腰椎后路融合术后cage后移危险因素的meta分析

目的:探讨腰椎后路融合术后cage后移的危险因素。方法:检索PubMed、Embase、Cochrane library、Web of Science、中国知网、万方数据库、中国生物医学文献服务系统自建库至2022年10月发表的有关腰椎后路融合术后cage后移的文献。采用RevMan5.2软件进行meta分析:计数资料采用比值比(OR),计量资料采用均数差值(MD)。结果:共纳入14项研究,分析11 094例患者,评估12个危险因素。Meta分析结果显示,梨形椎间盘[OR=6.74,95%置信区间(95%CI):2.41～18.83,P=0.000 3]、终板损伤(OR=8.27,95%CI:3.08～22.16,P<0.001)、螺钉松动(OR=13.83,95%CI:5.66～33.78,P<0.000 01)、单侧钉棒系统固定(OR=4.20,95%CI:1.72～10.26,P=0.002)与腰椎后路融合术后cage后移有关;性别(OR=0.61,95%CI:0.29～1.27,P=0.19)、术前诊断(OR=1.04,95%CI:0.70～1.57,P=0.84)...     

单侧双通道内镜腰椎融合术安全性的荟萃分析

[目的]系统评价单侧双通道内镜（unilateral biportal endoscopic, UBE）辅助腰椎融合术与传统腰椎融合手术的安全性。[方法]检索The Cochrane Library、PubMed、Embase、Web of Science、Clinical Trals.gov、CBM、CNKI、VIP和万方数据库，收集所有UBE与传统腰椎融合手术的对照研究，检索时限均为建库至2022年4月13日，采用RevMan5.3软件进行荟萃分析，对数据不能合并者进行描述性定性分析。[结果]共纳入9篇文献，均为回顾性队列研究，其中高质量文献7篇，中等质量2篇。总共纳入患者796例，其中UBE组365例，传统组431例。荟萃分析结果显示：UBE组和传统组的总并发症发生率（OR=0.94,95%CI 0.57～1.53,P=0.800）、硬膜外血肿发生率（OR=1.16,95%CI 0.38～3.52,P=0.800）、硬脊膜撕裂发生率（OR=1.80,95%CI 0.76～4.30,P=0.180）、感染发生率（OR=0.35,95%CI 0.09～1.30,P=0.120）差异均...     

中国人群PVP术后非手术椎体骨折的危险因素

目的 :系统评价中国人群椎体成形术(PVP)术后非手术椎体骨折的危险因素,为临床制定非手术椎体骨折的预防控制措施提供参考。方法:检索Pubmed数据库、Embase数据库、Cochrane Library数据库、中国知网数据库(CNKI)、维普数据库(VIP)、万方数据库等,纳入1987年1月～2018年2月期间关于中国人群PVP术后非手术椎体骨折发生的危险因素的文献。纳入标准为公开发表且可提取有效数据的文献。排除标准为病理性骨折以及NOS文献质量评分6分的文献。2名研究员严格评价文献质量及提取文献资料。应用Revman 5.3软件统计分析提取的数据,研究指标有:性别、术前椎体骨折数量、未抗骨质疏松治疗、椎间盘骨水泥漏、BMI指数、后凸畸形矫正度、年龄、甲状旁腺素、骨密度(BMD)上述9项指标。结果:最后纳入15篇符合标准的文献,8篇中文文献,7篇英文文献,共包含3177例患者,发生PVP术后非手术椎体骨折588例。Meta分析结果显示,与中国人群PVP术后非手术椎体骨折发生相关的危险因素有:术前多个椎体骨折[OR=1.61,95%CI=(1.08,2.39),P0.05]、骨水泥漏入椎间盘[OR=2.44,95%CI=(1.32,4.51),P0.05]、术后未抗骨质疏松治疗[OR=3.47,95%CI=(2.36,5.09),P0.05]、女性[OR=1.36,95%CI=(1.06,1.75),P0.05]、高龄[WMD=0.86,95%CI=(0.10,1.62),P0.05]、低骨密度[WMD=-0.66,95%CI=(-1.09,-0.22),P0.05]、高甲状旁腺素[WMD=4.67,95%CI=(4.22,5.13),P0.05],而BMI指数[WMD=-0.13,95%CI=(-1.55,1.28),P0.05]、后凸畸形矫正度[WMD=1.92,95%CI=(-1.16,4.99),P0.05]与PVP术后非手术椎体骨折的发生率无关。结论:术前多个椎体骨折、骨水泥漏入椎间盘、术后未抗骨质疏松治疗、高龄、高甲状旁腺素、女性、低骨密度是国人PVP术后非手术椎体骨折发生的危险因素。     

腰椎手术患者术后发生症状性硬膜外血肿危险因素的Meta分析

【摘要】 目的：通过系统评价的方法分析腰椎手术患者术后症状性硬膜外血肿（postoperative symptomatic epid-ural hematoma,PSEH）发生的相关危险因素。方法：计算机检索PubMed、Embase、Web of Science、Cochrane Library、CBM、CNKI、万方和维普数据库,搜集有关腰椎手术患者术后发生PSEH危险因素的病例-对照研究和队列研究,检索时限均为建库至2022年3月。由2名研究者独立筛选文献、提取纳入研究的基本信息、基线特征及PSEH相关的危险因素,如手术时间、术中出血量、抗凝治疗等所关注的结局指标和结果测量数据。评价纳入研究的偏倚风险后,采用RevMan 5.3软件进行Meta分析。结果：共纳入17项研究,包括14项病例-对照研究和3项队列研究,共132363例患者,发生症状性硬膜外血肿525例。16篇文献的质量评分均≥6分,仅1篇文献质量评分为5分。Meta分析结果显示,年龄≥65岁[比值比（odds ratio,OR）=3.36,95%可信区间（confidence interval,CI）（2.13,5.30）,P<0.00001]、术前血小板计数[OR=1.89,95%CI（1.31,2.71）,P=0.0006]、合并高血压[OR=1.50,95%CI（1.22,1.85）,P=0.0001]、止血材料使用[OR=2.91,95%CI（1.93,4.39）,P<0.00001]、凝血障碍[OR=6.95,95%CI（1.76,27.43）,P=0.006]、翻修手术[OR=5.87,95%CI（3.77,9.12）,P<0.00001]、手术时间＞2h[OR=3.52,95%CI（1.84,6.71）,P=0.0001]、术中出血量≥600ml[OR=3.77,95%CI（1.31,10.89）,P=0.01]、冰冻血浆输注[OR=8.13,95%CI（4.46,14.81）,P<0.00001]及多节段手术[OR=1.98,95%CI（1.54,2.56）,P<0.00001]是腰椎术后患者PSEH发生的危险因素。结论：当前证据表明,年龄≥65岁、术前血小板降低、合并高血压、止血材料使用、凝血障碍、翻修手术、手术时间＞2h、术中出血量≥600ml、冰冻血浆输注及多节段手术为腰椎术后患者PSEH发生的危险因素。对具有以上危险因素的高危患者应高度关注及早期干预,以降低PSEH的发生率,改善患者临床预后。     

颈椎终板抗压强度分布规律的生物力学研究

[目的]研究颈椎终板不同位点抗压强度及其分布规律。[方法]选用5具成年男性新鲜颈椎标本(C3～7),共25个椎体50个终板。对终板平面49个测试点用直径1.5 mm的平底压头以12 mm/min的速度进行连续压缩加载试验,获得最大压缩力,进行统计分析。[结果](1)抗压强度自C3～7逐渐减小(P﹤0.05);(2)下终板抗压强度大于上终板(P=0.000);(3)椎间隙相邻面上一椎体下终板的抗压强度大于下一椎体上终板抗压强度(P<0.05);(4)随着压力点逐渐外移,抗压强度逐渐增大(P﹤0.05);(5)处于不同角度的压力点,其抗压强度存在差异(P=0.029);(6)终板后部强于前部(P=0.003)。上终板后部抗压强度大于前部(P=0.000)。[结论]颈椎终板抗压强度自C3～7逐渐减小,下终板强于上终板,外周大于中央,后部强于前部。椎间隙相邻面上一椎体下终板的抗压强度大于下一椎体上终板抗压强度。     

腰椎椎间融合术后笼架后移危险因素分析

[目的]探讨腰椎椎间融合术后笼架后移危险因素。[方法]回顾分析692例腰椎后路椎间融合手术患者临床资料。将患者性别、年龄、合并症、住院天数、支具佩戴时间、椎间隙高度恢复情况、笼架置入深度、椎弓根钉棒稳定情况、椎间隙前凸角恢复情况纳入分析,采用单项因素与二元多因素逻辑回归分析笼架后移的相关因素。[结果] 629例患者中,发生笼架移位的23例,占3.32%。单项因素分析表明:与未后移组相比,后移组年龄大、术后佩戴支具时间短、椎间盘突出症比率低、骨质疏松比率高、激素使用比率高、超重比率高、双节段融合比率高、术后椎间隙高度恢复不良比率高、术后前凸角恢复不良比率高、术后笼架置入深度不良比率高、术后椎弓根钉棒系统稳定不良比率高,差异均有统计学意义(P0.05)。逻辑回归表明:术后佩戴支具时间是笼架后移的保护因素(OR=0.374,P0.001)。而术后椎间隙高度恢复不良(OR=263.109,P0.001),笼架置入深度不良(OR=27.931,P0.001),骨质疏松症(OR=13.609,P=0.007)和超重(OR=8.133,P=0.038)是笼架后移的危险因素。[结论]腰椎椎间融合术后笼架后移由多因素导致。骨质疏松、超重、术后椎间隙高度恢复不良、笼架置入深度不良和术后佩戴支具时间为笼架后移独立影响因素。     

腰椎融合术后发生邻近节段椎间盘退变的系统评价

[目的]对腰椎融合术加速邻近节段椎间盘退变进行系统评价.[方法]按照Coehrane协作网制订的检索策略进行检索,计算机检索MEDLINE(1966～2010年8月)、EMBASE(1974～2010年8月)、Cochrane图书馆(2010年第8期)、中国生物医学文献数据库(CBM,1978～2010年8月)、中国期刊全文数据库(CNKI,1994～2010年8月)、中文科技期刊全文数据库(VIP,1989～2010年8月)及万方数据库(1979～2010年8月).手工检索相关的中英文骨科杂志和会议论文.纳入腰椎融合术后发生邻近节段椎间盘退变的所有临床试验,由2名评价员独立提取资料,并对其方法学质量进行评价.对符合纳入标准的研究用RevMan 5.0软件进行Meta分析.[结果]共纳入4个试验,451例患者.Meta分析结果显示:相对功能洲练(保守治疗)来说腰椎融合术后发生邻近节段椎问盘退变(adjacent segment disc degeneration,ASD)的概率增高[RR=0.63,95%CI(0.52,0.78)P<0.000 1];腰椎融合术中椎板切除后ASD发生率比不行椎板切除的高[RR=3.74,95%CI(0.99,14.18)P=0.05];腰椎融合术前存在ASD比术前无ASD在术后发生ASD的概率高[RR=3.13,95%CI(1.20,8.15)P=0.02];腰椎融合术后ASD的发生与是否有内固定和融合节段的多少无关.[结论]腰椎融合术能增加术后ASD的发生率,与椎板切除和术前就存在ASD有关,但与是否有内固定和融合节段的多少无关.限于纳入研究在方法学方面的局限性,尚需开展大样本、高质量的RCT进一步论证其疗效和安全性.     

Kümmell's病相关危险因素分析

[目的]探讨Kümmell's病发生的相关危险因素。[方法] 2009年7月—2019年1月,90例Kümmell's病患者和90例骨质疏松压缩性骨折非手术治疗未发生Kümmell's病患者作为研究对象。记录患者一般与临床资料,单项因素比较Kümmell's病与非Kümmell's病的各项资料。以是否发生Kümmell's病的二分变量为因变量,其他因素为自变量,行二元多因素逻辑回归分析。[结果]骨质疏松压缩性骨折主要发生在T11、T12和L1节段,单椎体骨折比多椎体骨折更容易发生Kümmell's病。单因素比较表明,两组在骨密度、是否抗骨质疏松治疗情况、是否糖尿病、是否甲状腺疾病史、是否糖皮质激素服用史及是否独居的差异有统计学意义。逻辑回归表明：独居（OR=8.19,95%CI:4.81-31.25,P0.001）、服用糖皮质激素（OR=36.07,95%CI:3.08-422.57,P0.001）、有甲状腺疾病史（OR=5.51,95%CI:1.59-19.14,P0.001）、高BMI (OR=3.48,95%CI:1.22-9.89,P=0.019)、低骨密度（OR=3.07,95%CI:1.10-7.37,P=0.036）是Kümmell's病发生的危险因素;而抗骨质疏松治疗（OR=0.159,95%CI:0.03-0.24,P0.001）是Kümmell's病发生的保护性因素。[结论]低骨密度值、甲状腺疾病史、糖皮质激素服用史、独居及高BMI值是Kümmell's病发生的危险因素;抗骨质疏松治疗是其保护因素。     

骨质疏松对后路单节段腰椎融合术后融合器沉降程度的影响

目的:探讨单节段后路腰椎椎间融合术治疗合并骨质疏松的腰椎退变性疾病术后融合器沉降程度的相关影响因素,分析不同程度沉降与临床疗效的相关性。方法:回顾性分析2013年6月～2015年6月在我院行单节段后路腰椎融合手术治疗合并骨质疏松的腰椎退变性疾病患者的一般情况(年龄、性别、体重、病程)及手术相关资料[手术时间、出血量、单侧/双侧减压、传统/皮质骨螺钉(CBT)置钉、手术节段等],收集术前、术后各随访时间点的影像学资料,评估腰椎骨密度(BMD)、融合器沉降度、腰椎退变等级、终板改变Modic分型,测量手术节段椎间隙高度、节段性前凸角、腰椎前凸角和骶骨倾斜角等,并依据融合器沉降度分为轻度沉降组(沉降≤1mm)、中度沉降组(1mm沉降3mm)和重度沉降组(沉降≥3mm),采用日本骨科协会(Japanese Orthopaedic Association scores,JOA)评分改善率评价临床疗效。单因素及Logistic回归法统计分析融合器沉降度相关的影响因素;Pearson相关性分析融合器沉降程度与临床疗效的关系。结果:共纳入186例行单节段后路腰椎融合手术的腰椎退变性疾病合并骨质疏松的患者,其中162例获得随访,随访时间17～26个月(21.9±4.8个月),融合器重度、中度、轻度沉降分别为46例、64例、52例,三组术后腰椎JOA评分改善率差异无统计学意义[(64.38±18.20)%vs (63.74±22.76)%vs (59.90±25.01)%,P0.05)]。单因素分析结果表明三组间腰椎BMD T值、Modic分型、椎间隙高度矫正值、手术节段前凸角矫正值、CBT置钉法为影响融合器沉降程度的相关因素(P0.05),其余因素无统计学差异。Logistic回归分析显示手术节段椎间隙高度矫正值(OR=1.902,95%CI=1.323～2.509)、节段性前凸角矫正值(OR=1.605,95%CI=1.207～2.367)为融合器沉降程度的影响因素(P0.05)。腰椎JOA评分改善率与融合器沉降程度无明显相关性(r=0.354,P=0.435);腰痛VAS评分与融合器沉降度呈弱相关(r=0.434,P0.05)。结论:合并骨质疏松的腰椎退变性疾病患者行腰椎融合术后易发生融合器沉降,手术节段椎间隙高度矫正值和前凸角矫正值是融合器沉降程度的独立影响因素,过度撑开椎间隙、过度矫正节段性前凸会增加融合器沉降程度,融合器沉降程度与术后腰痛程度呈弱相关。     

腰椎后路融合术后急性手术部位感染的危险因素分析

目的探讨腰椎后路融合术后发生急性手术部位感染的相关危险因素。方法回顾性分析2016年1月至2018年12月于我院脊柱外科行腰椎后路融合手术的330例病人的临床资料。病人主要诊断包括腰椎椎管狭窄、腰椎间盘突出症、腰椎骨折、肿瘤等。根据术后是否发生急性手术部位感染将病人分为感染组和非感染组,选择年龄、性别、身体质量指数(body mass index, BMI)、吸烟、高血压、糖尿病、骨质疏松症、手术节段数、手术时间、出血量、切口长度、术后引流时间、尿路感染和脑脊液漏等可能影响术后急性手术部位感染的因素,先后应用单因素分析和二元Logistic回归分析腰椎后路融合术后急性手术部位感染的危险因素。结果共有19例术后发生了急性手术部位感染,发生率为5.76%(19/330)。单因素分析结果显示:两组病人的年龄、BMI、糖尿病、骨质疏松、手术节段、手术时间、出血量、脑脊液漏、尿路感染以及切口长度的差异均有统计学意义(P均<0.05)。二元Logistic回归分析结果显示:BMI[OR=1.429,95%CI(1.059,1.929),P=0.020]、合并糖尿病[OR=9.568,95%CI(2.183,41.935),P=0.003]、手术时间[OR=8.868,95%CI(1.992,39.482),P=0.004]、切口长度[OR=7.257,95%CI(2.937,16.719),P<0.001]为腰椎后路融合术后急性手术部位感染的独立危险因素。结论为了降低腰椎术后急性手术部位感染的发生率,围术期应合理评估控制相关危险因素,以获得更好的治疗效果和病人满意度。     

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.     

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.     

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.     

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.