依托咪酯靶控输注复合瑞芬太尼用于妇科腹腔镜手术病人麻醉的效果

目的 评价依托咪酯靶控输注(TCI)复合瑞芬太尼用于妇科腹腔镜手术病人麻醉的效果.方法 择期行妇科腹腔镜手术病人60例,年龄25 ～ 56岁,体重指数18 ～ 27 kg/m2,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将其分为2组(n=30):TCI丙泊酚复合瑞芬太尼麻醉组(PR组)和TCI依托咪酯复合瑞芬太尼麻醉组(ER组).2组静脉注射咪达唑仑0.1 mg/kg、芬太尼4 μg/kg和顺阿曲库铵0.15 mg/kg麻醉诱导,PR组TCI丙泊酚,效应室靶浓度(Ce) 2.5 μg/ml,ER组TCI依托咪酯,Ce 0.8μg/ml,气管插管后行机械通气.麻醉维持:PR组TCI丙泊酚,Ce 2.0～ 2.5μg/ml,ER组TCI依托咪酯,Ce 0.5～0.7 μg/ml,2组静脉输注瑞芬太尼0.1～0.2μg·kg-1·min-1,间断静脉注射顺阿曲库铵5 mg,维持BIS值40 ～ 60.分别于术前(基础状态,T0)、术毕(T1)、术后24 h(T2)和术后48 h(T3)时采集静脉血样,测定血清皮质醇和醛固酮的浓度;记录苏醒时间、拔除气管导管时间和术中血管活性药物使用情况;记录麻醉诱导时注射痛和肌颤、术中知晓和术后躁动、恶心呕吐的发生情况.结果 与T0时比较,T1时ER组血清皮质醇浓度降低(P＜0.05),2组各时点血清醛固酮浓度差异无统计学意义(P＞0.05).与PR组比较,ER组血管活性药物使用率和注射痛发生率降低,肌颤发生率升高(P＜0.05),苏醒时间、拔除气管导管时间、躁动和恶心呕吐发生率差异无统计学意义(P＞0.05).结论 与TCI丙泊酚复合瑞芬太尼比较,TCI依托咪酯复合瑞芬太尼用于妇科腹腔镜手术时有助于维持血流动力学稳定,对肾上腺皮质功能的抑制作用是一过性的,注射痛发生较少.     

阿片类药物对老年患者经尿道激光碎石术苏醒质量的影响

目的 观察阿片类药物对老年患者经尿道激光碎石术苏醒质量的影响. 方法 择期经尿道激光碎石手术患者134例,年龄65～79岁,ASA分级Ⅰ、Ⅱ级,采用随机数字表法分为3组:瑞芬太尼组(R组)46例、瑞芬太尼+芬太尼组(RF组)44例、芬太尼组(F组)44例.R组,采用丙泊酚和瑞芬太尼靶控输注(target-controlled infusion,TCI)进行麻醉诱导和麻醉维持;RF组,丙泊酚TCI麻醉诱导,静脉注射芬太尼2μg/kg,丙泊酚+瑞芬太尼TCI麻醉维持;F组,丙泊酚TCI麻醉诱导,芬太尼4 μg/kg,丙泊酚TCI麻醉维持.手术结束后送入PACU,记录患者被转入PACU时(T1)、拔除喉罩前2 min (T2)、拔除喉罩即刻(T3)和拔除喉罩后5 min(Td)4个时间点的MAP、HR,记录拔除喉罩后VAS评分和苏醒期芬太尼用量,记录患者睁眼时间、拔除喉罩时间和PACU驻留时间. 结果 麻醉苏醒期间R组在T1～T3时点MAP[(110±18)、(122±13)、(121±14) mmHg(1 mmHg=0A33 kPa)]和HR[(79±15)、(97±17)、(99±18)次/min]高于RF组(P＜0.05);R组VAS[(1.8±1.4)分]高于RF组[(0.9±0.9)分]和F组[(0.9±0.9)分](P＜0.05);R组需芬太尼镇痛患者比例高于其他两组(P＜0.05);F组的睁眼时间、拔喉罩时间以及PACU驻留时间比RF组和R组长(P＜0.05). 结论 老年患者经尿道激光碎石术应用丙泊酚复合瑞芬太尼+芬太尼全凭静脉麻醉比丙泊酚单纯复合瑞芬太尼或芬太尼苏醒期间血流动力学平稳、苏醒迅速、术后镇痛效果好.     

BIS指导靶控输注依托咪酯复合瑞芬太尼用于非心脏手术麻醉的效果:前瞻性、随机、单盲、多中心、临床对比研究

目的 评价脑电双频谱指数(BIS)指导靶控输注(TCI)依托咪酯复合瑞芬太尼用于非心脏手术麻醉的效果.方法 择期非心脏手术患者244例,性别不限,年龄20～60岁,体重54～76 kg,身高151～176 cm,ASA分级Ⅰ或Ⅱ级,预计手术时间＜3h.采用随机数字表法,将患者随机分为2组:丙泊酚TCI复合麻醉组(P组,n=121)和依托咪酯TCI复合麻醉组(E组,n=123).麻醉诱导:2组静脉注射舒芬太尼0.3～0.4 μg/kg;E组TCI依托咪酯,效应室靶浓度(Ce)0.5～1.0 μg/ml,P组TCI丙泊酚,Ce3～4μg/ml,静脉注射罗库溴铵0.9 mg/kg,气管插管后机械通气,维持PET CO2 35～ 40 mm Hg.麻醉维持:E组TCI依托咪酯,Ce 0.3～0.8 μg/ml;P组TCI丙泊酚,Ce 3 ～4 μg/ml,静脉输注瑞芬太尼0.1～1.0μg·kg-1·min-1,间断静脉注射罗库溴铵10 ～ 20 mg,维持BIS值40～60.记录意识消失时、麻醉维持和苏醒时依托咪酯的Ce,记录麻醉诱导时药物注射痛发生情况及术中血管活性药物使用情况、瑞芬太尼用量、苏醒时间、拔除气管导管时间、麻醉恢复期恶心呕吐及躁动的发生情况.结果 意识消失和苏醒时依托咪酯Ce分别为(0.50±0.22)、(0.16±0.09)μg/ml,麻醉维持时Ce 0.22～0.39μg/ml.与P组比较,E组注射痛发生率与血管活性药物使用率降低,瑞芬太尼用量增加,躁动及恶心呕吐发生率升高(P＜0.05或0.01),苏醒时间和拔除气管导管时间差异无统计学意义(P＞0.05).结论 与丙泊酚TCI复合瑞芬太尼麻醉比较,BIS指导依托咪酯TCI复合瑞芬太尼用于3h内非心脏手术麻醉时,血液动力学更平稳,无明显注射痛,而麻醉恢复期躁动及恶心呕吐的发生机率升高.     

丙泊酚复合瑞芬太尼行腹腔镜卵巢囊肿切除术的临床观察

目的观察丙泊酚复合瑞芬太尼行腹腔镜卵巢囊肿切除术麻醉诱导和拔管期的临床效果。方法选择ASAⅠ或Ⅱ级,腹腔镜下卵巢囊肿切除术患者60例,随机均分为丙泊酚复合瑞芬太尼组(PR组)和丙泊酚复合芬太尼组(PF组)。麻醉诱导:PR组丙泊酚2～3mg/kg、瑞芬太尼1μg/kg,然后泵注0.5μg·kg-1·min-1;PF组丙泊酚2～3mg/kg、芬太尼2～3μg/kg。麻醉维持:PR组丙泊酚75μg·kg-1·min-1、瑞芬太尼0.2μg·kg-1·min-1,根据血流动力学调整瑞芬太尼给药速度和丙泊酚靶浓度;PF组丙泊酚75μg·kg-1·min-1,于手术开始前加芬太尼4～5μg/kg,两组患者均在手术结束时同时停麻醉药。观察并记录患者麻醉前、气管插管后、气腹后5min、手术结束时的HR、MAP。记录诱导时间、睁眼时间、拔管时间。结果与麻醉前比较,PF组气管插管后和气腹后5min的HR增快、MAP升高(P<0.05);与PF组比较,PR组气管插管后和气腹后5min的HR减慢、MAP降低(P<0.05),且诱导时间、睁眼时间、拔管时间均缩短(P<0.05)。结论腹腔镜下卵巢囊肿切除术患者丙泊酚复合瑞芬太尼麻醉较之复合等效剂量芬太尼,术中血流动力学更稳定,术后清醒快、恢复迅速。     

丙泊酚复合瑞芬太尼靶控输注在腹腔镜胆囊切除术中的应用

目的:观察丙泊酚复合瑞芬太尼靶控输注全凭静脉麻醉对腹腔镜胆囊切除术血流动力学及术后苏醒时间的影响。方法:50例择期行腹腔镜胆囊切除术的患者均采用丙泊酚复合瑞芬太尼靶控输注全凭静脉麻醉。设定诱导时静注咪达唑仑2mg,先血浆靶控输注瑞芬太尼4ng/ml,1min后血浆靶控输注丙泊酚3μg/ml或3.5μg/ml,患者意识消失后静注维库溴铵0.1mg/kg,3min后气管内插管,插管后丙泊酚靶浓度调至2μg/ml,术中维持根据需要调整丙泊酚靶浓度,以0.2μg/ml递增或递减,瑞芬太尼维持不变。记录诱导前、诱导后2min、插管即刻、插管后5min、气腹时、气腹后5min的收缩压(systolic bloodpressure,SBP)、舒张压(diastolic blood pressure,DBP)、心率(heart rate,HR)及术后呼吸恢复时间、呼之睁眼时间。结果:诱导后2min的SBP、DBP、HR与诱导前差异均有统计学意义(P0.05),气腹时SBP、DBP、HR有所升高,但差异无统计学意义,其他时点经适当调整丙泊酚靶浓度处理后逐渐平稳,术后呼吸恢复时间为(6.5±2.2)min,呼之睁眼时间(8.9±3.1)min。结论:丙泊酚复合瑞芬太尼靶控输注用于腹腔镜胆囊切除术安全,术中血流动力学平稳,术后苏醒快。     

两种麻醉方法在隆乳术中的应用

目的：探讨靶控输注（TCI）瑞芬太尼、丙泊酚在经腋路小切口隆乳手术中的应用。方法：选择60侈0要求隆乳的女性,随机分为两组,I组为靶控输注瑞芬太尼、丙泊酚,Ⅱ组为丙泊酚和氯胺酮。手术开始前,I组诱导靶浓度：丙泊酚4μg／ml,瑞芬太尼3ng／ml,患者进入麻醉状态后维持靶浓度丙泊酚3μg,瑞芬太尼2ng／ml,术中根据患者体动反应及心律血压变化随时调整靶控浓度,Ⅱ组手术前静注丙泊酚2mg／kg,氯胺酮0．8mg／kg,然后持续泵注丙泊酚6mg／kg·min,术中根据患者体动反应间断推注氯胺酮0．5mg／kg术中监测血压、脉搏、呼吸、血氧饱和度,观察手术中及术后病人的不良反应,观察术后苏醒时间及离院时间。结果：I组循环系统较Ⅱ组平稳,呼吸抑制较Ⅱ组明显,但SP02多在95%左右,无明显统计学差异。术后苏醒时间及空向力恢复时间I组较Ⅱ组短。术后恶心呕吐、苏醒期谵妄、头晕等不良并发症I组较Ⅱ组少。结论：靶控输注丙泊酚瑞芬太尼与静脉泵注丙泊酚复合氯胺酮都可用于隆胸手术的麻醉,但靶控输注瑞芬太尼丙泊酚具有术中循环稳定,术后苏醒快定向力恢复时间短及术后并发症少等优点。     

瑞芬太尼对丙泊酚靶控输注患者意识消失及诱发脑电爆发抑制时的半数有效浓度的影响

目的探讨丙泊酚TCI时患者意识消失(LOC)及诱发脑电爆发抑制(BS)时的效应室半数有效浓度(EC50)的影响。方法择期全麻手术患者60例,随机均分为瑞芬太尼组(R组)和生理盐水组(N组)。R组:以4ng/ml靶浓度TCI瑞芬太尼10 min后开始TCI丙泊酚,靶浓度从1μg/ml开始递增,递增梯度为1μg/ml,每一靶浓度输注1min,至脑电监测爆发抑制比(BSR)达到15%后结束试验;N组:以等量生理盐水模拟瑞芬太尼TCI,其余方法与R组相同,期间所有患者每间隔20秒行改良OAA/S评分,改良OAA/S评分2分定义为LOC,BSR15%定义为出现BS现象。记录LOC和BSR达15%时的丙泊酚EC50及其95%可信区间(CI)。结果 LOC时R组丙泊酚效应室EC50为1.73μg/ml(95%CI 1.68~1.79μg/ml),N组为2.35μg/ml(95%CI 2.29~2.41μg/ml)(P0.05)。BSR达15%时R组和N组丙泊酚EC50分别为6.25μg/ml(95%CI 6.18~6.42μg/ml)和6.31μg/ml(95%CI 6.13~6.47μg/ml),两组差异无统计学意义。结论复合TCI瑞芬太尼可降低丙泊酚TCI意识消失时的效应室EC50,但对出现脑电爆发抑制时的丙泊酚效应室浓度无明显影响。     

中低速率输注瑞芬太尼不改变脑电双频指数监测下维持麻醉所需靶控输注丙泊酚的浓度

背景本文旨在观察不同速率输注瑞芬太尼是否会降低使脑电双频指数（bispectral index，BIS）≤50的丙泊酚EC50（半数有效浓度）值。方法将72例ASA分级Ⅰ或Ⅱ级拟行气管内插管并靶控输注（TCI）丙泊酚维持麻醉的成人患者，随机分为6组。瑞芬太尼输注速率分别为：B组0．1μg·kg^-1·min^-1,C组0．15μg·kg^-1·min^-1,D组0．2μg·kg^-1·min^-1,E组0．3μg·kg^-1·min^-1,F组0．4μg·kg^-1·min^-1,A组作为对照组不使用瑞芬太尼。在同一浓度瑞芬太尼组中，以第1例患者对TCI4μg/ml丙泊酚的反应决定岳一例患者的效应室浓度（Dixon的“序贯法”）。如果BIS〉50，后一例患者TCI丙泊酚的效应室浓度增加，如果BIS≤50，后一例患者TCI丙泊酚的效应室浓度则减少。同时研究了联合用药的血流动力学效应。结果EC50变化范围为2．4-2．9μg/ml.未发现瑞芬太毫对丙泊酚EC50的累加效应。但是未使用瑞芬太尼的空白对照组对丙泊酚的反应差异较大。使用瑞芬太尼组患者心率下降。结论瑞芬太昆输注不会减少无刺激麻醉患者丙泊酚需求量。在联合输注瑞芬太尼时不应当降低丙泊酚TCI浓度．     

丙泊酚血浆靶控输注与不同镇痛药物用于人工流产术的麻醉效果

目的比较丙泊酚血浆靶控输注分别复合芬太尼或舒芬太尼单次静脉注射及雷米芬太尼血浆靶控输注用于人工流产术的效果。方法选择120例行人工流产术的患者,随机分为芬太尼单次静脉注射组(F组)、雷米芬太尼血浆靶控输注组(R组,靶浓度为4ng/ml)和舒芬太尼单次静脉注射组(S组),分别复合丙泊酚血浆靶控输注(靶浓度为4μg/ml)行静脉全麻,观察起效时间、恢复时间、准确定向时间、术中体动(程度和次数)、镇痛效果、呼吸抑制、HR、MAP、SpO2变化及术后并发症等。结果R组麻醉起效时间显著低于F组和S组(P<0·01),麻醉恢复时间显著高于F组和S组(P<0·01),R组的丙泊酚总用量、吸宫时术中最低SpO2、术中体动及术后恶心呕吐、嗜睡均低于F组和S组(P<0·05,P<0·01),R组的呼吸抑制显著高于F组和S组(P<0·01)。结论丙泊酚血浆靶控输注复合雷米芬太尼血浆靶控输注的麻醉方法用于人工流产术,其镇痛效果优于丙泊酚血浆靶控输注复合芬太尼或舒芬太尼单次静脉注射的麻醉方法,但要注意雷米芬太尼呼吸抑制作用较强的特点。     

瑞芬太尼复合丙泊酚麻醉应用于腹腔镜下腹股沟疝修补术的麻醉效果

目的观察瑞芬太尼复合丙泊酚应用与腹腔镜下腹股沟疝修补术麻醉的优越性和安全性。方法将2015-04—2015-10接受芬太尼和瑞芬太尼复合丙泊酚全凭静脉麻醉实施腹腔镜下腹股沟疝修补术的患者作为观察对象。根据不同麻醉用药分为2组,各34例。对照组依次给予咪唑安定0.04 mg/kg,芬太尼1.5~2μg/kg,罗库溴铵0.6 mg/kg,丙泊酚1.5~2 mg/kg诱导。术中间断静注芬太尼和泵注丙泊酚维持麻醉。观察组给予咪唑安定0.04 mg/kg,瑞芬太尼1.0~1.5μg/kg,罗库溴铵0.6 mg/kg,丙泊酚1.5~2 mg/kg诱导。插管成功后以0.2μg/(kg·min)持续泵注瑞芬太尼,4.2 mg/(kg·min)泵注丙泊酚维持麻醉。比较2组患者在诱导前、诱导后、切皮时、气腹后5 min和拔管后各时间点的血压、心率变化及术毕麻醉恢复过程中的呼叫睁眼、呼吸恢复、吞咽反射等指标变化。结果观察组患者各时间点的血压、心率变化明显小于对照组,且患者苏醒时间和拔管时间明显短于对照组。2组比较,差异均有统计学意义(P0.05)。结论瑞芬太尼复合丙泊酚麻醉在腹腔镜下腹股沟疝修补术中循环更稳定,具有起效快、操作简单、苏醒时间短等优越性和安全性。     

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.