合并症对股骨颈骨折人工全髋关节置换术后髋关节功能的影响

目的 探讨何种合并症对股骨颈骨折人工全髋关节置换术（total hip arthroplasty,THA）术后髋关节功能及死亡率有影响;美国麻醉医师协会（American Society of Anesthesiologists,ASA）分级和Charlson合并症指数（Charlson Comorbidity Index,CCI）是否是术后髋关节功能水平降低及死亡率升高的危险因素。方法 纳入2020年1月至2022年1月于苏州大学附属张家港医院就诊并接受THA的175例老年股骨颈骨折病人,年龄为65~86岁,其中男42例,女133例,收集包括合并症在内的临床资料,术后12个月随访使用Harris髋关节评分（Harris Hip Score,HHS）评价髋关节功能并进行回顾性分析。采用Logistic回归分析术后12个月髋关节功能不良和死亡事件发生的危险因素。结果 脑血管疾病［OR=6.917,95% CI（2.983,16.023）,P＜0.001］、痴呆［OR=11.531,95% CI（1.774,74.963）,P=0.010］、中重度肾功能不全［OR=12.629,95% CI（2.998,53.197）,P=0.001］、肿瘤（不伴转移）［OR=63.118,95% CI（5.419,734.360）,P=0.001］、ASA分级［OR=25.305,95% CI（3.337,191.905）,P=0.002］和CCI［OR=12.367,95% CI（1.876,81.451）,P=0.009］为术后12个月髋关节功能不良的危险因素;心肌梗死［OR=52.985,95% CI（3.575,785.248）,P=0.004］、帕金森病［OR=58.850,95% CI（5.618,616.464）,P=0.001］以及ASA分级［OR=16.643,95% CI（2.264,122.486）,P=0.006］是术后12个月死亡的危险因素。结论 在股骨颈骨折THA术后髋关节功能恢复方面,脑血管疾病、痴呆、中重度肾功能不全和肿瘤是需要被特别关注的合并症;为降低术后12个月死亡率,应对合并心肌梗死和帕金森病的病人加强护理、支持和合并症治疗。此外,CCI和ASA分级在THA术后髋关节功能评估方面有一定的临床意义,ASA分级同样可以用于术后死亡率的评估。     

影响老年髋部骨折病人术后自理能力恢复的危险因素分析

目的 探讨影响老年髋部骨折病人术后自理能力恢复的危险因素。方法 回顾性分析西安交通大学医学院附属红会医院2017年6月至2018年12月收治的195例老年髋部骨折病人的临床资料,并通过门诊复查、电话询问和社区走访等方式获取病人术后康复信息,根据病人术后1年的Barthel指数将病人分为不能自理组（Barthel指数评分≤60分）和基本自理组（Barthel指数评分＞60分）。先采用单因素分析筛选危险因素,再通过多因素Logistic回归确定独立危险因素。结果 195例病人中,不能自理组65例,基本自理组130例。单因素分析显示年龄、美国麻醉医师协会（America Society of Anesthesiologists,ASA）分级、术前合并内科疾病种类、受伤至手术时间、术前血浆白蛋白、血红蛋白、居住环境、术后是否行抗骨质疏松治疗、术后是否于康复机构康复均与老年髋部骨折术后自理能力恢复有关（P均＜0.05）;多因素Logistic回归分析显示高龄［OR=1.326,95% CI（1.036,1.096）,P=0.025］是老年髋部骨折病人术后自理能力恢复的独立危险因素,术前血浆白蛋白高［OR=0.543,95% CI（0.276,0.895）,P=0.002］、居住环境为农村［OR=0.225,95% CI（0.076,0.462）,P=0.007］、术后抗骨质疏松治疗［OR=0.647,95% CI（0.427,0.947）,P=0.002］、术后在康复机构康复［OR=0.438,95% CI（0.229,0.835）,P＜0.001］是老年髋部骨折病人术后自理能力恢复的保护因素。结论 对高龄、术前白蛋白低的病人应加强干预;术后抗骨质疏松治疗以及在康复机构康复对老年髋部骨折病人术后自理能力的恢复有一定积极作用。     

经皮椎体成形术治疗老年骨质疏松性椎体压缩骨折骨水泥渗漏的危险因素分析

目的 探讨经皮椎体成形术（percutaneous vertebroplasty，PVP）治疗骨质疏松性椎体压缩骨折（osteoporotic vertebral compression fractures，OVCF）中骨水泥渗漏的危险因素。方法 回顾性分析2020年10月至2022年6月于我院行PVP手术治疗的160例（167个椎体）OVCF病人的临床资料，其中男39例，女121例，年龄为（72.8±7.9）岁（58~93岁）。根据术后是否发生骨水泥渗漏分为渗漏组（42例，42个椎体）和无渗漏组（118例，125个椎体），采用单因素分析两组性别、年龄、身体质量指数（body mass index，BMI）、骨密度、骨折部位、伤椎皮质缺损情况、椎内裂隙征、椎基静脉孔、伤椎体积、椎体压缩率、骨水泥注入量、骨水泥注入量/伤椎体积比、骨水泥注入量/伤椎丢失体积比之间的差异，将与骨水泥渗漏有关的因素纳入Logistic回归分析，明确PVP术后骨水泥渗漏的独立危险因素。绘制ROC曲线，根据曲线下面积（area under curve，AUC）来评估模型的诊断价值。结果 单因素分析结果显示，皮质缺损、椎内裂隙征、椎基静脉孔、骨水泥注入量及骨水泥注入量/伤椎丢失体积比与术后骨水泥渗漏有关（P＜0.05），多因素Logistic回归分析显示椎内裂隙征［OR=5.215，95% CI（2.006，13.159），P＜0.001］、椎基静脉孔［OR=3.357，95% CI（1.205，9.356），P=0.021］、骨水泥注入量［OR=2.519，95% CI（1.148，4.477），P=0.002］及骨水泥注入量/伤椎丢失体积比［OR=12.305，95% CI（1.875，80.756），P=0.009］为PVP术后骨水泥渗漏的独立危险因素。ROC曲线图显示骨水泥注入量/伤椎丢失体积比预测骨水泥渗漏的受试者工作特征AUC为0.641，且P＜0.01，具有一定的预测价值。骨水泥注入量/伤椎丢失体积比预测骨水泥渗漏的Cut-off值为61.82%，敏感度为69.00%，特异性为38.4%。结论 椎内裂隙征、椎基静脉孔、骨水泥注入量和骨水泥注入量/伤椎丢失体积比为术中骨水泥渗漏的独立危险因素，治疗时应保持骨水泥注入量/伤椎丢失体积比在61.82%以下，以降低发生骨水泥渗漏的风险。     

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。     

年龄校正Charlson合并症指数对髋部骨折病人内科并发症的预测效果分析

目的 探讨年龄校正Charlson合并症指数（age-adjusted Charlson comorbidity index,ACCI）对髋部骨折病人内科并发症的预测效果。方法 回顾性分析2015年1月至2020年12月于天津医院住院治疗的1 062例髋部骨折病人的资料,其中男317例,女745例,年龄为（69.81±13.43）岁。对病人住院病历资料进行回顾性ACCI评分,计算出每个病人的ACCI总评分,将其归类为低危0~2分,中危3~5分,高危6~8分,极高危≥9分。根据病人髋部骨折后是否出现并发症分为内科并发症组（593例）和非内科并发症组（469例）。比较两组病人年龄、骨折类型、住院时间、ACCI评分、冠心病、糖尿病、脑血管疾病、心力衰竭、贫血、低蛋白血症、脑萎缩、动脉硬化性疾病的差异,对上述差异有统计学意义的变量进一步行多因素Logistic回归分析。结果 两组年龄、骨折类型、住院时间、ACCI评分、冠心病、糖尿病、脑血管疾病、心力衰竭、贫血、低蛋白血症、动脉硬化性疾病的差异有统计学意义（P＜0.05）,多因素Logistic回归分析显示住院时间［OR=1.011,95% CI（1.006,1.017）,P＜0.001］、ACCI评分［OR=6.333,95% CI（4.949,8.103）,P＜0.001］、冠心病［OR=0.579,95% CI（0.409,0.872）,P=0.008］和贫血［OR=1.536,95% CI（1.097,2.150）,P=0.012］是髋部骨折病人发生内科并发症的独立危险因素。结论 单独使用ACCI预测髋部骨折病人的内科并发症具有一定的价值。     

下肢骨折病人术后35天内深静脉血栓的发生情况及危险因素分析

目的 探讨下肢骨折病人出院后35 d内深静脉血栓形成（deep vein thrombosis, DVT）的发生率及危险因素。方法 回顾性分析2014年7月至2017年7月西安交通大学医学院附属红会医院创伤骨科收治的402例住院期间未发生DVT的下肢骨折病人的临床资料。所有病人术前、术后都常规用物理方法和药物抗凝预防DVT,嘱咐病人出院后口服利伐沙班抗凝至术后35 d,记录术后35 d复查时双下肢DVT的发生情况。根据术后35 d门诊复查双下肢超声结果将病人分为DVT组和非DVT组,分析比较两组病人的性别、年龄、骨折部位、身体质量指数、合并其他骨折、合并内科疾病、术后的实验室检查（D-二聚体）、术后住院时间的差异,对上诉结果中差异有统计学意义的变量进一步采用多因素Logistic回归分析,分析病人出院后DVT的危险因素。结果 402例下肢骨折病人出院后发生DVT的有56例（13.9%）,其中2例（0.50%）发生肺栓塞,2例均合并有小腿肌间静脉血栓,1例发生在术后3周,1例在术后4周发生致死性肺栓塞。周围型52例,单纯中央型0例,混合型4例。膝关节以近的骨折病人DVT发生率为15.5%（36/232）,膝关节周围骨折病人DVT发生率为13.8%（8/58）,膝关节以远骨折病人DVT发生率10.7%（12/112）。两组间年龄、合并其他骨折、术后住院时间、冠心病、术后1 d D-二聚体、出院时D-二聚体的差异有统计学意义（P＜0.05）,多因素Logistic回归分析显示年龄＞60岁［OR=3.207,95% CI（2.007,8.553）,P=0.009］、合并其他骨折［OR=7.111,95% CI（2.297,22.011）,P＜0.001］、术后住院时间＜7 d［OR=1.448,95% CI（1.225,1.718）,P=0.020］、出院时D-二聚体偏高［OR=1.355,95% CI（0.892,12.626）,P=0.027］是出院后DVT的独立危险因素。结论 虽然出院前常规使用物理方法和药物抗凝预防DVT,出院后嘱咐病人口服利伐沙班35 d,但是出院时没有DVT的下肢骨折病人术后35 d仍有发生DVT的可能（13.9%）,严重者还会发生肺栓塞,年龄、合并其他骨折、术后住院时间较短、出院时D-二聚体是出院后DVT发生的独立危险因素。     

经皮椎体后凸成形术治疗骨质疏松性椎体压缩骨折后再骨折的危险因素分析

目的 探讨骨质疏松性椎体压缩骨折（OVCF）病人行经皮椎体后凸成形术（PKP）术后再骨折的危险因素。方法 回顾性分析2005年1月至2021年8月于我院诊断为骨质疏松性椎体压缩骨折并行PKP治疗的病人1 829例,其中女1 412例,男417例。根据PKP术后是否发生再次骨折,将病人分为再发骨折组（224例）和未再发骨折组（1 605例）。统计病人的性别、年龄、身体质量指数（BMI）、骨密度、术后侧（后）凸畸形的度数、椎体高度恢复率、初始骨折椎体数量、术前保守治疗时间、术后抗骨质疏松药物的使用、骨水泥渗漏、疼痛视觉模拟量表（VAS）评分、Oswestry功能障碍指数（ODI）进行单因素分析及多因素Logistic回归分析。结果 单因素分析显示性别、年龄、BMI、骨密度、术后抗骨质疏松药物的使用、骨水泥渗漏及术前保守治疗时间均与再骨折的发生有关（P＜0.05）;病人术后侧（后）凸畸形的度数、初始椎体骨折数量、术后椎体高度的恢复率、手术前后VAS评分和ODI与再骨折无明显相关性（P＞0.05）。通过Logistic回归分析发现女性（OR=4.355,95% CI：1.598~17.908,P=0.006）、65岁及以上（OR=6.431,95% CI：1.756~23.233,P=0.003）、BMI≥23 kg/m²（OR=3.561,95% CI：0.787~12.065,P=0.037）、骨密度T值＜-2.5 SD（OR=10.352,95% CI：2.857~41.761,P＜0.001）、术后未使用抗骨质疏松药物（OR=6.070,95% CI：1.731~21.165,P=0.003）、骨水泥渗漏（OR=6.150,95% CI：1.671~16.177,P=0.004）为PKP术后再发骨折的独立危险因素。结论 PKP术中应仔细操作,尽量避免骨水泥渗漏;对于女性、高龄、BMI高、骨密度过低的病人行PKP术后应重点关注;术后进行规律的抗骨质疏松治疗,避免再骨折的发生。     

肌肉减少症对胰十二指肠切除术后临床结局影响的Meta分析

背景与目的 肌肉减少症可导致机体四肢功能障碍、生活质量下降、死亡等不良事件风险增加。关于肌肉减少症对胰十二指肠切除术（PD）患者影响的研究较少,结论也不一致。本研究系统评价肌肉减少症对接受PD术患者术后临床结局的影响,以期通过有效干预来改善临床结局。方法 利用PubMed、Embase、Cochrane Library、CNKI、维普、万方数据库检索相关文献,检索时间为建库至2022年6月1日。由2名研究者独立筛选文献、提取资料并评价纳入研究的质量和偏倚风险后,采用RevMan 5.3软件对数据进行分析。结果 纳入14项研究,共计2 198例患者,其中肌肉减少症组737例,非肌肉减少症组1 461例,均为队列研究。Meta分析结果显示,两组的手术时间和伤口感染、尿路感染、胆汁漏、术后出血等并发症发生率均无明显差异（均P>0.05）;与非肌肉减少症组患者比较,肌肉减少症组患者术前BMI（WMD=-1.22,95% CI=-1.82~0.62,P<0.001）、术前白蛋白水平（WMD=-0.30,95% CI=-0.41~0.19,P<0.001）均较低;术中出血量较多（WMD=88.12,95% CI=6.94~169.31,P<0.05）;术后总体并发症（OR=3.53,95% CI=2.52~4.94,P<0.001）、Clavien-Dindo ≥3级并发症（OR=1.57,95% CI=1.17~2.12,P=0.003）、菌血症（OR=4.46,95% CI=1.42~13.98,P=0.01）、肺炎（OR=2.07,95% CI=1.31~3.25,P=0.002）、胰瘘（OR=1.34,95% CI=1.05~1.72,P=0.02）发生率较高;住院时间延长（OR=3.18,95% CI=1.97~4.39,P<0.001）,病死率增加（OR=3.17,95% CI=1.55~6.50,P=0.002）。结论 PD术患者术前合并肌肉减少症的比例较高。合并肌肉减少症对患者的临床结局有不利影响,并发症发生率和病死率增加,住院时间延长。     

意外胆囊癌二次术后早期复发的危险因素及辅助化疗疗效分析

背景与目的 术后早期复发是胆囊癌预后不良的重要危险因素，越来越多的证据表明辅助化疗可以改善患者的预后。但目前有关意外胆囊癌（IGBC）二次术后早期复发及辅助化疗对患者预后的影响尚未见报道。因此，本文探讨IGBC二次术后早期复发的危险因素及分析辅助化疗对于早期复发和非早期复发患者的疗效，以为临床提供决策支持。方法 回顾性收集2011年1月—2021年12月于西安交通大学第一附属医院肝胆外科因IGBC行意向性根治术的170例患者的临床病理资料，分析患者术后早期复发的影响因素（早期复发定义为二次意向根治术后12个月内），以及患者术后无复发生存（RFS）与总体生存（OS）的影响因素。结果 170例行IGBC意向性根治术后患者，随访期间复发者73例（42.94%）、早期复发者41例（24.12%）。IGBC术后早期复发患者中位OS时间明显短于非早期复发患者（χ²=192.910，P<0.001）。病理分化程度（OR=20.758，95% CI=5.557~80.239）、CA19-9水平（OR=7.920，95% CI=1.557~39.771）及病灶残留（OR=8.050，95% CI=3.062~21.160）是IGBC术后早期复发的独立危险因素（均P<0.05）。病理分化程度（HR=6.160，95% CI=2.877~13.193）、CA19-9水平（HR=2.538，95% CI=1.297~4.965）、手术切除范围（HR=2.111，95% CI=1.154~3.860）、病灶残留（HR=2.571，95% CI=1.547~4.273）是IGBC术后RFS时间的独立危险因素（均P<0.05）。病理分化程度（HR=3.225，95% CI=1.461~7.121）、早期复发（HR=29.558，95% CI=14.250~61.311）、病灶残留（HR=2.416，95% CI=1.361~4.287）是IGBC术后OS时间的独立危险因素（均P<0.05），辅助化疗是术后OS时间的独立保护性因素（HR=0.260，95% CI=0.123~0.551，P<0.05）。按有无病灶残留及是否早期复发分层分析的结果显示，辅助化疗可延长病灶残留患者术后RFS时间及OS时间，亦可延长早期复发患者术后OS时间（均P<0.05）。结论 病灶残留是IGBC二次术后早期复发及预后的独立危险因素，术后辅助化疗可以有效改善病灶残留及早期复发患者的预后。     

医院获得性肺血栓栓塞症的临床特征与危险因素分析

背景与目的 有关医院获得性肺血栓栓塞症（HA-PTE）的流行病学数据大多来自单一病种的调查研究,对于全院范围内HA-PTE的调查研究尚少。因此,本研究对全院范围内HA-PTE患者流行病学及临床特征等进行分析,以期为HA-PTE防治与管理提供参考依据。 方法 收集中南大学湘雅医院2018年1月1日—12月31日确诊HA-PTE患者（病例组）的临床资料和实验室检验数据,并根据性别、年龄、入院Caprini血栓风险评分等级、是否接受外科手术及手术等级,按1∶1匹配同期非HA-PTE患者作为对照组。分析HA-PTE患者的发病率、病死率、相关临床病理因素、危险因素及有价值的预测指标等。 结果 2018年度122 942例住院患者中确诊新发HA-PTE患者68例（0.55‰）,无HA-PTE相关死亡病例。42.65%（29/68）的HA-PTE患者同时合并有深静脉血栓形成。HA-PTE患者主要分布在神经内科（14/68,20.59%）、普通外科（11/68,16.18%）和呼吸内科（8/68,11.76%）。单因素分析结果显示,病例组呼吸系统疾病、肺部感染及入住ICU的比例高于较对照组（OR=4.60,95% CI=1.75~12.10,P=0.002;OR=2.38,95% CI=1.04~5.43,P=0.040;OR=11.00,95% CI=1.42~85.20,P=0.022）,总住院时长与住院总费用高于对照组（OR=1.11,95% CI=1.05~1.18,P<0.005;OR=1.01,95% CI=1.00~1.03,P=0.005）,纤维蛋白原降解产物（FDP）水平高于对照组（OR=1.11,95% CI=1.03~1.20,P=0.004）。多因素分析结果显示,呼吸系统疾病（校正OR=3.58,95% CI=1.32~9.71,P=0.012）和入住ICU（校正OR=11.38,95% CI=1.38~93.54,P=0.024）是HA-PTE的独立危险因素。 结论 患有呼吸系统疾病和入住过ICU的患者为HA-PTE的高危人群,神经内科、普通外科和呼吸内科是HA-PTE的高危科室,HA-PTE会导致患者的住院时长和医疗费用显著增高。FDP水平对于HA-PTE可能有一定的预测价值。     

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.