经皮椎体成形术和经皮椎体后凸成形术治疗骨质疏松性椎体压缩骨折

目的:观察经皮椎体成形术(percutaneous vertebroplasty,PVP)和经皮椎体后凸成形术(percutanous kyphoplasty,PKP)治疗骨质疏松性椎体压缩骨折的疗效。方法:2007年10月～2009年4月收治骨质疏松性椎体压缩骨折患者106例,其中61例82个椎体接受PVP治疗,男21例29个椎体,女40例53个椎体,年龄65～96岁,平均78.3岁;45例55个椎体接受PKP治疗,男17例21个椎体,女28例34个椎体,年龄68～90岁,平均77.1岁。术前及术后1d进行疼痛视觉类比评分(VAS),测量伤椎高度,随访伤椎高度丢失情况,记录骨水泥渗漏及随访期间邻近椎体骨折情况。结果:PVP组术前和术后1d VAS分别为6.7±1.4分和2.1±0.7分,PKP组分别为6.9±1.2分和2.2±0.9分,每组术后VAS与术前比较有统计学差异(P<0.05),同时间点组间比较无统计学差异(P>0.05)。PVP组55例、PKP组41例获得随访,随访时间为12～36个月,平均18个月。PVP组和PKP组术后伤椎高度分别较术前增加2.4±1.8mm和9.2±2.2mm,术后12个月随访伤椎高度分别丢失0.8±0.5mm和1.9±0.8mm,两组比较有统计学差异(P<0.05)。PVP组术中骨水泥渗漏28例33个椎体,PKP组15例17个椎体,PKP组骨水泥渗漏率明显低于PVP组(P<0.05)。随访期间PVP组发生相邻椎体骨折9例,PKP组6例,两组相邻椎体骨折发生率无统计学差异(P>0.05)。结论:PVP和PKP治疗骨质疏松性椎体压缩骨折的止痛效果均较好;PKP的复位效果优于PVP,较少发生骨水泥渗漏,但术后椎体高度再次丢失较明显;两者术后相邻椎体骨折发生率无明显差异。     

椎体后凸成形术治疗骨质疏松性椎体压缩性骨折疼痛的疗效分析

目的 评估经皮椎体后凸成形术(PKP)治疗骨质疏松性椎体压缩性骨折(OVCF)的疗效.方法 本组OVCF共468例,采用单球囊双侧扩张PKP治疗,累及T6～L5共608个椎体.其中男性93例120椎, 女性375例488椎,年龄54～94岁,平均68.2岁.单椎体360例,双椎体76例,三椎体32例.采用疼痛视觉类比评分(VAS),止痛药使用评分,活动能力评分,伤椎高度测定及胸腰段脊柱后凸角度等指标评估PKP术的疗效,同时观察并发症.结果 412例(540椎)术后得到6个月～5年随访,平均3.6年.本组术后疼痛明显缓解,术前VAS评分(8.26±0.98)分,术后2天降低到(1.63±0.83)分,末次随访时(1.85±0.89)分(P<0.01).止痛药使用评分由术前的(1.62±0.94)分下降到术后2天的(0.18±0.45)分, 末次随访时(0.21±0.54)分(P<0.01).活动能力评分由术前的(3.15±0.83)分改善到术后2天的(1.41±0.56)分,末次随访时(1.47±0.62)分(P<0.01).术后X线检查,压缩骨折的椎体高度恢复满意,术前椎体前、中份高度分别为(19.39±2.22) mm、(19.19±2.06) mm,术后2天改善到(24.47±2.04) mm、(24.38±1.93) mm,末次随访时(23.88±2.25) mm、(23.57±2.12) mm(P<0.01).胸腰段脊柱后凸Cobb角术前20.28°±4.64°,术后2天12.2°±4.36°,末次随访时13.12°±3.38°(P<0.01).本组73椎(12%)发生骨水泥渗漏,除2例术后出现神经损害表现经对症治疗缓解外,其余均无不适主诉.末次随访时,18例(4.4%)出现疼痛复发或出现新的疼痛,16例(3.9%)出现邻近椎体骨折,再次行PKP治疗.结论 PKP治疗OVCF,是一种安全、复位可靠、止痛效果确切的脊柱微创外科技术.     

经皮椎体后凸成形术联合射频消融术治疗脊柱转移瘤的临床疗效分析

目的 探讨经皮椎体后凸成形术（percutaneous kyphoplasty,PKP）联合射频消融术（radiofrequency ablation,RFA）治疗脊柱转移肿瘤的安全性与临床疗效.方法 2011年1月～2012年3月,对21例脊柱转移瘤28个椎体行PKP联合RFA治疗,采用术前、术后当天、1周视觉疼痛评分（VAS）和患者术前后服用止痛药的剂量对临床效果进行评价.结果 术后疼痛均缓解,术前VAS评分（7.5±0.5）分,术后当天VAS评分（3.0±0.5）分,术后1周VAS评分（4.0±0.5）分,术前后比较有显著性差异（F=446.67,P=0.000）.术中每个椎体填充骨水泥3.0～7.5 ml,平均4.5 ml.术后无皮肤灼伤、血管神经损伤等并发症.1例术后并发肺部感染死亡,余20例均入住肿瘤科行放疗及化疗.20例术后3个月VAS评分（4.5±0.5）分,15例术后6个月VAS评分（5.0±0.5）分.结论 PKP联合RFA对脊柱转移瘤具有良好的止痛效果,增强脊柱的稳定性.     

骨水泥注射微创治疗椎体病理性骨折的治疗体会

目的研究骨水泥注射微创(椎体后凸成形术、经皮椎体成形术)治疗脊柱转移瘤伴病理性骨折中的作用,分析两者疗效的优劣、适应证的选择和并发症的防治。方法选择自2009年8月至2012年9月确诊为脊柱转移瘤致病理性骨折的患者43例(共127个椎体),其中28例(共68个椎体)行经皮椎体成形术(percutaneous vertebroplasty,PVP),15例(共59个椎体)行椎体后凸成形术(percutaneous kyphoplasty,PKP)。术后平均随访16个月(2~24个月),记录患者术前1 d、术后2 d、2周、6个月、12个月的疼痛视觉模拟评分(visual analogue scale,VAS)和患者的生活质量评分(quality of life,QOL),术后椎体后凸矫正率及1年后椎体高度丢失率,术后骨水泥渗漏率,并绘制生存曲线图。结果所有患者术后VAS分数均有不同程度下降,术后2周PVP组平均下降6.5分(4~7分),PKP组平均下降7分(5~8)分;术后1年PVP组平均下降4.5分(3~6分),PKP组平均下降5分(4~6分)。两组术前及术后对比,疼痛缓解率有统计学差异(P0.01),两组间对比无统计学差异(P0.05)。后凸畸形矫正率PKP组和PVP组分别为(68.72±3.23)%和(66.72±4.73)%,术后1年椎体高度再丢失率为(19.23±1.47)%和(21.32±2.68)%,两组对比无统计学差异(P0.05)。PVP组术后发现骨水泥渗漏11例,渗漏率39.2%,PKP组术后发现骨水泥渗漏2例,渗漏率13.3%,均无临床症状。PVP、PKP组术后平均生存期分别为14.5个月(2~24个月)和16个月(3~24个月),所有患者均未发现相邻椎体肿瘤转移情况。结论经皮椎体成形术和椎体后凸成型术同为骨水泥微创注射技术,近远期疗效及生存预后无明显差异,PVP价格低廉且操作简单,但骨水泥渗漏率发生较高,PKP经改良后大大降低骨水泥渗漏的发生,对骨皮质不完整者建议行PKP治疗。椎体骨折较新鲜时(小于2个月),PKP恢复椎体高度可能性大,建议采用,而骨折时间较长者建议行PVP治疗。     

经皮椎体后凸成形术治疗老年骨质疏松性胸腰椎骨折的近期疗效

目的 探讨经皮椎体后凸成形术(PKP)治疗骨质疏松性胸腰椎骨折的安全性和有效性.方法 对32例(34椎)老年骨质疏松压缩性骨折在DSA机监测下行PKP治疗,观察手术操作、术后疼痛、并发症情况.对止痛效果行视觉模糊评分(VAS),测量手术前后椎体前缘和中线高度及Cobb角情况.结果 34椎均获得穿刺成功,手术时间25～90(52±7) min,单椎体注射骨水泥量2.5～5.5(3.7±0.3) ml, 8个椎体有骨水泥轻微渗漏.VAS评分:术前为6.9～9.1(7.8±0.97)分,术后24 h为3.7～4.8(4.2±0.3)分,术后15 d为3.3～4.2(3.5±0.3)分,术前术后比较差异有统计学意义(P<0.05).术后椎体前缘高度恢复(3.9±1.1)mm,椎体中线高度恢复(3.1±0.9)mm,Cobb角矫正5.5°±1.61°,无神经损伤和感染的并发症.结论 PKP治疗骨质疏松的胸腰椎骨折具有微创、止痛效果明确,增加椎体刚度和强度,恢复椎体部分力线等优点,是有效治疗手段.     

新型3D打印个体化人工椎体在脊柱重建中的初步研究

目的探讨新型3D打印个体化人工椎体在脊柱重建中的优势,并对其重建效果进行临床评估。方法收集2017年1月至2018年12月行全椎体切除术后采用3D打印个体化人工椎体行脊柱重建的15例肿瘤患者的临床资料,其中男8例,女7例;年龄(39.5±13.4)岁(范围:20~57岁)。原发肿瘤12例,转移肿瘤3例。依据肿瘤位置及周围软组织侵及范围,采取单纯后路或前后路联合手术方式行全椎体切除,并进行3D打印人工椎体重建。分析手术时间、术中出血量、术后人工椎体稳定情况、与相邻椎体骨长入情况,手术前后神经功能改变情况、疼痛视觉模拟评分(visual analogue scale,VAS),局部控制情况及患者生存情况。结果本组15例的手术时间(412.0±166.1)min(范围:135~740 min);术中出血量(4140.0±3809.3)ml(范围:100~14000 ml);术后随访(23.2±7.0)个月(范围:12~35个月)。术前VAS评分(4.7±1.1)分,术后7 d(1.6±0.6)分,末次随访时(1.0±0.5)分,术后7 d及末次随访较术前的差异均有统计学意义(P<0.001)。术后7 d术前Frankel分级C级的3例逐渐恢复到D级,余12例D级和E级无变化,差异无统计学意义(Z=-1.732,P=0.083);术后末次随访时Frankel分级较术后7 d无明显变化。影像学表现:术后3个月时人工椎体与临近椎体已有初步的骨愈合;术后12个月时人工椎体和邻近椎体有大量骨连接形成,形成骨整合;术后24个月时可见人工椎体与邻近椎体骨整合更加确实。在随访期内人工椎体无松动移位,内固定无断裂失效。术中1例出现胸膜破裂,术后1例发生脑脊液漏,1例出现L5神经根麻痹,积极对症处理后均痊愈。1例血管内皮细胞瘤和1例上皮样血管肉瘤,分别于术后33个月和35个月死亡,1例软骨肉瘤术后16个月局部复发,服用安罗替尼治疗,肿瘤无进展,余12例无肿瘤复发及远处转移。结论利用3D打印个体化人工椎体对脊柱肿瘤切除后重建,有利于精确恢复脊柱连续性,提供更好的界面匹配,利于骨的长入,同时人工椎体植入后即刻及远期稳定性良好,可满足脊柱重建的需要。     

3D打印个体化人工椎体在多节段脊柱肿瘤切除后脊柱稳定性重建中的应用

目的:探讨3D打印个体化人工椎体在多节段脊柱肿瘤切除后脊柱稳定性重建中应用的安全性和有效性。方法:回顾性分析2017年5月～2019年12月在我院行多节段脊柱肿瘤全切并行3D打印人工椎体脊柱稳定性重建的患者9例,其中男性3例,女性6例;年龄25～64岁,平均41.7±10.5岁,随访18.3±11.4个月(6～36个月)。9例均为原发肿瘤:T5～T7骨母细胞瘤术后复发1例,T7～T8上皮样血管肉瘤1例,T10～T11未分化小圆细胞肉瘤1例,T11～L1软骨肉瘤1例,骨巨细胞瘤5例(T6～T8共2例,T2～T3、T4～T5、T11～L1各1例)。依据肿瘤位置及周围软组织侵袭程度,采取单纯后路手术方式8例,前后路联合手术方式1例行多节段全椎体切除,并通过激光选区融化技术构建个体化3D打印人工椎体进行脊柱稳定性重建。记录手术时间、出血量,通过术后X线片(1个月、3个月、6个月、12个月)及CT(6个月、12个月、24个月)定期复查,之后每6个月复查1次。应用BrantiganSteffee脊柱融合分级评估人工椎体稳定性、界面骨融合情况,手术前及术后1周进行Frankel神经功能评分及疼痛视觉模拟(visual analogue scale,VAS)评分。术后定期观察肿瘤是否复发生原位复发、远处转移以及患者生存情况。结果:所有患者均成功接受多节段脊柱肿瘤切除3D打印人工椎体脊柱稳定性重建术,其中2个节段椎体切除4例,3个节段椎体切除5例。患者手术时间433.3±174.6min(235～740min),术中出血量4816.7±3221.2ml(1000～14000ml)。术前的VAS评分4.1±1.1分,术后7d患者的VAS评分1.2±0.4分,差异具有统计学意义(P0.001)。术前Frankel分级为D级的3例患者术后7d时有2例恢复到E级,1例无明显变化,6例E级患者无明显变化。随访期内3D打印人工椎体与邻近椎体匹配情况良好,无松动、下沉及移位,同时未出现断钉、断棒等内固定失败情况。术后6个月,人工椎体与邻近椎体接触紧密,开始出现界面骨长入,术后12个月,人工椎体与邻近椎体出现骨性连接,发生骨性融合。随访期内7例患者无肿瘤复发转移,1例软骨肉瘤患者术后16个月局部复发,安罗替尼治疗后肿瘤无恶化,1例上皮样血管肉瘤患者全身多发转移于术后18个月死亡,患者中位生存期18个月。结论:3D打印个体化人工椎体可以满足多节段脊柱肿瘤切除后脊柱稳定性重建的要求,精确恢复椎体连续性,精准匹配相邻椎体,自身孔隙结构利于骨的长入,是一种多节段脊柱肿瘤切除后理想的脊柱稳定性重建方法。     

两种经皮椎体成形术治疗脊柱转移癌疗效比较

目的比较单纯经皮椎体成形术(PVP)和内固定联合PVP治疗脊柱转移癌的疗效。方法将43例脊柱转移癌患者按治疗方法分为两组,分别采用PVP及内固定联合PVP治疗。术后7 d及术后12个月时采用疼痛视觉模拟评分(VAS)和Oswestry功能障碍指数(ODI)进行疗效比较。结果患者均获得随访,时间24~59个月。术后7 d及术后12个月VAS:PVP组分别为2.70~3.90(3.39±0.44)分、2.00~3.40(2.73±0.57)分,内固定联合PVP组分别为2.60~4.00(3.39±0.54)分、2.10~3.50(2.83±0.56)分;术后7 d及术后12个月时ODI:PVP组分别为19.00~25.50(22.54±2.17)分、24.10~25.67(25.37±0.15)分,内固定联合PVP组分别为19.11~25.52(25.54±2.17)分、22.12~24.42(23.37±0.13)分。两项指标两组比较差异均有统计学意义(P0.05),内固定联合PVP组优于PVP组。术后PVP组l例肿瘤复发,内固定联合PVP组2例肿瘤复发,两组比较差异无统计学意义(P0.05)。结论对脊柱转移癌,尤其是多节段转移患者内固定联合PVP较单纯PVP能更加有效地缓解疼痛,恢复脊柱稳定,提高生活质量。     

经皮椎体后凸成形术治疗创伤性胸腰椎椎体压缩性骨折的近期疗效观察

目的:观察经皮椎体后凸成形术(PKP)治疗50岁以上创伤性胸腰椎椎体压缩性骨折患者的近期疗效.方法:2006年10月～2008年10月收治创伤性胸腰椎椎体压缩性骨折患者36例,男11例,女25例,年龄50～61岁,平均54.5岁,累及T11～L2共36个椎体.均在C型臂X线机引导下行经皮椎体后凸成形术,椎体填充物均应用MIIGX3人工骨.采用疼痛视觉类比评分(VAS)、止痛药使用评分、伤椎高度及胸腰椎后凸角度等指标评估PKP术的近期疗效.结果:所有患者均顺利完成手术,手术时间平均32.5min/椎,出血量平均38.5ml,椎,MIIGX3填充量平均5.0ml/椎,无肺栓塞、MIIGX3渗漏等并发症发生.随访6个月～2年6个月.术前VAS评分平均8.5±0.8分,术后2d时降低到2.2±0.8分,末次随访时为2.5±0.8分;止痛药使用评分由术前的1.8±0.6分下降到术后2d的0.2±0.6分,末次随访时为0.3±0.5分;伤椎椎体前、中柱高度分别由术前的21.5±3.1mm、20.3±2.9mm,改善到术后2d的24.6±2.8mm、24.3±2.1mm,末次随访时为24.4±2.6mm、24.1±2.5mm:脊柱后凸Cobb角术前18.5°±4.5°,术后2d改善为13.5°±3.5°,末次随访时为14.0°±4.5°.各指标术后及末次随访时与术前比较均有显著性差异(P<0.01).影像学复查示术后MIIGX3充填均匀,术后3个月时已基本吸收.为自体松质骨替代.结论:PKP治疗创伤性胸腰椎椎体压缩性骨折是一种安全、复位可靠、止痛效果确切的微创脊柱外科技术.     

胸腰椎转移性肿瘤的手术治疗

目的探讨不同手术方法治疗胸腰椎转移瘤的疗效。方法对25例胸腰椎转移性肿瘤患者,根据术前Tokuhashi评分、肿瘤侵犯的节段、范围和有无神经症状,采取不同的手术方式治疗。术前与术后均对患者的疼痛、脊髓功能进行评估。结果 25例均获得随访,时间5～60个月。患者术后疼痛均较术前减轻或消失,VAS评分:术前平均为(7.2±2.1)分,术后1个月为(2.4±1.5)分,差异有统计学意义(P<0.05)。16例脊髓损伤的患者术后3个月脊髓功能Frankel分级评估:14例分别提高1～2级,2例无改善。骨水泥渗漏6例,未引起临床症状。随访期内未出现骨水泥下沉、松动、椎体塌陷及成角畸。1例术后1年出现原位复发,行二次手术。8例术后6～12个月出现其它节段椎体转移,均带瘤生存,无神经受损症状,未行外科治疗。结论根据患者术前Tokuhashi评分、肿瘤侵犯的节段、范围和有无神经症状采取不同的手术方法治疗,能稳定和重建脊柱稳定性,减轻或缓解疼痛,维持和改善神经功能,从而提高患者生存质量。     

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.     

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.     

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.