胸腰筋膜平面阻滞在脊柱外科手术围术期的应用进展

胸腰筋膜平面（TLIP）阻滞是一种用于腰椎术后镇痛的筋膜间平面阻滞技术。随着超声技术的普及,TLIP阻滞被广泛应用,能提供良好的术后镇痛,减少术中及术后阿片类药物的用量,且操作简单、并发症少。目前TLIP阻滞主要用于腰椎融合术、腰椎间盘切除术以及椎板成型术等腰椎手术的多模式镇痛。此外,TLIP阻滞还可用于微创脊柱外科手术的麻醉,如经皮椎间孔镜手术、经椎间孔入路腰椎椎间融合术和脊髓刺激器的植入等。本文对TLIP阻滞的解剖学基础、作用机制、临床应用及并发症等方面作一综述,以期为脊柱外科手术的麻醉及多模式镇痛提供参考。     

胸腰筋膜间平面阻滞对后路腰椎融合术后镇痛效果的影响

目的 探讨超声引导下胸腰筋膜间平面（thoracolumbar interfascial plane, TLIP）阻滞对后路腰椎融合手术病人术后镇痛效果的影响。方法 前瞻性选择2017年4月至2018年5月在我院择期行后路腰椎融合手术病人50例。采用随机数字表法分为两组,每组25例,TLIP阻滞联合静脉自控镇痛（patient controlled intravenous analgesia, PCIA）组（TLIP组）和单纯PCIA组（对照组）。TLIP组,男12例,女13例,年龄为（49.4±7.7）岁;对照组,男10例,女15例,年龄为（49.5±7.1）岁。TLIP组在全麻诱导后行超声引导下双侧TLIP阻滞,每侧注入0.375%罗哌卡因20 ml。两组术后均使用舒芬太尼行PCIA,维持术后24 h内静息疼痛视觉模拟量表（visual analogue scale, VAS）评分≤3分。记录两组病人围手术期阿片类药物用量及补救镇痛例数,术后2、4、6、12、24 h的静息VAS评分和Ramsay镇静评分,术后24 h 内恶心呕吐、头晕、瘙痒和呼吸抑制的发生情况以及TLIP组阻滞相关并发症的发生情况。结果 与对照组比较,TLIP组术中瑞芬太尼用量及术后24 h内PCIA舒芬太尼用量明显减少（P＜0.05）,术后恶心呕吐发生率明显降低（P＜0.05）,两组均未行补救镇痛。两组间各时间点静息VAS评分和Ramsay镇静评分,以及术后头晕、瘙痒和呼吸抑制等发生率的差异均无统计学意义（P均＞0.05）,TLIP组未发生阻滞相关并发症。结论 超声引导下TLIP阻滞可减少后路腰椎融合术病人围术期阿片类药物用量,降低术后恶心呕吐的发生率。     

超声引导下胸腰筋膜平面阻滞对胸腰椎骨折术后镇痛的作用分析

目的 分析超声引导下胸腰筋膜平面(thoracolumbar interfascial plane,TLIP)阻滞对胸腰椎骨折术后镇痛的作用.方法 选择本院2018年10月-2020年10月收治的100例胸腰椎骨折患者,随机分为对照组和研究组各50例.对照组给予静脉麻醉,研究组在对照组的基础上行超声引导下TLIP阻滞.比较两组的手术情况、术后不同阶段VAS评分、不良反应.结果 对照组的镇痛泵使用时间、下床时间、住院时间显著长于研究组,差异均有统计学意义(P<0.05).对照组的镇痛泵药物、氟比洛芬酯用量显著高于研究组,差异均有统计学意义(P<0.05).对照组术后2 h、6 h、12 h、24 h的VAS评分显著高于研究组,差异均有统计学有意义(P<0.05);两组术后48 h的VAS评分差异无统计学意义(P>0.05).两组不良反应发生率比较,差异无统计学意义(P>0.05).结论 超声引导下TLIP阻滞可促进胸腰椎骨折术后早期康复,减少镇痛药物用量,提高术后镇痛效果,且安全性好.     

超声引导下胸腰筋膜平面阻滞在脑瘫患儿选择性脊神经后根切断术中的应用

目的 探讨超声引导下胸腰筋膜平面（TLIP）阻滞在脑瘫患儿选择性脊神经后根切断术（SPR）中的应用效果。

方法 选择行SPR的脑瘫患儿56例，男31例，女25例，年龄6～12岁，体重18～47 kg，ASA Ⅰ或Ⅱ级。采用随机数字表法将患儿分为两组：超声引导下TLIP阻滞联合全麻组（T组）和单纯全麻组（C组），每组28例。所有患儿静脉全麻用药方案一致。T组插管翻身后行超声引导下双侧TLIP阻滞，0.2%罗哌卡因 0.5 ml/kg，最大用量小于20 ml，30 min后开始手术。C组不行阻滞。记录术中丙泊酚和瑞芬太尼用量，镇痛泵首次按压时间、术后24 h内镇痛泵总按压次数和有效按压次数，术后2、6、12、24 h静息和活动时VAS疼痛评分，术后住院时间、补救镇痛情况、患儿家属满意情况，皮肤瘙痒、低氧血症、恶心呕吐等不良反应发生情况。

结果 与C组比较，T组术中丙泊酚和瑞芬太尼用量均明显减少（P＜0.05），镇痛泵首次按压时间明显延长（P＜0.05），术后24 h内镇痛泵按压的总次数和有效按压次数明显减少（P＜0.05），术后2、6、12 h静息和活动时VAS疼痛评分明显降低（P＜0.05），术后住院时间明显缩短（P＜0.05），补救镇痛率明显降低（P＜0.05），患儿家属满意率明显升高（P＜0.05）。两组皮肤瘙痒、呼吸抑制、恶心呕吐等不良反应的发生率差异无统计学意义。

结论 超声引导下TLIP阻滞可为行SPR的脑瘫患儿提供较为完善的镇痛，减少全麻药用量，加速术后康复。     

罗哌卡因复合倍他米松胸腰筋膜平面阻滞在腰椎手术后静脉镇痛中的效果

目的比较罗哌卡因单独或复合倍他米松胸腰筋膜平面(TLIP)阻滞对腰椎手术术后镇痛效果的影响。方法选择2018年8月至2019年12月拟在全身麻醉下行后正中入路腰椎手术患者90例,男46例,女44例,年龄45～65岁,BMI 18～25 kg/m~2,ASAⅠ—Ⅲ级。随机分为三组:对照组(C组)、罗哌卡因阻滞组(R组)和罗哌卡因复合倍他米松阻滞组(RB组),每组30例。C组全身麻醉诱导后在L_3平面超声引导下双侧胸腰筋膜分别给予生理盐水20 ml。R组全身麻醉诱导后在L_3平面超声引导下双侧胸腰筋膜分别给予0.375%罗哌卡因20 ml,RB组全身麻醉诱导后在L_3平面超声引导下双侧胸腰筋膜分别给予0.375%罗哌卡因复合倍他米松5 mg的混合液20 ml,三组术后均行舒芬太尼PCIA。记录术中瑞芬太尼、丙泊酚用量,术后2、6、12、24、36、48 h静息和翻身时VAS疼痛评分,术后0～24、24～48 h PCIA有效按压次数、舒芬太尼用量、氟比洛芬酯追加剂量,术后呼吸抑制、恶心呕吐、颜面部水肿、寒战等不良反应发生情况。结果与C组比较,R组和RB组术中瑞芬太尼和丙泊酚用量明显减少(P0.05),术后2、6、12 h静息时VAS疼痛评分和术后2、6、12、24 h翻身时VAS疼痛评分明显减少(P0.05),术后0～24 h PCIA有效按压次数、舒芬太尼用量、氟比洛芬酯追加量明显减少(P0.05);RB组术后24～48 h PCIA有效按压次数、舒芬太尼用量、氟比洛芬酯追加量明显减少(P0.05);RB组术后恶心呕吐发生率明显减少(P0.05)。与R组比较,RB组术后36、48 h翻身时VAS疼痛评分明显降低(P0.05),术后24～48 h PCIA有效按压次数、舒芬太尼用量、氟比洛芬酯追加量明显减少(P0.05)。三组术后均未出现呼吸抑制,术后颜面部水肿、寒战发生率差异无统计学意义。结论罗哌卡因复合倍他米松TLIP阻滞有效缓解了腰椎手术术后疼痛,延长了单药TLIP阻滞术后镇痛作用时间,减少了术后相关不良反应。     

超声引导下神经阻滞技术用于患儿腹部手术后镇痛的进展

区域神经阻滞是多模式镇痛的基础方案。与静脉镇痛比较,区域神经阻滞具有更强的针对性和有效性,神经阻滞麻醉镇痛可有效减少阿片类药物使用带来的不良反应。联合应用超声引导技术,能够提高神经阻滞的安全性和精确性。患儿腹部神经阻滞解剖结构以及局麻药物扩散途径、临床应用以及并发症的报道较少,药物浓度与剂量缺乏统一标准,需要进一步的临床研究。本文分别从患儿腰方肌阻滞（QLB）、腹横肌平面阻滞（TAPB）、腹直肌鞘阻滞（RSB）、竖脊肌平面阻滞（ESPB）和椎旁阻滞（PVB）的局麻药物扩散途径、浓度剂量、临床应用及相关并发症等方面进行综述,以期为患儿术后镇痛提供参考。     

超声引导下胸壁神经阻滞与胸椎旁神经阻滞用于乳腺癌改良根治术的镇痛效果

目的比较超声引导下胸壁神经阻滞[胸横肌平面-胸神经阻滞(transversus thoracic muscle plane-pectoral nerves,TTP-PECS)]与胸椎旁神经阻滞(thoracic paravertebral block,TPVB)用于乳腺癌改良根治术围术期的镇痛效果与安全性。方法择期行乳腺癌改良根治术的女性患者64例,年龄35～72岁,BMI 20～26 kg/m~2,ASAⅠ或Ⅱ级。所有患者随机均分为两组:TTP-PECS组(A组)和TPVB组(B组)。麻醉诱导前A组在超声引导下行患侧TTP-PECS,B组在超声引导下行患侧TPVB,均注入0.5%罗哌卡因30 ml,分别于操作结束后30 min测定痛觉减退范围。术毕两组患者均给予PCIA,并静注氟比洛芬酯50 mg补救镇痛,维持静息VAS评分≤3分或运动VAS评分≤5分。记录神经阻滞操作时间、阻滞范围、阻滞相关并发症的发生情况;记录术中芬太尼消耗量、阻滞镇痛维持时间、镇痛泵有效按压次数及补救镇痛例数;评估术后2、6、12、24及48 h的静息及运动状态下的VAS评分;记录术中血管活性药物使用量、术后不良反应的发生情况。结果 A组阻滞范围主要为T_2—T_6,B组主要为T_3—T_7,A组T_2皮区的阻滞者明显多于B组,T_6、T_7皮区的阻滞者少于B组(P0.05);与B组比较,A组阻滞操作时间缩短,阻滞镇痛时间延长,镇痛泵有效按压次数和补救镇痛例数明显减少,术后12 h的VAS评分明显降低(P0.05);A组术中血管活性药物使用量明显减少,术后低血压和心动过缓发生率明显低于B组(P0.05)。结论超声引导下TTP-PECS用于乳腺癌改良根治术的围术期镇痛效果和安全性优于TPVB。     

胸腰筋膜平面阻滞对老年患者椎体后突成形术后镇痛及免疫功能的影响

目的 探讨超声引导下胸腰筋膜平面（TLIP）阻滞在老年患者椎体后突成形术后镇痛中的作用及对免疫功能的影响。
方法 择期行经皮后入路脊柱后突成形术老年患者100例,男41例,女59例,年龄70～90岁,ASA Ⅱ或Ⅲ级,采用随机数字表法分为两组：TLIP阻滞组（P组）和对照组（L组）,每组50例。P组在超声引导下进行双侧TLIP阻滞,分别在两侧最长肌和髂肋肌之间注射0.375%罗哌卡因15 ml;L组不进行神经阻滞操作。记录麻醉诱导前、术后4、24、48 h T淋巴细胞亚群（CD3⁺、CD4⁺、CD8⁺）含量,计算CD4⁺/CD8⁺比值;记录术后4、12、24、48 h静息和运动时VAS疼痛评分。记录术中及术毕麻醉穿刺相关不良反应,如穿刺部位感染、血肿,局麻药中毒、神经损伤等。
结果 与麻醉前比较,术后4、24、48 h两组CD3⁺、CD4⁺含量和CD4⁺/CD8⁺比值明显升高（P<0.05）。与L组比较,术后4、24、48 h P组CD3⁺、CD4⁺含量明显升高,术后24、48 h P组CD4⁺/CD8⁺比值明显升高,术后4、12、24、48 h P组静息和运动时VAS疼痛评分明显降低（P<0.05）。两组均未见相关不良反应。
结论 在老年患者经皮后入路椎体后突成形术中,超声引导下胸腰筋膜平面阻滞可减轻术后疼痛并改善细胞免疫功能。     

椎管内阻滞用于分娩镇痛的研究进展

背景 椎管内阻滞用于分娩镇痛效果可靠,产妇满意度高,在产科麻醉中已经广泛流行.目的 比较不同椎管内阻滞镇痛的方法,探讨分娩镇痛的前景.内容 描述硬膜外阻滞、硬膜外自控镇痛(patient controlled epidural analgesia,PC EA)、腰硬联合阻滞(combined spinal-epidural analgesia,CSEA)、连续蛛网膜下腔阻滞(continuous spinal anesthesia,CSA)在分娩镇痛中的应用;硬膜外阻滞镇痛对产妇的影响;CSEA与PCEA的比较;CSEA潜在的并发症;CSA的神经系统并发症.趋向 椎管内阻滞是实施分娩镇痛较为理想的方法.但是目前仍然没有一种绝对满意、安全、简单的分娩镇痛方法,有关的内容仍需进一步研究.     

区域阻滞在剖宫产术后镇痛的研究进展

随着加速康复外科理念的广泛普及,超声引导下行区域神经阻滞成为围手术期镇痛的有效方法之一,目前该方法已在剖宫产术后镇痛中广泛应用。文章通过查阅相关研究文献,对腹横肌平面阻滞(transversus abdominis plane block,TAPB)、腰方肌阻滞(quadratus lumborum block,QLB)、髂腹下⁃髂腹股沟神经阻滞(iliohypogastric and ilioinguinal nerve block,IINB)及腹腔内注射局部麻醉等剖宫产术后镇痛常用的几种区域神经阻滞方法的应用效果进行比较,旨在为临床疼痛治疗提供新的方法和思路。     

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 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.     

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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

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.     

Intrathecal administration of sameridine to patients subjected to arthroscopic knee joint surgery

Background: Sameridine, a new substance with both local anesthetic and opioid effects, was administered intrathecally for the first time to humans, i. e. in patients subjected to arthroscopic knee joint surgery.
Method: A dose-escalating (10, 15, 20 and 25 mg), open study was performed in 33 patients. Only two patients were included in the 25 mg group.
Results: Sameridine provided good quality of surgical anesthesia in all patients except those receiving 10 mg. The maximum level of sensory block, Th5–Th7, was reached within 30 min with a median duration of 3.6–3.9 h. The motor block was more profound with increasing dose, but never lasted longer than the sensory block. The influence on heart rate and blood pressure was minor and atropine and ephedrine were needed in four patients. No clinically significant ECG-changes were detected and no arrhythmias were recorded. Oxygen saturation and respiratory rate did not decrease in a clinically significant way and were not affected by concomitant morphine given i. v. postoperatively. There were few side-effects, the most frequent being mild pruritus (10/33).
Conclusion: Sameridine provided clinically adequate anesthesia for the patients receiving the doses of 15, 20 and 25 mg. Further studies are needed to evaluate the substance and it is of great interest to clinically investigate the opioid component with respect to postoperative analgesia.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.