不同年龄患儿罗库溴铵药效学的比较

目的 比较新生儿、婴儿、幼儿和儿童罗库溴铵的药效学.方法 择期全麻手术患儿160例,ASAⅠ或Ⅱ级,根据年龄分为4组(n=40):新生儿组、婴儿组、幼儿组及儿童组.各组随机选取患儿20例,采用4次累积给药法静脉注射罗库溴铵,初始剂量:新生儿组40 μg/kg,婴儿组80 μg/kg,幼儿组及儿童组均为120 μg/kg,后3次均追加罗库溴铵40μg/kg.每次给药后.观察TOF反应.当T1连续3次稳定不变时,给予下一次剂量.采用概率单位法计算T1抑制50%、90%、95%的用药量(ED50、ED90、ED95).各组随机选取20例患儿,静脉注射2倍ED95剂量的罗库溴铵,记录肌松起效时间、高峰时间、临床肌松时间、体内作用时间和恢复指数.结果 与新生儿组比较,幼儿组和儿童组罗库溴铵ED50、ED90和ED95均升高(P<0.01),婴儿组上述指标差异无统计学意义(P>0.05).婴儿组、幼儿组和儿童组罗库溴铵起效时间、临床肌松时间和体内作用时间缩短,恢复指数降低(P<0.01);与幼儿组比较.儿童组罗库溴铵ED50、ED90和ED95升高(P<0.01).结论 不同年龄患儿对罗库溴铵的量效关系和时效关系存在明显的差别,新生儿对罗库溴铵的敏感性最强.     

罗库溴铵用于婴儿骨科手术的临床效果

目的观察罗库溴铵用于婴儿骨科手术的药效学和临床效果。方法 80例择期全麻骨科手术患儿,年龄1~12月。研究分为两部分:(1)量效关系测定:40例婴儿随机分为L1、L2、L3、L4组,建立罗库溴铵量-效关系曲线,计算ED50和ED95。(2)肌松时效观察:其余40例随机给予1倍ED95(L5组)、1.5倍ED95(L6组)、2倍ED95(L7组)、3倍ED95(L8组)罗库溴铵,记录插管条件、起效时间、恢复时间、恢复指数。结果婴儿罗库溴铵ED50为175.14μg/kg,95%可信区间(CI)69.96~533.62μg/kg;ED95为232.31μg/kg,95%CI 90.42~728.62μg/kg。随着罗库溴铵剂量的增大,L6组、L7组、L8组起效时间明显短于L5组(P0.05或P0.01),肌颤搐恢复时间明显长于L5组(P0.05);L7组和L8组恢复指数明显慢于L5组和L6组(P0.05或P0.01)。结论 1.5倍ED95即350μg/kg罗库溴铵即能够提供婴儿良好的气管插管条件,适用于手术时间短而又需要全麻插管的手术。     

罗库溴铵在快速气管插管中的应用

罗库溴铵是目前起效最快的非去极化肌松药,其对喉肌的作用快于拇指内收肌,用2ED95剂量罗库溴铵的插管 条件较琥珀胆碱差,不同麻醉诱导药物可影响罗库溴铵的气管插管条件,用限时原则或预注原则行快速诱导气管插管时 2ED95剂量的罗库溴铵与1.5mg·kg-1琥珀胆碱插管条件相当。     

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%。     

异氟醚对罗库溴铵肌松效应影响的实验研究

目的　通过在体兔坐骨神经一胫前肌标本的制备,研究异氟醚对单次静注和连续输注罗库溴铵肌松效应的影响。方法　实验家兔均采用异氟醚全麻。10只家兔分为两组观测,观察组间单次静注罗库溴铵的肌松时效的变化;另取10只家兔分为两组,观察组间罗库溴铵连续输注后的肌松时效和输注量的变化。结果　单次静注罗库溴铵(2 倍 ED95 )时,异氟醚使其作用时间延长约 7min(P<0 .05),同时罗库溴铵对血液动力学影响轻微;连续静注罗库溴铵时,异氟醚使罗库溴铵的静脉输注需要量减少40%(P<0 .05),而对起效和恢复指数无明显影响。结论　异氟醚能增强罗库溴铵的肌松时效。     

阿曲库铵与哌库溴铵在预注法中的复合应用

目的 观察阿曲库铵和哌库溴铵在预注法中的复合应用。方法 选择平衡麻醉下择期手术病人70例。研究分两部分：第一部分，将30例病人随机均分为阿曲库铵组和哌库溴铵组，采用累计给药法建立两药量一效关系曲线，计算ED50和ED95；第二部分，根据两药ED95将另40例病人随机均分为单纯阿曲库铵预注组和复合哌库溴铵预注组。观察预注期间肌颤搐抑制值、起效时间和临床作用时间。结果 阿曲库铵ED50和ED95分别为117．5μg／kg和272．8μg／kg，哌库溴铵ED50和ED95分别为23．7μg／kg和42．6μg／kg；复合哌库溴铵预注组起效快于单纯阿曲库铵预注组；复合哌库溴铵预注组临床作用时间长于单纯阿曲库铵预注组。结论 在预注法中采用化学结构不同的肌松药可进一步加快起效，延长临床作用时间。     

罗库溴铵用于小儿的量效关系和肌松时效

目的　研究罗库溴铵用于小儿的量效关系和作用时效。方法　选择小儿与成人各40 例,用单次给药技术建立量效关系曲线,计算ED50、ED90和ED95;选择小儿与成人各10例,静脉注射 罗库溴铵600μg/kg后,记录起效时间、作用时间和恢复时间。结果　小儿与成人罗库溴铵的ED50 分别为199.6μg/kg和177.0μg/kg,ED90分别为297.8μg/kg和264.2μg/kg,ED95分别为 333.6μg/kg和295.9μg/kg;小儿与成人的起效时间分别为(84.4±15.4)s和(111.0±17.7)s,临床 肌松时间分别为(22.2±5.3)min和(28.8±6.2)min,恢复指数分别为(9.0±3.0)min和(12.5± 4.1)min,组间比较有显著性差异(P<0.05,P<0.01)。结论　小儿罗库溴铵的ED50、ED90和ED95 均大于成人,且起效快、作用时间短、恢复快。     

不同浓度异氟醚对罗库溴铵肌松作用的影响

目的 观察不同浓度异氟醚对罗库溴铵肌松作用的影响。方法 60例ASA Ⅰ-Ⅱ择期手术患者,随机分为3组,每组20例。组Ⅰ静脉注射罗库溴铵0.6 mg·kg-1;组Ⅱ吸入0.6％异氟醚后静脉注入罗库溴铵0.6mg·kg-1;组Ⅲ吸入1.2％异氟醚后从静脉注入罗库溴铵0.6mg·kg-1。分别记录各组注药后肌松作用的起效时间、作用时间及T1恢复时间。结果 与组Ⅰ相比,组Ⅱ、Ⅲ起效时间明显缩短(P<0.05),TOF无反应期明显延长(P<0.01),T1恢复25％、50％、90％时间明显延长(P<0.01),且组Ⅲ较组Ⅱ延长(P<0.05),恢复指数明显延长,且组Ⅲ较组Ⅱ延长(P<0.05)。结论 吸人异氟醚能明显缩短罗库溴铵起效时间,延长罗库溴铵作用时间,临床合并使用时应注意减少用量。     

罗库溴铵预注和麻黄碱预处理对小儿罗库溴铵肌松起效的影响

目的 观察小儿在罗库溴铵预注、麻黄碱预处理和罗库溴铵预注复合麻黄碱预处理对罗库溴铵起效时间、插管条件和肌松时效的影响.方法 选择全麻下行择期手术的患儿80例,ASA Ⅰ或Ⅱ级,随机均分为四组.在麻醉诱导前预先静注:Ⅰ组生理盐水O.5 ml,Ⅱ组罗库溴铵0.06 mg/kg,Ⅲ组麻黄碱70 μg/kg,Ⅳ组罗库溴铵0.06 mg/kg和麻黄碱70 μg/kg.预注和预处理4min后,Ⅰ、Ⅲ组静注罗库溴铵0.6 mg/kg,Ⅱ、Ⅳ组静注罗库溴铵0.54 mg/kg.待四个成串刺激(TOF)第1个颤搐反应高度(Th)达最大阻滞程度后行气管插管.记录肌颤搐抑制75%、90%和达最大阻滞程度的时间,并评估气管插管条件,同时观察HR、BP变化.结果 Ⅰ、Ⅱ、Ⅲ、Ⅳ组的最大阻滞起效时间分别为(196±43)、(140±43)、(144±35)和(100±33)s,Ⅱ、Ⅲ、Ⅳ组的起效时间明显短于Ⅰ组(P＜0.05),Ⅳ组的起效时间较Ⅱ、Ⅲ组短(P＜0.05).各组气管插管条件均达到6～9分,优良率100%.各组麻醉诱导期间均无明显的心血管不良反应.各组的临床肌松作用时间和恢复指数差异均无统计学意义.结论 罗库溴铵预注和麻黄碱预处理分别使用均能缩短小儿罗库溴铵的肌松起效时间,而两种方法复合使用可进一步加快肌松起效,但该方法对罗库溴铵的肌松时效无明显的影响.     

2倍ED95剂量罗库溴铵在老年患者麻醉诱导插管的应用

非去极化肌松药罗库溴铵具有起效快、对血流动力学影响小、不良反应少等优点.本研究观察了2倍ED95剂量的罗库溴铵在老年患者麻醉诱导插管中的应用,并与同等效剂量的阿曲库铵、维库溴铵进行比较.     

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.