右美托咪定经鼻腔给药对妇科全麻围拔管期应激反应的影响

目的观察不同剂量右美托咪定经鼻腔给药对妇科全麻围拔管期应激反应的影响,并探讨最佳剂量。方法择期妇科手术患者80例,随机分为对照组(C组)和不同剂量右美托咪定滴鼻组(D1组、D2组、D3组)。手术结束前30 min,D1、D2、D3组分别经鼻滴注右美托咪定0.6、1.2、1.8μg/kg,C组用生理盐水滴鼻。记录给药前即刻(T_1)、手术结束时(T_2)、患者可唤醒时(T_3)、拔管时(T_4)、拔管后1min(T_5)、5min(T_6)、10min(T_7)的HR、MAP、SBP与HR乘积(RPP);检测T_1、T_2、T_4、T_6时血浆去甲肾上腺素(NE)和皮质醇(Cor)浓度。记录患者术后恢复指标。结果与C组比较,T_3~T_5时D1组、T_2~T_7时D2、D3组MAP和RPP均明显降低,HR明显减慢(P0.05);T_4、T_6时D1组、T_2、T_4和T6时D2、D3组血浆NE、Cor浓度明显降低(P0.05)。C组、D1组和D2组唤醒时间、拔管时间及PACU留观时间均明显短于D3组(P0.05)。结论手术结束前30min给予右美托咪定1.2μg/kg滴鼻可有效抑制全麻手术拔管期的应激反应,同时不影响术后恢复。     

注药型气管导管对腭咽成形术后留置导管期应激反应的影响

目的评价注药型气管导管用于腭咽成形术后留置导管期对应激反应的影响。方法选择择期行悬雍垂腭咽成形术患者60例,均为男性,年龄18~60岁,ASAⅠ或Ⅱ级,随机分为A、B、C三组,每组20例。三组均静脉持续输注舒芬太尼5μg/h,A组每隔2小时经注药型气管导管注入2%利多卡因2ml,B组持续泵注右美托咪定0.4μg·kg~(-1)·h~(-1),C组不做处理。如出现高血压及心动过速,给予额外药物处理。记录入ICU即刻(T_0)、2h(T_1)、6h(T_2)、12h(T3)、拔管前即刻(T4)的HR、MAP、动脉血肾上腺素(E)及去甲肾上腺素(NE)水平,并记录入室至停药期间三组需药物调整HR、MAP的例数及呛咳反应发生情况。结果 T_1~T_4时A、B组HR明显慢于C组,T_2~T_4时B组HR明显慢于A组(P0.05);T1~T4时A、B组MAP明显低于C组(P0.05),且T2时A组MAP高于B组。T_1~T_4时A、B组动脉血E水平明显低于C组,且T1时A组动脉血E水平明显高于B组(P0.05);T_1~T_4时A、B组动脉血NE水平明显低于C组,且T_1~T_3时A组动脉血E水平明显高于B组(P0.05)。A组带管时间及ICU停留时间明显短于B组(P0.05);A组药物干预例数明显少于C组,但多于B组,A、B组医患满意度均明显高于C组(P0.05)。A组呛咳发生率(55%)明显低于C组(80%),呛咳程度明显轻于C组(P0.05)。结论注药型气管导管间断注入局麻药可明显降低腭咽成形术后患者带管期间应激反应,稳定循环,并缩短患者拔管及ICU停留时间。     

不同剂量右美托咪定对腹腔镜下胃肠手术老年患者围术期应激反应的影响

目的观察不同剂量右美托咪定对腹腔镜下胃肠手术老年患者围术期应激反应的影响。方法择期行腹腔镜下胃肠手术老年患者80例,性别不限,年龄≥65岁,ASAⅠ或Ⅱ级。随机分为四组,每组20例。所有患者均采用全凭静脉麻醉。D1、D2组和D3组麻醉诱导前10min静脉泵注右美托咪定0.5μg/kg,插管后分别静脉泵注右美托咪定0.2、0.5、0.8μg·kg~(-1)·h~(-1)至术毕前30min;C组麻醉诱导前10min静脉泵注7ml生理盐水,插管后静脉泵注生理盐水10ml/h至术毕前30min。记录术中麻醉药物用量,记录给药前(T_0)、气管插管后即刻(T_1)、气腹后5min(T_2)、气腹后60min(T_3)、拔管后即刻(T_4)和拔管后10min(T_5)的HR、SBP、DBP,分别于T_0、T_1、T_3、T_5时抽取桡动脉血,测定Glu、Cor、E和NE浓度。结果 D1组、D2组和D3组术中瑞芬太尼的用量明显少于C组,且D2组和D3组明显少于D1组(P0.05)。与T_0时比较,T_1~T_5时C组HR明显增快(P0.05)。T_2~T_5时,D2组和D3组的HR明显慢于C组和D1组,SBP明显低于C组(P0.05);T_1时D2组和D3组Cor和NE浓度也明显低于C组(P0.05)。T_3和T_5时,D2组和D3组Glu、Cor、E和NE浓度明显低于C组,D2组和D3组Cor和NE浓度明显低于D1组(P0.05)。结论与0.2和0.8μg·kg~(-1)·h~(-1)右美托咪定静脉泵注维持比较,0.5μg·kg~(-1)·h~(-1)能更有效抑制腹腔镜下胃肠手术老年患者围术期应激反应。     

右美托咪定对脊柱侧弯矫形术全麻苏醒期间血流动力学的影响

目的观察右美托咪定对脊柱侧弯矫形术全麻苏醒期间血流动力学的影响。方法随机将40例择期行脊柱侧弯矫形术的患者分为2组,每组20例。手术结束前30 min A组静脉泵注右美托咪定。B组静脉泵注生理盐水。观察2组麻醉前(T_0)、气管拔管即刻(T_1)、气管拔管后1 min(T_2)、5 min(T_3)、10 min(T_4)患者的的收缩压(SBP)、舒张压(DBP)、心率(HR)和苏醒时间(min)。结果 A组患者气管拔管各时点的SBP、DBP和HR与T_0比较,差异无统计学意义(P0.05)。B组气管拔管各时点的SBP、DBP和HR与T0比较,差异有统计学意义(P0.05)。2组患者苏醒时间比较,差异无统计学意义(P0.05)。结论右美托咪定有助于脊柱侧弯矫形术,患者全麻苏醒期间血流动力学稳定,且不延迟苏醒时间,安全性高。     

右美托咪定滴鼻联合氟比洛芬酯应用于小儿扁桃体及腺样体切除术的安全性及有效性

目的观察右美托咪定滴鼻联合氟比洛芬酯应用于小儿扁桃体及腺样体切除术的安全性及有效性。方法随机将60例择期行扁桃体及腺样体切除术的患儿分为3组,每组20例。D组及DF组经鼻滴入右美托咪定1.5μg/kg(容量为1 mL),C组经鼻滴入等量生理盐水。DF组在麻醉诱导前给予1 mg/kg的氟比洛芬酯,C组及D组给予2 mL生理盐水。记录滴鼻前(T_0)、滴鼻后10 min(T_1)、滴鼻后30 min(T_2)、拔管即刻(T_3)及拔管后5 min(T_4)的MAP及HR。记录3组患儿与家长分离时的镇静情绪评分和静脉穿刺接受程度评分。记录苏醒时间、拔管时间,并在T_4、拔管后10 min(T_5)及拔管后30 min(T_6)对患儿进行苏醒期躁动评分及疼痛评分。结果与C组比较,D组及DF组在T_3、T_4时间点时MAP及HR显著下降(P0.05);D组及DF组与家长分离时的镇静情绪评分及静脉穿刺接受程度评分均高于C组(P0.05);与C组及D组比较,DF组T_4～T_6时间点的躁动及疼痛评分均降低(P0.05)。3组患儿苏醒时间、拔管时间差异无统计学意义(P0.05)。结论右美托咪定滴鼻联合氟比洛芬酯可为患儿提供满意的术前镇静和良好的术后镇痛效应。降低术后的苏醒期躁动。     

曲马多与右美托咪定预防全麻术后患儿苏醒期躁动的临床研究

目的评价右美托咪定与曲马多预防全身麻醉下扁桃体切除术患儿苏醒期躁动的临床应用效果。方法选取本院2013年3月至2016年12月于全身麻醉下行扁桃体切除术的患儿共计62例。纳入患儿采用随机软件随机分为曲马多组(Tramadol group,T组)和右美托咪定组(Dexmedetomidine group,D组),每组患儿各31例。T组患儿于麻醉诱导后缓慢静注曲马多2mg/kg;D组患儿泵注右美托咪定1μg/kg。记录两组患儿麻醉诱导前(T_0)、气管拔管即刻(T_1)、入PACU后10分钟(T_2)、入PACU后20分钟(T_3)及出PACU即刻(T_4)的平均动脉压(MAP)和心率(HR)。采用儿童麻醉后躁动(PAED)评分评价患儿苏醒期躁动情况;采用Ramsay镇静评分(RSS)评价患儿镇静情况。记录患儿拔管时间、喉痉挛、支气管痉挛及气道梗阻发生情况。结果两组患儿T_0时点MAP、HR差异无统计学意义(P0.05);D组患儿T_1时点MAP、HR显著高于T组患儿,差异有统计学意义(P0.05);D组患儿T_2～T_4时点MAP、HR显著低于T组患儿,差异有统计学意义(P0.05)。两组患儿苏醒期各时点PAED评分与RSS评分差异均无统计学意义(P0.05)。D组患儿拔管时间显著长于T组,差异有统计学意义(P0.05)。结论右美托咪定与曲马多均能降低扁桃体切除术患儿苏醒期躁动发生风险,但曲马多在维持血流动力学方面具有明显优势。     

右美托咪定复合氟比洛芬酯预防全麻苏醒期躁动的临床研究

目的观察右美托咪定复合氟比洛芬酯对全麻患者苏醒期躁动及拔管期心血管反应的影响。方法择期行全身麻醉的口腔颌面部肿瘤手术患者80例,ASAⅠ或Ⅱ级,随机分为氟比洛芬酯组(F组)、右美托咪定组(D组)、右美托咪定复合氟比洛芬酯组(DF组)和对照组(C组),每组20例。F组于手术结束前30min经静脉注射氟比洛芬酯50mg;D组于手术结束前30min经静脉注射右美托咪定0.5μg/kg;DF组手术结束前30min经静脉注射氟比洛芬酯50mg,同时经静脉注射右美托咪定0.25μg/kg;C组静脉注射与D组等容量的生理盐水。记录四组患者拔管前(T0)、拔管时(T1)、拔管后5min(T2)MAP、HR的变化;记录苏醒时间、拔管时间以及拔管前Riker镇静躁动评分、拔管后5min的Ramsay镇静评分。结果 T1、T2时F组、C组MAP明显高于,HR明显快于T0时(P0.05或P0.01);D组、DF组MAP明显低于,HR明显慢于C组(P0.01)。D组苏醒时间、拔管时间明显长于,Ramsay镇静评分明显高于其他三组(P0.05);D组、DF组Riker镇静躁动评分明显低于C组(P0.05);D组、DF组患者躁动发生率明显低于C组(P0.05或P0.01)。结论右美托咪定0.25μg/kg复合氟比洛芬酯50mg可有效降低全麻患者苏醒期躁动并能降低患者拔管期心血管反应,不会延长患者的苏醒时间和拔管时间。     

右美托咪定预防神经外科全麻术后躁动的临床观察

目的观察右美托咪定预防神经外科手术患者术后躁动的临床效果。方法选择神经外科全麻手术患者60例,随机均分为右美托咪定组(D组)和生理盐水组(C组)。患者手术结束前10min停用麻醉药,D组静脉泵注右美托咪定0.4μg/kg10min,C组静注等剂量的生理盐水。记录麻醉前、拔管即刻、拔管后5min血流动力学变化,并对拔管后5、30、60、120min躁动程度、镇静状态、躁动发生率进行评估。观察呼吸恢复时间、唤醒时间和拔管时间。结果与C组比较,D组拔管即刻及拔管后5min的MAP明显降低,HR明显减慢(P<0.05);与麻醉前比较,D组拔管后5min的MAP明显降低,HR明显减慢,C组拔管即刻及拔管后5min的MAP明显升高,HR明显增快(P<0.05)。D组麻醉苏醒期躁动发生率、躁动程度明显低于C组,D组VAS评分在拔管后5、30、60、120min均明显低于C组(P<0.05),Ramsay镇静评分拔管后5、30min明显高于C组(P<0.05)。结论静脉泵注0.4μg/kg右美托咪定能减轻拔管期应激反应,减少躁动,不延迟呼吸恢复时间、唤醒时间和拔管时间,可预防神经外科全麻术后躁动。     

右美托咪定对老年患者脊柱手术苏醒期躁动的影响

目的观察右美托咪定对老年患者脊柱手术后苏醒期躁动(EA)的影响。方法老年患者(年龄≥60岁)60例,随机分为右美托咪定组(D组)和对照组(C组),每组30例。麻醉诱导后D组患者持续泵注右美托咪定每小时0.4μg/kg,C组持续泵注等容量的生理盐水,手术结束时停药。入麻醉恢复室(PACU)后进行Richmond躁动镇静(RASS)评分,记录EA发生率。记录患者清醒时间、气管导管拔除时间及PACU停留时间。术后24小时记录患者对苏醒期治疗的满意度。结果 D组患者EA发生率为16.67%,C组为46.67%,两组比较差异有统计学意义(P0.05),D组患者PACU停留时间为(42.17士17.40)分钟,C组为(52.50±22.12)分钟,两组比较差异有统计学意义(P0.05)。D组患者清醒时间为(16.67±7.58)分钟,拔管时间为(21.67±7.58)分钟,C组分别为(14.40±8.47)分钟和(19.10±8.86)分钟,两组比较差异无统计学意义(P0.05)。结论右美托咪定可以有效地降低老年患者脊柱手术后EA发生率,提高患者苏醒质量。     

不同剂量右美托咪定对乳腺癌手术患者苏醒期的影响

【摘要】 目的 评价不同剂量右美托咪定对乳腺癌手术患者苏醒期的影响。方法〓选择因乳腺癌改良根治手术而行气管内插管全麻的患者80例,ASAⅠ~Ⅱ级,分成4组(n=20,每组),分别于手术结束前30 min静脉注射右美托咪定或等量生理盐水。C组(对照组)静脉注射0.9%生理盐水,D1组静脉注射右美托咪啶0.2 μg/kg,D2组静脉注射右美托咪啶0.5 μg/kg,D3组静脉注射右美托咪啶0.8 μg/kg。各组患者术中机械通气的模式采用容量控制通气持续至气管导管拔出。记录手术结束后呼之睁眼时间及拔管时间,记录气管拔管时Riker镇静、躁动评分及Ramsay镇静评分,记录拔管即刻(T1)、拔管后2 min(T2)、5 min(T3)、10 min(T4)各时点患者的平均动脉压、心率。结果〓与C组比较,D1、D2组呼之睁眼时间及拔管时间差异均无统计学意义(P>0.05),而D3组明显延长(P<0.01)。C组气管拔管时,大多患者Riker镇静及躁动评分为5分,拔管时心率明显增快、血压升高。与C组比较,D2、D3组躁动的发生率明显降低(P<0.01),T1至T4各时间点心血管不良反应明显减少。D2组患者Ramsay镇静评分为2~4分,镇静适度,T0至T4各时间点心率、血压无显著性变化。D3组患者中,Ramsay镇静评分为5~6分的患者比例为70%,呈现镇静过度的状态。结论〓在手术结束前30 min中等剂量右美托咪定(0.5 μg/kg)既可很好的预防乳腺癌手术患者苏醒期因气管导管引起的躁动,又不会导致苏醒延迟。     

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.