超声引导下单次竖脊肌平面阻滞对胸腔镜下肺叶切除患者静脉自控镇痛效果的影响

目的探讨超声引导下单次竖脊肌平面(erector spinae plane,ESP)阻滞联合患者自控静脉镇痛(PCIA)在胸腔镜下肺叶切除患者术后的镇痛效果。方法择期行胸腔镜下肺叶切除术患者40例,男20例,女20例,ASAⅠ或Ⅱ级。随机分为单次ESP阻滞联合PCIA组(EP组)和单纯PCIA组(P组)。EP组麻醉诱导前行ESP阻滞,20 min后测定阻滞范围,术毕两组均采用PCIA。记录术后1、6、18、24、48h静息和咳嗽时VAS评分,镇痛泵按压次数,输注总量,氟比洛芬酯给药次数,以及术后不良反应发生情况。结果 ESP阻滞20min后可阻滞T_2~T_8或T_3~T_7脊神经支配区域,术后1~48h EP组静息和咳嗽时VAS评分明显低于P组(P0.05),镇痛泵按压次数、输注总量和氟比洛芬酯给药次数明显少于P组(P0.05)。两组术后恶心、呕吐发生率差异无统计学意义。结论超声引导下单次竖脊肌平面阻滞联合PCIA的胸科手术辅助镇痛方式较单纯PCIA方式更为安全有效。     

竖脊肌平面阻滞镜下肺叶切除镇痛效果分析

目的探讨分析超声引导下单次竖脊肌平面阻滞用于胸腔镜下肺叶切除术后的镇痛效果。方法择期行胸腔镜下肺叶切除术的患者132例,年龄32～68岁,BMI 20～24kg/m2,ASAⅠ或Ⅱ级。采用随机数字表法分成两组(n=66),超声引导下单次竖脊肌平面阻滞(E组)和对照组(C组)。麻醉诱导前30分钟,E组行超声引导下竖脊肌平面阻滞,单次给予0.5%罗哌卡因30ml;C组不予处理。两组患者均采用全身麻醉。术毕接患者静脉自控镇痛,配方:舒芬太尼2μg/kg+阿扎司琼10mg+0.9%NS稀释至100ml,背景剂量5ml,PCA 2ml,锁定时间15分钟。若VAS静息评分4分,予静滴曲马多100mg补救镇痛。对比两组患者术中瑞芬太尼用量,术后48小时舒芬太尼用量和补救镇痛例数;记录术后2、4、8、12、24及48小时的VAS静息评分及相应时间点的BCS评分;记录术后恶心、呕吐,皮肤瘙痒,尿潴留,呼吸抑制等不良反应的发生情况;术后48小时对患者进行满意度调查。结果与C组比较,E组患者术中舒芬太尼用量,术后48小时舒芬太尼用量和补救镇痛例数明显减少(P0.05);术后2、4、8、12小时E组患者的VAS静息评分明显降低,BCS评分明显升高(P0.05);E组患者术后不良反应发生情况明显减少(P0.05),病人满意度明显提高(P0.05)。结论超声引导下0.5%罗哌卡因30ml单次竖脊肌平面阻滞可安全有效的用于胸腔镜下肺叶切除术,能为该类手术患者提供完善的术后镇痛效果。     

超声引导下竖脊肌平面阻滞在慢性脓胸患者术中及术后镇痛中的效果

目的观察超声引导下竖脊肌平面(erector spinae plane, ESP)阻滞对慢性脓胸患者术中及术后镇痛效果的影响。方法择期行胸腔镜下胸膜纤维板剥脱术的慢性脓胸患者60例,男35例,女25例,年龄30～70岁,ASAⅠ或Ⅱ级,随机分为两组:ESP阻滞复合全身麻醉组(E组)和单纯全身麻醉组(G组)。两组均行全身麻醉,E组全身麻醉前实施超声引导下ESP阻滞,术毕均采用患者自控静脉镇痛(patient controlled intravenous analgesia, PCIA)。记录E组超声下胸椎旁间隙显示情况,ESP阻滞20 min后在锁中线处感觉阻滞范围;记录两组术中瑞芬太尼用量、PACU停留时间、术后PCIA泵有效按压次数、术后1、4、12、24、48 h静息和活动时VAS评分。结果 E组有24例胸椎旁间隙显示不清,ESP阻滞20 min后感觉阻滞节段为4.9±1.0。E组术中瑞芬太尼用量和术后PCIA泵有效按压次数明显少于G组(P0.05),PACU停留时间明显短于G组(P0.05),术后1、4、12、24 h静息和活动时VAS评分明显低于G组(P0.05)。结论超声引导下ESP阻滞对慢性脓胸患者是一种安全的镇痛方法,能够提供有效的术中及术后镇痛。     

超声引导竖脊肌平面阻滞对多发肋骨骨折术后镇痛效果的影响

目的观察超声引导竖脊肌平面(erector spinae plane,ESP)阻滞对肋骨骨折病人术后镇痛效果的影响。方法选择择期行全麻肋骨骨折手术治疗的病人,随机分为两组:ESP组和对照组,每组30例。麻醉诱导后,ESP组行超声引导下术侧ESP阻滞,对照组注射等容积的生理盐水,术后均行病人自控静脉镇痛(PCIA)。记录术中病人生命体征、麻醉药物用量,手术后VAS评分和Prince-Henry(P-H)疼痛评分,PCIA按压次数和输注总量,不良反应发生情况。结果两组病人术中生命体征差异无统计学意义,手术中ESP组瑞芬太尼使用量少于对照组(P0.05),术后48小时内ESP组镇痛泵按压次数和输注总量明显少于对照组(P0.05),ESP组术后VAS评分和P-H疼痛评分明显低于对照组(P0.05)。结论超声引导下竖脊肌平面阻滞能减少肋骨骨折病人围术期阿片类药物的用量,减少PCIA的按压次数和输注总量,减轻术后疼痛。     

超声引导下竖脊肌平面阻滞和胸椎旁神经阻滞用于胸腔镜下肺叶切除术的比较

目的比较超声引导下竖脊肌平面阻滞(erector spinae plane block,ESPB)和胸椎旁神经阻滞(thoracic paravertebral nerve block,TPVB)应用于胸腔镜下肺叶切除术中血流动力学变化及术后联合PCIA的效果。方法选择行胸腔镜下肺叶切除术的患者60例,男38例,女22例,年龄18~64岁,BMI 18~24 kg/m^2,ASAⅠ或Ⅱ级,随机分为ESPB组(E组)和TPVB组(T组),每组30例。E组术前0.4%罗哌卡因25 ml行超声引导下单次ESPB,T组术前0.4%罗哌卡因25 ml行单次TPVB。罗哌卡因注入20 min后用冰块测定阻滞平面。术毕两组均给予PCIA至术后48 h。记录穿刺时间、深度;记录术中血管活性药使用情况、丙泊酚、瑞芬太尼用量;记录镇痛泵首次按压时间、有效按压次数、曲马多补救例数;记录胸闷、皮肤瘙痒等术后不良反应的发生情况。结果与T组比较,E组穿刺时间明显缩短(P<0.05),穿刺深度明显变浅(P<0.05),术中去氧肾上腺素使用率明显降低(P<0.05)。两组术中丙泊酚、瑞芬太尼用量、镇痛泵首次按压时间、有效按压次数、曲马多补救率及术后不良反应差异无统计学意义。结论超声引导下ESPB较TPVB操作更简单快捷,术中低血压发生率更低,术后两种阻滞联合PCIA均能为胸腔镜肺叶切术患者提供有效的镇痛。     

超声引导下竖脊肌平面阻滞联合静脉镇痛用于肝叶切除术患者的效果

目的观察超声引导下单次竖脊肌平面阻滞(erector spinae plane block,ESPB)联合静脉镇痛用于肝叶切除术患者的效果。方法择期肝叶切除术患者90例,男63例,女27例,年龄30～65岁,BMI 20～29 kg/m~2, ASAⅠ或Ⅱ级,随机分为三组:单次ESPB联合静脉镇痛组(EP组)、硬膜外镇痛组(EA组)、单纯自控静脉镇痛组(IA组),每组30例。三组患者均采用全身麻醉。EP组于麻醉诱导前行0.33%罗哌卡因30 ml+地塞米松5 mg单次ESPB。EA组患者于麻醉诱导前行T_(10～11)间隙穿刺置入硬膜外导管,术毕硬膜外镇痛。EP组和IA组术毕使用静脉镇痛泵。记录ESPB的阻滞平面和术后2、6、12、24和48 h的静息和咳嗽时VAS评分;记录镇痛泵按压次数、追加曲马多例数;记录皮肤瘙痒、恶心呕吐、尿潴留、胸闷等不良反应发生情况和ESPB相关并发症;记录患者对术后镇痛的满意度评分。结果 EP组痛觉阻滞范围,T_5—T_(12)脊神经支配区域16例,T_4—T_(11)脊神经支配区域11例,T_6—L_1脊神经支配区域3例。术后2、6、12、24和48 h EP组和EA组静息和咳嗽时VAS评分明显低于IA组(P0.05)。EP组和EA组镇痛泵按压次数和追加曲马多例数明显少于IA组(P0.05)。三组均未出现呼吸抑制不良反应。EP组术后恶心呕吐发生率明显低于IA组(P0.05),EA组皮肤瘙痒和尿潴留发生率明显高于IA组(P0.05)。EP组和EA组患者对术后镇痛效果的总体满意度评分明显高于IA组(P0.05)。结论超声引导下竖脊肌平面阻滞联合患者自控静脉镇痛技术用于肝叶切除术后镇痛能够获得硬膜外镇痛的效果,且不良反应发生率低,患者满意度更高。     

前锯肌平面阻滞对非小细胞肺癌胸腔镜根治术患者术后镇痛效果的影响

目的探讨前锯肌平面阻滞对胸腔镜手术患者术后镇痛效果的影响。方法选取2017年7—12月住院治疗的早期非小细胞肺癌患者40例,性别不限,年龄48～67岁,BMI 21.3～26.7 kg/m~2,ASAⅠ或Ⅱ级,按照随机分组的原则,将患者分为前锯肌平面阻滞组(SP组,n=20)和对照组(C组,n=20)。记录术后在PACU内舒芬太尼追加剂量及总用量、48 h内疼痛VAS评分、48 h内镇痛泵有效按压次数及总按压次数;记录功能锻炼依从性及慢性疼痛的发生率;记录患者局麻药中毒、皮下血肿、感染、皮肤瘙痒、头晕、恶心呕吐、尿潴留、便秘等不良反应的发生情况。结果与C组比较,SP组术后舒芬太尼追加剂量及总舒芬太尼用量明显减少(P0.05);术后2、4、8、24、48 h疼痛VAS评分明显降低(P0.05);48 h内PCIA有效按压次数及总按压次数明显减少(P0.05);功能锻炼依从性明显较好(P0.05)。两组慢性疼痛发生率差异无统计学意义。两组镇痛不良反应差异无统计学意义。结论对于非小细胞肺癌胸腔镜手术患者,前锯肌平面阻滞联合静脉自控镇痛的多模式镇痛可有效控制术后疼痛,减少镇痛药的用量、镇痛泵按压次数和慢性疼痛的发生率,提高患者呼吸功能锻炼的依从性。     

右美托咪定复合罗哌卡因竖脊肌平面阻滞对腰椎手术后镇痛效果及睡眠质量的影响

目的探讨右美托咪定(Dexmedetomidine,DEX)复合罗哌卡因竖脊肌平面(erector spine plane,ESP)阻滞对腰椎手术后镇痛效果及睡眠质量的影响。方法选择择期行腰椎后路手术患者40例,采用随机数字表法分为两组,每组20例:DEX复合罗哌卡因组(A组)和罗哌卡因组(B组)。全麻诱导前行双侧ESP阻滞,A组每侧注入含1μg/kg DEX的0. 375%罗哌卡因20 m L,B组每侧注入0. 375%罗哌卡因20 m L后全麻诱导。术后行自控静脉镇痛(PCIA)至术后48 h,若VAS≥4分,静脉给予地佐辛5 mg或帕瑞昔布钠40 mg或氟比洛芬酯50 mg补救镇痛。记录两组术后2、4、6、12、24和48 h时的BCS舒适度评分。记录术后48 h内PCIA有效按压次数(D1)和实际按压次数(D2),计算D1/D2比值及补救镇痛情况;记录ESP阻滞并发症(局麻药中毒、穿刺部位血肿、感染)及术后恶心呕吐、头晕、皮肤瘙痒、呼吸抑制等不良反应的发生情况;采用匹兹堡睡眠质量指数(PSQI)分别评估术前、术后1 d、2 d及出院前患者睡眠质量。结果与B组比较,A组术后2、4、6、12、24和48 h时BCS舒适度评分明显升高,D1/D2值明显升高,补救镇痛率明显减少,恶心呕吐发生率明显降低,术后1 d、2 d及出院前的PSQI评分明显降低(P0. 05)。两组术后头晕、皮肤瘙痒、呼吸抑制等发生情况差异无统计学意义(P0. 05),两组均未出现局麻药中毒、穿刺部位血肿、感染等并发症。结论 1μg/kg DEX复合0. 375%罗哌卡因用于ESP阻滞,可为腰椎后路手术患者提供更好的术后镇痛,改善术后睡眠质量。     

超声引导下竖脊肌平面阻滞对胸腔镜肺叶切除术患者术后肺功能的影响

目的观察超声引导下竖脊肌平面阻滞(erector spinae plane block, ESPB)对胸腔镜肺叶切除术患者术后肺功能的影响。方法选择择期全麻下行胸腔镜肺叶切除术患者130例,男65例,女65例,年龄40～75岁,BMI 18～25 kg/m~2,ASAⅠ或Ⅱ级,随机分为ESPB组(E组)和对照组(C组),每组65例。E组于术毕即刻行手术侧超声引导下ESPB,在竖脊肌深面注入0.375%罗哌卡因25 ml。C组不行神经阻滞。两组术后均行PCIA。记录麻醉诱导前(T_0)、术后拔除气管导管后(T_1)、拔除胸腔引流管后(T_2)的一秒种用力呼气容积(FEV_1)、用力肺活量(FVC)和最高呼气流速变异率(PEFR),记录T_1、T_2时术后限制性通气障碍、阻塞性通气障碍、混合型通气障碍的发生情况和Prince-Henry疼痛评分。记录PCIA泵有效按压次数(D_1)、实际按压次数(D_2)和术后补救镇痛次数。记录术后恶心呕吐(PONV)、呼吸困难等发生情况;记录拔气管导管时间(拔管时间)、胸腔引流管留置时间、住院时间。结果 T_1时E组FVC、PEFR明显高于C组(P0.05),术后限制性通气障碍、阻塞性通气障碍、混合型通气障碍发生率和Prince-Henry评分明显低于C组(P0.05)。T_2时E组FEV1、FVC、PEFR明显高于C组(P0.05),Prince-Henry评分明显低于C组(P0.05)。E组D_2明显少于C组(P0.05),补救镇痛次数明显低于C组(P0.05)。E组PONV、呼吸困难等并发症发生率明显低于C组(P0.05),胸腔引流管留置时间、住院时间明显短于C组(P0.05)。结论超声引导下ESPB明显改善胸腔镜肺叶切除术患者术后肺功能,降低并发症,可能与充分的术后镇痛作用有关。     

超声引导下腹横肌平面阻滞用于妇科腹腔镜手术患者术后镇痛的临床研究

目的评价超声引导下腹横肌平面阻滞应用于妇科腹腔镜手术患者术后镇痛的有效性。2019年1月拟于本院行妇科腹腔镜手术的患者共计162例。年龄18～65岁,ASA分级Ⅰ～Ⅱ级,体重指数(BMI)18.5～27.9kg/m~2。患者随机分为腹横肌平面阻滞组(Transversus abdominis plane block group,T组)和对照组(Control group,C组),每组各81例。T组患者行超声引导下腹横肌平面阻滞;C组患者不进行其他干预。使用数字评价量表(NRS)评价患者疼痛程度。使用BCS舒适评分评价患者术后舒适度。记录患者出PACU即刻、术后2、4、12、24小时的NRS评分及BCS舒适度评分。记录患者PCIA有效按压次数、PCIA总按压次数、术后恶心呕吐(PONV)、结果 T组患者出PACU即刻、术后2、4、12、24小时NRS评分均显著低于C组患者,差异有统计学意义(P0.05)。T组患者出PACU即刻、术后2、4、12、24小时BCS评分均显著高于C组患者,差异有统计学意义(P0.05)。T组患者PCIA有效按压次数、PCIA总按压次数以及PONV、头晕、皮肤瘙痒发生率显著低于C组患者,差异有统计学意义(P0.05)。所有患者均未发生穿刺部位血结论超声引导下腹横肌平面阻滞用于妇科腹腔镜手术患者具有较高的安全性与有效性,值得在临床中推广使用。     

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.     

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.