不同剂量右美托咪定对腹腔镜下胃肠手术老年患者围术期应激反应的影响

目的观察不同剂量右美托咪定对腹腔镜下胃肠手术老年患者围术期应激反应的影响。方法择期行腹腔镜下胃肠手术老年患者80例,性别不限,年龄≥65岁,ASAⅠ或Ⅱ级。随机分为四组,每组20例。所有患者均采用全凭静脉麻醉。D1、D2组和D3组麻醉诱导前10min静脉泵注右美托咪定0.5μg/kg,插管后分别静脉泵注右美托咪定0.2、0.5、0.8μg·kg~(-1)·h~(-1)至术毕前30min;C组麻醉诱导前10min静脉泵注7ml生理盐水,插管后静脉泵注生理盐水10ml/h至术毕前30min。记录术中麻醉药物用量,记录给药前(T_0)、气管插管后即刻(T_1)、气腹后5min(T_2)、气腹后60min(T_3)、拔管后即刻(T_4)和拔管后10min(T_5)的HR、SBP、DBP,分别于T_0、T_1、T_3、T_5时抽取桡动脉血,测定Glu、Cor、E和NE浓度。结果 D1组、D2组和D3组术中瑞芬太尼的用量明显少于C组,且D2组和D3组明显少于D1组(P0.05)。与T_0时比较,T_1~T_5时C组HR明显增快(P0.05)。T_2~T_5时,D2组和D3组的HR明显慢于C组和D1组,SBP明显低于C组(P0.05);T_1时D2组和D3组Cor和NE浓度也明显低于C组(P0.05)。T_3和T_5时,D2组和D3组Glu、Cor、E和NE浓度明显低于C组,D2组和D3组Cor和NE浓度明显低于D1组(P0.05)。结论与0.2和0.8μg·kg~(-1)·h~(-1)右美托咪定静脉泵注维持比较,0.5μg·kg~(-1)·h~(-1)能更有效抑制腹腔镜下胃肠手术老年患者围术期应激反应。     

右美托咪定对腹腔镜前列腺癌根治术老年患者局部脑氧饱和度和术后认知功能的影响

目的观察右美托咪定对腹腔镜前列腺癌根治术老年患者对局部脑氧饱和度(rSO_2)和术后认知功能的影响。方法选择择期行腹腔镜前列腺癌根治手术的老年患者60例,年龄65~80岁,ASA分级Ⅰ~Ⅲ级,随机均分为两组:右美托咪定组(D组)在全麻诱导插管后泵注右美托咪定0.5μg/kg,10min泵注完毕,然后以0.5μg·kg~(-1)·h~(-1)的速度持续泵注至手术结束前30min,对照组(C组)泵入等量的生理盐水。术中使用FORE-SIGHT_脑氧饱和度监测仪监测rSO_2。记录入室时(T_0)、诱导插管后(T_1)、气腹后60min(T_2)和苏醒后(T_3)的rSO_2、MAP、PaCO_2和PaO_2。记录丙泊酚和瑞芬太尼的使用情况、术后躁动和恶心呕吐的发生情况。于术前1d、术后1d和3d使用蒙特利尔认知功能评分量表(MoCA)进行评分,记录患者术后认知功能障碍(POCD)发生情况。结果T_2时两组rSO_2、PaCO_2明显高于T_1时(P0.05)。D组患者丙泊酚和瑞芬太尼用量明显少于C组(P0.05)。D组MoCA评分明显高于C组(P0.05);D组2例(6.7%)患者发生POCD,明显低于C组的9例(30%)(P0.05)。结论右美托咪定用于老年患者腹腔镜前列腺癌根治手术对rSO_2未见明显影响,但可以减少POCD的发生。     

磷酸肌酸钠对老年患者全麻恢复期BIS值和苏醒质量的影响

目的观察磷酸肌酸钠对老年患者全麻恢复期BIS值和苏醒质量的影响。方法选择择期全麻下行经腹胆囊切除术患者60例,男31例,女29例,年龄65~80岁,ASAⅠ或Ⅱ级,按照计算机产生的随机数字将患者分为两组,每组30例。P组在切皮时开始静脉输注磷酸肌酸钠1.0g(溶于100ml生理盐水),输注时间30min,C组静脉输注相同容量的生理盐水。记录诱导前(T0)、吸痰时(T_1)、拔管时(T_2)、拔管后1min(T_3)、5min(T_4)、10min(T_5)、15min(T_6)的HR和BIS值,T_3~T_6的Steward苏醒评分;记录患者麻醉时间、手术时间、清醒时间、拔管时间、意识恢复时间和丙泊酚、瑞芬太尼、顺苯阿曲库铵用量,并观察术中心动过速发生情况。结果与T0时比较,T_1~T_4时两组患者BIS值明显降低,HR明显增快(P0.05);T_1~T_4时P组BIS值明显高于C组(P0.05);P组清醒时间、拔管时间、意识恢复时间明显短于C组(P0.05);C组患者术中有6例发生心动过速,P组有2例,C组术中心动过速发生率明显高于P组(P0.05);T_3、T_4时P组Steward苏醒评分明显高于C组(P0.05)。结论术中静脉输注1.0g磷酸肌酸钠可明显提高经腹胆囊切除术的老年患者全麻恢复期BIS值及苏醒质量,且可降低术中心动过速的发生率。     

右美托咪定预防骨科脊柱手术患者全麻后寒战的临床观察

目的 观察右美托咪定对骨科脊柱手术患者全麻后寒战的预防作用.方法 全麻下行脊柱手术的患者90例,随机均分为右美托咪定组(D组)和对照组(C组).D组麻醉诱导后泵注右美托咪定(负荷剂量0.5 μg/kg,10 min泵完,以0.4 μg·kg-1·h-1维持);C组泵注生理盐水,泵注速度及方法同D组.监测并记录诱导前(基础值)、插管后5、15、30、60 min及拔管前后HR、MAP、SpO2、肛温(T),观察并记录术后入麻醉后恢复室(PACU)即刻、30、60 min VAS评分、Ramsay镇静评分(RSS);记录寒战分级、寒战出现的时间.结果 与基础值及与C组比较,插管后30、60 min、拔管前和拔管后D组HR明显减慢(P＜0.05);拔管前、拔管后D组MAP明显降低(P＜0.01).与基础值比较,插管后30、60 min和拔管前、拔管后两组患者T降低(P＜0.05).D组术后寒战发生率明显降低(P＜0.01);入PACU后即刻、30 min D组VAS评分明显降低(P＜0.05或P＜0.01);入PACU后即刻、30、60 min D组RSS评分明显升高(P＜0.01).结论 术中泵注右美托咪定可有效预防骨科脊柱手术患者全麻后寒战的发生.     

不同剂量右美托咪定对成年患者心脏电生理平衡的影响

目的观察不同剂量右美托咪定对成年患者心脏电生理平衡的影响。方法择期全麻手术患者80例,男28例,女52例,年龄18～60岁,BMI 18.5～23.9 kg/m~2,ASAⅠ或Ⅱ级。采用随机数字表法分为四组:对照组(C组)、右美托咪定低浓度组(L组)、中浓度组(M组)和高浓度组(H组),每组20例。L组、M组和H组10 min内输注0.6、0.8、1.0μg/kg负荷量右美托咪定后,分别泵注0.3、0.4、0.5μg·kg~(-1)·h~(-1)维持量右美托咪定20 min;C组静脉泵注等容量生理盐水。在右美托咪定泵注前(T_0)、右美托咪定负荷量输注10 min(T_1)、右美托咪定维持量输注20 min(T_2)时采集12导联心电图,测量计算QT间期、QTc间期、Tp-e间期、Tp-e/QT比值及心脏电生理平衡指数(icEB),同时记录HR和MAP。结果与T_0和C组比较,L组、M组及H组T_1时HR明显减慢,T_2时MAP明显降低,HR明显减慢(P0.05)。与T_1时比较,T_2时L组、M组及H组MAP明显降低(P0.05)。与T_0时比较,T_1—T_2时L组、M组及H组QT间期明显延长,QTc间期明显缩短,Tp-e/QT比值明显减小,iCEB明显增大(P0.05)。与C组比较,T_2时L组、M组及H组QT间期明显延长,QTc间期明显缩短(P0.05)。结论右美托咪定持续输注可破坏心脏电生理平衡,导致心电稳定性降低,增加恶性心律失常的发生风险,但在所用剂量范围内对其影响无剂量依赖性。     

右美托咪定对异体肾移植患者围术期肾功能的影响

目的研究右美托咪定对同种异体肾移植患者围术期肾功能的影响。方法选择行同种异体肾移植患者60例,男36例,女24例,年龄25~45岁,ASAⅡ或Ⅲ级,随机分为两组:右美托咪定组和对照组,每组30例。右美托咪定组麻醉诱导前给予右美托咪定1μg/kg泵注10min,随后以0.6μg·kg~(-1)·h~(-1)维持泵注至手术结束前30min;对照组以等容量生理盐水维持至手术结束前30min。记录两组患者在麻醉诱导前(T_1)、吻合血管开放前(T_2)、吻合血管开放后即刻(T_3)、吻合血管开放后30min(T_4)和手术结束后(T_5)的HR和SBP,于T_2、T_4、术后24h(T6)及术后48h(T7)采取静脉血检测血尿素氮(BUN)、血肌酐(Cr)、IL~(-1)8和半胱氨酸蛋白酶抑制剂C(Cys C)的浓度;记录术中液体输注量和尿量。结果 T_3时右美托咪定组HR明显慢于对照组;T_2、T_3时右美托咪定组SBP明显高于对照组(P0.05)。与T_2时比较,T6、T7时两组Cys C、BUN、Cr浓度明显降低,且T7时右美托咪定组Cys C浓度明显低于对照组(P0.05)。与T_2时比较,T6、T7时两组IL~(-1)8浓度明显降低,且右美托咪定组降低幅度明显大于对照组(P0.05)。右美托咪定组围术期尿量明显多于对照组(P0.05)。两组术中液体输注量差异无统计学意义。结论围术期应用右美托咪定可有效保护肾移植患者的肾功能。     

闭环靶控输注静脉全麻中持续泵注艾司洛尔对麻醉药用量和术后疼痛的影响

目的探讨闭环靶控输注静脉全麻过程中持续泵注艾司洛尔对麻醉药用量及术后疼痛的影响。方法选择择期行腹腔镜胆囊切除手术的患者60例,男29例,女31例,年龄25~45岁,ASAⅠ或Ⅱ级。随机分为艾司洛尔组(E组)和生理盐水组(C组)。E组麻醉诱导前5 min静注艾司洛尔0.5mg/kg,麻醉维持过程中持续泵注艾司洛尔50μg·kg~(-1)·min~(-1)直至拔管,C组输注等量生理盐水。两组均采用闭环靶控输注系统进行麻醉诱导和维持。记录丙泊酚和瑞芬太尼用量、术后入PACU时、术后30min和术后1h的VAS疼痛评分以及术后恶心呕吐发生情况。结果诱导时E组丙泊酚用量为(87.9±13.8)mg,明显少于C组的(110.2±20.4)mg(P0.05)。麻醉维持时E组瑞芬太尼用量为(606.8±204.4)μg,明显少于C组的(870.0±208.2)μg(P0.05)。两组丙泊酚总用量差异无统计学意义。E组术后30 min和术后1h的VAS疼痛评分明显低于C组(P0.05)。两组术后恶心呕吐发生率差异无统计学意义。结论闭环靶控输注静脉全麻中持续泵注艾司洛尔能减少麻醉镇痛药用量,减轻术后早期疼痛程度。     

参附注射液对止血带引起的下肢缺血-再灌注肺损伤的影响

目的探讨参附注射液对止血带引起的下肢缺血-再灌注肺损伤的影响。方法选择行单侧下肢手术患者60例,男36例,女24例,ASAⅠ或Ⅱ级。将患者随机分为参附注射液组(SF组,n=32)和对照组(C组,n=28)。两组患者均采用腰-硬联合麻醉,给予0.75%布比卡因1.5ml,上电脑气压止血带(压力为300mm Hg)止血。SF组于上止血带致缺血前30min静脉泵入参附注射液1ml/kg(加入100ml生理盐水中),松止血带前5min再次泵入1ml/kg(加入50ml生理盐水中);C组在相同时点分别静脉注射等量复方乳酸钠。记录上止血带前(T_0)、松止血带后5min(T_1)、15min(T_2)、30min(T_3)的MAP和HR;采集静脉血测定血浆血栓素B2(TXB2)和丙二醛(MDA)浓度。结果与T_0时比较,T_1~T_3时两组MAP明显降低(P0.05);T_2、T_3时SF组MAP明显高于C组(P0.05)。两组患者HR组间组内差异均无统计学意义。T_2、T_3时SF组TXB2和MDA浓度明显低于C组(P0.05或P0.01)。结论参附注射液具有抗氧化作用,可减轻止血带所致的下肢缺血-再灌注肺损伤。     

间苯三酚复合达克罗宁胶浆防治全麻患者麻醉恢复期导尿管相关膀胱刺激征的效果

目的评价间苯三酚复合达克罗宁胶浆预防全麻患者麻醉恢复期导尿管相关膀胱刺激征(catheter-related bladder discomfort,CRBD)的效果。方法择期全麻下拟行腹腔镜胆囊切除术男性患者120例,年龄18～60岁,体重46～80kg,ASAⅠ或Ⅱ级。采用随机数字表法将其分为三组,每组40例:间苯三酚复合达克罗宁胶浆组(P组)、舒芬太尼组(S组)和对照组(C组)。P组于全麻诱导行气管插管术后,经尿道口注入达克罗宁胶浆5 ml,S组和C组于相同时点注入等容量生理盐水并用石蜡油润滑导尿管,之后行导尿术,导尿成功后夹闭导尿管,30 min后打开。手术结束前15min P组静脉注射间苯三酚80mg,S组静脉注射舒芬太尼0.10μg/kg,C组给予等容量生理盐水5ml。术后待患者完全清醒后拔除导尿管。记录苏醒时间、气管导管拔除时间及拔除气管导管后5min(T_1)、15min(T_2)、30min(T_3)、1h(T_4)、和2h(T_5)Riker镇静-躁动评分;记录导尿管拔除时间,记录术后2h内CRBD的发生情况及其程度以及恶心呕吐和呼吸抑制的发生情况。结果与C组比较,S组苏醒时间和气管导管拔除时间明显延长,T_1～T_4时Riker镇静-躁动评分、CRBD发生率和程度明显降低(P0.05);P组T_1～T_5时Riker镇静-躁动评分、CRBD发生率和程度明显降低(P0.05)。与S组比较,P组苏醒时间和气管拔管时间明显缩短,T_1～T_4时P组Riker镇静-躁动评分明显升高,T_5时Riker镇静-躁动评分、CRBD发生率和程度明显降低(P0.05)。三组恶心呕吐、呼吸抑制发生率和导尿管拔除时间差异无统计学意义。结论经尿道注入达克罗宁胶浆复合手术结束前15min静脉注射间苯三酚,可明显减少全麻患者麻醉恢复期CRBD的发生,并减轻其严重程度,效果优于舒芬太尼。     

右美托咪定对重症肌无力患者围术期血流动力学及苏醒质量的影响

目的 探讨全麻术中静脉泵注右美托咪定对重症肌无力患者围术期血流动力学及苏醒质量的影响.方法 选择60例择期行胸腺扩大切除术的重症肌无力患者(Ossermann Ⅰ～Ⅱb型)随机均分为右美托咪定组(D组)和对照组(C组).D组患者麻醉诱导前,给予右美托咪定负荷剂量0.5 μg/kg,然后静脉泵注0.5 μg·kg-1·h-1至手术结束前30 min,C组在同一时段静脉泵注同等容量的生理盐水.记录麻醉前(T1)、插管时(T2)、切皮时(T3)、劈胸骨时(T4)及拔管时(T5)的MAP、HR、单位时间内全麻药的用量;记录自主呼吸恢复时间、呼之睁眼时间和意识完全清醒时间及Steward苏醒评分.结果 与T1时比较,T2～T5时两组MAP明显升高,HR明显增快(P＜0.05);C组全麻药用量明显高于D组(P＜0.05);C组自主呼吸恢复时间、呼之睁眼时间、完全清醒时间和拔管时间明显长于D组,Steward苏醒评分明显低于D组(P＜0.05).结论 全麻术中静脉泵注右美托咪定能够保证重症肌无力患者围术期血流动力学稳定、减少全麻药用量、缩短拔管时间,改善了患者的苏醒质量.     

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.     

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.     

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.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

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.