三尖瓣瓣环扩张伴轻度反流的二尖瓣置换术患者同期行三尖瓣成形术的随机对照试验

目的分析三尖瓣瓣环扩张伴轻度三尖瓣反流(TR)的二尖瓣置换术(MVR)患者同期行三尖瓣成形术对患者心功能及TR程度的影响,为临床决定是否为二尖瓣置换术(MVR)患者同期处理三尖瓣瓣环扩张伴轻度三尖瓣反流(TR)提供客观依据。方法纳入2013年4~10月四川大学华西医院心脏大血管外科36例需施行MVR的患者,术前超声心动图提示全组患者轻度TR、且三尖瓣瓣环舒张期末内径/体表面积21 mm/m2。36例患者被随机分为三尖瓣成形组(TAPG组,n=18,其中男7例、女11例)和非三尖瓣成形组(NTAPG组,n=18,其中男6例、女12例),术后1周、半年复查超声心动图。结果两组患者的年龄、性别、心律、体表面积、术前心功能分级(NYHA)、左心房径(LAD)、左心室径(LVD)、右心房最大长轴径(RAmla)、右心房中部短轴径(RAmmd)、心尖四腔心中部的右心室径(RVD2)、左心室射血分数(LVEF)、左心室短轴缩短分数(LVFS)之间的差异无统计学意义(P0.05)。两组患者术后半年左心房室径较术前减小(P0.05)。TAPG组患者术后半年左心室长轴切面的右心室径(RVD1)、舒张期右心室游离壁厚度(RVWT)、三尖瓣瓣环舒张期末内径(TVAEDD)、三尖瓣瓣环收缩期末内径(TVAESD)较术前减小(P0.05),三尖瓣环缩短分数(PSTVA)较术前差异无统计学意义(P0.05),TR程度较术前减轻(P0.05),右心室面积变化分数(RVFAC)、右心室射血分数(RVEF)较术前增加(P0.05);NTAPG组患者术后半年RVD1、RVWT较术前增加,TVAEDD、TVAESD、PSTVA较术前差异无统计学意义(P0.05),3D RVEF较术前减小(P0.05),RVFAC增加但小于同期TAPG组患者,TR程度构成比改变(P0.05),但术后出现6例中度及中度以上TR。结论三尖瓣瓣环扩张伴轻度TR的MVR患者同期行三尖瓣成形术将更有利于患者RVD1、RVWT及TVAEDD、TVAESD的减小,TR程度构成比的改善,RVFAC及RVEF的升高。     

以三尖瓣瓣环径作为三尖瓣成形手术指征的初步临床观察

目的初步观察采用三尖瓣瓣环径作为三尖瓣成形术指征是否有助于减少二尖瓣置换术（MVR）患者术后中重度三尖瓣反流（TR）的发生。方法选择2005年4月至2006年6月期间我科56例术前无或轻度TR的MVR患者纳入研究。以三尖瓣瓣环径/体表面积≥21mm/m2将患者分为三尖瓣成形组（TA组）和非三尖瓣成形组（NTA组）。TA组：22例,男8例,女14例;年龄45.0±7.7岁;三尖瓣瓣环径36.8±3.8mm,体表面积1.57±0.15m2;心功能分级（NYHA）级18例,～级4例;窦性心律2例,心房颤动20例。NTA组：34例,男9例,女25例;年龄42.9±11.0岁;三尖瓣瓣环径28.5±4.4mm,体表面积1.58±0.13m2;心功能分级级28例,～6例;窦性心律9例,心房颤动25例。TA组患者采用Kay法施行三尖瓣成形术。术后随访及术后6个月完成超声心动图检查。结果56例患者术后均康复出院。术后随访11.0±2.4个月,除2例外54例患者完成术后6个月超声心动图复查。两组患者一般临床特征比较差异无统计学意义（P〉0.05）。与NTA组比较,术前TA组患者右房径（49.3±7.0mm）、三尖瓣瓣环径较大（36.8±3.8mm）,有三尖瓣反流的患者较多（P〈0.05）,术后TA组患者右房径（44.1±8.9mm）、三尖瓣瓣环径（28.9±6.1mm）明显缩小,三尖瓣反流程度明显改善（P〈0.05）。NTA组患者术前、术后右房径、三尖瓣瓣环径和三尖瓣反流程度变化不明显（P〉0.05）,有3例患者出现TR。结论对术前无或轻度TR的MVR患者,采用三尖瓣瓣环径作为三尖瓣成形手术指征可能有助于减少这些患者术后中-重度TR的发生。     

基于倾向性得分匹配对心包软环成形术治疗功能性三尖瓣关闭不全的疗效研究

目的比较心包软环三尖瓣成形术与DeVega成形术、人工瓣环成形术的手术疗效。方法回顾性分析因风湿性心脏病合并功能性三尖瓣关闭不全行三尖瓣成形术的227例患者临床资料, 按三尖瓣成形术分成3组动态队列:心包环组(89例)、人工瓣环组(61例)、DeVega组(77例), 分别进行1∶1倾向性得分匹配(匹配A:心包环组与人工瓣环组, 匹配B:心包环组与DeVega组), 成功匹配后纳入随访和资料收集, 随访过程中临床资料不完整的患者按匹配情况成对移出研究队列。比较术后1、6、24个月的随访结果。结果术后1个月各组的三尖瓣反流均较术前明显减少甚至消失, 右心房及右心室也较术前缩小, 差异有统计学意义(P<0.05)。术后6个月各组的三尖瓣反流面积、右心房/室内径与术后1个月的结果对比, 差异无统计学意义(P>0.05), 三尖瓣反流复发率各组之间差异无统计学意义(P>0.05)。术后24个月匹配A中的两组在三尖瓣反流复发率、三尖瓣反流面积、右心房/室内径的差异均无统计学意义(P>0.05);匹配B中的心包环组与Devega组的右心房/室内径的差异无统计学意义, 但De...     

MC3成形环在功能性三尖瓣反流中的应用

目的探索MC3三尖瓣成形环治疗功能性三尖瓣反流(FTR)的方法和疗效。方法回顾性分析我院2012年6月至2014年5月连续312例FTR患者应用MC3人工瓣环行三尖瓣成形术(TVP)的临床资料。其中男147例、女165例,平均年龄(55.7±7.3)岁。结果全组没有与三尖瓣环植入相关的死亡及不良事件。随访率为99.4%(310/312),随访时间0~24(14.2±4.7)个月。术后心脏超声证实本组患者术后各不同时期右心室射血分数(EF)值较术前有明显改善(P0.05),肺动脉收缩压力(SPAP)、右心室内径及三尖瓣每搏反流量较术前均有明显减小(P0.05)。310例患者中TR为0~Ⅰ级302例(97.4%),Ⅱ级5例(1.6%),Ⅲ级3例(1.0%),无严重的TR。暂无需要再次手术的患者。结论 MC3人工瓣环植入容易,重复性好,可以持久有效地纠正功能性TR,产生的残余分流或者反流复发罕见,术后效果优于目前临床上常用的三尖瓣成形方法,可以在最大程度上防止术后残余或再次出现TR。     

二尖瓣置换术患者同期行三尖瓣成形术后两年超声心动图评价的随机对照试验

目的评价同期行三尖瓣成形(tricuspid anunloplasty,TAP)的二尖瓣置换(mitral valve replacement,MVR)术患者术后2年三尖瓣及右心室功能。方法纳入我院2012年4~11月术前超声心动图(ultrasonic cardiogram,UCG)检查提示存在三尖瓣瓣环扩张,仅有轻度三尖瓣反流(tricuspid regurgitation,TR),需行MVR手术的患者36例,年龄22~64(45.56±11.36)岁。按照随机数字表将患者分为两组:TAP组,18例,行MVR同期行TAP,其中男7例、女11例,年龄(45.67±12.49)岁;NTAP组,18例,MVR同期不行TAP,其中男6例、女12例,年龄(45.44±10.48)岁。记录患者一般临床资料及体外循环资料。于术前、术后1周、术后6个月及术后2年分别进行UCG评价。结果术后2年TAP组患者的右心房最大长轴径(the maximal long-axis of RA,RAmla)、中部短轴径(mid-RA minor distance,RAmmd)、左心室长轴切面右心室径(right ventricle dimension,RVD1)、右心室面积变化分数(right ventricular fractional area change,RVFAC)、三维右室收缩期末容积(3D RV end-systolic volume,3DRVESV)、三尖瓣瓣环舒张期末内径(tricuspid valve annular end-diastolic dimension,TVAEDD)及收缩期末内径(tricuspid valve annular end-systolic dimension,TVAESD)均明显小于NTAP组患者,而右心室射血分数(right ventricular ejection fraction,RVEF)、三尖瓣瓣环缩短分数(percent shorting of tricuspid valve annulus,PSTVA)则明显高于NTAP组患者,虽然术后2年两组患者三维右心室舒张期末容积(3D RV end-diastolic volume,3DRVEDV)之间的差异不明显,但TAP组患者上述指标的变化趋势明显优于NTAP组患者,此外术后2年TAP组患者的TR构成比明显优于NTAP组患者。结论三尖瓣瓣环扩张仅有轻度TR的MVR患者同期行TAP有利于患者术后2年三尖瓣及右心室功能的恢复,这对于减少术后远期患者TR的残留及加重是有益的。     

肺动脉环缩术在矫正型大动脉转位形态学左心室功能锻炼中的应用

目的探讨肺动脉环缩术在矫正型大动脉转位形态学左心室功能锻炼的临床应用效果。方法回顾性分析2007年1月至2011年12月上海交通大学医学院附属上海儿童医学中心手术治疗矫正型大动脉转位患者89例中行肺动脉环缩术11例的临床资料,其中男9例,女2例;年龄除1例12岁外,其余为3～42(16.40±11.67)个月;体重6～32(11.70±7.20)kg。所有患者均经超声心动图和心血管造影检查确诊。结果 11例行肺动脉环缩术患者无死亡,术前肺循环与体循环压力比(Pp/Ps)值0.3～0.6(0.44±0.09),术后为0.6～0.8(0.70±0.04),差异有统计学意义(P<0.01)。术前三尖瓣反流轻度2例(18.2%),中度5例(45.4%),重度4例(36.4%);术后无反流2例(18.2%),轻度反流7例(63.6%),轻-中度反流2例(18.2%)。11例中5例术后(15.20±8.31)个月行二期双心室解剖纠治术,其中1例死亡;余6例行单纯肺动脉环缩术后随访(18.83±3.43)个月,超声心动图检查提示:三尖瓣反流轻微2例(33.3%),轻度3例(50.0%),中度1例(16.7%)。结论矫正型大动脉转位通过肺动脉环缩术可减轻三尖瓣反流,锻炼形态学左心室功能,为二期解剖纠治做好准备,手术效果较好。但术后必须定期随访,观察术后形态学左心室功能和三尖瓣反流情况。     

自体心包“C”形环三尖瓣成形术疗效观察

目的观察自体心包"C"形环对功能性三尖瓣关闭不全行三尖瓣成形术的疗效。方法 2009年3月至2011年1月贵州省人民医院行三尖瓣成形术11例,男5例,女6例;年龄32～57(43.80±12.20)岁。三尖瓣轻度反流3例,中度反流7例,重度反流1例。同期行二尖瓣置换术和/或主动脉瓣置换术和/或左心房血栓清除。术中用0.8%戊二醛固定15 min的自体心包片制作"C"形环,间断褥式缝合"C"形环至三尖瓣瓣环行三尖瓣成形术。随访患者心功能、超声心动图指标。结果 11例患者住院期间无死亡,住院时间15～28(21.10±3.80)d。11例均获得随访,随访时间8～28(18.50±7.00)个月。随访期间无死亡,无因三尖瓣反流或狭窄需再次手术者。术后有10例检查仍有三尖瓣反流,其中轻度反流9例,轻-中度反流1例,无重度反流。三尖瓣反流程度较术前降低(Z=-2.81,P<0.05)。术前与术后右心室内径[(19.95±5.11)mm vs.(21.57±12.81)mm,P=0.705]、右心房内径[(37.55±6.79)mm vs.(35.55±5.22)mm,P=0.317]比较差异无统计学意义。结论自体心包"C"形环三尖瓣成形术效果满意。     

二尖瓣手术后重度三尖瓣反流患者的临床特征及治疗

目的 总结二尖瓣手术后重度三尖瓣反流(TR)的临床特征及治疗体会,以提高对该类患者的治疗效果.方法 30例重度TR患者,其中男1例,女29例;年龄32～65岁(47.1±9.2岁),窦性心律2例,心房颤动28例.第一次手术时:轻度TR 13例,中度TR 10例,重度TR 7例;5例在第一次手术时接受三尖瓣De Vega成形术,2例患者在第1次手术时接受三尖瓣Kay成形术.患者主要临床表现:腹胀28例(93.3%,28/30),下肢水肿20例(66.7%、20/30),活动后心悸17例(56.7%、17/30),腹水6例(20%、6/30).结果 9例患者接受了第二次手术,其中三尖瓣置换术6例,二尖瓣、三尖瓣置换术2例,三尖瓣Kay成形术1例.9例患者中8例术后康复出院,1例因术后右心房切口出血和低心排血量死亡.21例患者目前仍继续保守治疗.随访期间失访1例.结论 对二尖瓣手术后重度TR患者的治疗应根据患者具体的临床特征考虑手术或保守治疗,手术方式的选择亦应根据患者三尖瓣的具体情况及手术者的经验考虑三尖瓣成形术或三尖瓣置换术.     

超声心动图对继发性三尖瓣反流术疗效的评价

【摘要】〓目的〓通过超声心动图比较继发性三尖瓣反流患者行三尖瓣缝线成形术和成形环成形术的早期和中期效果,评价两种三尖瓣成形方法的疗效。方法〓回顾性分析我院2008年1月~2013年6月行三尖瓣成形术治疗的,并能追踪到而且进行了随访的继发性三尖瓣反流患者 175 例,根据成形方法分成两组:缝线成形术组 143例(82%),使用成形环成形术组 32 例(18%),分别于术前、术后一个月、术后一年通过超声心动图测量左室射血分数(LVEF)、三尖瓣反流束面积(TRA)、三尖瓣反流分数(TRF)、右室前后径(RVD)、右房上下径(RAD1)及右房左右径(RAD2),比较术前、术后半个月及术后1年时各参数的变化。结果〓两组患者,与术前相比,所有患者术后一个月TRA、TRF及RVD、RAD1及RAD2均显著降低(P<0.05),LVEF无显著变化(P>0.05);术后1年,缝线成形术组的患者TRF较术后一个月显著增加(P<0.05),其余指标无明显变化(P>0.05);而使用成形环组术后一年,所有指标较术后一个月无显著变化(P>0.05)。结论〓三尖瓣成形环成形术治疗三尖瓣反流,在术后中期仍可维持良好的疗效。超声心动图对三尖瓣反流的程度可提供半定量信息,在术前及术后随访中有着重要的应用价值。     

二尖瓣置换术患者同期行非环三尖瓣成形的远期效果

目的评价采用非环的三尖瓣成形技术的远期临床结果。方法纳入2006年1月至2011年3月我们施行的机械瓣二尖瓣置换且同期行三尖瓣成形术并完成了术后≥5年超声心动图复查的患者401例,其中女309例、男92例,年龄17~71(46.2±12.0)岁;窦性心率66例、心房扑动2例、心房颤动333例,心功能分级(NYHA)Ⅱ级19例、Ⅲ级380例、Ⅳ级2例。三尖瓣成形根据患者具体情况行瓣叶修补、二瓣化(bicuspidization)和改良Kay成形术。结果本组患者术后随访5~10(7.4±1.4)年。与术前相比,患者术后远期右心房[RA,(57.6±13.0)mm vs.(49.3±13.2)mm]、右心室[RV,(23.2±4.7)mm vs.(22.0±3.6)mm]、左心房[LA,(59.7±19.0)mm vs.(53.6±14.7)mm]及左心室[LV,(49.3±8.6)mm vs.(47.7±6.2)mm]均明显缩小,差异有统计学意义(P0.01)。与术前相比,术后远期患者左心室射血分数(LVEF,60.3%±8.9%vs.61.7%±8.3%)及左心室缩短分数(LVFS,32.6%±6.3%vs.33.8%±5.5%)均明显增加,差异有统计学意义(P0.01)。与术前相比,术后远期患者三尖瓣瓣环舒张期末内径[TEDD,(35.9±5.7)mm vs.(32.8±5.9)mm]、三尖瓣瓣环收缩期末内径[TESD,(9.4±5.7)mm vs.(26.5±4.9)mm]均明显缩小,差异有统计学意义(P0.01)。与术前相比,术后远期患者三尖瓣反流(TR)构成比明显改善,差异有统计学意义(P0.01)。结论二尖瓣病变患者以三尖瓣瓣环径作为同期行三尖瓣成形的手术指征是合理的,采用非环联合的个体化三尖瓣成形术同样可获得较好的远期结果,此外对患者术后TR应积极给予口服利尿剂。     

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.     

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.