七氟醚麻醉下瑞芬太尼抑制小儿气管插管心血管反应的半数有效血浆靶浓度

目的 确定七氟醚麻醉下瑞芬太尼抑制小儿气管插管心血管反应的半数有效血浆靶浓度(Cp<50).方法 择期全麻手术患儿,年龄2～5岁,ASA Ⅰ或Ⅱ级.初始七氟醚吸入浓度为8%,氧流量3 L/min,待患儿意识消失后调整七氟醚吸入浓度,使呼气末七氟醚浓度为2.5%(1 MAC),2 min后采用Minto药代动力学模型靶控输注瑞芬太尼,10 min后进行气管插管.瑞芬太尼血浆靶浓度按序贯法确定,瑞芬太尼血浆靶浓度从6μg/L开始,相邻浓度的比值为1.2,气管插管心血管反应的标准:插管后2 min内MAP和/或HR较插管前升高≥15%.结果 瑞芬太尼抑制气管插管心血管反应的Cp50为3.6μg/L,95%可信区间为3.1～4.0μg/L.结论 七氟醚1 MAC麻醉下瑞芬太尼抑制小儿气管插管心血管反应的Cp50为3.6 μg/L,95%可信区间为3.1～4.0μg/L.     

老年和成年患者依托咪酯诱导时雷米芬太尼抑制气管插管反应的半数有效血浆浓度

目的测定老年和成年患者依托咪酯诱导时雷米芬太尼抑制气管插管反应的半数有效血浆浓度(Cp50)。方法择期全麻手术患者40例,ASAⅠ或Ⅱ级,年龄19~80岁,体重指数20~30kg/m2,按年龄分为青壮年组(19~64岁)和老年组(65~80岁),每组20例。雷米芬太尼靶控输注5min后,静脉注射0.3mg/kg的依托咪酯,患者意识消失后给予罗库溴铵行气管插管。雷米芬太尼的血浆靶浓度按序贯法确定,相邻血浆靶浓度之间的比率为1.2。结果0.3mg/kg依托咪酯诱导时,老年组和青壮年组雷米芬太尼抑制气管插管的Cp50分别为4.11μg/L和3.37μg/L,95%可信区间分别为3.90~4.34μg/L和3.02~3.75μg/L。结论老年和青壮年患者在复合0.3mg/kg的依托咪酯行麻醉诱导时,雷米芬太尼抑制气管插管反应的Cp50分别为4.11g/L和3.37μg/L。     

复合靶控输注异丙酚时瑞芬太尼抑制重症肌无力患者气管插管反应的药效学

目的 探讨复合靶控输注异丙酚时瑞芬太尼抑制重症肌无力患者气管插管反应的药效学.方法 拟行经胸骨正中劈开胸腺切除术的重症肌无力患者45例,ASA Ⅰ或Ⅱ级,TCI异丙酚和瑞芬太尼进行麻醉诱导,异丙酚血浆靶浓度为4 μg/ml,瑞芬太尼初始效应室靶浓度(Ce)为1.8 ng/ml,依次按2.7、4.0、6.0 ng/ml梯度递增,至患者可耐受喉麻管置入声门下进行气管内表麻后,进行气管插管.采用概率单位回归分析法分别计算瑞芬太尼抑制气管插管反应的Ce50和Ce95.结果 瑞芬太尼抑制气管插管反应的Ce50为2.2 ng/ml,其95%可信区间为2.0～2.3 ng/ml;抑制气管插管反应的Ce95为3.0 ng/ml,其95%可信区间为2.8～3.5 ng/ml.结论 复合靶控输注异丙酚(血浆靶浓度为4 μg/ml)时,瑞芬太尼抑制重症肌无力患者气管插管反应的Ce50和Ce95分别为2.2、3.0 ng/ml.     

小儿臂丛神经阻滞丙泊酚TCI的半数有效浓度

目的:测定小儿臂丛神经阻滞丙泊酚靶控输注的半数有效血浆靶控浓度。方法:择期臂丛麻醉下行前臂或手外科手术患儿,术前30min口服咪达唑仑镇静,序贯法靶控输注丙泊酚,初始血浆靶浓度设为5.0μg/mL,待患儿睫毛反射消失和对言语指令无反应时,行腋路臂丛神经阻滞。结果:丙泊酚TCI抑制小儿臂丛神经阻滞时患儿体动反应的半数有效血浆靶控浓度为3.9μg/mL,95%可信区间为3.6～4.2μg/mL。结论:口服咪达唑仑镇静下,丙泊酚抑制臂丛神经阻滞时患儿体动反应的半数有效血浆靶控浓度为3.9μg/mL。     

瑞芬太尼抑制患者清醒气管插管反应的半数有效剂量

目的 确定咪达唑仑镇静下瑞芬太尼抑制患者清醒气管插管反应的半数有效剂量(ED50).方法 择期全麻下行整形外科手术的成年女性患者36例,ASAⅠ级,采用改良Dixon序贯法进行试验,静脉输注咪达唑仑0.1 mg/ks 10 min后,第1例快速静脉输注瑞芬太尼1 μg/kg后以0.1μg·min-1·kg-1静脉输注,若未发生气管插管反应,则下一例瑞芬太尼降低0.1μg/kg,速率降低0.01μg·min-1·kg-1,直至第n例发生气管插管反应.将第n例和第n=1例剂量的平均值作为初始剂量,以0.05μg/kg和0.005μg·min-1·kg-1为梯度进行调整.根据对直接喉镜显露声门及气管插管操作的反应及镇静评分评价是否发生气管插管反应.采用改良Dixon序贯法计算瑞芬太尼抑制清醒气管插管反应的ED50,并采用logistic回归模型进行概率单位转换分析ED50及其95%可信区问.结果 采用改良Dixon序贯法计算瑞芬太尼抑制清醒气管插管反应的ED50为0.62 μg/ks,概率单位转换法计算的ED50及其95%可信区间分别为0.63(0.54～0.70)μg/kg.未发生气管插管反应的19例患者中,有18例对气管插管耐受良好,并可对言语指令作出正确反应.术后随访患者对气管插管操作均无不良记忆.结论 咪达唑仑0.1 mg/kg镇静下,快速静脉输注瑞芬太尼0.62 μg/kg后以0.062 μg·min-1·kg-1静脉输注可为50%的患者提供较好的清醒气管插管条件,且无气管插管反应发生.     

舒芬太尼抑制老年患者McGrath视频喉镜下气管插管反应的半数有效浓度

目的 测定舒芬太尼抑制老年患者McGrath视频喉镜气管插管反应的半数有效浓度(median effectiveconcentration,EC50).方法 选择全身麻醉下气管插管行外科手术的老年患者29例,年龄66岁～75岁.患者入室建立静脉通路后给予咪达唑仑0.02 mg/kg.诱导同时以效应室靶浓度(target effect-site concentration,Ce)靶控输注(target-controlled infusion,TCI)丙泊酚和舒芬太尼,丙泊酚的初始Ce为1.5 mg/L,2 min后调至2.5 mg/L;舒芬太尼的Ce浓度为0.3 μg/L.当镇静/警醒评分≤2时,给予罗库溴铵0.6 mg/kg.待舒芬太尼Ce与血浆浓度(plasma concentration,Cp)平衡后McGrath视频喉镜下气管插管.观察患者的气管插管反应,若插管反应呈阳性,按序贯法依次升高下一例舒芬太尼的Ce,若插管反应呈阴性,则降低下一例舒芬太尼的Ce,各相邻浓度间比例为1.2.结果 舒芬太尼TCI抑制老年患者McGrath视频喉镜下气管插管反应的EC50为0.194 μg/L,95％置信区间(confidence interval,cI)为0.174 μg/L～0.212 μg/L(P＜0.01).麻醉诱导过程中舒芬太尼的平均用量为(0.211±0.039) μg/kg(P＜0.01).结论 丙泊酚Ce为2.5 mg/L时,舒芬太尼抑制50％老年患者McGrath视频喉镜下气管插管反应的Ce为0.194 μg/L.     

不同剂量依托咪酯麻醉诱导时瑞芬太尼抑制病人气管插管反应的半数有效血浆靶浓度

依托咪酯是临床常用短效静脉麻醉药,起效快、安全界限大、ED50/LD50.比值为26.4、清醒迅速、对呼吸无明显抑制、无术中知晓是其突出优点[1].瑞芬太尼是超短效μ受体激动剂,可抑制气管插管反应[2].本试验拟研究不同剂量依托咪酯麻醉诱导时瑞芬太尼抑制病人气管插管反应的半数有效血浆靶浓度(Cp50),为临床提供参考.     

瑞芬太尼抑制喉罩插入心血管反应的半数效应室靶浓度

目的 测定同一麻醉深度下,瑞芬太尼抑制妇科腹腔镜手术患者喉罩插入心血管反应的半数效应室靶浓度(EC<,50>).方法 择期妇科腹腔镜手术患者31例,采用咪达唑仑-丙泊酚-维库溴铵-雷米芬太尼顺序诱导,给予达咪唑仑、丙泊酚,脑电双频指数(BIS)稳定在45～55时,给予维库溴铵,然后按上下序贯法靶控输注(TCI)瑞芬太尼.瑞芬太尼血浆浓度与效应室浓度平衡时开始插入喉罩.出现8个心血管反应阳性阴性拐点时终止研究.结果 研究进行至第31例患者时出现8个心血管反应阳性阴性拐点,其中29例患者纳入分析.瑞芬太尼抑制喉罩插入心血管反应的EC<,50>为2.0 ng/ml,95%可信区间为1.8～2.2 ng/ml.结论 维持BIS 45～55的情况下,瑞芬太尼抑制喉罩插入心血管反应的EC<,50>为2.0 ng/ml.     

右美托咪啶与瑞芬太尼用于纤维支气管镜引导经鼻清醒气管插管效果的比较

目的 比较右美托咪啶与瑞芬太尼用于纤维支气管镜引导经鼻清醒气管插管的效果.方法 预期困难气道择期拟行纤维支气管镜引导经鼻清醒气管插管的外科手术患者40例,年龄18～73岁,ASA分级Ⅰ～Ⅲ级,采用随机数字表法,将其分为2组(n=20):右美托咪啶组(D组)和瑞芬太尼组(R组).D组先静脉注射右美托咪啶负荷量1.0 μg/kg,再以0.5 μg·kg-1·h-1的速率静脉输注;R组靶控输注瑞芬太尼,血浆靶浓度3.2ng/m.D组负荷量注射结束、R组达血浆靶浓度时进行气管插管.气管插管期间行Ramsay镇静评分;评价气管插管条件和患者对气管插管的耐受性;记录气管插管时间、气管插管成功情况、气管插管期间心血管反应、低氧血症的发生情况;术后24h回访,记录咽喉疼痛、声音嘶哑的发生情况,记录患者对气管插管的满意度评分和对气管插管的记忆情况.结果 与R组比较,D组Ramsay镇静评分升高,气管插管条件和耐受性提高,气管插管时间缩短,气管插管首次成功率升高,术后满意度评分升高,不良反应发生率降低,气管插管记忆评分降低(P＜0.05).结论 与瑞芬太尼比较,右美托咪啶用于纤维支气管镜引导清醒气管插管时能提供更好的插管条件,不良反应少,且可抑制气管插管知晓的发生.     

丙泊酚镇静下瑞芬太尼对不同年龄患者抑制气管插管反应的半数有效浓度

目的 测定丙泊酚镇静深度下瑞芬太尼抑制不同年龄患者插管反应的半数有效血浆靶控浓度(Cp50)、半数有效实测浓度(Cm50)值、半数有效效应室浓度(EC50)值.方法 60例上腹部手术患者,男37例、女23例,年龄22岁～82岁,分为:青年组(n=20),22岁～44岁,中年组(n=20),45岁～64岁,老年组(n=20),65岁～82岁.所有患者靶控输注丙泊酚、调节丙泊酚靶控输注血浆浓度将脑电双频指数(bispectral index,BIS)目标值定为45～55,待BIS目标值稳定5 min,靶控输注瑞芬太尼.瑞芬太尼的血浆靶控浓度按序贯法确定,输注5 min给予维库溴铵0.1 mg/kg行气管插管,记录血流动力学变化和计算瑞芬太尼Cp50、Cm50、EC50值.结果 3组患者瑞芬太尼抑制插管反应的Cp50和95%CI分别是5.77 μg/L.,4.76 μg/L～7.01 μg/L;4.80 μg/L,3.56 μg/L～6.48 μg/L;4.06 μg,/L,3.52 μg,/L～4.92 μg/L.青年组与中年组、老年组差异有统计学意义(P<0.01),中年组与老年组差异有统计学意义(P<0.05).EC50和95%CI分别是5.90μg/L,4.47 μg/L～7.68 μg/L;4.60 μg/L,3.03 μg/L～5.90 μg/L;4.06 μg/L,2.97 μg/L～5.42 μg/L.青年组与中年组、老年组差异有统计学意义(P<0.05),中年组与老年组差异有统计学意义(P<0.01).Cm50和95%CI分别是4.25 μg/L,2.04 μg/L～6.47 μg/L;3.62 μg/L,1.70 μg/L～5.54 μg/L;3.09 μg/L,1.3μ/L～4.89 μg/L.青年组与老年组差异有统计学意义(P<0.01).3组患者在达到目标BIS值时丙泊酚靶控浓度分别为(3.6±0.6)mg/L、(3.4±0.8)mg/L、(2.7±0.8)mg/L,青年组与老年组差异有统计学意义(P<0.05).结论 丙泊酚复合瑞芬太尼用于抑制气管插管反应,在维持BIS值为45～55时,各年龄组之间的丙泊酚靶控输注血浆浓度、瑞芬太尼的Cp50、Cm50、EC50差异有统计学意义.     

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.     

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.     

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.     

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.