患者随机均分为4组,麻醉诱导方法分别为：Ⅰ组（对照组）依次静脉注射咪达唑仑0.05mg/kg、舒芬太尼0.4μg/kg、异丙酚1.5mg/kg、罗库溴胺1mg/kg;Ⅱ组（预注组）依次静脉注射咪达唑仑0.05mg/kg、舒芬太尼0.1μg/kg、异丙酚1.5mg/kg、罗库溴胺1mg/kg、舒芬太尼0.3μg/kg,Ⅲ组（稀释组）依次静脉注射咪达唑仑0.05mg/kg、舒芬太尼0.4μg/kg（2.5μg/mL）、异丙酚1.5mg/kg、罗库溴胺1mg/kg;Ⅳ组（后注射组）依次静脉注射咪达唑仑0.05mg/kg、异丙酚1.5mg/kg、罗库溴胺1mg/kg、舒芬太尼0.4μg/kg;除组Ⅲ外其余3组舒芬太尼浓度为10μg/mL。4组患者于诱导后2min进行气管插管,观察插管前咳嗽反应的发生率及严重程度,记录诱导前、诱导后、咳嗽时、插管时的SpO2、ABP和HR。结果 4组患者咳嗽的发生率Ⅱ组为8%（4/50）,Ⅲ组为10%（5/50）,Ⅳ组为2%（1/50）,Ⅱ、Ⅲ、Ⅳ组明显低于Ⅰ组的38%（19/50）（P〈0.01）,Ⅱ、Ⅲ组低于Ⅳ组（P〈0.05）;4组患者T1、T2、T3、T4时间点的SBP和HR差异无统计学意义;T3的SBP、HR均较T1、T2明显升高（P〈0.01）。结论快速诱导全身麻醉时舒芬太尼最后给药、稀释给药或给予预注剂量均可以明显降低舒芬太尼诱发咳嗽反应的发生率,其中以最后给药效果最佳。     

不同剂量喷他佐辛用于全麻诱导气管插管反应

目的 对比研究喷他佐辛不同剂量与舒芬太尼用于全麻诱导的气管插管反应.方法 选择腹腔镜手术患者100例,ASA Ⅰ或Ⅱ级,随机分为四组:Ⅰ组喷他佐辛0.5 mg/kg,Ⅱ组喷他佐辛0.75 mg/kg,Ⅲ组喷他佐辛1.0 mg/kg,Ⅳ组为舒芬太尼0.4 μg/kg,各组药物分别静注4min后行全麻诱导.诱导后四组BIS值降到60以下时行气管插管.观察记录诱导前(T1)、诱导后3min(T2)、插管即刻(T3)、插管后3 min(T4)的BIS值、MAP、HR、SpO2的变化.结果 四组患者T2～T4时BIS均明显低于T1时(P<0.05).T3时Ⅰ、Ⅱ、Ⅲ组的MAP明显高于、HR明显快于T1时和Ⅳ组(P<0.05);T3时Ⅰ组MAP明显高于、HR明显快于Ⅲ组(P<0.05).结论 1.0 mg/kg喷他佐辛用于全麻气管插管诱导期间血流动力学较0.5 mg/kg稳定,但不如舒芬太尼0.4 μg/kg稳定.     

异丙酚麻醉诱导期间不同剂量瑞芬太尼对病人气管插管心血管反应的影响

目的比较异丙酚麻醉诱导期间不同剂量瑞芬太尼对病人气管插管心血管反应的影响，寻找瑞芬太尼复合异丙酚气管插管的合适剂量。方法择期行腹腔镜胆囊切除术病人36例，ASAⅠ或Ⅱ级，年龄20～65岁，随机分为3组（n=12）：瑞芬太尼1、1．5、2μg／kg分别为复合异丙酚1．5μg／kg组（Ⅰ、Ⅱ、Ⅲ组）。依次静脉注射咪唑安定0．03mg／kg、异丙酚1．5mg/kg、维库溴铵0．1mg／kg以及瑞芬太尼麻醉诱导，2min后气管插管，进行机械通气，呼吸频率12次／min，潮气量8～10ml／kg，维持呼气末二氧化碳分压35～45mmHg。持续监测血压（平均动脉压、舒张压、收缩压）、心率（HR）以及听觉诱发电位指数（AAI），并记录病人有无气管插管时呛咳和肌肉强直、术中知晓等反应。结果与基础值比较，三组气管插管前即刻血压及Ⅲ组气管插管后即刻舒张压均降低，Ⅲ组气管插管后即刻血压低于Ⅰ组（P〈0．05）；HR组间及组内比较差异无统计学意义；三组间AAI差异无统计学意义。结论异丙酚1．5mg／kg麻醉诱导期间瑞芬太尼1或1．5μg／kg是病人气管插管时的合适剂量。     

不同剂量舒芬太尼对气管插管应激反应的影响

目的探讨不同剂量舒芬太尼对气管插管应激反应的影响。方法 60例(ASAI—Ⅱ级)择期气管内插管全麻手术患者随机分为A、B、C3组,全麻诱导均采用地塞米松10mg,咪唑安定0.05mg/kg,异丙酚1.5mg/kg和维库溴铵0.15mg/kg,A组使用芬太尼3μg/kg,B组使用舒芬太尼0.3μg/kg,C组使用舒芬太尼0.5μg/kg。分别观察3组患者于T0、T1、T2、T3和T4各个时间点SBP、MAP、HR和RPP。并比较3组患者SBP、MAP、HR和RPP。结果气管插管后均出现不同程度心血管应激反应,T2、T3、T4各时点SBP、MAP、HR和RPP等应激反应指标均高于T1时点指标(P0.05);A组和B组T2、T3时点SBP、MAP、HR和RPP等应激反应指标高于C组(P0.05)。结论 0.5μg/kg舒芬太尼全麻诱导比传统芬太尼3μg/kg和舒芬太尼0.3μg/kg插管时血流动力学更稳定,可以获得较理想的抑制气管插管反应的效果。     

靶控输注舒芬太尼复合丙泊酚对诱导期血流动力学的影响

目的 比较不同靶浓度舒芬太尼复合丙泊酚对诱导期血流动力学的影响.方法 择期全麻手术患者45例随机分为三组,每组15例.首先效应室分梯度靶控输注(TCI)丙泊酚.Ⅰ、Ⅱ、Ⅲ组TCI浓度依次为1.0、2.0、3.0 μg/ml.然后效应室TCI舒芬太尼,舒芬太尼浓度分别为0.2μg/ml(Ⅰ组)、0.3 μg/ml(Ⅱ组)和0.4 μg/ml(Ⅲ组),记录基础值(T0)、丙泊酚达1.0 μg/ml(T1)、2.0μg/ml(T2)、3.0 μg/ml(T3)、舒芬太尼靶控达平衡后1 min(T4)、插管即刻(T5)、插管后1 min(T6)、3 min(T7)、5 min(T8)的MAP和HR、BIS.结果 Ⅰ组T5～T7时、Ⅱ组和Ⅲ组T5、T6时的MAP较T4时增高(P＜0.05).Ⅰ组T6～T8和Ⅲ组T6时HR均增快(P＜0.05),但均未超过T0时.三组间BIS值差异无统计学意义.结论 在复合丙泊酚3.0 μg/ml输注时,舒芬太尼效应室浓度为0.3 μg/ml比较适宜气管插管.     

不同剂量舒芬太尼对老年患者气管插管心血管反应的影响

目的观察不同剂量舒芬太尼对老年患者气管插管时心血管反应的影响,探讨其减轻老年患者气管插管心血管反应的适宜剂量。方法拟行择期结、直肠癌腹腔镜手术;老年患者90例,随机分为舒芬太尼0．1μg／kg组（S1组）,舒芬太尼0．2μg／kg组（S2组）,舒芬太尼0．3μg／kg组（S3组）,每组各30例。监测患者人室静卧后5min（T0,基础值）、插管前1min（T1）、插管后1min（T2）、3min（T3）、5min（T4）各时点患者的收缩压（SBP）、舒张压（DBP）、心率（HR）,并在以上各时点抽取上肢静脉血,以高效液相色谱法测定血浆去甲肾上腺素（NE）和肾上腺素（N）水平。结果S1组患者气管插管后血流动力学及血浆去甲肾上腺素（NE）和肾上腺素（N）浓度与插管前比较明显增高,呈一过性;S2组患者患者气管插管后血流动力学及血浆去甲肾上腺素（NE）和。肾上腺素（N）浓度与插管前比较,轻度增高;S3组患者患者气管插管后血流动力学及血浆去甲肾上腺素（NE）和肾上腺素（N）浓度与插管前比较无明显变化。结论气管插管前静脉注射舒芬太尼0．3μg／kg能减轻气管插管引起的应激反应,用于老年患者可能有利于减少气管插管引起的心脑血管意外的发生。     

不同剂量右美托咪啶复合舒芬太尼用于清醒气管插管的比较

目的 观察比较不同剂量右美托咪啶(dexmedetomidine,DEX)复合舒芬太尼麻醉诱导用于清醒气管插管的效果.方法 选择Mallampati试验Ⅲ～Ⅳ级患者90例,采用区组随机化法分为3组(每组30例).DEX泵注:Ⅰ组0.8 μg/kg,Ⅱ组1.0 μg/kg,Ⅲ组1.2 μg/kg;均静脉推注舒芬太尼0.1μg/kg.观察并记录入室(T0)、插管前(T1)、插入导管即刻(T2)时的平均动脉压(mean arterial pressure,MAP)、心率(heart rate,HR)、血氧饱和度(oxygen saturation,SpO2)、血浆皮质醇浓度;记录患者插管前镇静(ramsay)评分及插管反应,并术后随访患者. 结果 与T0时(78±10)次/min比较,HR T1时Ⅱ组(68±9)次/min减慢(P＜0.05);Ⅲ组T1(68±17)次min、T2时(64±6)次min均减慢(P＜0.05).与Ⅰ组(81±12)次/min比较,HR T1时Ⅱ组(68±9)次/min、Ⅲ组(68±17)次/min有所减慢(P＜0.05),T2时Ⅲ组(64±6)次/min降低明显(P＜0.01).MAPⅡ组T1(102±19) mm Hg(1 mm Hg=0.133 kPa)、T2(109±24) mm Hg时、Ⅲ组T1(104±15) mm Hg、T2(111±9) mm Hg时均有所升高(P＜0.05);Ramsay评分,Ⅱ组、Ⅲ 组患者都在4分～5分,结论 DEX 1.0 μg/kg复合0.1 μg/kg舒芬太尼用于清醒气管插管时效果最好,并发症也较少.     

小儿气管内插管时舒芬太尼静注的ED50与ED95

目的测定七氟醚全麻诱导时舒芬太尼为小儿提供满意气管内插管条件的ED50与ED95。方法选择2～8岁择期行气管内插管全麻患儿100例,ASAⅠ级,随机均分为五组,七氟醚诱导后分别给予不同剂量舒芬太尼0.1μg/kg(S1组)、0.2μg/kg(S2组)、0.3μg/kg(S3组)、0.4μg/kg(S4组)、0.5μg/kg(S5组)行气管内插管。同时记录插管前1min(T1)、插管即刻(T2)、插管后1min(T3)、3min(T4)、5min(T5)、10min(T6)BP、HR及Narcotrend麻醉深度数值变化。在Viby-Mogensen气管内插管条件评价法评价气管内插管条件基础上使用概率单位分析法计算舒芬太尼为小儿提供满意气管内插管的ED50及ED95。结果在七氟醚呼气末浓度3%,Viby-Mogensen气管内插管条件评价为"优秀"时,结合患儿气管内插管心血管反应阴性作为满意气管内插管条件,舒芬太尼为小儿提供满意气管内插管的ED50为0.305μg/kg[95%可信区间(CI)为0.239～0.354μg/kg],ED95为0.598μg/kg(95%CI为0.484～1.019μg/kg)。结论在七氟醚呼气末浓度3%时,小儿气管内插管舒芬太尼静注ED50与ED95分别为0.305μg/kg和0.598μg/kg。     

不同剂量舒芬太尼复合靶控输注异丙酚麻醉诱导对患者血液动力学的影响前瞻性、多中心、随机、双盲研究

目的 评价不同剂量舒芬太尼复合靶控输注异丙酚麻醉诱导对患者血液动力学的影响,探讨复合异丙酚时舒芬太尼的适宜麻醉诱导剂量.方法 本试验为前瞻性、多中心、随机、双盲的临床研究.拟行腹部手术患者165例,ASA Ⅰ或Ⅱ级,年龄18～63岁,性别不限,体重42～90 kg,根据舒芬太尼不同麻醉诱导剂量分为4组:舒芬太尼0.4 μg/kg组(S1组,n=44)、0.6 μg/kg组(S2组,n=43)、0.8 μg/kg组(S3组,n=38)、1 μg/kg组(S4组,n=40).麻醉诱导:静脉注射咪达唑仑0.05 mg/kg,靶控输注异丙酚,血浆靶浓度3.0 μg/ml,当BIS<60且异丙酚达设定血浆靶浓度时,各组经30 s分别静脉注射舒芬太尼0.4、0.6、0.8、1 μg/kg,四组均静脉注射罗库溴铵0.9 mg/kg,静脉注射舒芬太尼后3 min(BIS 35～45)行气管插管、机械通气.于麻醉诱导前(T0)、异丙酚血浆靶浓度3.0 μg/ml时(T1)、静脉注射舒芬太尼后1 min(T2)、3 min(T3)、气管插管后即刻(T4)、1 min(T5)、3 min(T6)、5 min(T7)时记录SP、DP、MAP和HR.记录心血管不良事件和气管插管反应的发生情况.结果 四组麻醉诱导期间低血压、高血压和心动过速的发生率比较差异无统计学意义(P>0.05),T4-7时S4组心动过缓发生率较其余各组升高(P<0.05);S1组和S2组气管插管反应发生率较S3组和S4组升高(P<0.05或0.01).结论 舒芬太尼0.8 μg/kg复合靶控输注异丙酚(血浆靶浓度3.0 μg/ml)麻醉诱导时患者血液动力学平稳,是复合异丙酚时舒芬太尼适宜的麻醉诱导剂量.     

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.