右美托咪定联合复方利多卡因乳膏在功能性鼻内镜鼻窦手术的应用

目的 观察右美托咪定联合复方利多卡因乳膏对功能性鼻内镜鼻窦手术(functional endoscopic sinus surgery,FESS)的影响.方法 将90例ASA分级Ⅰ级、择期全身麻醉患者,完全随机分为右美托咪定(D)组、右美托咪定+复方利多卡因乳膏(DL)组和空白对照(N)组(每组30例).D组和DL组麻醉诱导前15 min,静脉输注右美托咪定0.6 μg/kg,后以0.6 μg·kg-1·h-1持续泵注,N组静脉输注等剂量0.9％氯化钠;手术开始前15 min DL组给予1g复方利多卡因乳膏的棉球涂抹鼻腔,D组、N组用不含复方利多卡因乳膏作为对照,丙泊酚和瑞芬太尼持续泵注镇痛镇静[MAP维持于70 mmHg(1 mmHg=0.133 kPa)左右].记录手术时间、术中出血量及丙泊酚、瑞芬太尼总用量,诱导前15 min(T0)、手术开始后15 min(T1)、30 min(T2)、45 min(T3)及拔管即刻(T4)的HR、MAP,观察术野质量评分,记录PACU停留时间、拔管后警觉/镇静评分(modified assessment of alertness/sedation,MOAMS)和术后3 h VAS评分.结果 3组患者年龄、体重、性别比、手术时间比较差异无统计学意义(P＞0.05).与N组比较,D组和DL组丙泊酚和瑞芬太尼用量和术中出血量明显减少(P＜0.05),而D组与DL组之间差异无统计学意义(P＞0.05);与D组比较,DL组T0～T4时的MAP和HR差异无统计学意义(P＞0.05),N组MAP在T0～T3时差异无统计学意义(P＞0.05),T4时显著升高(P＜0.05),N组HR在T1～T4时显著升高(P＜0.05),DL和D组T4时MAP、HR显著低于T0,而N组显著高于T0(P＜0.05);D组和DL组术野质量评分优于N组(P＜0.05),D组和DL组之间差异无统计学意义(P＞0.05);与D组[(49±9)min]比较,N组PACU停留时间[(35±6) min]缩短(P＜0.05),DL组[(50±10) min]无明显变化;与D组[(3.0±0.3)分]比较,N组拔管后警觉/镇静评分[(4.5±0.5)分]升高(P＜0.05),DL组拔管后警觉/镇静评分[(2.9±0.5)分]无明显变化;与D组[(1.8±0.6)分]比较,N组VAS评分[(2.8±0.5)分]升高(P＜0.05),DL组VAS评分[(0.9±0.5)分]明显降低(P＜0.05).结论 全身麻醉鼻内镜手术中应用右美托咪定联合复方利多卡因乳膏安全有效,减少术中出血,提高手术术野质量,减少拔管反应,提高患者拔管期的舒适度和术后镇痛质量,减少麻醉药物用量.     

脑电双频指数监测对老年慢性贫血患者术后谵妄发生率的影响

目的 探讨BIS监测对老年慢性贫血患者腹部手术术后谵妄(postoperative delirium,POD)发生率的影响. 方法 180例择期行全身麻醉手术患者,按随机数字表法分为两组(每组90例):BIS监测组及对照组,对照组采用常规麻醉,BIS监测组维持BIS值于40～60.记录患者入室后(T0)、诱导后(T1)、插管即刻(T2)、插管后3 min(T3)、切皮(T4)、术中1h(T5)及手术结束(T6)各时间点的血流动力学指标.观察记录患者麻醉期间丙泊酚用量、手术时间、拔管时间、清醒时间,及POD发生情况. 结果 BIS监测组谵妄总发生率17.8％,低于对照组的31.1％(P＜0.05);其中,BIS监测组谵妄第1天发生率13.3％,明显低于对照组的28.9％(P＜0.05),第2天发生率5.6％,低于对照组的14.4％(P＜0.05);BIS监测组谵妄持续时间明显低于对照组(P＜0.05).BIS监测组术后清醒拔管时间[(26±8) min]及住院时间[(11.5±2.3)d]显著短于对照组[(41±12) min、(12.6±4.4)d](P＜0.05). 结论 BIS监测下麻醉可降低老年合并慢性贫血患者POD发生率,减少谵妄持续时间.     

喉罩全身麻醉复合骶管阻滞在非洲儿童手术中的应用

目的 观察喉罩全身麻醉复合骶管阻滞与单纯气管插管全身麻醉在非洲儿童手术中的应用,为儿童麻醉提供参考. 方法 4～6岁行下腹部及下肢部位择期手术的患儿60例,完全随机分为喉罩全身麻醉复合骶管阻滞麻醉组(A组)和单纯气管插管全身麻醉组(B组),每组30例.观察记录患儿麻醉诱导前(T0)、置入喉罩/气管导管前后(T1、T2)及术毕拔出喉罩/气管导管(T3)时的MAP、HR和Sp02,以及麻醉苏醒时间、术后VAS疼痛评分及副作用情况. 结果 两组患儿MAP、HR和Sp02在To和T1时比较,差异无统计学意义(P＞0.05);A组MAP和HR[(68±10) mmHg(1 mmHg=0.133 kPa)、(108±17)次/min]在T2时明显低于B组[(91±8) mmHg、(139±18)次/min] (P＜0.05);A组MAP和HR[(67±9) mmHg、(121±16)次/min]在T3时也明显低于B组[(85±9) mmHg、(141±17)次/min] (P＜0.05);A组术后VAS评分[(1.5±0.5)分]明显低于B组[(6.5±1.5)分](P＜0.05),A组苏醒时间[(5.8±2.4)min]明显短于B组[(12.2±2.8) min](P＜0.05),A组术后躁动(4例)明显低于B组(17例)(P＜0.05),术后A组啼哭和呛咳的发生率也明显低于B组(P＜0.05). 结论 喉罩全身麻醉复合骶管阻滞麻醉在患儿诱导期和苏醒期有更加平稳的血流动力学,且术后疼痛明显降低、苏醒时间明显缩短、术后副作用发生率明显降低,是非洲儿童下腹部及下肢部位手术的一种较理想的麻醉方法.     

地佐辛和舒芬太尼用于老年患者宫腔镜取环术临床比较

目的 比较地佐辛和舒芬太尼在老年患者行宫腔镜取环术中的应用效果. 方法 选择拟行宫腔镜取环术患者40例,按照完全随机法均分为地佐辛组(D组)和舒芬太尼组(S组),每组20例.记录患者入室后(T0)、麻醉诱导后1 min(T0、扩宫颈时(T2)、手术结束时(T3)、苏醒时(T4)的MAP、HR、SpO2和呼吸频率(respiratory,RR);观察患者术中呼吸抑制(SpO2＜90％或呼吸暂停＞15 s)、丙泊酚用药量、术毕呼之睁眼时间、定向力恢复时间和恶心呕吐、头晕等副作用的发生率以及术后疼痛情况. 结果 T1时D组MAP和SpO2[(77±4) mmHg(1 mmHg=0.133 kPa)和(96.3±1.3)％]高于S组[(72±4) mmHg和(93.6±1.5)％](P＜0.05);HR和RR[(65±5)次/min和(14.6±1.3)次/min]快于S组[(61±5)次/min和(12.4±1.6)次/min] (P＜0.05).T2时D组HR[(72±4)次/min]快于S组[(66±5)次/min] (P＜0.05).D组呼之睁眼时间和定向力恢复时间[(3.6±1.2)min和(5.5±1.7) min]明显短于S组[(5.5±0.9) min和(7.4±1.4) min] (P＜0.05);D组呼吸抑制发生率(5％)显著低于S组(15％)(P＜0.05). 结论 在老年患者宫腔镜取环术中,地佐辛较舒芬太尼麻醉呼吸抑制轻,血流动力学更平稳,且可明显缩短患者苏醒时间及定向力恢复时间,提高患者的舒适度.     

羟考酮与舒芬太尼用于无痛人工流产术的镇痛效果比较

目的 研究羟考酮注射液复合丙泊酚在无痛人工流产术中应用的有效性与安全性. 方法 采用随机数字表法将60例行无痛人工流产术患者分为3组(每组20例):丙泊酚与羟考酮组(A组),丙泊酚与舒芬太尼组(B组),丙泊酚与安慰剂组(C组).记录3组麻醉诱导前(T1)、扩张官颈时(T2)、苏醒即刻时(T3)的MAP、HR、Sp02,围手术期的副作用,T3、苏醒后30 min(T4)、苏醒后3.5 h(T5)的VAS评分,3组患者应用阿托品与间羟胺的次数与离院时间,并进行比较. 结果 3组患者一般资料及手术时间差异无统计学意义(P＞0.05).A组、B组的丙泊酚用量[(130±22)、(141±27) mg]与苏醒时间[(1.2±0.8)、(1.3±1.1) min]比C组[(164±40) mg和(2.6.±1.6)min]明显减少(P＜0.01).A组T2时的MAP与HR[(77±10) mmHg(1 mmHg=0.133 kPa)和(67±8)次/min]比T1时[(88±8) mmHg和(78±12)次nin]明显降低(P＜0.01).C组T2时的HR[(80±15)次/min]比T1时[(74±7)次/min]增加(P＜0.05).体动发生次数A组、B组比C组明显减少(P＜0.01),头晕发生次数A组、B组比C组明显增加(P＜0.01),且A组少于B组(P＜0.05).A组T3、T4、T5时的VAS评分明显低于C组(P＜0.01),B组T3、T4时的VAS评分明显低于C组(P＜0.01).A组T3、T5时的VAS评分低于B组(P＜0.05),尤其T5时更低(P＜0.01).3组之间的用药次数比较,差异无统计学意义(P＞0.05).C组的离院时间比A组、B组长(P＜0.05). 结论 丙泊酚联合羟考酮比丙泊酚联合舒芬太尼或单用丙泊酚在无痛人工流产术中具有更好的镇痛效果、更少的副作用,可安全、有效地用于无痛人工流产术.     

腹膜后腔镜手术二氧化碳气腹并发皮下气肿临床观察

目的 探讨腹膜后腔镜手术中二氧化碳气腹并发皮下气肿对患者血流动力学、血气及麻醉苏醒的影响.方法 回顾分析87例择期行腹膜后腔镜肾癌根治手术患者,依据皮下气肿严重程度把患者分为3组:无皮下气肿患者组(A组,66例)、1级和2级的轻度皮下气肿患者组(B组,15例)、3级的重度皮下气肿患者组(C组,6例).B组和C组发生皮下气肿后行过度通气.分别于气腹前(T0)、气腹后30 min(T1)、气腹后60 min(T2)、气腹后90 min(T3)及手术结束时(T4)、拔管时、拔管后30 min监测患者血气、呼气末二氧化碳分压(end-tidal carbon dioxide partial pressure,PETO2)、心率(heart rate,HR)、平均动脉压(mean artery pressure,MAP),同时观察麻醉苏醒情况.结果 C组在T2～T4时间点的动脉血二氧化碳分压(partial pressureof carbon dioxide in artery,PaCO2)、PETCO2、HR、MAP值均显著高于A组(P＜0.05),pH值均显著低于A组(P＜0.05).C组患者术后呼唤睁眼时间[(16±6) min]显著长于A组[(11±3) min](P＜0.05),定向力恢复时间[(30±7) min]显著长于A组[(23±6) min](P＜0.05).C组拔管时PaCO2[(52±7) mmHg(1 mmHg=0.133 kPa)]显著高于A组[(45±4) mmHg](P＜0.05),拔管后30 min的PaCO2[(48±7)mmHg]显著高于A组[(39±4) mmHg(P＜0.05)].结论 后腹腔镜手术并发重度皮下气肿导致患者高碳酸血症,患者血压升高、HR加快,苏醒时间延长.     

阿片类药物对老年患者经尿道激光碎石术苏醒质量的影响

目的 观察阿片类药物对老年患者经尿道激光碎石术苏醒质量的影响. 方法 择期经尿道激光碎石手术患者134例,年龄65～79岁,ASA分级Ⅰ、Ⅱ级,采用随机数字表法分为3组:瑞芬太尼组(R组)46例、瑞芬太尼+芬太尼组(RF组)44例、芬太尼组(F组)44例.R组,采用丙泊酚和瑞芬太尼靶控输注(target-controlled infusion,TCI)进行麻醉诱导和麻醉维持;RF组,丙泊酚TCI麻醉诱导,静脉注射芬太尼2μg/kg,丙泊酚+瑞芬太尼TCI麻醉维持;F组,丙泊酚TCI麻醉诱导,芬太尼4 μg/kg,丙泊酚TCI麻醉维持.手术结束后送入PACU,记录患者被转入PACU时(T1)、拔除喉罩前2 min (T2)、拔除喉罩即刻(T3)和拔除喉罩后5 min(Td)4个时间点的MAP、HR,记录拔除喉罩后VAS评分和苏醒期芬太尼用量,记录患者睁眼时间、拔除喉罩时间和PACU驻留时间. 结果 麻醉苏醒期间R组在T1～T3时点MAP[(110±18)、(122±13)、(121±14) mmHg(1 mmHg=0A33 kPa)]和HR[(79±15)、(97±17)、(99±18)次/min]高于RF组(P＜0.05);R组VAS[(1.8±1.4)分]高于RF组[(0.9±0.9)分]和F组[(0.9±0.9)分](P＜0.05);R组需芬太尼镇痛患者比例高于其他两组(P＜0.05);F组的睁眼时间、拔喉罩时间以及PACU驻留时间比RF组和R组长(P＜0.05). 结论 老年患者经尿道激光碎石术应用丙泊酚复合瑞芬太尼+芬太尼全凭静脉麻醉比丙泊酚单纯复合瑞芬太尼或芬太尼苏醒期间血流动力学平稳、苏醒迅速、术后镇痛效果好.     

BIS指导下丙泊酚闭环靶控输注在老年患者开腹手术中的应用

目的探讨BIS指导下丙泊酚闭环靶控输注在老年患者开腹手术中的应用效果。方法择期全麻下行开腹手术的老年患者60例,男38例,女22例,年龄65~80岁,ASAⅠ~Ⅲ级,随机分为两组:闭环组(A组)和开环组(B组),每组30例。两组采用相同的诱导方式。BIS下降至60且连续15s小于或等于60时A组丙泊酚以BIS值45~55为目标自动闭环反馈输注,B组手动调节丙泊酚维持BIS在45~55之间。两组均用肌松监测反馈仪闭环输注顺阿曲库铵,手动调节瑞芬太尼。记录入室后5min(T0)、插管即刻(Tl)、插管后3min(T2)、切皮后3min(T3)、腹腔探查时(T4)、缝皮结束时(T5)的BIS值、MAP、HR,记录两组麻醉时间、拔管时间及丙泊酚、瑞芬太尼、顺阿曲库铵、阿托品、麻黄碱、乌拉地尔和硝酸甘油等使用量,统计闭环系统性能指标:总体分数(GS),充分麻醉(40BIS60)所占时间比例。用MMSE表对两组患者术前1d、术后第3天和第5天的认知功能进行评分。结果两组患者各时点HR差异无统计学意义。T4时A组MAP、BIS明显高于B组(P0.05)。A组丙泊酚用量和靶控浓度明显低于B组(P0.05),两组患者瑞芬太尼、顺阿曲库铵使用量,麻黄碱、阿托品、乌拉地尔、硝酸甘油的使用例数差异无统计学意义。A组术后拔管时间[(27±8)min]明显短于B组[(36±10)min](P0.05),A组GS[(28±10)分]明显低于B组[(49±11)分](P0.05),充分麻醉(40BIS60)所占时间比例A组(82%±9%)明显高于B组(67%±9%)(P0.05)。术后第5天MMSE,A组[(28.57±0.87)分]明显高于B组[(26.83±0.91)分](P0.05),但术后认知功能障碍的发生率差异无统计学意义。结论 BIS指导下丙泊酚闭环靶控输注用于开腹手术的老年患者,麻醉效果良好,但在腹腔探查时患者血压有波动;BIS指导下丙泊酚闭环靶控输注可很好地维持BIS在设定的范围内;可减少全身麻醉药物的使用,缩短拔管时间,减轻对术后早期认知功能的影响。     

创伤休克患者不同麻醉深度下诱导插管的血流动力学变化

目的 比较创伤休克患者在不同麻醉深度下诱导插管时的血流动力学变化. 方法 根据进入手术室的时序,按区段随机分组法将40例非颅脑损伤的创伤休克患者随机分为A、B两组,每组各20例.患者入室后行脑电双频指数(bispectral index,BIS)监测,麻醉诱导以咪达唑仑1.5 mg/min缓慢静注,当BIS达到预定值(A组60±3,B组45±3)时立即给予芬太尼3μg/kg、琥珀胆碱1.5mg/kg,肌肉松弛后气管插管.分别记录两组入室时(T0)、BIS达预定值时(T1)、气管插管即刻(T2)、插管后1 min(T3)、插管后3 min(T4)的BIS值、心率(HR)、收缩压(SBP)和咪达唑仑的用量. 结果 组内比较A组各时点HR、SBP差异无统计学意义,B组T1[(138±15)次/分]、T2[(146±15)次/分]、T3[(147±11)次/分]、T4(146±10)次/分]时点的HR较T0[(127±16)次/分]明显增加,而T2[(72±10)mm Hg(1 mm Hg=0.133 kpa)]、T3[(74±10)mm Hg]、T4[(76±11)mm Hg]时点的SBP较T0[(82±7)mm Hg]明显下降(P<0.05);两组间HR的差异出现在T3(P=0.005)、T4(P<0.001)时点;两组间SBP的差异出现在T4(P=0.005)时点.A组咪达唑仑用量约为0.117 mg/kg,较B组减少约17%(P<0.001). 结论 麻醉诱导插管时采用相对较浅的麻醉深度(BIS=60)更有利于创伤休克患者血流动力学的相对平稳.     

脑电双频指数-靶控输注注射泵闭环丙泊酚靶控输注应用于妇科腹腔镜手术的安全效益研究

目的 观察BIS-靶控输注(target controlled infusion,TCI)注射泵闭环丙泊酚TCI对妇科腔镜手术患者丙泊酚的节约效应及血流动力学的影响. 方法 纳入ASA分级Ⅰ、Ⅱ级择期行妇科腔镜手术的患者40例,采用计算机随机数字表分组分为闭环组和开环组,每组20例.闭环组采用BIS监测闭环丙泊酚TCI维持全身麻醉,开环组采用BIS监测下人工调整丙泊酚TCI血浆效应浓度2～5 mg/L维持全身麻醉,BIS目标值50±5;瑞芬太尼血浆效应浓度4μg/L TCI.记录两组在入室后5 min(T0)、诱导后气管插管前(T1)、插管后1 min(T2)、插管后5 min(T3)、手术切皮时(T4)、切皮后30 min(T5)、缝皮(T6)、手术结束(T7)、意识恢复(T8)、拔管即刻(T9)及拔管后5 min(T10)等时点MAP、HR、BIS值的变化,同时记录两组患者诱导及维持丙泊酚用药量、苏醒时间及进入PACU时的疼痛数字评分(numerical rating scale,NRS)及Ramsay镇静评分. 结果 术中维持丙泊酚剂量闭环组[(6.2±1.4) mg· kg-1·h-1]较开环组[(6.9±1.0)mg·kg-1·h-1]降低了10％,两组各时点MAP、HR、BIS差异无统计学意义(P＞0.05),闭环组切皮时MAP、HR、BIS波动明显小于开环组(P＜0.05).两组患者苏醒时间、NRS及Ramsay镇静评分差异无统计学意义(P＞0.05). 结论 BIS-TCI注射泵闭环丙泊酚TCI与常规BIS监测下开环丙泊酚TCI可同样安全地应用于临床,可对患者个体化合理给予全身麻醉药物,并可部分降低术中丙泊酚使用剂量,降低麻醉后手术前的循环波动.同时,避免麻醉医师手动调控TCI靶控血浆浓度,极大地降低了麻醉医师的工作量,并使围麻醉期更加平稳安全.     

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.