右美托咪定辅助舒芬太尼用于胃癌术后静脉镇痛的剂量探讨

目的探讨右美托咪定辅助舒芬太尼用于胃癌患者术后自控静脉镇痛(PCIA)的安全、有效剂量。方法 80例ASAⅠ或Ⅱ级胃癌根治手术的患者,采用随机双盲抽签方法均分为四组。PCIA镇痛液配方:舒芬太尼组(SF组),舒芬太尼3μg/h+托烷司琼5mg;右美托咪定1组(D1组),右美托咪定0.05μg·kg-1·h-1+舒芬太尼2μg/h+托烷司琼5mg;右美托咪定2组(D2组),右美托咪定0.1μg·kg-1·h-1+舒芬太尼2μg/h+托烷司琼5mg;右美托咪定3组(D3组),右美托咪定0.15μg·kg-1·h-1+舒芬太尼2μg/h+托烷司琼5mg,均用生理盐水配成100ml。清醒拔管后行PCIA,记录术后4、8、16、24和48h的MAP、HR、SpO2、RR,并进行疼痛、镇静、情绪、睡眠质量的评分,记录不良反应发生率,术后第3天对使用PCIA治疗的患者满意度进行综合评价。结果与SF组比较,术后4、8、16、24和48hD2、D3组MAP明显降低,D1、D2、D3组HR明显减慢(P<0.05或P<0.01);Ramsay镇静评分明显升高(P<0.05或P<0.01)。术后48h内睡眠、情绪评分D1、D2、D3组明显优于SF组(P<0.05或P<0.01);D1、D2、D3组术后恶心呕吐和寒颤发生率明显低于SF组(P<0.05);随着右美托咪定剂量增加需干预的心动过缓明显增加,术后第3天D2、D3组患者对PCIA的满意程度明显优于SF组(P<0.05)。结论右美托咪定0.1μg·kg-1·h-1复合舒芬太尼2μg/h术后行PCIA在获得满意镇痛效果的同时,还能提供适度镇静,消除患者焦虑情绪,提高围术期的安全性和患者满意度。     

右美托咪定经鼻喷雾治疗术后睡眠障碍的效果

目的 观察右美托咪定经鼻喷雾治疗术后睡眠障碍的临床效果。
方法 选择全麻气管插管下行颌面外科手术患者78例，男12例，女66例，年龄18～40岁，ASAⅠ或Ⅱ级。将患者随机分为两组：对照组（C组）和右美托咪定组（D组），每组39例。术后当天21:30 C组和D组分别给予生理盐水0.01 ml/kg和右美托咪定1 μg/kg经鼻喷雾。采用多导睡眠监测仪（PSG）记录术后当天N1期、N2期、N3期、REM期睡眠时间、清醒时间、觉醒次数和睡眠效率。采用匹兹堡睡眠质量指数（PSQI）量表评估术前1个月及术后当天的睡眠情况。记录术后当天补救镇静镇痛情况。
结果 与C组比较，术后当天D组N2期睡眠明显延长（P＜0.05），清醒时间明显缩短（P＜0.05），觉醒次数明显减少（P＜0.05），睡眠效率明显提高（P＜0.05）。与术前1个月比较，术后当天两组PSQI总分明显升高（P＜0.05），与C组比较，术后当天D组PSQI总分明显降低（P<0.05）。术后当天两组补救镇静镇痛率差异无统计学意义。
结论 通过右美托咪定经鼻喷雾，可有效延长颌面外科手术患者术后当天的N2期睡眠，缩短清醒时间，减少觉醒次数，明显提高睡眠效率。     

右美托咪定关胸前滴鼻对胸腔镜肺癌根治术患者苏醒期镇静镇痛的影响

目的评价右美托咪定滴鼻对胸腔镜下肺癌根治术患者苏醒期镇静镇痛的影响。方法择期全麻下行胸腔镜下肺癌根治术患者120例,男67例,女53例,年龄38～65岁,BMI 18.9～24.6 kg/m~2,ASAⅠ或Ⅱ级,TNM分期Ⅱ或Ⅲ期,采用随机数字表法将患者分为三组(n=40):右美托咪定静脉组(DV组)、右美托咪定滴鼻组(DN组)和对照组(C组)。DV组于关胸前静脉泵注右美托咪定1μg/kg(生理盐水稀释为10 ml,10 min注完);DN组于关胸前双侧鼻孔等量滴入右美托咪定1μg/kg(生理盐水稀释为1 ml),滴速为20滴/分;C组给予等量生理盐水滴鼻。术后患者均采用舒芬太尼PCIA。于拔管后5 min、用药后1、2 h记录Ricker镇静躁动评分(SAS评分)和VAS疼痛评分,记录术后首次追加舒芬太尼时间,术后24 h舒芬太尼总用量和不良反应发生情况。结果与C组比较,DN组和DV组SAS评分在拔管后5 min和用药后1 h明显降低,拔管后5 min VAS评分明显降低,术后首次追加舒芬太尼时间明显延长,术后24 h内舒芬太尼总用量明显减少,出现呛咳反应、高血压和心动过速情况明显减少(P0.05);与DV组比较,DN组心动过缓发生率明显降低(P0.05)。结论右美托咪定静注和滴鼻可改善胸腔镜下肺癌根治术患者苏醒期镇静水平,减少术后阿片类药物使用,同时,滴鼻方式简便易行,临床安全性较高。     

术前睡眠质量对老年患者术后谵妄发生的影响

目的探讨术前睡眠质量对老年患者术后谵妄(POD)发生的影响。方法选择择期全凭静脉麻醉下经腹行肿瘤根治术患者,年龄65~86岁,BMI 18~25kg/m2,ASAⅠ-Ⅲ级。术前根据匹兹堡睡眠质量指数(pittsburgh sleep quality index,PSQI)分为睡眠障碍组(≥5分,D组)和睡眠正常组(5分,C组),每组50例,男71例,女29例。两组均采用丙泊酚、舒芬太尼和罗库溴铵进行麻醉诱导和维持,麻醉深度维持在BIS值40~60。记录术中丙泊酚、舒芬太尼、阿托品、麻黄碱、艾司洛尔、硝酸甘油等使用情况,记录麻醉时间、手术时间、PACU停留时间和术后住院时间,记录术后1~5d数字疼痛(NRS)评分和恢复质量评分量表-40(QoR-40)总分。采用意识模糊评定量表(CAM)于术前1d和术后1~5d进行谵妄评估。结果 D组术前PSQI评分明显高于C组(P0.05)。两组患者术中丙泊酚、舒芬太尼用量和血管活性药使用例数差异无统计学意义,麻醉时间、手术时间和PACU停留时间差异无统计学意义。D组术后住院时间明显长于C组(P0.05)。术后1、2和3d,D组NRS评分明显高于C组,QoR-40总分明显低于C组(P0.05)。术后1~5d,两组总计21例(21.0%)发生POD,其中D组15例(30.0%)和C组6例(12.0%),D组POD发生率明显高于C组(P0.05)。D组POD患者的谵妄持续时间明显长于C组(P0.05)。术后2dD组POD发生率明显高于C组(P0.05)。结论术前睡眠障碍可增加老年患者POD发生率并对术后早期恢复质量产生负面影响,应引起重视。     

右美托咪啶联合舒芬太尼用于断指再植术后静脉镇痛的临床研究

目的 右美托咪啶联合舒芬太尼用于断指再植术后静脉镇痛,观察对术后疼痛、镇静效果及血管痉挛的影响.方法 60例急诊行单指断指再植患者,随机分为2组(n=30),即对照组(A组)和右美托咪啶组(B组),观察术后镇痛、镇静效果,不良反应,以及断指再植后的血管痉挛发生率.结果 术后两组患者的镇静评分、不良反应和血管痉挛发生率差异无统计学意义(P＞0.05);B组镇痛评分小于A组(P＜0.05).结论 断指再植术后应用右美托咪啶复合舒芬太尼静脉自控镇痛,右美托咪啶可以增强舒芬太尼的镇痛效果,无明显不良反应,但对血管痉挛的影响不明显.     

喷他左辛在老年患者髋关节置换术后镇痛效果观察

目的观察喷他左辛在老年患者髋关节置换术后镇痛的临床疗效。方法本院行髋关节置换术的老年患者60例,随机分为舒芬太尼镇痛组(A组)和小剂量喷他佐辛联合右美托咪定、舒芬太尼镇痛组(B组)各30例。两组髋关节置换术术后均进行静脉自控镇痛术(PCIA),比较两组患者术后疼痛情况、手术当晚睡眠情况、补救性镇痛药物用量、术后5天内并发症发生情况。结果 6、24小时B组VAS评分低于A组(P0.05);B组手术当晚SRSS评分低于A组(P0.05);B组补救性镇痛药用量低于A组(P0.05),两组并发症统计差异无显著性(P0.05)。结论小剂量喷他佐辛、右美托咪定、舒芬太尼镇痛方案可改善患者睡眠质量,镇痛效果好,术后补救性镇痛药物用量少。     

右美托咪定对老年患者骨科手术后睡眠质量的影响

目的探讨右美托咪定改善老年骨科患者手术后睡眠质量。方法选择2016年5月至2017年12月骨科老年手术患者120例,男66例,女54例,年龄75~93岁,BMI 18.5~23.9kg/m2,ASAⅡ或Ⅲ级。随机分为两组:右美托咪定组(D组)和对照组(C组),每组60例。所有患者气管插管全麻下行手术治疗,缝皮时停止使用麻醉药物,静注托烷司琼5 mg后接静脉自控镇痛(PCIA)并开启术后镇痛,D组镇痛药物为舒芬太尼1.5~2.5μg/kg+托烷司琼5 mg+右美托咪定2μg/kg。C组镇痛药物为舒芬太尼1.5~2.5μg/kg+托烷司琼5mg,泵注速度1.0~2.5ml/h,单次追加量为0.5ml,锁定时间15min,总容量100ml。术后疼痛视觉模拟评分(VAS评分)3分时患者行自控镇痛或非甾体抗炎药物辅助。自主呼吸恢复后拔管前给予静注氟马西尼0.3~0.5 mg、新斯的明0.5~1mg、阿托品0.2~0.5mg。于术前1天(T0)、术后第1天(T1)、术后第2天(T2)、术后第3天(T3)和术后第4天(T4)分别收集患者晨起第一次尿液2ml,检测并记录6-羟基硫酸褪黑素(aMT6s)浓度。于术前、术后24、48h和出院前进行匹兹堡睡眠质量指数(PSQI)评分,记录术后4、8、12、24和48h的VAS评分。结果 D组T1-T4时aMT6s明显高于C组(P0.05)。D组术后24、48h和出院前PSQI评分明显低于C组(P0.05)。两组不同时点VAS评分差异无统计学意义。结论右美托咪定对老年患者骨科手术后睡眠质量有明显的改善。     

不同剂量右美托咪定复合舒芬太尼在老年患者肝癌射频消融术中的应用

目的探讨右美托咪定复合舒芬太尼0.3μg/kg在老年患者肝癌射频消融术(radio frequency ablation,RFA)中的适宜应用剂量。方法选择择期行RFA患者60例,男53例,女7例,年龄65～84岁,BMI 18.1～35.4kg/m2,ASAⅡ或Ⅲ级,Child-Pugh A或B级,随机分为三组,每组20例。射频治疗前20min开始泵注右美托咪定,D1组:0.3μg·kg~(-1)·h~(-1);D2组:0.5μg·kg~(-1)·h~(-1);D3组:0.7μg·kg~(-1)·h~(-1),同时给予舒芬太尼0.3μg/kg缓慢静滴。于入室时(T_0)、给药20min时(T_1)、消融开始时(T_2)、消融开始后10min时(T_3)和术毕时(T_4)测定Ramsay评分。记录术毕、术后2、4、8、16h的VAS评分;记录依托咪酯、硝酸甘油、乌拉地尔和纳洛酮用量;记录术中知晓、呼吸道梗阻、穿刺针移位和肝被膜下血肿、一过性高血压、低血压、心动过缓和口干等不良反应情况。结果与T_0时比较,T_2和T_3时D2和D3组Ramsay评分明显升高(P0.05);与D1组比较,D2、D3组术后2、4和8hVAS评分明显降低(P0.05),D2和D3组依托咪酯、硝酸甘油、乌拉地尔用量明显减少(P0.05);与D2组比较,D1组术中知晓明显增多(P0.05),D3组纳洛酮用量明显增多(P0.05),D3组呼吸道梗阻、一过性高血压、心动过缓发生率明显增多(P0.05)。结论右美托咪定0.5μg·kg~(-1)·h~(-1)复合舒芬太尼0.3μg/kg在老年RFA中可提供良好的清醒镇痛效果,减少呼吸道梗阻等不良反应的发生,是较为合理的临床用药剂量。     

羟考酮联合右美托咪定在纤维支气管镜清醒气管插管中的应用

目的观察羟考酮复合右美托咪定在清醒气管插管中的镇痛镇静效果以及对呼吸和循环功能的影响。方法选择术前预计困难气道的择期手术患者40例,随机分为舒芬太尼组和羟考酮组。两组患者静脉泵注右美托咪定1μg/kg后以0.2μg·kg~(-1)·h~(-1)维持,舒芬太尼组静注舒芬太尼0.2μg/kg,羟考酮组静注羟考酮0.08mg/kg。监测患者用药及插管期间HR、MAP和SpO_2变化,并记录插管前Ramsay评分以及插管后PETCO_2和舒适度评分。结果两组患者用药及插管期间的血流动力学变化、镇静及舒适度差异无统计学意义。羟考酮组患者静注后SpO_2明显高于舒芬太尼组(P0.05),气管插管后PETCO_2明显降低(P0.05)。结论羟考酮复合右美托咪定可安全地用于清醒气管插管,镇痛、镇静效果良好,与舒芬太尼相比,呼吸抑制轻,不良反应少。     

依托咪酯靶控输注在全胸腔镜二尖瓣置换术中的应用

目的观察依托咪酯靶控输注(TCI)在全胸腔镜二尖瓣置换术中的使用效果及安全性。方法选择拟在全胸腔镜下行二尖瓣置换术的风湿性二尖瓣病变患者110例,男48例,女62例,年龄29~55岁,ASAⅡ或Ⅲ级,随机分为依托咪酯TCI组(E组)和丙泊酚TCI组(P组),每组55例。E组使用依托咪酯-舒芬太尼TCI(依托咪酯初始血浆靶浓度为0.2μg/ml,根据BIS值以0.1μg/ml梯度逐步增加,舒芬太尼效应室靶浓度1.0ng/ml)进行麻醉诱导与维持,P组使用丙泊酚-舒芬太尼TCI(丙泊酚初始血浆靶浓度为1.0μg/ml,根据BIS值以0.3μg/ml梯度逐步增加,舒芬太尼效应室靶浓度1.0ng/ml)进行麻醉诱导与维持。记录两组患者诱导期低血压发生情况、诱导期血管活性药物用量、诱导期睫毛反射消失时间、麻醉期舒芬太尼用量、手术时间、体外循环时间、升主动脉阻断时间、入CCU时APACHE II评分、术后24h正性肌力药物评分、术后清醒时间、机械通气时间、CCU停留时间、术后住院时间、记录术前、术后2、6、24h血浆中血糖、乳酸浓度,术前及术后24h血浆皮质醇、醛固酮、ACTH浓度以及术后并发症情况。结果 E组患者诱导期低血压发生率明显低于P组,诱导期去甲肾上腺素用量明显少于P组(P0.05);E组清醒时间、机械通气时间、CCU停留时间、术后住院时间明显短于P组(P0.05);与术前比较,术后2、6、24h两组患者血糖和乳酸浓度明显升高(P0.05),6h达到高峰,24h开始下降,两组患者各时点血糖、乳酸浓度差异无统计学意义;与术前比较,术后24hP组皮质醇浓度明显升高(P0.05);术后24hP组皮质醇和醛固酮浓度明显高于E组(P0.05);两组ACTH浓度差异无统计学意义;E组院内肺部感染发生率明显低于P组(P0.05)。结论依托咪酯靶控输注可以维持麻醉诱导期血流动力学平稳,患者术后恢复时间明显缩短,术后肺部感染发生率明显降低,能安全应用于全胸腔镜二尖瓣置换术。     

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.     

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.     

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.