新斯的明拮抗小儿和成年患者维库溴铵的残余肌松作用

目的 观察麻醉恢复期新斯的明拮抗小儿和成年全麻患者维库溴铵的残余肌松作用的剂量反应和安全性.方法 全麻下择期手术的小儿和成年患者各50例,维库溴铵首剂0.1 mg/kg,术中必要时追加0.05 mg/kg.采用加速度肌松监测仪监测四个成串反应的比值(train-of-four ratio,TOFR).当TOFR恢复至0.55时,小儿和成年患者分别随机分为5个亚组,分别给予新斯的明10、20、30、50 μg/kg及阿托品5、10、15、25μg/kg,对照组静脉注射生理盐水2 ml.观察TOFR恢复至0.7、0.9、1.0的时间及术后6、24 h恶心呕吐的发生情况.结果 新斯的明明显加快TOFR的恢复(P＜0.05),其中30μg/kg～50μg/kg效果均更明显(P＜0.05).小儿和成年患者新斯的明拮抗维库溴铵残余肌松作用的剂量反应曲线的差异无统计学意义(P＞0.05),拮抗5min时,小儿和成年患者新斯的明的ED95分别为(6.4±10.5)μg/kg和(2.7±19.2)μg/kg.术后6、24 h恶心呕吐情况的差异无统计学意义(P＞0.05).结论 在TOFR恢复至0.55时,小儿和成年患者新斯的明拮抗维库溴铵的残余肌松作用的效果无统计学差异,推荐使用小剂量的新斯的明进行拮抗,剂量不宜超过30μg/kg.     

急性高容量血液稀释对全麻患者顺式阿曲库铵药效学的影响

目的 探讨急性高容量血液稀释(AHH)对全麻患者顺式阿曲库铵药效学的影响.方法 择期腹部手术患者印例,年龄18～60岁,ASAI或Ⅱ级,随机分为对照组(C组)和AHH组,每组30例,各组按顺式阿曲库铵首剂量(首剂量分别为30、40、50μg/kg,总用量100 μg/kg)分为3个亚组,每亚组10例.采用TOF-Wateh~(R)SX肌松监测仪监测神经肌肉阻滞情况.AHH组经30～40 min静脉输注6%羟乙基淀粉130/0.4 15 ml/kg行血液稀释,AHH后各亚组分别给予首剂量顺式阿曲库铵,当T_1达最大抑制后再注入余量.记录肌松起效时间、临床肌松作用时间、体内作用时间及恢复指数.采用概率单位法计算T_1抑制50%、90%、95%时顺式阿曲库铵的用量(ED_(50)、ED_(90)、ED_(95).结果 与C组比较,AHH组顺式阿曲库铵ED_(50)、ED_(90)、ED_(95)升高,肌松起效时间延长,临床肌松作用时间及体内作用时间缩短(P<0.05或0.01),恢复指数差异无统计学意义(P>0.05).结论 AHH可降低顺式阿曲库铵的肌松效应.     

肌松拮抗用于短时腹腔镜手术的临床观察

目的:观察不同剂量新斯的明肌松拮抗用于短时腹腔镜手术的疗效与副作用。方法:选择60例择期行腹腔镜卵巢囊肿剥除术的患者,采用单次插管剂量罗库溴铵全身麻醉,手术结束时随机分为3组(n=20),N0组静脉注射生理盐水5 ml,N1组静脉注射新斯的明20μg/kg、阿托品10μg/kg,N2组静脉注射新斯的明40μg/kg、阿托品20μg/kg,根据临床征象判断拔除喉罩。检测手术结束时、拔除喉罩时及10 min后四联串刺激比率(train-of-four ratio,TOFR),记录麻醉时间(麻醉诱导至手术结束)、手术时间、拔除喉罩时间(手术结束至拔除喉罩),观察肌松拮抗用药10 min内心动过速、心动过缓及拔除喉罩10 min内低氧血症(吸入空气状态脉搏血氧饱和度<93%)发生情况。随访早期(0~6 h)及延迟(7~24 h)术后恶心呕吐(postoperative nausea and vomiting,PONV)发生情况。结果:3组患者年龄、体重、麻醉时间、手术时间、拔除喉罩时间、手术结束时TOFR及拔除喉罩后10 min内低氧血症发生率差异无统计学意义(P>0.05);拔除喉罩时TOFR N1组(0.87±0.10)、N2组(0.85±0.12)高于N0组(0.55±0.15,P<0.05);拔除喉罩10 min后TOFR N1组(0.88±0.08)、N2组(0.86±0.09)高于N0组(0.62±0.16,P<0.05);肌松拮抗用药10 min内心动过速及心动过缓发生率,N2组高于N0组、N1组(P<0.05);早期PONV发生率,N2组高于N0组(P<0.05);延迟PONV发生率,3组相比差异无统计学意义(P>0.05)。结论:对于短时腹腔镜手术,采用单次插管剂量罗库溴铵全麻后,推荐采用小剂量(20μg/kg)新斯的明进行肌松拮抗。     

美维库铵持续静滴与单次静注肌松效应及恢复过程的临床药效学观察

目的 :观察美维库铵持续静滴和单次静注肌松效应及术后恢复的临床药效学指标。方法 :6 0例ASA分级Ⅰ～Ⅱ级复合全麻患者随机分为四组 ,每组 15例。美维库铵 0 2 5mg/kg给药后行气管插管 ,Ⅰ、Ⅱ组以微量泵持续静滴美维库铵 ,Ⅲ、Ⅳ组单次静注美维库铵维持肌松。术后Ⅰ、Ⅲ组患者待肌松自主恢复 ,Ⅱ、Ⅳ组静注新斯的明5 0 μg/kg、阿托品 10 μg/kg拮抗。结果 :实验提示 0 2 5mg/kg的美维库铵剂量可于 2 4± 0 6分钟内产生满意的插管条件 ,优秀率 95 %以上。Ⅰ、Ⅱ、Ⅲ、Ⅳ组平均用药量分别为 4 7± 1 2、5 0± 1 9、5 2± 2 2和 4 9± 1 8μg·kg-1·min-1,持续静滴组与单次静注组用药量无显著性差异 (P >0 0 5 )。Ⅰ、Ⅲ组恢复指数分别为 8 1± 2 3分钟和 8 7± 2 2分钟 (P >0 0 5 )。Ⅱ、Ⅳ组的恢复指数亦无明显差异 ,但比自然恢复组约缩短 2分钟左右。结论 :美维库铵持续静滴与单次静注用药量无明显差异 ,持续静滴可获得较好的肌松效果。术后使用新斯的明拮抗虽可加快肌缩力的恢复 ,但因其短效作用 ,故术后无需常规拮抗。     

小剂量新斯的明拮抗罗库溴铵残余肌松的效果

术后残余肌松可引起上呼吸道阻塞、术后缺氧等严重并发症[1-3].临床常规应用40μg/kg新斯的明拮抗残余肌松,但有研究表明,40μg/kg新斯的明可能导致肌张力已恢复的病人肌力下降[4-5].     

罗库溴铵和阿曲库铵肌松作用的对比研究

目的 比较两种短效非去极化肌松药罗库铵在妇科腹腔镜手术全麻中的肌松作用。方法 选择妇科腹腔镜手术病人40例，术前检查无明显肝肾功能损害。随机分罗库溴铵组（Ⅰ组，n1=20例）和阿曲库铵组（Ⅱ组，n2=20例）。麻醉诱导；静注咪唑安定0.1mg/kg，芬太尼5μg/kg，琥珀胆碱1.5mg/kg，丙泊酚1.5mg/kg，经口明视插管，接Datex-OhmedaAS/3麻醉机，用TOF-guard肌松监测仪（丹麦），采用TOF刺激模式，当肌颤搐恢复至T125%时，静注罗库溴铵0.8mg/kg或阿曲库铵0.5mg/kg维持肌松；当T15%-10%时，分别追加罗库溴铵0.4mg/kg或阿曲库铵0.2mg/kg。麻醉维持丙泊酚80-120mg/h和苏太尼40-60μg/h速率用微量注射泵静脉注射，同时吸入氧化亚氮（N2O：O2为1：1）。结果 I组起效时间明显较Ⅱ组短，并且T125%时间，T190%时间以及恢复指数均较Ⅱ组短。Ⅱ组的循环变化主要表现在注药后1，3，5分钟的SBP较注射前呈明显下降，5分钟后呈回升趋势，结论 罗库溴铵比阿曲库铵肌松起效快，恢复较迅速，对循环影响小，是内腔镜手术麻醉时的良好肌松药选择。     

罗库溴铵和阿曲库铵联合应用的肌松效应分析

目的探讨罗库溴铵和阿曲库铵联合应用时的肌松效应。方法择期全麻手术女性成年患者147例,丙泊酚和舒芬太尼静脉诱导,输注丙泊酚维持麻醉。面罩辅助或控制呼吸,用加速度仪以连续4次刺激(TOF)方式透皮刺激腕部尺神经,获取肌松药作用起效时间和T1最大抑制程度(Tmax)。按观测项目将患者均分成四组。结果阿曲溴铵ED95为(220.8±3.6)μg/kg,罗库溴铵ED95为(286.3±3.1)μg/kg。0.5×ED95的罗库溴铵与阿曲库铵联合使用,肌松效应达到T1抑制93%~97%时,阿曲库铵的剂量为63.6μg/kg。罗库溴铵0.5×ED95与阿曲库铵63.6μg/kg联合使用,Tmax为(95.3±0.9)%,变异系数1.0%。Ⅳ组中三个亚组的Tmax基本相同,合用组作用起效时间比阿曲库铵组快(P<0.01)。给予肌松药前和注药后5min内,MAP和HR的波动幅度均小于5%。结论罗库溴铵与阿曲库铵合用呈协同作用。当罗库溴铵剂量为0.5×ED95时,为获得T1抑制95%的肌松效应,阿曲库铵的合理用量为63.6μg/kg,比阿曲库铵的ED95减少71.2%。     

终末期肾病患者顺式阿曲库铵量效关系测定

目的采用单次剂量注射法测定终末期肾病患者顺式阿曲库铵量效关系。方法选取接受肾移植的终末期肾病患者40例,按完全随机方法分为4组,每组10例,对4个剂量组患者按体重注射20、30、40、50μg／kg的顺式阿曲库铵。选取无神经肌肉病变的患者20例作为对照组,给予相同剂量的苯磺酸顺式阿曲库铵。记录每个患者最大抑制效应,并对最大抑制效应进行概率转换,对应的肌松药剂量进行对数转换,用直线回归方法建立顺式阿曲库铵的剂量-反应曲线。结果终末期肾病患者顺式阿曲库铵50％有效剂量（ED50）、75％有效剂量（ED75）、90％有效剂量（ED90）、95％有效剂量ED95分别为30．88、35．65、40．62、43．85μg/kg,无神经肌肉病变患者顺式阿曲库铵ED。ED。ED。ED。分别为35．37、42．22、49．60、54．55μg/kg,终末期肾病患者顺式阿曲库铵ED。明显低于无神经肌肉病变患者ED95（P〈0．01）。结论终末期肾病患者因周围神经病变累及神经肌肉接头可导致对肌松药的敏感性增加。     

不同性别患者预注顺阿曲库铵加快起效的半数有效剂量

目的 探讨不同性别患者预注顺阿曲库铵加快起效的半数有效剂量(ED50).方法 择期拟在全身麻醉下行腹部手术的患者90例,年龄18～55岁,分为2组(n=45):男性组(M组)和女性组(F组).采用TOF-Watch SX型加速度肌松监测仪对尺神经行单次颤搐刺激,监测拇内收肌肌颤搐情况.静脉注射咪达唑仑0.04 mg/kg、芬太尼1 μg/kg,患者意识消失后开启加速度肌松监测仪,静脉注射顺阿曲库铵预注剂量,3 min后静脉注射芬太尼5 μg/kg、异丙酚2 mg/kg,静脉注射预注量后4 min,静脉注射顺阿曲库铵剩余插管剂量(3×ED95即0.15 mg/kg减去预注量),当单刺激颤搐值与对照值的比值下降至10%,行气管插管.静脉输注异丙酚、瑞芬太尼,吸入异氟烷维持麻醉.预注量根据序贯法确定,预注量从5μg/kg(10%ED95)开始,各相邻剂量比值为1.2.记录给予预注量后4min时单刺激颤搐值与对照值的比值、90%起效时间、起效时间、最大阻滞程度、临床作用时间.计算预注顺阿曲库铵加快起效的ED50及其95%可信区间(CI).结果 M组90%起效时间长于F组(P＜0.05),其余肌松效应指标两组比较差异无统计学意义(P＞0.05).预注顺阿曲库铵加快起效的ED50:男性为21.36μg/kg,95%CI为20.52～22.23μg/kg;女性为14.53 μg/kg,95%CI为13.77～15.33μg/kg,男性高于女性(P＜0.05).结论 预注顺阿曲库铵加快起效的ED50:男性为21.36μg/kg,女性为14.53 μg/kg,男性高于女性.     

二氧化碳气腹对腹腔镜手术患者顺阿曲库铵肌松效应的影响

目的 评价二氧化碳(C02)气腹对腹腔镜手术患者顺阿曲库铵肌松效应的影响.方法 择期子宫切除术患者60例,年龄35 ～ 60岁,BMI 18～ 24 kg/m2,ASA分级Ⅰ或Ⅱ级.采用随机数字表法,将其随机分为2组(n=30):气腹组(P组)和对照组(C组);每组根据肌松拮抗剂使用情况随机分为2个亚组(n=15):非拮抗组(P0组或C0组)和拮抗组(P1组或C1组).静脉注射芬太尼、丙泊酚、顺阿曲库铵麻醉诱导,气管插管后行机械通气.靶控输注丙泊酚和瑞芬太尼维持麻醉.采用TOF-Watch SX加速度仪监测肌松程度,P组于气腹建立后T1恢复达5％时静脉注射顺阿曲库铵0.05mg/kg,术毕P1组和C1组于 T1恢复至25％时静脉注射新斯的明拮抗,P0组和C0组自然恢复.记录气腹建立后追加顺阿曲库铵的临床作用时间和恢复指数.于诱导前即刻、气腹30 min、60 min及术毕时,分别抽取动脉血样行血 气分析.结果 与C0组比较,P0组临床作用时间及恢复指数延长(P＜0.05);与C1组比较,P1组临床作用时间及拮抗恢复指数延长(P＜0.05);与 C0组比较,P0组于气腹30、60 min、术毕时pH值下降,PaCO2升高(P＜0.05);与C1组比较,P1组于气腹30、60 min、术毕时pH值下降,PaCO2升高(P＜0.05).结论 CO2气腹可强化顺阿曲库铵的肌松效应,且可延长拮抗后肌松恢复时间.     

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.