Lenke 1A型青少年特发性脊柱侧凸后路选择性胸弯融合术后远端附加现象的长期随访研究

目的 探讨Lenke 1A型青少年特发性脊柱侧凸（adolescent idiopathic scoliosis，AIS）行后路选择性胸弯融合术后出现远端附加现象的长期随访结果。方法 回顾性分析2010年1月至2017年6月于我院行后路选择性胸弯融合术治疗的114例Lenke 1A型AIS病人的病例资料，筛选出术后出现远端附加现象病人共21例（18.4%），其中男4例，女17例。测量发生远端附加现象病人在术后即刻、发生远端附加现象时、术后1年、术后2年与末次随访的站立位脊柱全长正位片，对比上述时间节点的冠状面平衡、远端Cobb角、远端固定椎（lowest instrumented vertebra，LIV）下位椎间隙冠状面成角、LIV下位椎体偏离骶骨中垂线（center sacral vertical line，CSVL）距离、双肩高度差（shoulder height difference，SHD）、T₁倾斜角、锁骨角等影像学参数。评估远端附加现象发生后的长期随访变化。结果 21例出现远端附加现象的病人均获完整随访，随访时间为（64.7±3.2）个月（61~68个月）。19例病人（90.5%）于术后6个月内出现远端附加现象，余2例（9.5%）在术后1年随访时出现。2例病人均采用支具治疗后好转。本组病人中无再手术病例。病人在发生远端附加现象时的肩平衡参数（SHD、T₁倾斜角及锁骨角）较术后即刻时显著降低，差异有统计学意义（P＜0.05）。对比发生远端附加现象时、术后1年、术后2年及末次随访时，病人的影像学参数无明显变化（P＞0.05）。结论 Lenke 1A型AIS选择性胸弯融合术后远端附加现象多在术后6个月内发生，发生远端附加现象时病人的肩平衡参数与术后有显著差异。长期随访表明远端附加现象多数进展缓慢，长期随访相对稳定，而对于出现进展的远端附加现象可采用支具保守治疗。     

Lenke 5C型青少年特发性脊柱侧凸病人弯型特征及矫形疗效的性别差异

目的 探讨不同性别间Lenke 5C型青少年特发性脊柱侧凸（AIS）病人弯型特征及矫形疗效的差异。方法 回顾性分析2014年1月至2019年12月接受后路选择性胸腰椎融合术且有2年以上完整随访资料的Lenke 5C型AIS病人70例,男性组20例,女性组50例。对两组病人术前、术后即刻及末次随访时的胸腰弯/腰弯Cobb角、胸弯Cobb角等冠状面参数,胸椎后凸角（TK）、腰椎前凸角（LL）、近端交界性后凸角（PJA）等矢状面参数及脊柱侧凸研究学会-22简明量表调查问卷（SRS-22）评分进行比较分析。结果 男性组不典型弯型的比例高于女性组（20% vs. 12%）,但组间差异无统计学意义（P＞0.05）。女性组和男性组的胸腰弯/腰弯Cobb角、胸弯Cobb角均较术前显著改善,且两组病人术后即刻和末次随访时的胸弯Cobb角比较,差异有统计学意义（P＜0.05）。两组术后胸腰弯/腰弯矫正率分别为70.6%±12.9%和72.6%±17.9%,末次随访时两组的矫正丢失率分别为5.3%±15.8%和7.6%±15.7%。女性组术前的TK明显低于男性组（19.2°±7.0° vs. 24.5°±14.5°）,术前和术后即刻的矢状面平衡（SVA）均大于男性组,差异有统计学意义（P＜0.05）。末次随访时,男性组的近端交界性后凸（PJK）发生率高于女性组（30% vs. 16%）,但差异无统计学意义（P＞0.05）。男性组在SRS-22量表疼痛维度上的得分显著高于女性组［（4.8±0.2）分 vs. （3.9±0.5）分］,差异有统计学意义（P＜0.05）。结论 男性Lenke 5C型AIS病人中表现为左胸弯右腰弯的不典型弯型的比例稍高于女性,女性病人的术前和术后即刻的SVA大于男性,但均可获得良好的长期矫形疗效。     

Lenke 1型青少年特发性脊柱侧凸病人矫形术后肩平衡的相关因素分析

目的 探讨术前右肩高Lenke 1型青少年特发性脊柱侧凸（adolescent idiopathic scoliosis,AIS）病人术后的肩关节高度变化,并分析术后肩平衡的影响因素。方法 回顾性分析2015年1月至2017年12月于我院手术治疗的术前右肩高Lenke 1型AIS病人41例,根据术后肩部平衡状态分为双肩平衡组和双肩失衡组。分别测量两组病人术前、术后3个月及术后2年的影像学肩关节高度差（radiographic shoulder height,RSH）、上胸弯Cobb角、主胸弯Cobb角、锁骨角、胸廓锁骨角度差（clavicle chest cage angle difference,CCAD）和T₁倾斜角,并计算主胸弯矫正率、上胸弯矫正率、主胸弯柔韧度、上胸弯柔韧度等;分析双肩失衡组病人末次随访时RSH与术前影像学指标的相关性。结果 双肩失衡组术前的锁骨角和CCAD值均高于双肩平衡组,上胸弯柔韧度低于双肩平衡组（P＜0.05）。Pearson相关分析显示术前锁骨角、CCAD与术后RSH呈正相关（P＜0.05,r＞0）;上胸弯柔韧度与术后RSH呈负相关（P＜0.05,r＜0）;锁骨角变化、主胸弯及上胸弯矫正率、主胸弯角度变化与RSH变化呈正相关（P＜0.05,r＞0）。Logistic回归分析未见双肩失平衡的独立危险因素。结论 术前锁骨角、CCAD及上胸弯柔韧度是Lenke 1型AIS病人术后RSH的预测因素,应避免主胸弯过度矫正导致术后肩失衡的发生。     

Lenke 5C型青少年特发性脊柱侧凸病人行后路脊柱融合术后持续性冠状面失衡的危险因素分析

目的 探讨Lenke 5C型青少年特发性脊柱侧凸（adolescent idiopathic scoliosis,AIS）病人行后路脊柱融合术后持续性冠状面失衡（persistent coronal imbalance,PCI）的危险因素。方法 回顾性分析2015年1月至2020年1月在西安交通大学附属红会医院行后路脊柱融合术且随访2年以上的112例Lenke 5C型AIS病人的临床资料。根据病人术后2年的冠状面平衡状态分为PCI组和非PCI组。PCI定义为术后冠状面失衡持续时间≥2年。测量并比较两组病人术前、术后即刻和术后2年的各项冠状面参数和矢状面参数;采用脊柱侧凸研究学会-22评分量表（Scoliosis Research Society-22,SRS-22）评估病人临床疗效。并进一步对上述相关因素进行多元二分类Logistic回归分析确定PCI的独立危险因素。结果 112例病人中,50例（44.6%）术后发生即刻冠状面失衡,其中12例（10.7%）冠状面失衡持续至术后2年。多元二分类Logistic回归分析显示,年龄较大［比值比（odds ratio,OR）=1.841,95%可信区间（confidence interval,CI）：1.147~2.132,P=0.001］、术前胸弯柔韧性较差（OR=1.308,95% CI：1.041~2.015,P=0.016）、术前胸腰弯/腰弯顶椎偏移较大（OR=2.291,95% CI：1.120~4.719,P=0.001）、术前下端固定椎（lowest instrumented vertebra,LIV）倾斜角较大（OR=2.141,95% CI：1.491~3.651,P=0.011）、术后即刻冠状面失衡（OR=5.512,95% CI：4.531~6.891,P=0.001）是发生PCI的独立危险因素。PCI组术后2年SRS-22量表满意度和总分均显著低于非PCI组（P＜0.05）。结论 年龄较大、术前胸弯柔韧性较差、术前胸腰弯/腰弯顶椎偏移较大、术前LIV倾斜角较大和术后即刻冠状面失衡是预测PCI的重要参数。PCI对Lenke 5C型AIS病人后路脊柱融合术后临床效果产生不良影响。     

后路双棒同步异质性去旋转矫治Lenke 1A和2A型青少年特发性脊柱侧凸的下端融合策略及疗效分析

目的 探讨后路双棒异质性去旋转技术在Lenke 1A和2A型青少年特发性脊柱侧凸（adolescent idiopathic scoliosis,AIS）矫治中的临床疗效和远端融合策略。方法 回顾分析我院55例接受后路双棒异质性去旋转矫治的Lenke 1A和2A型AIS病人,所有病人随访1年以上。所有病人在手术前后及末次随访时均拍摄全脊柱正侧位片,测量侧凸Cobb角、顶椎偏距、冠状位平衡、矢状位平衡等参数。分析末次随访时远端叠加现象发生的危险因素。结果 55例病人的随访时间为（48.8±24.8）个月。术前主胸弯Cobb角为50.8°±10.4°,术后矫正至8.2°±4.9°,末次随访时为9.1°±4.9°,矫正率为82.3%±9.2%;术前腰弯Cobb角为28.5°±7.0°,术后矫正至5.1°±3.2°,末次随访时为6.3°±4.1°,矫正率为77.9%±13.6%。末次随访时7例病人出现远端叠加现象,发生率为12.7%。远端融合至最后实质性接触椎（LSTV）-1的病例中,发生远端叠加现象的病人与未发生的病人在手术年龄、Risser征、LSTV与下端椎（LEV）的位置关系方面的差异存在统计学意义（P=0.041,P=0.014,P=0.020）。结论 采用后路双棒同步异质性去旋转矫治Lenke 1A和2A型AIS,可以获得满意矫形效果,有助于重建和维持脊柱平衡,减少尾侧融合节段。对于Lenke 1A和2A型AIS病人,若骨骼成熟度正常,LIV可以选择LSTV-1。若骨骼成熟度低,LSTV与LEV相差两个椎体时,可以选择LSTV-1作为LIV。但在LSTV与LEV相差一个或少于一个椎体时,远端叠加现象的风险增加,LIV应选择LSTV。     

经皮椎体成形术与经皮椎体后凸成形术治疗相邻双椎体急性骨质疏松性椎体压缩骨折的临床对比研究

目的 比较经皮椎体成形术（percutaneous vertebroplasty,PVP）与经皮椎体后凸成形术（percutaneous kyphoplasty,PKP）治疗相邻双椎体急性骨质疏松性椎体压缩骨折（osteoporotic vetebral compression fractures,OVCF）的临床疗效。方法 回顾性分析西安交通大学医学院附属红会医院2015年1月至2017年12月收治的134例相邻双椎体急性OVCF病人的临床资料,根据手术方式分为PKP组（61例）与PVP组（73例）。比较两组术前、术后及末次随访时的疼痛视觉模拟量表评分（visual analogue scale,VAS）、Oswestry功能障碍指数（Oswestry disability index,ODI）、椎体前缘高度、伤椎局部Cobb角、骨水泥渗漏情况及邻近椎体新发骨折情况。结果 两组病人术后及末次随访时的VAS评分和ODI均显著优于术前,差异均有统计学意义（P均＜0.05）,但两组间术前、术后及末次随访时的VAS评分、ODI比较,差异均无统计学意义（P均＞0.05）。术后及末次随访时,PKP组的椎体前缘高度和伤椎局部Cobb角均显著优于PVP组,组间比较,差异均有统计学意义（P均＜0.05）。PKP组和PVP组的骨水泥渗漏率分别为14.75%、32.88%,邻近椎体新发骨折率分别为11.48%、27.40%,两组比较,差异均有统计学意义（P均＜0.05）。结论 与PVP手术治疗比较,PKP手术治疗相邻双椎体急性OVCF可有效恢复椎体高度,降低骨水泥渗漏率及邻近椎体新发骨折的风险,病人预后更好。     

Lenke 1、2型青少年特发性脊柱侧凸矫形术后内肩自发性平衡6个月观察

目的 观察Lenke 1、2型青少年特发性脊柱侧凸（adolescent idiopathic scoliosis，AIS）病人行脊柱后路椎弓根钉矫形内固定植骨融合术后短期内肩自发性平衡的恢复情况。方法 回顾性分析2018年1月至2020年1月在本中心行后路椎弓根钉矫形内固定植骨融合术治疗AIS的21例病人手术前后的影像学资料，根据术前、术后即刻、术后6个月标准站立位脊柱全长X线片，测量主胸弯Cobb角、上胸弯Cobb角、腰弯角度、影像学肩高、锁骨角，并采用T₁倾斜角和颈椎轴线角评价内肩自发性平衡情况。结果 术后即刻和术后6个月的主胸弯Cobb角、上胸弯Cobb角、腰弯角度均较术前明显改善，差异有统计学意义（P＜0.05）。术前T₁平衡2例（9.52%，2/21），术后即刻6例（28.57%，6/21），术后6个月13例（61.90%，13/21），术后6个月时达到T₁平衡的比例较术前显著提高，差异有统计学意义（P＜0.05）；术前颈部平衡3例（14.29%，3/21），术后即刻13例（61.90%，13/21），术后6个月17例（80.95%，17/21），术后即刻、术后6个月时的颈部平衡比例均较术前显著升高，差异有统计学意义（P＜0.05）。结论 Lenke 1、2型AIS病人矫形术后内肩平衡（尤其是T₁平衡性）会有一定程度的自发性改善。     

短节段钉棒固定结合伤椎骨水泥强化治疗Kümmell病伴后凸畸形

目的 探讨短节段椎弓根螺钉复位固定结合伤椎椎体骨水泥强化治疗Kümmell病伴后凸畸形的临床效果。方法 我科于2018年2月至2019年10月收治16例Kümmell病伴较严重后凸畸形病人,其中男10例,女6例。年龄为59~78岁,平均67.75岁。腰椎骨密度T值为（-3.48±2.65） SD。胸腰段12例,L₃ 3例,T₈ 1例;后凸角度为23.940°±0.803°。在邻近伤椎上下椎两侧置入椎弓根螺钉,通过钉棒作用进行伤椎撑开复位,再在伤椎两侧注入骨水泥强化治疗。比较病人术前、术后3 d及末次随访时的疼痛视觉模拟量表（VAS）评分、Oswestry功能障碍指数（ODI）、伤椎前缘高度及后凸角。结果 本组病例随访（12.1±2.3）个月,未出现神经损伤等并发症。术后3 d及末次随访时病人的VAS评分、ODI、伤椎前缘高度、后凸角较术前均有显著改善,差异有统计学意义（P均＜0.05）;但末次随访与术后3 d的数值比较,差异无统计学意义（P均＞0.05）。结论 短节段钉棒固定结合伤椎强化治疗Kümmell病伴后凸畸形疗效满意,值得临床进一步探讨。     

短节段骨水泥螺钉内固定联合椎体成形术治疗Ⅲ期Kümmell病的疗效研究

目的 评估短节段骨水泥强化椎弓根螺钉固定联合椎体成形术治疗Ⅲ期Kümmell病的临床疗效。方法 回顾性分析2016年9月至2020年9月我科收治的24例Ⅲ期Kümmell病病人,年龄为65~93岁,均采用短节段骨水泥强化椎弓根螺钉内固定联合椎体成形术治疗,记录术前、术后7 d、末次随访时的疼痛视觉模拟量表（visual analogue scale,VAS）评分、Oswestry功能障碍指数（Oswestry disability index,ODI）,测量X线片上病椎Cobb角、椎体前缘及后缘高度,根据术后病椎X线片观察骨水泥填充及渗漏情况。结果 24例病人平均随访12个月（6~22个月）。病人术中无血管神经损伤、椎管内骨水泥渗漏等严重并发症发生,术后24~72 h下地行走。3例术后12个月内出现邻近节段或其他椎体骨折,采用经皮球囊扩张椎体后凸成形术（percutaneous kyphoplasty,PKP）治疗后症状缓解。术后7 d及末次随访时的VAS评分、ODI和病椎Cobb角较术前显著降低,椎体前缘高度较术前显著升高,与术前比较,差异均有统计学意义（P＜0.05）;但末次随访时的数值与术后7 d时的比较,差异无统计学意义（P＞0.05）。术后7 d及末次随访时的椎体后缘高度与术前比较,差异无统计学意义（P＞0.05）。结论 短节段骨水泥强化椎弓根螺钉内固定联合椎体成形术治疗Ⅲ期Kümmell病,能够安全有效地改善临床症状、恢复病椎高度,并且对脊柱后凸畸形有满意的矫正效果。     

不同Risser征的胸弯青少年特发性脊柱侧凸前路矫形术后矢状面重建

 目的 探讨不同Risser征的胸弯青少年特发性脊柱侧凸(adolescent idiopathic scoliosis, AIS）行前路矫形术后胸椎及远端腰椎矢状面的重建模式。
方法 分析2002年6月至2006年11月行胸弯前路矫形内固定术且有2年完整随访资料的L enke 1型AIS患者43例,男3例,女40例;年龄11~18岁,平均（14.1±1.7）岁;胸弯Cobb角39°~ 65°,平均46.0°±7.5°。按照患者Risser征评分分为：A组（Risser 0）、B组（Risser 1～3）和C组（Risser 4～5）。分别测量这三组患者术前及术后历次随访时的胸弯Cobb角、腰弯Cobb角、胸椎后凸角、腰椎前凸角、内固定远端交界性后凸角、胸腰椎交界性后凸及骶骨后上缘与C 7铅垂线的距离。
结果 三组患者均获得随访,随访时间24~60个月,平均27.4个月。末次随访时,A组胸腰椎交界性后凸角为6.6°,较术前的- 1.7°增大8.3°;B组为0.6°,较术前的- 7.3°增大7.9°;C组术后历次随访与术前均无显著性差异。三组患者胸椎后凸角分别为21.2°、18.4°和14.7°,胸椎后凸角历次随访时的变化无统计学差异。三组患者的内固定远端交界性后凸角均表现为前凸丢失,后凸增大。
结论 低Risser征的Lenke 1型AIS患者行前路矫形内固定术后胸椎后凸角及胸腰椎交界性后凸增加,可能与胸椎后份生长后矢状面重建引起的胸腰椎交界区失代偿有关。     

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.     

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.     

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.     

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.     

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.     

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.