经皮椎体后凸成形术治疗骨质疏松性椎体压缩性骨折

目的评价球囊扩张椎体后凸成形术治疗老年骨质疏松椎体压缩性骨折的疗效和安全性。方法自2008年8月至2011年7月采用椎体后凸成形术治疗老年骨质疏松脊柱压缩骨折30例42椎,患者均有腰背部疼痛。取俯卧位调节手术床使椎体骨折部位过伸,达到满意的闭合复位后,经皮双侧或单侧椎弓根穿刺球囊扩张,填充骨水泥。随访观察患者的疼痛、日常功能以及影像学改变情况。根据术前和术后侧位X线片测量椎体高度、后凸畸形角度,进行统计学分析。利用Oswestry评分、视觉模拟评分（visualanaloguescale,VAS）评定临床疗效。观察有无骨水泥渗漏等并发症。结果术后随访6～24个月,平均10个月。术后伤椎处疼痛均明显缓解,VAS评分从术前平均（8．45±0．48）分降至术后平均（2．45±0．52）分,椎体高度明显恢复,后凸畸形得到矫正。随访期间疗效满意,伤椎高度无明显丢失。未出现严重的骨水泥渗漏并发症。术后椎体高度及伤椎后凸角度与术前比较有统计学差异（P〈0．05）,术后VAS及Oswestry评分与术前比较有统计学差异（P〈0．01）。结论球囊扩张椎体后凸成形术治疗骨质疏松脊柱压缩性骨折,能有效恢复椎体高度和矫正后凸畸形,能迅速缓解疼痛,减少骨折并发症,提高患者生活质量。     

临时单侧经皮椎弓根螺钉撑开联合PKP治疗椎体后壁破裂骨质疏松椎体压缩骨折

目的:评价临时单侧椎弓根螺钉撑开结合椎体后凸成形术治疗伴椎体后壁破裂的骨质疏松椎体压缩骨折的疗效。方法:选择我院2012年1月~2014年12月收治的35例单节段伴椎体后壁破裂且无神经功能损害的骨质疏松椎体压缩骨折患者,女性30例,男性5例,年龄55~80岁(平均65.5±7.13岁)。损伤节段从T11~L4共35个骨折椎体。均采用术中临时单侧椎弓根螺钉撑开,结合球囊扩张椎体后凸成形术治疗,随访观察治疗效果。影像学观测术前、术后伤椎Cobb角及椎体高度变化情况,采用视觉模拟评分(vasual analogue scale,VAS)、Oswestry功能障碍指数(Oswestry disability index,ODI)评价患者手术前后的疼痛和功能状况以判断临床疗效。结果:手术时间平均78.33±13.94min,每个病椎注入骨水泥量平均5.10±1.13ml。术中出血平均18.80±5.29ml。术中有2个椎体出现骨水泥渗漏,渗漏方向为椎体侧方1例,椎间隙1例,均无椎管内渗漏。术后随访12~24个月(平均15±5.50个月)。术前伤椎Cobb角为16.25°±6.50°,伤椎前缘高度为0.62±0.17,伤椎中央高度为0.63±0.09;末次随访时分别为12.26°±5.14°,0.71±0.11和0.70±0.14,较术前明显改善(P0.05);术前VAS为8.03±1.61分,ODI为0.73±0.17;末次随访时分别为0.60±0.74分和0.10±0.04,较术前明显改善(P0.05)。结论:伴有椎体后壁骨折的骨质疏松椎体压缩骨折,应用经皮邻椎临时椎弓根螺钉撑开结合椎体后凸成形术治疗,恢复椎体高度满意,骨水泥渗漏发生率低,可获得良好的临床疗效。     

单侧椎弓根穿刺椎体后凸成形术治疗骨质疏松性椎体压缩骨折

目的评价单侧椎弓根穿刺椎体后凸成形术治疗骨质疏松性椎体压缩骨折的临床效果.方法2005年5月～2007年7月应用SKY骨扩张器系统行单侧椎弓根穿刺椎体后凸成形术治疗30例骨质疏松性椎体压缩骨折患者,男10例,女20例;年龄58～86岁,平均70.2岁.患者均有腰背部疼痛,共34个椎体骨折,其中单椎体26例,两个椎体4例,骨折部位T8～L3.随访观察患者的疼痛、日常功能以及影像学改变情况.结果有2例共2个椎体出现骨水泥渗漏,但均未出现临床症状,无其他并发症发生.术后患者腰痛均明显缓解,随访7～28个月,平均12个月,术前VAS评分8.48±0.50分,术后1周时为2.50±0.54分,末次随访时为2.85±0.34分;Oswestry评分术前为58.00±1.93分,术后为31.00±1.88分,末次随访时为35.00±1.51分;椎体前缘高度术前平均为14.70±1.27mm,术后1周时为24.40±0.90mm,末次随访时为21.50±0.37mm;伤椎后凸角度术前平均为30.50°±1.24°,术后1周时为11.00°±1.07°,末次随访时为13.50°±0.49°.各指标术后及末次随访时与术前比较有显著性差异(P＜0.01或P＜0.05),而末次随访时与术后1周时比较无显著性差异(P＞0.05).患者均在术后1个月内恢复受伤前的生活.结论单侧椎弓根穿刺SKY骨扩张器系统椎体后凸成形术可有效恢复骨质疏松性骨折椎体的高度,迅速缓解疼痛,改善患者的生活质量.     

球囊扩张椎体后凸成形术治疗骨质疏松性脊柱压缩性骨折

目的探讨球囊扩张椎体后凸成形术治疗骨质疏松性椎体压缩性骨折的初步疗效及安全性。方法自2004年12月至2006年5月,采用球囊扩张椎体后凸成形术治疗骨质疏松性椎体压缩性骨折16例,24个伤椎,均经单侧椎弓根置入可扩张球囊使骨折塌陷椎体复位,然后使用骨水泥充填椎体,观察术后症状改善及骨折复位情况。结果16例手术均顺利,疼痛于术后48h内均明显缓解并可下床活动,患者4~12d内出院。随访6~18个月,平均11个月。平均VAS评分由术前(8.5±0.3)分到术后(2.1±0.2)分和最终随访(2.3±0.3)分(P<0.01);Oswestry功能评分由术前(43±1.32)分到术后(21±1.29)分和最终随访(22±1.25)分(P<0.01);手术椎体前中柱平均高度由术前(14.8±2.8)mm到术后(24.3±2.1)mm和最终随访(24.4±1.9)mm(P<0.05);cobb角平均由术前23.2°±4.6°到术后10.3°±3.1°和最终随访10.2°±4.3°(P<0.05);1例发生骨水泥渗漏,但无严重的并发症。结论球囊扩张椎体后凸成形术可有效恢复骨质疏松性椎体压缩性骨折椎体的高度,缓解疼痛,改善患者的功能,明显减少骨水泥的渗漏,是一种安全、有效的治疗方法。     

单球囊单侧和双侧扩张椎体后凸成形术临床疗效评价

摘要：目的评价单球囊单侧和双侧交替扩张椎体后凸成形术治疗骨质疏松性压缩骨折的临床效果。方法2010年4月至2011年5月应用单球囊单侧和双侧交替扩张椎体后凸成性术治疗骨质疏松性压缩骨折患者2l例21椎,分为单侧球囊扩张组12椎和双侧球囊扩张组9椎,两组均经椎弓根入路,分别采用单球囊单侧扩张和双侧交替扩张的方法。比较两组术前、术后的椎体压缩率,术前、术后VAS评分,术后骨水泥左右侧分布面积比值。结果患者术后疼痛均明显减轻或消失。单侧组VAS评分由术前平均7．17±1．12分改善为术后平均2．67±0．89分,双侧组由术前平均7．50±0．85分改善为3．11±0．60分;单侧组椎体压缩率由术前平均32．3％±12．6％矫正为术后平均27．8％±13．1％,双侧组由术前平均32．9％±15．5％矫正为术后平均28．2％±14．2％;单侧组术后左、右侧骨水泥分布面积比值平均为0．96±0．16,双侧组比值平均为0．98±0．15,均无统计学差异（P〉0．05）。结论椎体后凸成形术能有效缓解椎体骨质疏松性压缩骨折患者的疼痛,不同程度恢复椎体高度,改善后凸畸形;单球囊单侧和双侧交替扩张椎体后凸成形术同样使压缩骨折的椎体获到较好复位。     

单球囊双侧扩张椎体后凸成形术的探讨

目的探讨单球囊双侧扩张椎体后凸成形术治疗老年骨质疏松性脊柱压缩骨折的临床疗效。方法2002年3月～2004年2月,采用单球囊双侧扩张椎体后凸成形术治疗老年骨质疏松性脊柱压缩骨折15例17椎,男6例6椎,女9例11椎;年龄62～83岁,平均70.5岁。T12 8椎,L1 7椎,T8 1椎,T11 1椎。术前CT显示椎体后壁均完整。MRI显示骨折椎体在T1WI呈低信号,T2WI呈高信号。经骨密度仪测定证实脊椎均存在不同程度的骨质疏松,平均骨密度为0.603g/cm2。结果所有患者术后疼痛均明显减轻,疼痛视觉模拟数字评分由术前平均8.3分降至术后平均2.1分。平均椎体前缘高度恢复54.2%±34.1%,中部恢复60.5%±35.4%,后缘恢复40.7%±32.3%。矢状面排列改善明显。手术前后侧位X线片示Cobb角平均改善9.5°(0°～28°)。平均灌注骨水泥5.9ml(3.5～7.8ml)。除1个椎体前缘有少许未引起临床症状的骨水泥渗漏外,其余椎体在X线片上均无明显骨水泥渗漏。所有患者均获得随访,随访时间2～48个月,平均10.5个月,未发现与手术有关的并发症出现。结论单球囊双侧扩张椎体后凸成形术治疗老年骨质疏松性脊柱压缩骨折可以有效缓解疼痛,恢复椎体高度,改善椎体矢状面排列,疗效满意。     

“蛋壳”技术在经皮球囊扩张后凸成形术治疗严重骨质疏松性椎体压缩骨折中的应用

目的 探讨蛋壳技术在经皮球囊扩张后凸成形术治疗老年严重骨质疏松性椎体压缩骨折的可行性和疗效.方法 分析从2009年6月-2013年12月,采用蛋壳技术在经皮球囊扩张后凸成形术治疗老年人严重胸腰椎骨质疏松性压缩骨折43例46个椎体.局麻/全麻下经后路单侧椎弓根穿刺置入病椎,球囊缓慢扩张椎体,小剂量(0.5～1.0 mL)骨水泥注入撑开的空腔,再次插入球囊并撑开椎体高度,使之形成一薄的骨水泥蛋壳,撤出球囊,再次注入骨水泥填充.观察患者的视觉疼痛模拟评分(VAS)、活动能力评分、椎体高度测量及Cobb's角测量.结果 所有手术都顺利完成,无严重手术并发症.VAS评分由术前的(7.9±0.8)分下降至术后的(3.5±0.8)分(P＜0.05),活动能力评分由术前的(3.5±0.6)分改善到术后的(1.3±0.4)分(P＜0.05),椎体高度由术前的(13.5±2.0) mm增加到术后的(31.2±1.5) mm(P＜0.05),Cobb's角由术前的(31.8°±6.9°)矫正到术后的(18.2°±5.8°)(P＜0.05),差异均有统计学意义.所有患者门诊随访1～5个月,平均3.8个月,未出现椎体压缩、新发和相邻节段的骨折,临床表现明显改善.结论 蛋壳技术在经皮球囊扩张椎体后凸成形术中的应用是治疗老年严重骨质疏松性椎体压缩骨折的一种快速有效方法,具有可行性.     

单侧椎弓根穿刺椎体后凸成形术治疗高龄骨质疏松性椎体压缩骨折

目的评估单侧椎弓根穿刺椎体后凸成形术治疗高龄骨质疏松性椎体压缩骨折的临床效果。方法 2002年5月-2008年10月应用Kyphon球囊扩张系统行单侧椎弓根穿刺椎体后凸成形术治疗13例80岁以上的骨质疏松性椎体压缩骨折患者,男2例,女11例;年龄80～87岁,平均83.2岁。患者均有腰背部疼痛,共17个椎体骨折。随访观察患者的疼痛以及影像学改变情况。结果术后患者疼痛均明显缓解,术前VAS评分为(8.8±1.6)分,术后24h为(2.2±1.3)分,随访期末为(2.3±1.5)分,术前与术后24h比较差异有统计学意义(P0.05),术后24h与随访期末比较差异无统计学意义(P0.05);椎体前缘高度术前平均为14.60±1.25mm,术后244h为23.30±0.92mm,末次随访时为22.50±0.35mm;伤椎后凸角度术前平均为30.40±1.75°,术后24h为12.30±1.10°,末次随访时为13.51±0.50°。术后及末次随访时与术前比较有显著性差异(P0.05)。结论单侧椎弓根穿刺椎体后凸成形术治疗高龄骨质疏松性椎体压缩骨折可显著缓解疼痛、有效恢复骨折椎体的高度,是一种安全有效的治疗方法。     

椎体后凸成形术治疗骨质疏松性椎体压缩骨折

目的探讨单球囊扩张椎体后凸成形术治疗老年骨质疏松性脊柱压缩骨折的临床疗效。方法采用单球囊双侧扩张椎体后凸成形术治疗老年骨质疏松性脊柱压缩骨折8例17椎,均为新鲜骨折,腰背部疼痛剧烈,无神经症状及体征。术前CT显示椎体后壁均完整。MRI显示骨折椎体在T1WI呈低信号,T2WI呈高信号。在X线C形臂透视下,采用经皮经椎弓根穿刺,在伤椎内先后植入同一枚球囊,扩张使椎体复位后,将含钡骨水泥注入椎体扩张所形成的空腔内。结果所有患者术后疼痛均明显缓解或消失。平均椎体前缘高度恢复50·2%±12·1%。平均灌注骨水泥5·8mL(4·5~7·6mL),1例椎体前缘发生骨水泥渗漏,未引起临床症状。所有患者均获得随访,随访时间6~48个月,平均14·5个月,未发现与手术有关的并发症出现。结论单球囊扩张椎体后凸成形术治疗老年骨质疏松性脊柱压缩骨折可以有效缓解疼痛,恢复椎体高度,疗效满意。     

球囊扩张椎体后凸成形术治疗骨质疏松性椎体压缩骨折

目的:探讨球囊扩张椎体后凸成形术治疗骨质疏松性压缩骨折的疗效和安全性.方法:2006年6月至2009年8月采用球囊扩张椎体后凸成形术治疗26例骨质疏松性椎体压缩骨折,男10例,女16例;年龄59～78岁,平均70岁.T114椎、T1210椎、L112椎、L23椎、L41椎.观察椎体高度恢复、患者疼痛视觉模拟评分及并发症情况.结果:本组26例术后疼痛均得到有效控制,VAS评分由术前的平均(8.6±0.2)分下降为(2.0±0.3)分;手术前后椎体前缘高度分别为(18.34±3.25) mm和(20.51±1.34) mm(P＜0.05),中线高度分别为(14.36±2.56) mm和(19.66±1.28) mm(P＜0.05).未发生骨水泥渗漏到椎管现象.结论:球囊扩张椎体后凸成形术治疗骨质疏松性压缩骨折可有效恢复椎体的高度,缓解疼痛,改善患者的脊柱功能.     

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.