麻醉状态下氟马西尼对患者脑电双频指数的影响

目的 评估七氟醚麻醉下氟马西尼对患者麻醉深度及脑电双频指数(BIS)的影响.方法 20例ASA Ⅰ或Ⅱ级患者择期全麻下行妇科腹腔镜手术.当麻醉初期BIS(47±3)时静注氟马西尼0.01 mg/kg,记录给药(氟马西尼)前及给药后2、4、6、8、10、15、20 min 7个时点的SBP、DBP、MAP、HR、SpO_2及BIS值.结果 各时点的SBP、DBP、MAP、HR、SpO_2及BIS值差异均无统计学意义.结论 氟马西尼对七氟醚麻醉下患者的镇静程度无明显拮抗作用.     

氟马西尼对依托咪酯麻醉恢复期脑电双频指数值变化及清醒恢复影响的临床观察

目的 探讨氟马西尼对依托咪酯麻醉恢复期脑电双频指数(bispectral index,BIS)值变化及清醒恢复的影响.方法 40例择期全麻下行乳腺区段切除患者,应用随机数字表随机分为氟马西尼组(F组)和对照组(C组).术中采用以依托咪酯为主的全凭静脉麻醉,术毕分别给予氟马西尼0.5 mg或生理盐水5 ml,拔管后观察2h.分别记录注射氟马西尼或生理盐水后1、2、3、5、10 min的警觉/镇静(OAA/S)评级及BIS值.记录用药后的副作用. 结果 两组患者年龄、身高、体重、手术时间等差异均无统计学意义.用氟马西尼后1 min的OAA/S镇静评级及BIS值两组间差异无统计学意义,但用氟马西尼后2、3、5、10 minF组的OAA/S镇静评级(1.60±0.27、2.95±0.31、3.50±0.37、4.56±0.21)及BIS值(63.2±2.3、67.1±8.3、78.3±6.2、87.8±3.3)均较C组相应时点的OAA/S镇静评级(0.60±0.17、1.80±0.37、2.90±0.20、3.10±0.61)及BIS值(53.1±2.0、55.2±6.1、62.3±5.2、69.2±4.2)明显增高(P＜0.01).两组间术后副作用差异均无统计学意义.结论 氟马西尼对依托咪酯麻醉有催醒作用.     

胃镜检查时丙泊酚最佳初始剂量的随机对照研究

目的探讨丙泊酚用于胃镜镇静的最佳初始剂量.方法接受无痛胃镜检查67例为镇静组,按随机数字表随机分为3组,丙泊酚首次剂量不同:A组(n=22)1.0 mg/kg;B组(n=23)1.5 mg/kg;C组(n=22)2.0 mg/kg.普通胃镜检查20例为对照组.于丙泊酚给药后1 min进镜,当病人出现不良反应且影响操作时追加丙泊酚20～30 mg.监测血压、心率、血氧饱和度值(SpO2)、脑电双频指数(BIS),以BIS值反应镇静深度.结果进镜时各组BIS值差异有显著性(F=33.31,P=0.000),C组BIS值为(53.82±9.52),镇静深度最深,处于麻醉状态,B组BIS值为(64.52±8.30),接近镇静状态.首次剂量下各组无须追加给药,顺利进镜率B(65.2%,15/23)、C(86.4%,19/22)组高于A组(31.8%,7/22)(x2=5.020,13.538;P=0.025,0.000),B、C组间无差异(x2=2.722,P=0.099).3个镇静组给药后血压、心率均下降,对照组血压、心率均升高.检查中平均动脉压变化量C组高于其他3组(P＜0.05);心率变化量对照组最高,3个镇静组间差异无显著性.SpO2＜90%的发生率,C组(68.2%,15/22)明显高于A组(27.3%,6/22)和B组(34.8%,8/23)(x2=7.379,5.020;P=0.007,0.025),A、B组间差异无显著性(x2=0.296,P=0.586).结论丙泊酚1.5 mg/kg作为胃镜检查的首次剂量进镜效果好且安全.     

老年患者匀速注射丙泊酚的量效关系及其对痛阈的影响

目的 观察在不同剂量丙泊酚镇静下老年患者BIS、MAP及HR的变化趋势及其对痛阈的影响.方法 选择年龄65～89岁,ASA Ⅰ或Ⅱ级.行择期手术的患者40例,随机均分为四组,分别接受4个不同剂量的丙泊酚匀速静脉注射.即Ⅰ组0.75 mg/kg、Ⅱ组1 mg/kg、Ⅲ组1.25mg/kg、Ⅳ组1.5 mg/kg,注射时间均为1 min.改良警觉/镇静(OAA/S)评分法测各组丙泊酚镇静催眠深度.微电流致痛法测各组痛阈.分别于注药前、注药后1 min测四组BIS、HR、MAP及痛阈低值和高值.结果 注药后1 min,Ⅰ、Ⅱ组OAA/S评分均达到2或1分,Ⅲ、Ⅳ组0分.Ⅰ、Ⅱ组BIS值分别是70.4±12.3、68.7±6.4,Ⅲ、Ⅳ组的BIS是56.3±13.3及48.3±9.8,其中注药后1 minⅢ、Ⅳ组的BIS值分别显著低于Ⅰ、Ⅱ组(P<0.05或P<0.01).丙泊酚用药剂量与BIS之间呈显著负相关(r=-0.648,P<0.01),回归方程:BIS=96.626-31.719×丙泊酚剂量(r2=0.419,P<0.01).注药后1min,四组的MAP均显著低于注药前(P<0.01);组间比较,Ⅳ组显著低于同时点的Ⅰ、Ⅱ组(P<0.05),而注药前后各组HR值组内、组间比较差异均无统计学意义.注药后1 min的Ⅲ、Ⅳ组的痛阈低值高于注药前,也高于同时点的Ⅰ、Ⅱ组(P<0.05或P<0.01);两组的痛阈高值也显著高于注药前(P<0.05或P<0.01).结论 随着丙泊酚用药剂量的增加,BIS值相应降低,两者呈线性负相关.1.25、1.5 mg/kg的丙泊酚单次匀速静注后可满足老人全麻术中镇静催眠的需求,并使痛阈水平上升,疼痛敏感性降低.     

氟马西尼对全麻肝叶切除术患者促醒作用及恢复期脑电双频指数、认知功能的影响观察

目的观察氟马西尼对全麻肝叶切除术患者促醒作用及恢复期脑电双频指数(BIS)、认知功能的影响。方法选取50例全麻肝叶切除术患者,根据是否使用氟马西尼分为氟马西尼组(n=25)和非氟马西尼组(n=25),两组均采取瑞芬太尼复合丙泊酚靶控输注(TCI)全麻,术中维持BIS在40~60之间。术毕入麻醉苏醒室即刻,氟马西尼组给予氟马西尼静脉推注,非氟马西尼组给予等体积生理盐水静脉推注。记录两组术后复苏时间指标及入苏醒室后不同时间点BIS值变化,并分别于术前1 d及术后1 d、3 d、5 d采用简易智能精神检查量表(MMSE)评价患者认知功能。结果氟马西尼组较非氟马西尼组术后自主呼吸恢复时间、指令下睁眼时间、指令下握拳时间、拔管时间及回忆起出生日期时间均明显缩短(P0.05)。氟马西尼组BIS值从进入麻醉苏醒室后4 min开始明显增高(P0.05),非氟马西尼组BIS值从进入麻醉苏醒室后6 min开始明显增高(P0.05)。氟马西尼组进入麻醉苏醒室4 min、6 min、8 min、10 min、12 min、14 min、16 min的BIS值均明显高于非氟马西尼组(P0.05)。在术后1 d、3 d、5 d等时间上,氟马西尼组MMSE评分均明显高于非氟马西尼组,差异有统计学意义(P0.05)。结论氟马西尼可促进全麻肝叶切除术患者术后苏醒,改善患者认知功能。     

麻黄碱或去氧肾上腺素治疗全麻诱导期低血压时BIS值和AAI值的变化

目的 观察麻黄碱或去氧肾上腺素治疗全麻诱导期低血压时脑电双频谱指数(BIS)值和听觉诱发电位指数(AAI)值的变化.方法 择期拟行腹部手术患者,年龄30～50岁,体重指数＜30 kg/m2,性别不限,ASA分级Ⅰ或Ⅱ级.麻醉诱导:吸入8%七氟醚,静脉注射咪达唑仑0.1 mg/kg、芬太尼3μg/kg,待睫毛反射消失时,静脉注射琥珀胆碱2 mg/kg,气管插管后机械通气,调节七氟醚吸入浓度,维持BIS值40～50、AAI值20～30.当BIS值和AAI值达目标范围后,出现低血压[MAP＜诱导前(基础值)80%]的患者75例,随机分为3组(n=25):对照组(C组)、麻黄碱组(E组)和去氧肾上腺素组(P组).C组经5 min静脉输注6%羟乙基淀粉130/0.4 10 ml/kg,E组静脉注射麻黄碱0.1 mg/kg,P组静脉注射去氧肾上腺素2 mg/kg.分别于液体治疗开始或给升压药前即刻(T0)、液体治疗结束或给升压药后2 min(T1)、5 min(T2)、7 min(T3)和10 min(T4)时,监测MAP、HR、BIS值和AAI值,并记录T4时BIS值＞65、AAI值＞45患者的例数.结果 与T0时比较,3组在T1-4时MAP升高,E组T3,4时BIS值和AAI值升高(P＜0.05或0.01);与C组比较,E组T3.4时BIS值和AAI值升高(P＜0.05或0.01),P组各时点BIS值和AAI值差异无统计学意义(P＞0.05);E组T4时BIS值＞65、AAI值＞45的发生率均高于C组和P组(P＜0.05或0.01).结论 麻黄碱在治疗全麻诱导期低血压时可升高BIS值和AAI值,使麻醉状态减浅,而去氧肾上腺素则不会.     

右美托咪定和丙泊酚用于硬膜外麻醉下妇科手术患者镇静的比较

目的 比较右美托咪定(Dex)和丙泊酚用于硬膜外麻醉下妇科手术患者的镇静效果.方法 硬膜外麻醉下择期行子宫或(和)卵巢切除患者100例,随机均分成Dex组(D组)和丙泊酚组(P组),应用Ramsay镇静评分和脑电双频指数(BIS)对两组患者术中镇静效果进行观察.记录给药前(T0)、切皮前即给药后15 min(T1)、手术开始后15 min(T2)、30 min(T3)、45 min(T4)、术毕(T5)及术后1 h(T6)患者HR、MAP、BIS、Ramsay镇静评分及呼吸抑制情况.结果 T1～T5时D组BIS,MAP明显低于T0时和P组,Ramsay镇静评分低于P组,HR慢于T0时和P组(P<0.05).低血压的发生率P组明显高于D组(P<0.05).结论 Dex用于硬膜外麻醉下妇科手术患者镇静是安全和可行的.     

咪达唑仑和丙泊酚镇静用于结肠镜检查的比较(前瞻性随机对照研究)

目的借助脑电双频指数（bispectral index,BIS）监测,随机前瞻性比较咪达唑仑和丙泊酚用于结肠镜检查的镇静深度、镇静效果和安全性。方法接受无痛结肠镜检查患者60例,用随机数字表分为3组,每组20例：Ⅰ组,咪达唑仑首次剂量0．06mg／kg;Ⅱ组,丙泊酚首次剂量1．0mg／kg;Ⅲ组,丙泊酚首次剂量1．5mg／kg。于丙泊酚给药后1min、眯达唑仑给药后2min进镜。病人出现不良反应且影响操作时追加丙泊酚20～30mg。监测血压、心率、血氧饱和度值（SpO,）、BIS值,以BIS值反映镇静深度。结果进镜时镇静深度由浅到深依次为Ⅰ、Ⅱ、Ⅲ组（F=25．40,P=0．000）,检查中的BIS最低值无统计学差异。进镜时三组患者均无不良反应,丙泊酚追加剂量Ⅰ组明显少于Ⅱ、Ⅲ组,清醒时间Ⅰ组明显长于Ⅱ、Ⅲ组。Ⅰ组有1例心率〈60次／min,Ⅲ组有1例血压〈90／60inmHg,均为一过性,三组SpO2均大于90％。结论咪达唑仑0．06mg／kg和丙泊酚1．0mg／kg作为首次剂量用于结肠镜检查,检查中适时追加丙泊酚镇静深度,镇静效果满意且安全。     

合并肝肺综合征的老年患者实施胆囊切除术对七氟醚吸入麻醉的药效学研究

目的 研究合并肝肺综合征(hepatopulmonary syndrome,HPS)的老年患者实施胆囊切除术期间吸入七氟醚维持麻醉的药效学变化. 方法 48例肝硬化择期行胆囊切除术的患者,性别不限,年龄60～74岁,Child-Pugh分级A级或B级,ASA分级Ⅱ或Ⅲ级,肺、肾功能检测正常.利用对比增强超声心动图检查和动脉血气分析,根据是否合并HPS将患者分为HPS组(18例)和对照组(C组,30例).入室后常规开放静脉通路,泵注右美托咪定镇静.麻醉诱导使用丙泊酚2 mg/kg、舒芬太尼2μg/kg和维库溴铵0.1 mg/kg,插管后以预设七氟醚浓度维持麻醉,采用上下交叉点法测定MAC值,术中维持BIS值在40～50,保持BP、HR平稳.记录麻醉时间,观察比较两组患者吸入七氟醚MAC值的差异,术毕停药后患者呼之睁眼时间、BIS值恢复至85的时间以及拔管时间. 结果 HPS组的MAC值为(0.88±0.07)％,而C组的MAC值为(1.13±0.09)％,两组比较,差异有统计学意义(P＜0.05).与C组比较,HPS组患者术毕停药后呼之睁眼时间[(28±9) min比(16±6) min]、BIS值恢复至85的时间[(34±9) min比(21±7) min]以及拔管时间[(38±5) min比(26±3) min]延迟,差异有统计学意义(P＜0.05). 结论 合并HPS老年患者实施胆囊切除术期间使用七氟醚吸入麻醉维持,七氟醚的MAC值显著降低,麻醉维持后苏醒时间明显延迟.     

瑞马唑仑用于老年患者全麻诱导时的镇静效果

目的评价瑞马唑仑用于老年患者全麻诱导时的镇静效果。方法择期行气管插管全身麻醉的手术患者100例,性别不限,年龄65～75岁,ASA分级Ⅱ或Ⅲ级,采用随机数字表法分为4组(n=25):丙泊酚组(P组)和不同剂量瑞马唑仑组(R1组、R2组和R3组)。麻醉诱导:P组经30 s静脉注射丙泊酚1.5 mg/kg,待BIS值≤60时,静脉注射顺阿曲库铵0.2 mg/kg和芬太尼4 μg/kg,行气管插管术;R1组、R2组和R3组分别经30 s静脉注射瑞马唑仑0.2、0.3和0.4 mg/kg,待BIS值≤60时,静脉注射顺阿曲库铵0.2 mg/kg和芬太尼4 μg/kg,行气管插管术。麻醉诱导过程中若BIS值持续>60,P组静脉注射丙泊酚0.5 mg·kg-1·次-1进行补救镇静,R1组、R2组和R3组静脉注射瑞马唑仑0.05 mg·kg-1·次-1进行补救镇静,直至BIS值≤60,2次给药间隔时间>1 min。记录丙泊酚或瑞马唑仑起效时间;记录麻醉诱导过程高血压、低血压、心动过缓、低氧血症和注射痛的发生情况和补救镇静情况。术后1 d随访记录术中知晓发生情况。结果与P组比较,R1组补救...     

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.     

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.     

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.