脊柱均匀短缩减压治疗脊髓拴系综合征的临床研究

目的探讨脊柱均匀短缩脊髓轴性减压术(homogeneous spinal-shortening axial decompression,HSAD)治疗脊髓拴系综合征(tethered cord syndrome,TCS)的临床疗效。方法自2014年1月~2018年1月采用HSAD术治疗26例TCS患者,术后平均随访(28. 51±4. 81)个月,对患者临床资料及术后疗效进行比较。结果 26例患者均成功完成HSAD术,手术用时(264. 92±32. 94) min,平均失血量(648. 81±107. 21) m L,住院时间(15. 45±2. 65) d,平均手术节段(4. 13±0. 34)个,单节段平均缩短(4. 20±0. 40) mm,脊柱缩短长度(17. 30±2. 01) mm。术后1个月、末次随访的VAS评分、ODI指数、ICI-Q-SF评分均显著低于术前,膀胱安全容量、膀胱顺应性显著高于术前,差异有统计学意义(P0. 05)。术后发生1例切口感染、1例脑脊液漏、1例压疮,无其他并发症发生。结论 HSAD术能通过均匀短缩脊柱对受拴系神经组织进行直接轴性减压,术后功能障碍显著改善,膀胱功能明显改善,是TCS手术治疗的有效方案。     

脊柱截骨术治疗合并脊髓纵裂伴脊髓拴系综合征的先天性脊柱侧凸

目的:探讨脊柱截骨术治疗合并脊髓纵裂伴脊髓拴系综合征的先天性脊柱侧凸的安全性和有效性。方法:回顾性分析2007年6月~2013年6月在我院采用脊柱截骨手术治疗的23例合并脊髓纵裂伴脊髓拴系综合征的先天性脊柱侧凸患者。其中男6例,女17例;手术时年龄16.9±3.4岁(10~23岁)。腰骶部疼痛8例,其中5例仅表现为腰骶部疼痛,神经功能损害18例。术前冠状位Cobb角95.4°±25.2°(65°~156°)。Ⅰ型脊髓纵裂9例,Ⅱ型脊髓纵裂14例。脊髓圆锥位置均在L3水平以下。对合并Ⅰ型脊髓纵裂伴脊髓拴系的患者,采用骨性纵隔切除、一期脊柱截骨矫形;合并Ⅱ型脊髓纵裂伴脊髓拴系的患者单纯行一期脊柱截骨矫形(未处理纤维纵隔)。其中行全脊椎截骨13例,经椎弓根截骨10例。术前、术后3个月和末次随访时分别测量患者侧凸Cobb角,并按脊柱裂神经功能评分(SBNS)分级评估神经功能恢复情况。结果:手术时间571.1±136.5min(310~835min);术中失血量4888.3±2482.3ml(500~9600ml)。随访38.9±18.3个月(24~79个月)。术后冠状面Cobb角33.7°±15.9°(3°~73°),较术前明显改善(P0.05),矫正率平均为(62.3±14.1)%;末次随访时冠状面Cobb角37.4°±17.2°(5°~82°),矫正率平均为(58.1±14.7)%,较术后平均丢失4.2°±2.3°,与术后比较无明显矫形丢失(P0.05),但与术前相比有明显改善(P0.05)。末次随访时,18例患者神经损害症状获得不同程度改善,其中13例术前SBNS神经功能分级为Ⅱ级者术后恢复至Ⅰ级;2例Ⅲ级恢复至Ⅱ级;另外3例神经损害评分提高,SBNS分级维持不变,脊柱侧凸畸形及局部疼痛明显好转。围手术期出现并发症5例,其中2例术后出现单侧下肢肌力下降,1例术后2周下肢肌力恢复至4级,另1例于术后3个月恢复至术前水平,术后2年随访肌力基本恢复正常;术中发现胸膜破裂1例,术后脑脊液漏1例、泌尿系感染1例。所有病例术后无伤口感染、假关节形成、内固定松动/断裂及永久性神经损害并发症。结论:脊柱截骨术治疗合并脊髓纵裂伴脊髓拴系综合征的先天性脊柱侧凸患者安全有效,且对神经功能恢复有促进作用。     

术中应用超声乳化治疗脂肪瘤型脊髓拴系综合征

目的：探讨术中应用超声乳化治疗脂肪瘤型脊髓拴系综合征的疗效。方法：自2001年3月收治脂肪瘤型脊髓拴系综合征患者32例．术中均采用超声乳化切除脂肪瘤，临床上采用Hoffman功能性分级．术前及随访时均行电生理检查，对15例尿失禁患儿行尿动力学检查．随访观察治疗效果。结果：全部病例随访6～53个月．平均27个月。临床上Hoffman分级无加重，体感诱发电位（somatosensory evoked potential，SEP）明显改善（P〈0．05），伴尿失禁患者尿动力学主要参数亦均有显著性改善（P〈0．01）。结论：应用超声乳化治疗脂肪瘤型脊髓拴系综合征可取得较好治疗效果。     

成人与儿童脊髓拴系综合征的临床特点及手术疗效对比分析

[目的]通过分析、总结成人与儿童脊髓拴系综合征的临床特点,比较、分析二者的手术疗效。[方法]回顾分析2003年10月~2012年3月就诊于东直门医院骨科的76例脊髓拴系综合征患者,儿童组47例(年龄18岁),年龄8个月~17岁,平均(8.18±5.3)岁;成人组29人(年龄≥18岁),年龄18~54岁,平均(31.59±11.79)岁。所有患者术前均行影像学和尿流动力学检查(婴幼儿除外)。手术疗效通过患者术前、术后2周、术后3个月及末次随访的神经症状评分进行评估,平均随访时间(60±62)个月。[结果]疼痛是成人组患者最常见的主诉,存在严重神经障碍的患者很少。括约肌功能失调是儿童组患者最常见的主诉。儿童组47例中有44例接受了手术治疗,成人组29例中有24例接受了手术治疗。所有患者术后神经症状的稳定状态都得到了明显改善,儿童组患者术后括约肌功能改善显著,而成人组患者术后疼痛改善更明显。总体来看,两组患者术后3个月、末次随访时神经功能评分分别与术前比较,差异均有统计学意义(P0.01)。[结论]儿童脊髓拴系综合征患者一经发现应尽快手术治疗,以防止症状出现和(或)加重。对于神经症状不断发展的成人患者,建议行手术治疗,手术可有效缓解疼痛并延缓神经症状的进展,但手术治疗应慎重,尤其是伴有脂肪瘤和神经管囊肿的复杂成人脊髓拴系综合征患者,应特别注意手术方式及手术策略,由经验丰富的脊柱外科医生完成。同时,建议不存在神经症状的成人患者保守治疗,以保持长期、稳定的神经状态。     

建立人工膀胱反射弧治疗脊髓损伤后神经原性膀胱的临床研究

【摘要】目的：观察利用脊髓正常反射通路重建人工膀胱反射弧恢复脊髓损伤后神经原性膀胱功能的临床疗效。方法：对36例完全性脊髓损伤（ASIA分级A级）患者行人工膀胱反射弧重建,其中28例脊髓圆锥上脊髓损伤患者（痉挛性膀胱）,切断并显微吻合单侧S1前根与支配膀胱最强的神经根（一般为S2或S3）前根;8例脊髓圆锥损伤患者（弛缓性膀胱）采用腓肠神经移植并显微吻合T10/T11神经根前根及支配膀胱最强的神经根前根。通过对34例（2例痉挛性膀胱患者死亡）患者术前、术后6、12、18个月随访并行尿流动力学检查（无菌生理盐水灌注速度25ml/s）,评估痉挛性和弛缓性膀胱功能恢复情况。两种不同类型的神经原性膀胱患者均选其具有代表意义的尿流动力学检查指标,整理数据后进行统计学分析。结果：26例痉挛性膀胱患者,最大膀胱测压容积术后3个时间点间比较差异无显著性（P＞0.05）,但与术前比较均有显著性差异（P＜0.05）;残尿量、膀胱顺应性不同时间点间比较两两均有显著性差异（P＜0.05）。8例弛缓性膀胱患者,最大膀胱测压容积术后与术前比较差异无显著性（P＞0.05）;残尿量由术前的495.1±56.6ml降至术后18个月时的264.4±30.8ml,且术后不同时间点与术前比较均有统计学意义（P＜0.05）;最大逼尿肌压力由术前的6.3±3.9cmH2O升高到术后18个月时的82.9±4.3cmH2O,且术后3个时间点与术前比较差异均有显著性（P＜0.05）。未发现一例通过搔抓下腹部皮肤引起排尿。结论：利用脊髓正常反射通路重建神经原性膀胱人工反射弧改善膀胱功能是可行而有效的方法。     

分期手术治疗先天性脊柱侧凸合并脊髓纵裂和脊髓拴系的安全性与近期疗效

目的:评估分期手术治疗先天性脊柱侧凸合并脊髓纵裂和脊髓拴系患者的安全性与近期疗效。方法 :回顾性分析我院2009年1月~2014年1月收治的66例先天性脊柱侧凸合并脊髓纵裂和脊髓拴系患者的临床资料。其中男20例,女46例,年龄17.2±4.5岁(7~26岁)。5例患者术前存在下肢神经功能障碍。脊柱侧凸冠状位主弯Cobb角97.6°±23.5°(50°~165°),主弯位于颈胸段1例,胸段58例,胸腰段7例。23例同时存在矢状位后凸畸形,Cobb角89.5°±13.9°(47°~165°)。伴有Ⅰ型脊髓纵裂45例,Ⅱ型脊髓纵裂21例,均合并脊髓拴系。所有患者均行分期手术治疗:Ⅰ型脊髓纵裂组患者一期切除骨性分隔、松解脊髓拴系,Ⅱ型脊髓纵裂组患者一期松解脊髓拴系;一期术后3~4周,二期行侧凸矫形手术。结果:一期手术时间208.7±107.2min(60~505min),术中出血量297.1±192.6ml(20~2000ml);二期手术时间392.6±150.7min(196~600min),术中出血量2158.8±1158.4ml(450~6000ml)。术前存在下肢神经功能障碍的5例患者中,1例术后下肢肌力提高2级,感觉功能有所恢复;其余4例术后神经功能无明显变化。2例术前神经功能正常患者二期术中出现脊髓损伤(3.0%,2/66),其中1例术后双下肢肌力降为4级,感觉稍减退,术后1周感觉、运动功能完全恢复正常;另1例术后双下肢肌力降低至2级,双下肢及会阴部感觉减退,经脱水、激素冲击治疗及高压氧治疗,术后1个月双下肢肌力恢复至3级,术后2年随访时双下肢肌力恢复至4级,双下肢残留轻度麻木感,大小便功能正常。4例(6.1%,4/66)患者二期术后并发胸腔积液。均获得随访,随访时间12.4±3.5个月(6~24个月)。随访期间未发现椎弓根螺钉松动及断裂现象。脊柱侧凸矫形术后冠状位Cobb角为41.6°±17.8°(12°~107°),矫正率为(61.3±14.3)%;末次随访时冠状位Cobb角为43.7°±16.6°(15°~108°),丢失率为(1.9±1.1)%。术后矢状位后凸Cobb角为38.4°±11.0°(2°~78°),矫正率为(67.6±23.4)%,末次随访时矢状位Cobb角为39.7±11.2°(3°~87°),丢失率为(2.3±1.3)%。结论:分期手术治疗合并脊髓纵裂和脊髓拴系的先天性脊柱侧凸具有较高的手术安全性,并可获得较满意的矫形效果。     

骶神经前根电刺激治疗脊髓损伤患者排尿功能障碍

目的 探讨骶神经前根电刺激在脊髓损伤患者排尿功能障碍治疗中的应用及疗效.方法 总结2005年10月收治1例C6-7损伤后1年的完全性截瘫男性患者资料,患者留置尿管,尿动力学检查显示膀胱容量约200 ml,存在逼尿肌反射亢进,逼尿肌压力达90 cm H2O,膀胱顺应性降低,约为15 ml/cm H2O.气管插管全麻后行骶神经前根电刺激仪植入及骶神经后根切断术.结果 手术顺利,无手术并发症.术后1个月患者使用电刺激器控制排尿、排便良好,术后随访15个月,尿动力学检查显示膀胱容量增加到500 ml,膀胱顺应性正常,＞20 ml/cm H2O,膀胱依靠电刺激仪排尿良好.剩余尿30 ml.结论 骶神经前根电刺激技术+骶神经后根切断术对于骶髓以上的脊髓损伤造成的排尿功能障碍有较好的疗效.     

神经电生理监测在儿童脊髓拴系综合征显微外科手术中的应用及意义

目的:探讨神经电生理监测在儿童脊髓拴系综合征显微外科手术中应用的意义 . 方法:回顾性分析2005年～2011年收治的105例小儿脊髓拴系患者的临床资料.所有患者在显微镜辅助下行脊髓探查及拴系松解术,其中49例(2008年后病例)行术中电生理监测(A组),56例未进行电生理监测(B组).统计两组患者术后并发症发生及治疗情况并进行统计学分析,术后6个月随访了解患者大小便功能、下肢感觉运动功能及神经电生理恢复情况,疗效评定采用Hoffman分级标准,比较两组患者的拴系完全松解(脊髓末端与周围无粘连,术中脊髓末端上升)率及治疗的有效率.结果:105例患者均顺利完成手术,A组患者术后无下肢瘫痪发生,仅出现大小便失禁2例,脑脊液漏4例;而B组患者术后出现下肢瘫痪5例,大小便失禁8例,脑脊液漏8例,发生率均明显高于A组(P＜0.05);术后92例患者得以随访,时间为6个月～5年,平均2.5年,A组手术完全松解37例,松解率为75％,有效率为70％;B组完全松解36例,松解率为64％,与A组相比有显著性差异(P＜0.05),有效率为58％,与A组比较也具有显著性差异(P＜0.05).结论:显微外科手术配合神经电生理监测可明显降低儿童脊髓拴系综合征术后并发症,提高拴系完全松解率及改善中短期神经功能恢复情况.     

乙状结肠膀胱扩大术治疗神经原性低顺应性膀胱10例报告

目的探讨乙状结肠膀胱扩大术治疗神经原性低顺应性膀胱的疗效。方法采用乙状结肠膀胱扩大术治疗10例神经原性低顺应性膀胱患者。男6例,女4例。年龄4～32岁,平均16岁。病程4～20年。其中脊髓栓系综合征8例,脊髓损伤2例。术前均未接受过骶神经根切断和膀胱手术。有膀胱输尿管返流者同时作返流侧输尿管膀胱再植术。术后不能自行排尿或剩余尿量>50 ml者辅以间歇性清洁导尿。结果术后随访11～57个月。术前漏尿者10例,术后仅3例仍有漏尿,但程度明显减轻。血肌酐(SCr)由(263.8±109.8)μmol/L降至(113.1±23.2)μmol/L(P< 0.01),膀胱容量由(61.9±37.7)ml增至(373.0±88.1)ml(P<0.01),储尿期最大逼尿肌压力由(54.2±44.8)cm H2O(1 cm H2O=0.098 kPa)降至(17.7±10.6)cm H2O(P<0.01)。有膀胱输尿管返流者由9例17侧减少至1例1侧。需长期间歇性清洁导尿者4例,其中1例因未按时进行间歇性清洁导尿者导致代谢性酸中毒。按时间歇性清洁导尿后治愈。菌尿10例,其中1例需抗生素治疗。结论乙状结肠膀胱扩大术是治疗神经原性低顺应性膀胱的有效方法,能改善患者肾功能,提高患者生活质量。     

颈前路单cage植骨融合联合钢板内固定治疗无骨折脱位颈脊髓损伤

目的探讨颈前路单cage植骨融合联合钢板内固定治疗无骨折脱位颈脊髓损伤的临床疗效。方法采用颈前路单cage植骨融合联合钢板内固定治疗63例无骨折脱位颈脊髓损伤患者。比较术前、术后3周和末次随访的ASIA评分。结果患者均获得随访,时间4~60个月。ASIA评分:术前为(48.15±17.23)分,术后3周为(61.42±17.34)分,末次随访为(64.11±16.93)分;术后3周、末次随访与术前比较差异均有统计学意义(P0.05),末次随访与术后3周比较差异无统计学意义(P0.05)。患者融合节段3~12个月均获得良好骨性融合,影像学复查显示减压充分、内固定位置良好。患者均无神经、血管损伤,均无cage移位、沉陷及钢板松动、移位、断裂等并发症。结论颈前路单cage植骨融合联合钢板内固定是治疗无骨折脱位颈脊髓损伤较为理想的方法。     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.     

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.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.