超声引导下椎板阻滞对胸腔镜下肺叶切除术术后镇痛的影响

目的观察超声引导下椎板阻滞对胸腔镜下肺叶切除术患者术后镇痛效果的影响。方法择期行胸腔镜下肺叶切除术的患者40例,采用随机数字表法将患者分为两组(每组20例):椎板阻滞复合全身麻醉组(R组)和单纯全身麻醉组(G组)。R组患者全身麻醉前实施超声引导下椎板阻滞,阻滞20 min后测量患者感觉阻滞平面。两组患者全身麻醉方法相同,术毕两组患者均使用患者自控静脉镇痛(patient controlled intravenous analgesia,PCIA)。记录术后2、6、18、24、48 h静息和活动时VAS评分,记录患者PACU停留时间、术后PCIA按压次数、术后舒芬太尼用量、补救镇痛情况、副作用发生情况、住院时间及患者满意度。结果R组椎板阻滞20 min后测量锁骨中线处感觉阻滞节段为(5.7±0.9)个,R组患者术后2、6、18、24、48 h静息和活动时VAS明显低于G组(P<0.05);R组患者PACU停留时间、术后PCIA按压次数和术后舒芬太尼用量明显少于G组(P<0.05),其中R组2例(10%)患者、G组13例(65%)患者追加了曲马多补救镇痛,两组补救镇痛差异有统计学意义(P<0.05);R组患者术后满意度明显高于G组(P<0.05),两组患者术后恶心、呕吐发生率和住院时间差异无统计学意义(P>0.05)。结论超声引导下椎板阻滞可安全应用于胸腔镜下肺叶切除术,并能够提供良好的术后镇痛,患者满意度高。     

椎板后阻滞和竖脊肌平面阻滞在多发肋骨骨折手术患者术中及术后镇痛效果的比较

目的探讨超声引导下椎板后阻滞(RLB)和竖脊肌平面阻滞(ESPB)对多发肋骨骨折患者术中和术后镇痛效果的影响。方法选择行肋骨骨折内固定手术患者80例,男57例,女23例,年龄25～65岁,ASAⅠ或Ⅱ级。随机分为两组:RLB组和ESPB组,每组40例。两组在全身麻醉后实施超声引导下RLB和ESPB,均给予0.5%罗哌卡因0.4 ml/kg。术后两组均行静脉自控镇痛(PCIA)。记录术中瑞芬太尼用量。记录术前静息以及术后2、4、12、24、48 h静息和咳嗽时VAS疼痛评分。记录PACU滞留时间、PCIA有效按压次数、补救镇痛例数、穿刺相关并发症及不良反应的发生情况。结果与EAPB组比较,RLB组术中瑞芬太尼用量明显减少(P0.05),术后2、4、12、24 h静息和咳嗽时VAS疼痛评分明显降低(P0.05),PACU滞留时间明显缩短(P0.05),PCIA有效按压次数明显减少(P0.05),补救镇痛率、恶心呕吐发生率明显降低(P0.05)。结论与ESPB比较,全身麻醉联合超声引导下RLB可以有效减少多发肋骨骨折患者术中阿片类药物的用量,减轻术后疼痛。     

竖脊肌平面阻滞对袖状胃切除术患者术后恢复质量的影响

目的观察竖脊肌平面阻滞(ESPB)对肥胖患者袖状胃切除术后恢复质量的影响。方法选择拟行腹腔镜袖状胃切除术患者98例,男9例,女89例,年龄18～64岁,BMI≥28 kg/m~2,ASAⅡ或Ⅲ级。采用随机数字表法将患者随机分为两组:ESPB组(E组,n=50)和对照组(C组,n=48)。E组全麻诱导前行超声引导下每侧ESPB 0.33%罗哌卡因30 ml; C组行单纯全麻。两组全麻方案相同。术前及术后24、48 h进行恢复质量15(QoR-15)量表评估。记录术后0.5、2、6、12、24、48 h静息和活动时VAS疼痛评分。记录术后48 h内镇痛泵按压次数、术后镇痛类药物累计消耗量及补救镇痛例数。记录PACU停留时间、首次下床时间、首次排气时间和住院时间。记录术后头晕、恶心、呕吐、呼吸等并发症发生情况。结果术前及术后24、48 h两组QoR-15总体评分差异无统计学意义。术后12 h E组活动时VAS疼痛评分明显低于C组(P0.05),其余时点两组VAS疼痛评分差异无统计学意义。术后48 h内两组镇痛泵按压次数、镇痛药物累计消耗量、补救镇痛率差异无统计学意义。两组PACU停留时间、首次下床时间、首次排气时间、住院时间以及并发症发生率差异无统计学意义。结论与单纯全麻比较,全麻联合单次竖脊肌平面阻滞未能显著改善腹腔镜袖状胃切除术后恢复质量,但可增强镇痛效果。     

超声引导下椎旁阻滞对机器人辅助腹腔镜肾切除术患者术后肺功能的影响

目的 探讨超声引导下椎旁阻滞对机器人辅助腹腔镜肾切除术患者术后肺功能的影响。方法 选择择期行机器人辅助腹腔镜肾切除术患者80例,男40例,女40例,年龄30～70岁,BMI 18.5～35.0 kg/m²,ASAⅠ或Ⅱ级。根据随机数字表法将患者分为两组：椎旁阻滞联合全麻组(PG组)和单纯全麻组(SG组),每组40例。两组术后均使用羟考酮静脉镇痛。记录术前1 d、术后1～5 d的用力肺活量(FVC)、第1秒用力呼气容量(FEV₁)、最大呼气中期流量(MMEF)和SpO₂。记录术后1～5 d静息和活动(咳嗽)时VAS疼痛评分。记录丙泊酚用量、瑞芬太尼用量,镇痛泵有效按压次数、总按压次数和补救镇痛例数。记录术后首次下床活动时间、术后首次肛门排气时间、术后住院时间和不良反应的发生情况。记录术后5 d肺部并发症和术后30 d再次住院的发生情况。结果 与术前1 d比较,术后1～5 d两组FVC、FEV₁及MMEF均明显降低(P<0.05),PG组术后1～4 d、SG组术后1～5 d SpO₂     

舒更葡糖钠对胸腔镜肺切除术后恢复的影响

目的：探讨舒更葡糖钠对胸腔镜肺切除术后肺部并发症（PPCs）及术后恢复的影响。
方法：选择2021年11月至2023年7月接受择期胸腔镜肺段切除术或肺叶切除术的患者263例,男112例,女151例,年龄18～64岁,BMI 18.5～28.0 kg/m²,ASAⅠ—Ⅲ级。将患者随机分为三组：舒更葡糖钠组（S组,n=88）、新斯的明组（N组,n=87）和对照组（C组,n=88）。患者术后被送至PACU,当四个成串刺激（TOF）计数为2时,S组静脉注射舒更葡糖钠2 mg/kg,N组静脉注射新斯的明0.04 mg/kg+阿托品0.02 mg/kg,C组静脉注射等容量生理盐水。记录手术结束至出院前PPCs的发生情况,记录手术结束至拔管时间、给药至四个成串刺激比值（TOFr）恢复至0.9的时间、拔管时TOFr、PACU停留时间、拔管后低氧血症（SpO₂<90%）的情况并计算拔管时肌松残余（PRNB）发生率,记录首次下床活动时间、术后48 h内镇痛泵总按压次数、有效按压次数、补救镇痛例数、临床肺部感染评分（CPIS）、术后恶心呕吐（PONV）例数、胸管总引流量、胸管留置时间和术后住院时间。
结果：与C组比较,S组PPCs发生率、拔管时PRNB和拔管后低氧血症发生率明显降低,手术结束至拔管时间、给药至TOFr恢复至0.9的时间、PACU停留时间和术后首次下床活动时间明显缩短,拔管时TOFr明显升高,CPIS评分明显降低（P<0.05）;N组手术结束至拔管时间、给药至TOFr恢复至0.9的时间、PACU停留时间明显缩短,拔管时TOFr明显升高,拔管时PRNB发生率明显降低（P<0.05）。与N组比较,S组拔管时PRNB发生率明显降低,手术结束至拔管时间、给药至TOFr恢复至0.9的时间、PACU停留时间和术后首次下床活动时间明显缩短,拔管时TOFr明显升高（P<0.05）。三组其余指标差异均无统计学意义。
结论：舒更葡糖钠在胸腔镜肺切除术后可快速拮抗残余肌松,降低PPCs和拔管时PRNB发生率,促进患者术后快速康复。     

竖脊肌平面阻滞与椎旁神经阻滞对肥胖患者腹腔镜袖状胃切除术后恢复质量影响的比较北大核心CSCD

目的探讨竖脊肌平面阻滞(ESPB)与椎旁神经阻滞(PVB)对腹腔镜袖状胃切除术肥胖患者术后恢复质量的影响。方法选择2021年1—3月择期腹腔镜袖状胃切除术的肥胖患者107例,男25例,女82例,年龄18~45岁,BMI 30~40 kg/m^(2),ASAⅡ或Ⅲ级。将患者随机分成两组:ESPB组(E组,n=54)和PVB组(P组,n=53)。E组于T_(8)行双侧ESPB,P组于T_(8)行双侧PVB,每侧均给予0.33%罗哌卡因20 ml。两组术中麻醉方案相同,术后行标准化镇痛。采用恢复质量15(QoR-15)量表评估术后24、48 h恢复质量。记录术后0.5、2、6、12、24、48 h静息和活动时NRS评分。记录术后48 h内镇痛药物用量、镇痛泵总按压次数和有效按压次数、补救镇痛例数、术后首次下床活动时间、术后首次肛门排气时间、术后住院时间、术后恶心呕吐(PONV)和神经阻滞相关并发症发生情况。结果两组术后24、48 h QoR-15评分、术后0.5、2、6、12、24、48 h静息和活动时NRS评分、术后48 h内镇痛药物用量、镇痛泵总按压次数和有效按压次数、补救镇痛率、术后首次下床活动时间、术后首次肛门排气时间、术后住院时间、PONV发生率差异均无统计学意义。两组无一例发生穿刺部位出血、血肿、气胸、神经损伤等神经阻滞相关并发症。结论竖脊肌平面阻滞对肥胖患者腹腔镜袖状胃切除术后恢复质量的作用与椎旁神经阻滞相似,两种神经阻滞方法均能取得良好的镇痛效果。     

腹横肌平面阻滞与切口局部浸润麻醉在腹腔镜肾切除术后镇痛效果的比较

目的:研究超声引导下不同入路的腹横肌平面阻滞与切口局部浸润麻醉在腹腔镜肾切除术后镇痛的疗效。方法:收集静脉复合麻醉下后腹腔镜单侧肾切除术患者60例,按数字随机表法分三组(每组20例):超声引导下腹横肌平面阻滞侧路法组(TM1组),后路法组(TM2组)与切口局部浸润组(M组)。麻醉诱导采用静脉注射舒芬太尼、阿曲库铵和丙泊酚,气管插管后机械通气,全麻维持用静脉持续泵注丙泊酚和瑞芬太尼,间断注射阿曲库铵维持肌松,术中BIS值在40~60之间波动。麻醉诱导后三组均注射0.375%罗哌卡因30 mL,阻滞成功30 min后开始手术。三组患者拔管清醒后连接患者自控镇痛泵(PCA)作为镇痛补救用药。记录切皮前后患者心率、血压变化;术后2、6、12、24、48 h VAS评分、Ramsay评分及腹部阻滞平面范围;术后0~1、1~6、6~12和12~24 h时段记录舒芬太尼用量;记录患者术后首次下床活动时间、镇痛满意度及恶心、呕吐发生情况。结果:与M组相比,TM1和TM2组患者切皮前后血压、心率改变无明显差异(P0.05);与M组相比,TM1和TM2组患者术后6、12、24、48 h VAS评分均下降(P0.05),但TM1和TM2组患者术后2、4、6、12、48 h的VAS评分无明显差异(P0.05);TM1和TM2组患者术后6、12 h时间点Ramsay评分高于M组(P0.05),术后2、24、48 h无明显差异(P0.05),且TM1和TM2两组间无明显差异(P0.05);术后TM1和TM2两组患者腹壁阻滞平面6 h内在T4~T10之间,6~12 h平面在T9,12 h以后消失,能够维持较好的镇痛;与M组相比,TM1和TM2组术后0~1、1~6、6~12和12~24 h舒芬太尼量均低于M组(P0.05);与M组相比TM1和TM2组术后镇痛满意度的更高(P0.05),患者恶心呕吐发生率更低(P0.05)。结论:两种不同入路超声引导下腹横肌平阻滞均可对后腹腔镜肾切除术提供良好的术后镇痛效果,且均优于局部切口浸润阻滞。     

术后不同镇痛方式在单侧乳腺癌根治术患者中的应用

目的比较不同镇痛方式在单侧乳腺癌根治术患者术后镇痛中的应用效果,为乳腺癌根治术患者选择合适的术后镇痛模式。方法选择择期在全麻下行单侧乳腺癌根治术女性患者90例,年龄35~60岁,体重45~80kg,ASAⅠ或Ⅱ级,随机分成单纯静脉镇痛组(P组)、局部浸润+静脉镇痛组(R组)和超声引导下胸椎旁神经阻滞+静脉镇痛(TP组),每组30例。P组:右美托咪定2μg/kg+舒芬太尼2μg/kg;R组:0.375%罗哌卡因20ml局部浸润+右美托咪定2μg/kg+舒芬太尼2μg/kg;TP组:0.375%罗哌卡因20ml椎旁阻滞+右美托咪定2μg/kg+舒芬太尼2μg/kg。记录三组术后6、12、24、48hVAS评分和Ramsay评分;记录术前、术后24、48h深睡眠质量评分;记录术后24h内镇痛泵按压次数、舒芬太尼使用总量以及恶心、呕吐、瘙痒、心动过缓、呼吸抑制等不良反应的发生情况。结果术后6hR组和TP组VAS评分明显低于P组,术后12hTP组VAS评分明显低于R组和P组(P0.05);三组术后不同时点Ramsay评分差异无统计学意义。术后24hTP组深睡眠质量评分明显低于P组和R组(P0.05);术后24h内TP组镇痛泵按压次数和舒芬太尼使用总量明显少于R组和P组,R组镇痛泵按压次数和舒芬太尼使用总量明显少于P组(P0.05);三组术后24h内恶心、呕吐、瘙痒、心动过缓、呼吸抑制差异均无统计学意义;TP组未发生超声引导下椎旁神经阻滞相关并发症。结论三种术后镇痛方式均可安全有效地用于单侧乳腺癌根治术患者的术后镇痛,且超声引导下胸椎旁神经阻滞联合自控静脉镇痛方式的镇痛效果、睡眠质量、舒芬太尼使用总量明显优于切口局部浸润联合自控静脉镇痛与单纯静脉镇痛。     

腹腔镜肾切除术围术期中采用胸膜横突中间点阻滞的镇痛效果研究

目的 观察在腹腔镜肾切除术过程采取胸膜横突中间点阻滞（MTPB）的镇痛作用。方法 分析2020年2月至2022年2月在本院行腹腔镜肾切除患者共62例，根据不同的麻醉方法分为MTPB组及镇痛泵组，各纳入31例。MTPB组进行麻醉联合超声引导MTPB麻醉；镇痛泵组进行全身麻醉，两组术后采取静脉镇痛泵48 h。比较两组手术时间、术中瑞芬太尼总用量，镇痛泵有效按压次数、疼痛程度、麻醉不良反应发生率。结果 与镇痛泵组比较，MTPB组患者的手术时间（136.46±15.93） min、瑞芬太尼总用量（1.22±0.25） mg、镇痛泵有效按压次数（4.14±0.55）次显著降低（P<0.05）；术后苏醒即刻（2.72±0.41）分、术后6 h(2.67±0.40)分、术后12 h(2.59±0.39)分MTPB组的视觉模拟量表（VAS）评分分别明显少于镇痛泵组同时点（P<0.05）；术后MTPB组（6.45%）不良反应发生率显著低于镇痛泵组（29.03%）(P<0.05)。结论于腹腔镜肾切除术中采取MTPB的镇痛效果明显，能显著减少不良反应发生。     

竖脊肌平面阻滞与切口浸润麻醉对全麻胸腔镜肺部分切除术患者术后早期恢复影响的比较

目的比较竖脊肌平面阻滞与切口浸润麻醉对全麻胸腔镜肺部分切除术患者术后早期恢复的影响。方法选取拟在全麻胸腔镜下行肺部分切除术患者80例, 性别不限, 年龄50～78岁, BMI 18～30 kg/m2 , ASA分级Ⅱ或Ⅲ级, 采用随机数字表法分为2组(n=40):切口局部浸润组(D组)和竖脊肌平面阻滞组(E组)。E组在麻醉诱导完成, 改为侧卧位后, 在超声引导下行患侧竖脊肌平面阻滞, 注射0.25%盐酸罗哌卡因30 ml;D组切皮前采用0.25%盐酸罗哌卡因行切口浸润麻醉。术后行自控静脉镇痛, 当静态NRS评分>3分或咳嗽时NRS评分≥6分时, 静脉注射氟比洛芬酯补救镇痛。分别于术前1 d和术后24、48 h时行QOR-15评分。分别于切皮前、术毕和术后24 h时, 采用ELISA法测定血浆IL-6和IL-1β浓度。记录术中瑞芬太尼用量、术后48 h内镇痛泵有效按压次数、补救镇痛情况、术后首次下床活动时间、首次肛门排气时间、住院时间和术后48 h内恶心呕吐、肺部感染的发生情况。结果与D组比较, E组术后24和48 h时QOR-15评分升高, 术中瑞芬太尼用量和镇痛泵有效按压次数减...     

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.