关节镜下软骨成形术在胫骨高位截骨术治疗内翻型膝骨关节炎中的应用

目的 探讨关节镜下软骨成形术结合胫骨高位截骨术（high tibial osteotomy,HTO）治疗内翻型膝骨关节炎的临床疗效。方法 选取2018年5月至2020年5月我科收治的39例施行HTO的内翻型膝骨关节炎病人,其中在关节镜下对损伤的软骨行成形术的18例纳入观察组,另外21例未在关节镜下对软骨损伤进行处理的病人作为对照组,比较两组病人手术前后的西安大略和麦克马斯特大学（WOMAC）关节炎指数、疼痛视觉模拟量表（VAS）评分、胫骨近端内侧角（medial proximal tibial angle,MPTA）和股胫角（femora tibial angle,FTA）,以及两组病人手术前后屈伸角度和屈曲达90°所用时间。结果 两组病人手术后WOMAC指数、VAS评分和FTA均较术前显著降低,MPTA较术前明显增大,与术前比较,差异有统计学意义（P＜0.05）。另外,两组病人之间术前和术后随访中,MPTA、FTA并无明显差异（P＞0.05）,而观察组术后WOMAC指数及VAS评分显著低于对照组（P＜0.05）。观察组术后末次随访时屈曲和伸直角度明显优于对照组（P＜0.05）,并且观察组屈曲角度达90°所用时间明显少于对照组（P＜0.05）。结论 关节镜下软骨成形术结合HTO治疗内翻型膝骨关节炎,疗效肯定,可以显著缓解病人疼痛症状,使病人能够早期高效地开始功能锻炼,获得更好的功能状态。     

关节镜手术联合富血小板血浆治疗半月板损伤的Meta分析

目的：探讨关节镜手术联合富血小板血浆（platelet-rich plasma,PRP）治疗半月板损伤的临床疗效。方法：计算机检索PubMed、Science Direct、Cochrane library、中国期刊全文数据库、万方数据库和维普数据库中关节镜手术联合PRP与单纯关节镜手术修复半月板损伤的临床对照研究,检索时间自2015年1月至2019年12月。根据纳入和排除标准,进行文献筛查、数据提取并评价其方法学质量。采用RevMan 5.3软件比较两种治疗方式术后1,6,12个月的膝关节疼痛视觉模拟评分（visual analogue scale,VAS）,Lysholm评分和术后3,6,12个月西安大略和麦克马斯特大学骨关节炎指数（Western Ontario and McMaster University Osteoarthritis Index,WOMAC）。结果：共纳入9项研究,329例半月板损伤患者,关节镜手术联合PRP组146例,单纯关节镜手术组183例。两组术后1、6、12个月VAS评分比较差异无统计学意义（P>0.05）。两组术后1,6个月Lysholm评分[MD=3.85,95% CI （1.25,6.44）,P<0.05],[MD=2.88,95% CI （0.13,5.63）,P<0.05]比较差异有统计学意义;术后12个月Lysholm评分比较差异无统计学意义[MD=5.88,95% CI （-8.72,20.48）,P=0.43]。两组术后3、6个月WOMAC比较差异有统计学意义[MD=-8.07,95% CI （-11.17,-4.89）,P<0.000 01],[MD=-7.96,95% CI （-11.44,-4.48）,P<0.000 01];但术后12个月WOMAC评分比较差异无统计学意义[MD=-6.61,95% CI （-16.64,3.41）,P>0.05]。结论：关节镜手术联合PRP修复半月板损伤在改善膝关节功能,延缓关节炎方面短期疗效优于单纯关节镜手术,但两者长期疗效及缓解疼痛方面疗效相当。     

关节镜手术治疗对早期膝骨关节炎的中期临床疗效

目的：比较关节镜手术治疗与保守治疗对中老年人早期膝关节骨关节炎（early knee osteoarthritis,EKOA）的中期临床疗效,为中老年EKOA的个体化治疗提供临床依据。方法：回顾性纳入2015年1月至2016年12月行关节镜手术治疗或保守治疗的145例（182膝）中老年EKOA患者,其中男35例、女110例,年龄47~79（57.6±6.9）岁,病程6~48（14.6±8.9）个月。根据治疗方式分为关节镜治疗组（47例,58膝）和保守治疗组（98例,124膝）。治疗前患者主要临床症状包括膝关节疼痛、肿胀、交锁、屈伸受限及膝关节无力等,膝关节X线主要表现为关节间隙无狭窄或可疑狭窄、少量骨赘形成,膝关节MRI主要表现为关节软骨和半月板退变或损伤、关节内游离体及滑膜充血水肿等。收集两组患者治疗前的膝关节症状持续时间、半月板是否合并损伤、是否合并关节内游离体、是否存在膝关节交锁等机械性症状,以及治疗前和治疗后的疼痛视觉模拟评分（visual analogue scale,VAS）和Lysholm膝关节功能评分。统计分析组内和组间治疗前后VAS和Lysholm评分差异。结果：两组患者均获随访,时间60~76个月;关节镜手术组患者切口愈合良好,未发生手术并发症。两组间的年龄、性别、身体质量指数（body mass index,BMI）及随访时间差异无统计学意义（P>0.05）。治疗前,关节镜治疗组与保守治疗组相比,关节镜治疗组的症状持续时间更长（P<0.001）,合并半月板损伤（P<0.001）、游离体（P=0.001）及机械性症状（P<0.001）的比例更高,VAS评分（P<0.001）及Lysholm评分（P<0.001）更差。治疗后末次随访时,各组VAS评分、Lysholm评分均较治疗前明显改善（P<0.05）。末次随访时,VAS评分,关节镜治疗组（1.5±1.2）分,保守治疗组（1.6±1.0）分（P=0.549）;Lysholm评分,关节镜治疗组（84.9±12.5）分,保守治疗组（84.2±9.9）分（P=0.676）。结论：对中老年EKOA患者,关节镜手术治疗与保守治疗均具有较满意的中期临床疗效。尽管两组末次随访时疗效差异无统计学意义,但关节镜手术治疗组术前症状较重,多合并半月板损伤或游离体所导致的机械性交锁症状,故对于合并机械性交锁症状或保守治疗效果较差的中老年EKOA患者可考虑关节镜手术治疗。     

影响症状性外侧盘状半月板术后疗效的相关危险因素分析

目的：探讨关节镜治疗症状性外侧盘状半月板（discoid lateral meniscus,DLM）术后疗效的影响因素。方法：回顾性分析2008年9月至2015年9月于四川大学华西医院运动医学中心诊断为症状性DLM并行关节镜手术治疗的患者。膝关节功能由Lysholm评分系统进行评估,根据评分结果分为优（≥ 90分）、良（80~89分）、可（70~79分）、差（<70分）。收集患者临床资料,包括性别、手术年龄、体质量指数、工作强度、症状持续时间、膝关节创伤史、受累膝关节侧别、DLM分型、DLM损伤类型、DLM损伤部位、内侧半月板损伤、膝关节软骨损伤部位及损伤程度、Kellgren-Lawrence （K-L）分级、手术方式、末次随访时间共16项拟研究因素。根据数据类型,单因素分析采用Kruskall-Wallis秩和检验或χ²检验,多因素分析采用有序Logistic回归模型。单因素分析具有统计学意义的因素纳入多因素分析模型,最终获得影响症状性DLM术后疗效的独立危险因素。结果：根据纳入排除标准,共纳入502例患者。末次随访的Lysholm功能分级高于术前（P<0.001）。单因素分析显示：在Lysholm各功能分级之间,性别、体质量指数、工作强度、膝关节创伤史、手术年龄、症状持续时间、内侧半月板损伤、K-L分级、手术方式、膝关节软骨损伤部位及程度的差异均有统计学意义（P<0.05）。有序Logistic回归分析显示：女性是影响术后疗效的独立危险因素（P=0.002,OR=0.370）;体质量指数（P=0.007,OR=0.894）,工作强度（P=0.004,OR=0.525）,手术年龄（P<0.001,OR=0.953）,症状持续时间（P<0.001,OR=0.989）,膝关节软骨损伤程度（P=0.016,OR=0.631）与Lysholm膝关节功能分级呈负相关。结论：关节镜是治疗症状性DLM安全、有效的方法,性别、体质量指数、工作强度、手术年龄、症状持续时间以及膝关节软骨损伤程度是症状性DLM术后疗效的独立影响因素。     

前交叉韧带重建术后通过二次关节镜可发现明显的关节软骨损伤：系统综述

目的 评估前交叉韧带（anterior cruciate ligament, ACL）重建术后,关节软骨在二次关节镜下的软骨损伤情况。方法 基于PubMed和Embase两大数据库,两名研究人员独立检索2018年3月之前公开发表的关于ACL重建术后二次关节镜下软骨情况的临床研究,并对检索结果的参考文献进行了回顾性检索。两位研究者从研究设计、样本大小、手术技术等方面对所纳入文献进行质量评价,并独立地提取出各个研究的作者、发表时间、病人数量、移植物类型、手术方法、二次关节镜的发现（尤其是软骨的情况和相关影响因素）以及病人的术后表现等数据。结果 纳入10篇研究文献,共计788名在ACL重建术后进行了二次关节镜手术的病人,病人从重建手术到二次关节镜手术的平均时间为19.6个月。在所有研究中,通过二次关节镜均发现了明显的关节软骨退行性改变,以关节软骨的软化和纤维化最为常见;在不同区域的关节软骨中,以髌股关节的软骨损伤最为常见。可能影响ACL重建术后关节软骨改变的因素无确定结论,但多个研究证明半月板的完整性与软骨损伤有关。结论 ACL重建术后,通过二次关节镜,可以发现明显的以软骨的软化和纤维化为主要表现的退行性关节软骨改变,其中髌股关节软骨最易受影响;半月板的不完整可能是关节软骨损害的危险因素之一。     

应用抗生素骨水泥植入技术治疗第一跖趾关节痛风石并骨缺损的短期疗效研究

目的 研究对比痛风石病灶清理联合抗生素骨水泥植入技术与常规手术清除病灶在痛风石病人中的短期疗效。方法 回顾性分析2020年5月至2023年5月内蒙古科技大学包头医学院第一附属医院手足踝外科收治的40例第一跖趾关节痛风石伴骨缺损病人的临床资料,按照手术方法的不同分为观察组和对照组,每组20例,均为男性,年龄为22~82岁。观察组采用痛风石病灶清理联合抗生素骨水泥植入治疗,对照组则采用清理病灶的常规手术。比较两组白细胞（WBC）、C反应蛋白（CRP）、红细胞沉降率（ESR）、住院时间、换药次数、创面完全愈合时间。观察并记录病人入院时和随访3个月时美国足踝外科医师协会（AOFAS）评分、疼痛视觉模拟量表（VAS）评分和血尿酸（sUA）值。结果 病人术后随访时间3个月,观察组所有病人伤口均完全愈合,对照组20例病人中有7例伤口迁延不愈。观察组住院时间、换药次数、创面完全愈合时间、WBC、CRP、ESR、术后VAS评分均明显低于对照组,差异有统计学意义（P＜0.05）。对照组术后3个月AOFAS评分低于观察组,差异有统计学意义（P＜0.05）。两组术后3个月sUA值的差异无统计学意义（P＞0.05）。结论 对于第一跖趾关节痛风石并骨缺损病人,应用痛风石病灶手术清除联合抗生素骨水泥植入技术具有缩短住院时间,降低感染率,减轻病人疼痛,术后早期功能恢复快等优势,可作为严重痛风石合并骨缺损的外科治疗方法,值得推广应用。     

射频治疗对关节镜下半月板部分切除术早期疗效的影响

目的 探讨半月板部分切除术后使用射频汽化修整残留半月板对病人术后膝关节预后的影响。方法 前瞻性地纳入60例病人,随机分为两组,观察组（26例）病人采用膝关节镜下半月板部分切除+射频修整术,对照组病人（34例）采用膝关节镜下单纯半月板部分切除术。对比两组病人术后48 h伤口引流量及疼痛视觉模拟量表（visual analogue scale, VAS）评分;采用膝关节Lysholm评分标准评估膝关节功能,记录并比较两组病人术前及术后6个月随访时的Lysholm评分。结果 观察组和对照组病人的术后引流量分别为（51.15±22.69） ml、（63.24±23.45） ml,VAS评分分别为（1.45±0.50）分、（1.62±0.55）分,两组间比较,差异均无统计学意义（t=0.264,P=0.610;t=0.259,P=0.613）;所有入组病人术后的Lysholm评分为（91.58±5.78）分,均优于术前的（73.53±4.52）分,差异有统计学意义（t=8.012,P=0.005）;观察组及对照组术后的Lysholm评分分别为（90.00±5.54）分、（92.79±5.75）分,差异无统计学意义（t=0.219,P=0.641）。结论 关节镜下行半月板部分切除术的出血量与使用射频汽化仪无关,无论是否使用射频汽化修整残留半月板,病人术后膝关节的功能都能得到较好的恢复。     

高能量激光疗法联合本体感觉训练对半月板损伤病人术后膝关节疼痛及运动功能的疗效

目的 探讨高能量激光疗法（HILT）联合本体感觉训练对半月板损伤病人术后膝关节疼痛和功能的疗效。方法 选取2021年1月至2023年1月我院收治拟行关节镜半月板成形术的膝关节半月板损伤病人82例,采用随机数字表法分为观察组和对照组,每组41例。两组病人术后康复训练2周后,对照组采用本体感觉训练,观察组采用HILT联合本体感觉训练。观察两组治疗前后疼痛视觉模拟量表（VAS）评分,简版生活质量量表（SF-12）评分,美国膝关节协会（AKS）评分,膝关节主动活动度和下肢运动学指标（步频、步长、步速）,并发症发生率和病人满意度。结果 治疗10周后,两组VAS评分均较治疗前显著降低（P均＜0.05）,SF-12评分、AKS的膝关节评分和活动功能评分、膝关节屈曲和伸展角度以及下肢运动学指标均较治疗前显著提升（P均＜0.05）;观察组VAS评分显著低于对照组（P＜0.05）,SF-12评分、膝关节评分和活动功能评分、膝关节屈曲和伸展角度以及下肢运动学指标均显著高于对照组（P＜0.05）。结论 HILT联合本体感觉训练能够有效改善半月板损伤病人术后膝关节疼痛、运动功能和生活质量,并且还能够减少术后并发症、提高治疗满意度。     

体外冲击波联合康复治疗对早中期膝骨关节炎病人Coll2-1、COMP水平的影响

目的 探讨体外冲击波联合康复治疗对早中期膝骨关节炎（knee osteoarthritis, KOA）病人的治疗效果及其对关节液中胶原蛋白2-1（Collagen2-1, Coll2-1）、软骨寡聚基质蛋白（COMP）水平的影响。方法 选取2014年6月至2016年12月间收治的72例膝骨关节炎病人,随机分为对照组（36例）和观察组（36例）,对照组病人给予关节腔内注射玻璃酸钠治疗,观察组给予体外冲击波治疗,且两组均给予康复理疗措施。分别在治疗前及治疗后2个月时,采用活动时疼痛视觉模拟量表（visual analogue scale, VAS）评分、骨关节炎病人疼痛指数（Lequesne index）和美国西部安大略和麦克马斯特大学（the Western Ontario and McMaster Universities, WOMAC）骨关节炎指数评价两组的疗效,采用酶联免疫吸附试验（ELISA）测定关节液中Coll2-1、COMP的含量。结果 两组病人治疗后的VAS评分、Lequesne指数、WOMAC评分均明显降低（P均＜0.05）,治疗后观察组各项评分明显低于对照组（P均＜0.05）。治疗后两组病人关节液中Coll2-1、COMP的水平均比治疗前显著下降（P均＜0.05）,观察组下降程度明显优于对照组（P均＜0.05）。结论 体外冲击波联合康复治疗对膝骨关节炎病人的疗效较好,可明显减轻关节疼痛,改善膝关节活动功能,且明显降低病人关节液中的Coll2-1、COMP水平。     

膝骨关节炎患者关节滑液中骨桥蛋白和软骨寡聚基质蛋白水平与疾病严重程度相关性

目的:探讨膝骨关节炎（knee osteoarthritis,KOA）患者关节滑液中骨桥蛋白（osteopontin,OPN）和软骨寡聚基质蛋白（cartilage oligomeric matrix protein,COMP）水平与疾病严重程度的相关性。方法：选取2018年2月至2020年5月收治的59例KOA患者作为KOA组,其中男25例,女34例;年龄60~75（65.57±1.56）岁;体质量指数（body mass index,BMI）21.4~30.7（26.12±1.54） kg/m²。采用Kellgren-Lawrence（K-L）分级对X线结果进行评估,其中Ⅱ级（K-L2组）14例,Ⅲ级（K-L3组）27例,Ⅳ级（K-L4组）18例。另选取18例因韧带或半月板疾病进行关节镜检查且无软骨损伤患者作为对照组,男7例,女11例;年龄61~78（64.88±1.60）岁;BMI 22.8~29.9（25.89±1.49） kg/m²。治疗前采集研究对象关节滑液样本,采用酶联免疫吸附试验检测关节滑液OPN、COMP水平,比较KOA组与对照组关节滑液OPN、COMP水平。比较不同K-L分级KOA患者性别、年龄、BMI等临床资料,采用酶联免疫试验检测其关节滑液中白细胞介素-1β（interleukin -1β,IL-1β）,OPN,COMP,基质金属蛋白酶3（matrix metalloproteinase -3,MMP-3）水平,比较不同K-L分级KOA患者临床资料和生化指标,采用Logistic回归分析影响KOA患者K-L分级的因素,采用ROC曲线下面积（area under the curve,AUC）预测KOA疾病严重程度。结果：59例KOA患者获得随访,时间8~27（15.75±3.27）个月。KOA组关节滑液OPN、COMP水平高于对照组（P<0.001）。K-L2组、K-L3组、K-L4组IL-1β、OPN、COMP、MMP-3水平比较差异有统计学意义（P<0.001）;与K-L2组比较,K-L3、K-L4关节滑液关节滑液IL-1β、OPN、COMP、MMP-3 水平均升高（P<0.05）;与K-L3组比较,K-L4关节滑IL-1β、OPN、COMP、MMP-3水平均升高（P<0.05）。多因素Logistic回归分析结果显示：关节滑液OPN、COMP、MMP-3水平是影响KOA患者K-L分级的独立危险因素（OR=6.653, 4.229,1.579,P<0.001）。关节滑液OPN预测K-L4级KOA的AUC为0.720[95%CI（0.588-0.851）],灵敏度为94.4%,特异度为65.9%;关节滑液COMP预测K-L4级KOA的AUC为0.731[95%CI（0.592-0.870）],灵敏度为88.9%,特异度为63.4%;关节滑液OPN联合COMP预测K-L4级KOA的AUC为0.839[95%CI（0.724-0.953）],灵敏度为94.4%,特异度为51.2%;OPN联合COMP预测K-L4级KOA的AUC大于单独OPN、COMP的AUC（Z=4.037,3.540,P<0.05）。结论：KOA患者关节滑液OPN、COMP水平升高,并随着K-L分级增加而升高。关节滑液OPN、COMP是影响KOA患者K-L分级的独立危险因素,二者预测K-L4级KOA 的AUC、灵敏度、特异度高,可用于评估KOA疾病进展。     

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.     

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.