经皮穴位电刺激对髋关节置换术患者术后苏醒期躁动的影响

目的 观察经皮穴位电刺激对髋关节置换术患者术后苏醒期躁动的影响。
方法 选择择期全身麻醉下行髋关节置换术的患者60例,男38例,女22例,年龄60～85岁,BMI 18～28 kg/m ²,ASA Ⅱ或Ⅲ级。随机分为两组：经皮穴位电刺激组（T组）和对照组（C组）,每组30例。T组于麻醉诱导前30 min开始经皮穴位电刺激患侧合谷、内关穴持续至手术结束。C组不予电刺激。两组术中均采用全凭静脉麻醉。记录入室时、拔管时、拔管后5、30 min的MAP、HR以及血浆肾上腺素、去甲肾上腺素、β-内啡肽浓度。采用Riker镇静-躁动评分（SAS）评估苏醒期躁动发生情况。记录麻醉相关不良事件的发生情况。
结果 与入室时比较,拔管时、拔管后5、30 min时C组MAP明显升高（P<0.05）,拔管时、拔管后5 min时HR明显增快（P<0.05）。与C组比较,T组拔管时、拔管后5、30 min时MAP明显降低（P<0.05）,拔管时、拔管后5 min时HR明显减慢（P<0.05）。与入室时比较,拔管时、拔管后5、30 min时两组血浆肾上腺素、去甲肾上腺素浓度明显升高（P<0.05）,T组 β-内啡肽浓度明显升高（P<0.05）。与C组比较,拔管时、拔管后5、30 min时T组血浆肾上腺素和去甲肾上腺素浓度明显降低（P<0.05）,β-内啡肽浓度明显升高（P<0.05）。T组有2例（7%）发生苏醒期躁动,明显少于C组的10例（30%）（P<0.05）。两组麻醉相关不良事件的发生情况差异无统计学意义。
结论 经皮穴位电刺激有利于增加内源性阿片类物质释放,减轻应激反应,有利于苏醒期血流动力学平稳,可有效预防髋关节置换术患者苏醒期躁动。     

帕瑞昔布对腹腔镜胆囊切除术后全麻苏醒期应激反应的影响

目的探讨帕瑞昔布对腹腔镜胆囊切除术后全麻苏醒期应激反应的影响。方法择期在全麻下行腹腔镜胆囊切除术患者40例,随机分为芬太尼组（F组）和帕瑞昔布组（P组）,每组20例。所有患者均予丙泊酚、瑞芬太尼、顺阿曲库铵和七氟烷维持麻醉。皮肤缝合时,F组静注芬太尼0．1mg,P组静注帕瑞昔布钠40mg。记录拔管前5rain、拔管时、拔管后5min、10min和15min的MAP、HR、SpO2;记录拔管时Riker镇静躁动评分（SAS）和拔管后15min、30min、1h、2h的视觉模拟评分（VAS）;以酶联免疫吸附测定法检测拔管后1min的血浆肾上腺素、去甲肾上腺素和皮质醇的含量;记录拔管时间和气管拔管并发症发生率。结果与F组比较,P组各观测时间点MAP、HR、VAS和SAS均降低,拔管时间缩短,血浆。肾上腺素、去甲肾上腺素和皮质醇的浓度降低,拔管并发症发生率降低（P〈0．05）,两组SpO2比较差异无统计学意义。结论帕瑞昔布可有效抑制腹腔镜胆囊切除术后瑞芬太尼全麻苏醒期应激反应。     

经皮穴位电刺激对选择性脊神经后根切断术患儿苏醒期躁动的影响

目的： 探讨经皮穴位电刺激（TEAS）对选择性脊神经后根切断术（SPR）患儿苏醒期躁动（EA）的影响。
方法： 选择择期在全麻下行SPR的脑瘫患儿42例,男20例,女22例,年龄6～12岁,BMI 13～24 kg/m²,ASA Ⅰ或Ⅱ级。将患儿随机分为两组：经皮穴位电刺激组（T组）和对照组（C组）,每组21例。T组于麻醉诱导前30 min给予TEAS双侧合谷穴及内关穴,持续至手术结束。C组在相同的穴位放置电极片,但不予电刺激。所有患儿均采用全凭静脉麻醉。记录入室时、拔管即刻、拔管后5、15、30 min的HR、MAP。记录术中瑞芬太尼和丙泊酚的用量、手术时间、拔管时间。记录拔管后15 min的Wong-Baker面部疼痛表情（FPS-R）评分和儿童麻醉苏醒期躁动评估量表（PAED）评分,并计算苏醒期躁动（EA）发生率。记录术后恶心呕吐（PONV）发生情况。
结果： 与入室时比较,C组拔管即刻、拔管后5、15 min HR明显增快,拔管即刻、拔管后5、15、30 min MAP明显升高（P＜0.05）;T组拔管即刻、拔管后5、15 min HR明显增快,MAP明显升高（P＜0.05）。与C组比较,T组拔管即刻、拔管后5、15、30 min HR明显减慢,MAP明显降低（P＜0.05）;术中瑞芬太尼用量明显减少,拔管时间明显缩短,术后FPS-R评分、PAED评分和EA发生率明显降低（P＜0.05）。两组手术时间、术中丙泊酚用量和PONV发生率差异无统计学意义。
结论： TEAS可有效预防行SPR的脑瘫患儿EA发生,有利于维持血流动力学平稳,减少阿片类药物用量,减轻患儿术后疼痛,加快麻醉复苏时间。     

舒芬太尼应用于腹腔镜胆囊切除术全麻诱导期中的效果观察

目的探讨腹腔镜胆囊切除术全麻诱导期中给予舒芬太尼的效果。方法选取2018年10月至2019年12月320例拟于医院行腹腔镜胆囊切除术者作为研究对象,按照随机数字表法将其分成对照组(160例,采用芬太尼做麻醉诱导药物)与观察组(160例,采用舒芬太尼做麻醉诱导药物)。记录不同时点时平均动脉压(MAP)、心率(HR)、去甲肾上腺素及肾上腺素水平。记录两组手术期间循环波动调控次数及术后镇痛药物使用情况;术后6、12小时分别评价两组镇痛效果,记录研究期间安全性。结果两组气管插管前(T_1)MAPJHR较麻醉诱导前(T_0)显著下降,P0.05;对照组气管插管后1分钟(T_2)、5分钟(T_3)HR与麻醉诱导前存在明显差异,且组间比较,P0.05。两组T,时去甲肾上腺素、肾上腺素水平较T_0时明显升高,且对照组T_2时明显高于T_0时,组间比较,P0.05;T_3时均已恢复至正常水平。观察组术中循环波动调控次数明显少于对照组,术后24小时镇痛药物使用量明显少于对照组,P0.05。观察组术后6、12小时时疼痛程度评分明显低于对照组,P0.05;不良反应率比较,P0.05。结论舒芬太尼应用于腹腔镜胆囊切除术全麻诱导期中可减轻术中应激反应,镇痛效果更显著。     

瑞芬太尼联合舒芬太尼在老年患者全麻中的镇痛作用

目的 观察瑞芬太尼联合舒芬太尼TCI对老年患者围术期应激反应及术后疼痛的影响.方法 择期行腹部手术的全麻患者40例,年龄61～72岁,随机均分为两组:A组,瑞芬太尼5ng/ml麻醉诱导,4 ng/ml麻醉维持,缝皮时PCIA;B组:瑞芬太尼2 ng/ml复合舒芬太尼麻醉诱导和维持,缝皮时PCIA.于麻醉诱导前(T1)、插管前即刻(T2)、插管后1 min(T3)、5 min(T4)、进腹时(T5)和拔管后1 min(T6)、5 min(T7)记录患者的HR、MAP和SpO2值.并于T1、T3、T6和术后6(T8)、12(T9)、24 h(T10)时测定血浆NE和E浓度.记录患者术中血流动力学剧烈波动的调控次数、术毕停药后睁眼及拔管时间、拔管后RS、OAA/S和VAS评分以及术后24 h镇痛药用量.结果 与T1时比较,两组患者T2时MAP明显下降、HR明显减慢(P＜0.01),A组T3、T5～T7时,B组T3和T6时HR明显增快,A组T3、T6和T7时MAP明显升高(P＜0.05或P＜0.01),两组血浆NE和E浓度在T3、T6时明显上升(P＜0.01),T9、T10时明显下降(P＜0.05或P＜ 0.01).与A组比较,B组T3和T6时MAP明显降低,HR明显减慢(P＜0.05),血浆NE和E浓度在T6、T8和T9时明显降低(P＜0.05),术中循环波动调控次数明显减少(P＜0.01),拔管后RS评分和T8～T9时VAS评分明显降低(P＜0.01或P＜0.05),术后24 h镇痛药用量明显减少(P＜0.01).结论 舒芬太尼与瑞芬太尼联合应用于老年患者,能减轻瑞芬太尼导致的术后急性疼痛,减少围术期应激反应.     

不同麻醉方法用于胸科手术患者的效果

目的探讨胸科手术不同麻醉方法的效果。方法择期拟行胸科手术患者90例,性别不限,年龄18～65岁,ASA分级Ⅱ或Ⅲ级。采用随机数字表法,将患者分为2组(n=45):静吸复合全麻组(Ⅰ组)和全麻联合硬膜外麻醉组(Ⅱ组)。Ⅰ组麻醉诱导后,吸入七氟醚,持续输注丙泊酚维持麻醉;Ⅱ组先采取硬膜外麻醉,麻醉平面稳定后全麻诱导,吸入七氟醚维持麻醉。于术前30 min时、术中10 min时、术后10 min时记录患者的SBP、MAP、DBP、HR、SpO2。术毕记录患者气管导管拔管时间、自主呼吸恢复时间及完全清醒时间,并记录气管导管拔管即刻(T1)、拔管后5 min(T2)、10 min(T3)及20 min(T4)的RSS镇静评分。结果与Ⅰ组比较,Ⅱ组术中及术后10 min时SBP、MAP、DBP和HR降低,自主呼吸恢复时间、拔管时间及完全清醒时间显著缩短,T1-4时RSS镇静评分明显升高(P0.05)。结论全麻联合硬膜外麻醉用于胸科手术的效果优于静吸复合麻醉。     

右美托咪定对瑞芬太尼复合丙泊酚靶控输注全麻的影响

目的观察预先给予右美托咪定对瑞芬太尼复合丙泊酚靶控输注(TCI)全麻的影响。方法择期全麻行妇科腹腔镜手术患者40例,随机均分为右美托咪定组(D组)和对照组(C组),D组诱导前15min静脉泵注右美托咪定0.8μg/kg,C组则给予等量生理盐水。观察注药前(T1)、麻醉诱导前(T2)、插管前即刻(T3)、插管后即刻(T4)、插管后3min(T5)、拔管后即刻(T6)、拔管后3min(T7)的BIS、MAP、HR、肾上腺素(E)、去甲肾上腺素(NE)浓度变化;记录丙泊酚和瑞芬太尼的用量、麻醉恢复情况,随访术后延迟性呼吸抑制、术中知晓情况。结果 T2时D组BIS明显低于T1时和C组(P<0.01);与D组比较,T2、T4、T6时C组MAP明显升高,HR明显增快(P<0.05或P<0.01);T4、T6时C组的E、NE浓度明显高于T3时和D组(P<0.01),而D组则无明显变化;D组丙泊酚和瑞芬太尼的用量明显少于C组(P<0.05);D组拔管期间体动、呛咳的发生率明显低于C组(P<0.01),两组呼吸恢复时间、睁眼时间、拔管时间组间差异无统计学意义。结论瑞芬太尼复合丙泊酚靶控输注全麻预先静注右美托咪定0.8μg/kg可产生明显的镇静效应,有效抑制患者的应激反应,减少麻醉药的用量,且不延长麻醉恢复时间。     

腹腔镜胆囊切除术中不同麻醉方法对应激反应的影响

目的：观察以丙泊酚、瑞芬太尼为主的全凭静脉麻醉对腹腔镜胆囊切除术（laparoscopic cholecystectomy,LC）患者应激反应的影响。方法：将ASA I-II级需行LC的患者随机分成两组（A组丙泊酚、瑞芬太尼诱导并维持,B组丙泊酚、芬太尼诱导异氟醚吸入维持）,每组30例。记录两组麻醉前（T0）、插管后即刻（T1）、气腹后即刻（T2）、气腹后30min（T3）及术毕（T4）的平均动脉压（MAP）、心率（HR）,于T0、T2、T3及术后2h抽取静脉血检测患者血糖、血浆皮质醇、肾上腺素及去甲肾上腺素浓度。结果：T1和T2A组MAP、HR显著低于B组（P〈0.01）。两组血浆皮质醇、肾上腺素及去甲肾上腺素浓度,T2和T3浓度均明显升高（P〈0.01,P〈0.05）,A组患者上升幅度明显低于B组（P〈0.01,P〈0.05）。血糖于T3至T4两组患者均明显升高（P〈0.01,P〈0.05）,,两组间无明显差别。结论：以丙泊酚和瑞芬太尼为主的全凭静脉麻醉,较以异氟醚和芬太尼为主的传统麻醉用于LC,能够更有效的抑制气管插管和二氧化碳气腹所致的应激反应。     

舒芬太尼用于小儿神经外科手术麻醉的临床研究

目的观察舒芬太尼应用于小儿神经外科麻醉诱导期的血流动力学变化及术后恢复情况。方法 40例ASAⅠ或Ⅱ级、择期行脑积水手术的患儿,随机均分为舒芬太尼组(S组)和芬太尼组(F组)。麻醉诱导:两组分别给予等效剂量的舒芬太尼和芬太尼复合丙泊酚、维库溴铵;麻醉维持:瑞芬太尼持续微量泵静注复合七氟醚。术毕前10 min停七氟醚,同时两组分别给予等效剂量的舒芬太尼和芬太尼。观察两组麻醉诱导前即刻(T0)、气管插管前(T1)、气管插管后2 min(T2)、5min(T3)的血流动力学变化;记录术后患儿自主呼吸恢复时间、睁眼时间、拔管时间;记录拔管时(T4)、拔管后5 min(T5)、10 min(T6)的躁动(RS)评分、Ramsay镇静(RSS)评分。结果 T2、T3时F组MAP明显高于、HR明显快于T0时和S组(P<0.05)。两组苏醒期自主呼吸恢复时间、睁眼时间、拔管时间差异均无统计学意义;RS评分S组低于F组,RSS评分S组高于F组(P<0.05)。结论舒芬太尼在麻醉诱导期血流动力学更稳定,并可以有效预防小儿神经外科手术苏醒期的躁动,在小儿神经外科麻醉中具有很好的临床应用价值。     

针刺辅助全身麻醉对冠心病患者行非心脏手术时应激反应的影响

目的观察针刺辅助全身麻醉用于冠心病患者行非心脏手术时应激反应的影响。方法择期行腹部手术的冠心病患者80例,ASAⅡ或Ⅲ级,随机均分为单纯全麻组(A组)和针刺辅助全麻组(B组)。A组采用咪达唑仑、依托咪酯、芬太尼以及阿曲库铵麻醉诱导,麻醉维持采用丙泊酚、芬太尼及阿曲库铵,B组麻醉诱导前取"内关"、"足三里"穴持续刺激20min后行全身麻醉诱导,麻醉诱导及维持同A组,针刺辅助全身麻醉持续至手术结束。记录麻醉前(T1)、麻醉后30min(T2)、60min(T3)、180min(T4)及术毕30min(T5)血流动力学、Narcotrend指数及T1、T2、T5时心电图ST段变化。检测T1和T5血清皮质醇(Cor)、去甲肾上腺素(NE)、肾上腺素(E)、心肌肌钙蛋白I(cTnI)和糖原磷酸化酶BB(GP-BB)含量。结果与T1时比较,T2、T3时A组患者HR明显增快、MAP明显升高(P<0.05或P<0.01);T2时A组患者HR与SBP乘积(RPP)大于12000(P<0.05)。T5时A组患者ST段明显低于B组(P<0.05)。A组患者术中需用硝酸甘油14例(35%)、艾司洛尔10例(25%),明显多于B组6例(15%)和3例(7.5%)(P<0.05)。与术前比较,A组术毕30minCor、NE、E、cTnI及GP-BB含量均明显升高,且高于B组(P<0.05)。结论针刺辅助全身麻醉应用于冠心病患者行非心脏手术时可降低患者围术期应激反应,对心肌有良好的保护作用。     

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.     

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.