术前静脉输注6%羟乙基淀粉200/0.5溶液对患者术后免疫功能的影响

目的 探讨术前静脉输注6%羟乙基淀粉(HES)200/0.5溶液对患者术后免疫功能的影响.方法 择期胆囊切除术患者40例,年龄21～58岁,体重47～79 kg,性别不限,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将患者随机分为2组(n=20):6%HES 200/0.5组(H组)和复方醋酸钠组(A组).麻醉诱导前经15 min静脉输注6%HES 200/0.5溶液或复方醋酸钠溶液10 ml/kg.于术前、术后1 h、术后1和3 d时取静脉血样,测定血清IL-6、IL-8、TNF-α、IL-2和IL-10以及IgG、IgA和IgM的浓度.结果 与术前比较,两组患者术后血清IL-6、IL-8、TNF-α、IL-2和IL-10浓度均升高,A组术后血清IgA和IgG浓度降低(P＜0.05或0.01),IgM浓度差异无统计学意义,H组上述指标差异无统计学意义(P＞0.05);与A组比较,H组术后血清IL-6、IL-8和TNF-α浓度降低,IL-2、IL-10、IgA和IgG浓度升高(P＜0.05).结论 术前静脉输注6%HES 200/0.5溶液可改善患者术后的免疫功能.

Abstract：

Objective To investigate the effect of 6 % hydroxyethyl starch (HES) 200/0.5 infusion before operation on postoperative immne function in patients. Methods Forty ASA Ⅰ or Ⅱ patients of both sexes aged 21-58 yr weighing 47-79 kg were randomly divided into 2 groups ( n = 20 each): 6% HES 200/0.5 group (group H) and compound sodium acetate group (group A). 6% HES 200/0.5 10 ml/kg or compound sodium acetate solution was infused intravenously over 15 min before anesthesia induction. Anesthesia was induced with iv injection of propofol, fentanyl and vecuronium and maintained with target-controlled infusion of propofol and infusion of remifentanil. Venous blood samples were collected before operation and at 1 h, 1 day and 3 days after operation to detect the serum concentrations of IL-6, IL-8, TNF-α, IL-2, IL-10, IgG, IgA andIgM. Results Serum concentrations of IL-6, IL-8, TNF-α, II-2 and IL-10 were significantly higher after operation in the two groups, and serum concentrations of IgA and IgG were significantly lower after operation in group A than those before operation ( P ＜ 0.05 or 0.01 ). Serum concentrations of IL-6, IL-8 and TNF-α were significantly lower, while serum concentrations of IL-2, IL-10, IgA and IgG were significantly higher after operation in group H than in group A ( P ＜0.05). Conclusion Preoperative infusion with 6% HES 200/0.5 can improve the immune function after operation in patients.     

6%羟乙基淀粉130/0.4液体复苏对创伤性脑损伤合并失血性休克大鼠的脑保护作用

目的 探讨6%羟乙基淀粉130/0.4(6%HES 130/0.4)液体复苏对创伤性脑损伤合并失血性休克大鼠的脑保护作用.方法 健康成年雄性SD大鼠60只,体重300～350 g,随机分为5组(n=12):假手术组(S组)、模型组(M组)、生理盐水组(NS组)、6%.HES 130/0.4组(HES组)和晶体.胶体高渗透压混合液组(HHS组).分别参照Feeney改良法和Wiggers改良法制备大鼠创伤性脑损伤模型和失血性休克模型.S组仅切开头皮,钻开骨窗,不制备创伤性脑损伤和失血性休克模型;M组制备创伤性脑损伤和失血性休克模型;其余3组均制备创伤性脑损伤和失血性休克模型,并于休克60 min时开始复苏.NS组经股静脉输注3倍于放血量的生理盐水;HES组经股静脉输注等于放血量的6%HES 130/0.4;HHS组经股静脉输注等于放血量的HHS(10%HES 130/0.4与7.5%NaCl按1:1混合),各复苏组均在30 min内将液体输注完毕.实验期间记录平均动脉压(MAP),采用ELISA法测定血清S-100β蛋白浓度;于复苏180 min时取脑组织,计算脑组织含水量,采用EUSA法测定脑组织TNF-α和IL-6的含量.结果 与M组比较,NS组、HES组和HHS组复苏后MAP和脑组织含水量升高,HES组脑组织TNF-α和IL-6的含量降低,HES组和HHS组复苏后血清S-100蛋白浓度降低(P<0.05),NS组血清S-100β蛋白浓度差异无统计学意义(P>0.05);与NS组比较,HES组和HHS组复苏后MAP升高,脑组织含水量和血清S-100β蛋白浓度均降低,HES组脑组织TNF-α和IL-6的含量降低(P<0.05);与HES组比较,HHS组脑组织TNF-α和IL-6的含量升高,血清S-100β蛋白浓度升高(P<0.05),MAP差异无统计学意义(P>0.05).结论 6%HES 130/0.4液体复苏可对创伤性脑损伤合并失血性休克大鼠产生脑保护作用,且该作用强于HHS,其脑保护作用的机制可能与降低脑组织炎性反应有关.     

不同复苏方法用于重度非控制性失血性休克犬早期复苏效果的比较

目的 比较垂体后叶素复苏、高渗盐水复苏和胶体液复苏用于重度非控制性失血性休克(UHS)犬的早期复苏效果.方法 成年中华田园犬,雌雄不拘,体重10～ 12 kg,采用肠系膜动脉分支切断+股动脉穿刺放血法制备重度UHS模型.取重度UHS犬24只,采用随机数字表法,将其分为3组(n=8):血管加压素复苏组(P组):静脉注射垂体后叶素负荷量0.1U,继之以0.04 U·kg-1 ·min-1的速率静脉输注,间断追加0.1 U；高渗盐水复苏组(SA组):单次注射静脉输注7.5％高渗氯化钠注射液6 ml/kg;胶体液复苏组(HES组):静脉输注200/0.5羟乙基淀粉溶液,输注速率18 ～ 38 ml· kg-1·h-1,各组均维持MAP不低于50 mm Hg.各组复苏1h后结扎肠系膜动脉分支彻底止血,充分容量复苏.1h后结扎止血行充分容量复苏.于模型制备前(T0)、模型制备成功即刻(T1)、复苏15 min(T2)、30 min(T3)、45 min(T4)、60 min(T5)以及结扎肠系膜动脉并充分容量复苏2 h(T6)时记录血流动力学指标；T0、T1、T5和T6时取动脉血样,行血气分析；T0、T5、T6及拔除导管后3d采集静脉血样,采用双抗体夹心ABC-ELISA法,测定血清TNF-α、IL-10及促肾上腺皮质醇激素(ACTH)的浓度,计算TNF-α/IL-10比值.记录结扎肠系膜动脉并充分容量复苏后72 h内动物的生存情况.记录UHS模型制备期间(急性创伤失血期)和非控制性出血复苏期的出血量.结果 与P组比较,SA组SBP、DBP、CVP、HR升高,Hct降低,血清IL-10浓度降低,TNF-α浓度、TNF-α/IL-10比值升高,HES组SBP、HR和Lac升高,血清IL-10浓度降低,TNF-α和ACTH浓度、TNF-α/IL-10比值升高(P＜0.05或0.01)；与SA组比较,HES组SBP、DBP、CVP、HR降低,Lac升高,血清IL-10浓度降低,TNF-α和ACTH浓度、TNF-α/IL-10比值升高(P＜0.05).SA组非控制性失血期失血量明显多于P组和HES组(P＜0.05),P组和HES组非控制性失血期失血量比较差异无统计学意义(P＞0.05).3组动物生存率比较差异均无统计学意义(P＞0.05).结论 持续静脉输注小剂量垂体后叶素复苏能更好地维持血压平稳,抑制应激反应和炎性反应,出血相对较少,对于重度UHS犬的复苏效果优于高渗盐水复苏及胶体液复苏.     

A2B腺苷受体在6%羟乙基淀粉130/0.4降低脓毒症大鼠肺毛细血管通透性中的作用

目的 探讨A2B腺苷受体(A2BAR)在6%羟乙基淀粉(HES)130/0.4降低脓毒症大鼠肺毛细血管通透性中的作用.方法雄性SD大鼠50只,体重250～300 g,随机分为5组(n=10):假手术组(S组)、脓毒症组(CLP组)、低剂量HES组(H1组)、中剂量HES组(H2组)和高剂量HES组(H3组).CLP组、H1组、H2组和H3组采用盲肠结扎穿孔术(CLP)制备脓毒症模型,S组仅开腹后缝合.盲肠结扎穿孔术后4 h时,H1组、H2组及H3组分别经2 h输注6%HES 130/0.4 7.5、15.0、30.0 ml/kg,CLP组给予生理盐水30 ml/kg.CLP后6 h时处死动物,取肺组织,测定肺毛细血管通透性、A2BAR表达、环磷酸腺苷(cAMP)、蛋白激酶A(PKA)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和白细胞介素-10(IL-10)的含量.结果与S组比较,其余各组肺毛细血管通透性和A2BAR表达上调,CLP组肺组织cAMP、IL-6和TNF-α含量升高,H1组、H2组和H3组肺组织cAMP、PKA、IL-6、IL-10和TNF-α含量升高(P＜0.05或0.01);与CLP组比较,H1组、H2组和H3组肺毛细血管通透性均降低,A2BAR表达均上调,肺组织cAMP、PKA和IL-10含量升高,而肺组织IL-6和TNF-α含量降低(P＜0.05或0.01);6%HES 130/0.4降低肺毛细血管通透性及上调A2BAR表达的效应呈剂量依赖性(P＜0.05或0.01);6%HES 130/0.4 15.0ml/kg升高肺组织cAMP和PKA含量及抑制炎性反应的效应最明显(P＜0.05或0.01).结论 6%HES 130/0.4可上调脓毒症大鼠肺组织A2BAR表达,从而降低肺毛细血管通透性.     

复方乳酸钠和60羟乙基淀粉对毒血症犬呼吸动力学的影响

目的 研究复方乳酸钠(LR)或6％羟乙基淀粉溶液(6％HES)行液体复苏对毒血症犬呼吸动力学的影响.方法 健康杂种犬45只,随机均分为三组:对照组(假模型组,C组),腹腔注入生理盐水,无毒血症,用复方乳酸钠30 ml/kg作为输注液体;LR组,腹腔注入肠液,毒血症后用复方乳酸钠30 ml/kg作为复苏液体;HS组,腹腔注入肠液,毒血症后用6％ HES 10 ml/kg作为复苏液体.于毒血症注药前(T1)及注药后l h(T2)、4 h(T3)、8 h(T4)测定MAP、心输出量(CO)和肺毛细血管楔压(PCWP)等血流动力学指标.同时记录吸气峰压(PIP)、呼吸肌作功(Wob)、动态顺应性(Cdyn)及无效腔比率(Vd/Vt)等呼吸动力学指标.记录总尿量及体重,计算肺湿/干比.结果 T3、T4时LR、HS组MAP、CO明显低于T1时和C组,T4时HS组MAP、CO明显高于LR组(P＜0.05).T3、T4时LR、HS组PIP、Wob、Vd/Vt明显高于T1时和C组,T4时HS组PIP、Wob明显低于LR组(P＜0.05).HS组肺湿/干比明显低于LR组(P＜0.05).结论 6％HES更有利于毒血症犬血流动力学维持,保护了肺功能.     

羟乙基淀粉130/0.4对脓毒症大鼠肺毛细血管通透性、炎性细胞因子及NF-κB表达的影响

目的 研究羟乙基淀粉130/0．4（HES 130/0．4）对脓毒症大鼠肺毛细血管通透性、炎性细胞因子、中性粒细胞浸润及NF-κB表达的影响。方法 36只雄性SD大鼠,随机分为6组,每组6只,假手术组（Sham组）和HES 130/0．4对照组（HES组）大鼠只开腹、牵引盲肠、复位、关腹和复苏,但盲肠不结扎也不穿孔;脓毒症组（S组）采用盲肠结扎穿孔（CLP）的方法建立脓毒症大鼠模型;脓毒症＋ HES1-3组（S＋H1-3组）分别于CLP后4h时静脉输注HES 7．5、15、30ml/kg,Sham组和S组均于相应时点静脉输注生理盐水30 ml/kg,HES组静脉输注HES 130/0．4 30 ml/kg,输注速率为0．2 ml/min。于CLP后6h内持续监测心率和平均动脉压,CLP后6h处死大鼠,取肺组织,计算含水量,测定毛细血管通透性、炎性细胞因子（TNF-α、IL-6、IL-10）及细胞核内NF-κB的表达,光镜下观察肺组织病理学。Sham组、HES组、S组、S＋H1组、S＋H2组及S＋H3组各另取16只大鼠,于CLP后连续4d观察大鼠生存情况。结果 与Sham组比较,S＋H1组、S＋H2组、S＋H3组肺毛细血管通透性、含水量、TNF-α、IL-6、IL-10水平、NF-κB表达均升高（P＜0．05）;与S组比较,S＋H1组TNF-α的水平、S＋H2组、S＋H3组毛细血管通透性、含水量、TNF-α、IL-6水平降低,S＋H2组IL-10水平升高,S＋H1组、S＋H2组、S＋H3组NF-κB表达降低（P＜0．05）,S＋H2组肺组织中性粒细胞浸润程度减轻;S＋H1组、S＋H2组、S＋H3组4d内大鼠生存率差异无统计学意义（P＞0．05）。结论 HES 130/0．4 15 ml/kg可改善脓毒症大鼠肺毛细血管通透性,下调促炎细胞因子（TNF-α、IL-6）、上调抗炎细胞因子（IL-10）的表达,抑制中性粒细胞的浸润及NF-κB表达。     

不同剂量6%羟乙基淀粉130/0.4预先给药对大鼠内毒素性急性肺损伤的影响

目的 研究不同剂量6%羟乙基淀粉130/0.4(6% HES 130/0.4)预先给药对大鼠内毒素性急性肺损伤的影响.方法 72只健康清洁级雄性SD大鼠随机分为6组(n=12),对照组(C组)经尾静脉注射生理盐水30 ml/kg;肺损伤组(L组)经尾静脉注射脂多糖(LPS)5 mg/kg;不同剂量6%HES130/0.4组分别经尾静脉注射6%HES 130/0.4 7.5 ml/kg(H1组)、15 ml/kg(H2组)和30 ml/kg(H3组),1 h后再经尾静脉注射LPS 5 mg/kg;H4组经尾静脉注射6%HES 130/0.4 30 ml/kg.各组给药速率均为0.2ml/min.注射LPS后4 h行动脉血气分析,气管插管.每组取6只大鼠,测定肺组织微血管通透性指数(PMPI);每组取6只大鼠,测定支气管肺泡灌洗液(BALF)蛋白浓度、肺组织湿/干重比(W/D)、髓过氧化物酶(MPO)活性,血清肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-10(IL-10)、丙二醛(MDA)浓度和超氧化物歧化酶(SOD)活性,观察肺组织病理学.结果 与L组比较,H2组血清TNF-α、IL-1β、MDA浓度和肺组织MPO活性降低,血清IL-10浓度和SOD活性升高,H1组IL-1β浓度降低,H1组、H2组和H3组PMPI、BALF蛋白浓度和W/D均降低(P＜0.05);与H2组比较,H1组和H3组血清TNF-α、MDA浓度和肺组织MPO活性升高,血清SOD活性、IL-10浓度降低,H3组血清IL-1β浓度升高(P＜0.05).H1组、H2组和H3组较L组肺组织损伤较轻,其中H2组损伤最轻.结论 15 ml/kg6%HES 130/0.4预先给药可减轻大鼠内毒素性急性肺损伤,其机制可能与抑制炎性因子释放、减少肺内中性粒细胞聚集和氧自由基生成、改善肺微血管通透性有关.     

不同液体治疗对感染性休克新生兔全身炎性反应的影响

目的 探讨不同液体治疗对感染性休克新生兔全身炎性反应的影响.方法 健康新西兰长耳新生兔100只,采用盲肠结扎穿孔(CLP)法制备感染性休克模型,随机分为5组(n=20):假手术组(S组)、CLP组、乳酸钠林格氏液组(R组)、乳酸钠林格氏液+6%羟乙基淀粉组(R+HES组)和6%羟乙基淀粉组(HES组).CLP后即刻,R组静脉输注乳酸钠林格氏液30 ml/kg 1 h;R+HES组依次静脉输注乳酸钠林格氏液20 ml/kg 40 min和6%羟乙基淀粉10 ml/kg 20 min;HES组静脉输注6%羟乙基淀粉30 ml/kg 1 h.于CLP后即刻、0.5、1、2、4、8 h(T1～6)时记录MAP.于T6时取颈总动脉血样,测定血浆IL-6和IL-10的浓度.结果 与T1时比较,CLP组T4～6时MAP降低,R组T5.6时MAP降低(P＜0.05),其余各组差异无统计学意义(P＞0.05).与S组比较,CLP组MAP降低,血浆IL-6浓度升高,IL-10浓度降低,R组MAP降低,血浆IL-6浓度升高,HES组血浆IL-10浓度升高(P＜0.05).与CLP组比较,R+HES组和HES组血浆IL-6浓度降低,IL-10浓度升高,R组血浆IL-10浓度升高(P＜0.05).结论 新生兔感染性休克早期静脉输注乳酸钠林格氏液与6%羟乙基淀粉(2∶1)治疗,有利于维持促炎细胞因子和抑炎细胞因子的平衡,从而减轻全身炎性反应,其效果优于单独静脉输注乳酸钠林格氏液或6%羟乙基淀粉.     

羟乙基淀粉术前血液稀释联合术中控制性降压对全身炎症反应的影响

目的 观察羟乙基淀粉(HES 130/0.4)术前行中度急性高容量血液稀释(AHHD)联合术中控制性降压(CH)对椎间盘摘除术患者全身炎症反应(SIR)的影响.方法 择期行椎间盘摘除术男性患者54例,随机均分为:复方乳酸钠组(Ⅰ组)、HES 200/0.5组(Ⅱ组)和HES 130/0.4组(Ⅲ组).三组输注速率均为20 ml/kg,30 min输完.术中采用硝酸甘油行CH,维持MAP存65～70mm Hg.分别于麻醉诱导前(T0)、手术开始前即刻(T1)、降压至目标值即刻(T2)、停止降压即刻(T3)及术毕(T4)抽取中心静脉血5 ml,ELESA法检测各时点血浆肿瘤坏死因子α(TNF-α)、白细胞介素-8(IL-8)浓度,流式细胞术检测T0、T1、T4多形核白细胞(PMNL)凋亡数.结果 与T0时比较,三组T3～T4时TNF-α、IL-8浓度和PMNL凋亡数显著高于T0时(P<0.05);Ⅱ组和Ⅲ组存T1～T4时TNF-α、IL-8均低于Ⅰ组(P<0.05).T4时Ⅱ组和Ⅲ组PMNL凋亡数高于Ⅰ组(P<0.05),Ⅲ组明显高于Ⅱ组(P<(0.05).结论 HES 200/0.5和HES 130/0.4均可降低椎间盘摘除术患者术中炎症反应,后者作用更显著.     

雷米芬太尼后处理对心肺转流诱导犬心肌损伤和炎症因子的影响

目的 探讨雷米芬太尼后处理对心肺转流(CPB)诱导犬心肌损伤和炎症因子的影响.方法 健康成年雄性犬12只,随机均分为雷米芬太尼组(R组)和对照组(C组).两组动物经麻醉和开胸后,建立CPB心肌缺血-再灌注模型,阻断升主动脉60 min.R组于主动脉阻断55 min时自主动脉根部随温血灌注液持续输注雷米芬太尼5 min,速度为4μg·kg-1·min-1,灌注液输注速率2 ml·kg-1·min-1持续5 min.C组于相同时点行温血再灌注,灌注液输注速率同R组.分别于CPB前5 min(T0)、阻断升主动脉后30 min(T1)、开放升主动脉后5 min(T2)、停CPB 30 min(T3)和停CPB 2 h(T4)采集股动脉血,检测心肌肌钙蛋白I(cTnI)的浓度和血浆肿瘤坏死因子α(TNF-α)、白细胞介素-6(IL-6)、IL-8.记录主动脉开放后心脏自动复跳情况,电镜下观察心肌组织超微结构改变.结果 与T0时比较,两组cTnI、TNF-α在CPB后各时点均明显升高(P＜0.05或P＜0.01),升主动脉开放后各时点IL-6、IL-8均明显升高(P＜0.01).R组升主动脉开放后各时点cTnI、TNF-α、IL-6、IL-8均明显低于C组(P＜0.01).R组心肌组织结构损伤程度轻于C组.结论 雷米芬太尼后处理可抑制犬CPB诱导促炎细胞因子的释放,减轻心肌再灌注损伤.     

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.     

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.     

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.     

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.     

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.
Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.
Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r²=0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.
Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.     

缺氧对肾小管上皮细胞分泌外泌体的影响

目的    观察缺氧对肾小管上皮细胞分泌外泌体的影响,探讨外泌体在缺氧致肾脏损伤中的作用及机制。 方法    （1）常氧（21% O₂）及缺氧（1% O₂）分别处理大鼠肾小管上皮细胞（NRK-52E）48 h,收集细胞上清液并使用高速梯度离心法分离外泌体。采用透射电镜、纳米示踪分析、Western印迹、蛋白浓度定量鉴定并比较两组外泌体的基本特性。（2）在共培养实验中,以不同浓度（1、10、50、100、300 mg/L）的常氧外泌体、缺氧外泌体分别干预脂多糖（LPS）诱导的大鼠原代腹腔巨噬细胞,使用实时荧光定量PCR与酶联免疫吸附试验（ELISA）法分别检测巨噬细胞白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、诱导型氮氧化物合酶（iNOS）水平;使用Western印迹法检测巨噬细胞磷酸化（p）STAT/STAT及细胞因子信号传导抑制蛋白1（SOCS1）的蛋白表达;最后,使用实时荧光定量PCR法检测常氧外泌体与缺氧外泌体中炎性反应相关微RNA（microRNA,miR）的表达差异。 结果    （1）离心得到的囊泡具有外泌体典型的结构,粒径小于150 nm,表达外泌体标志蛋白CD63,说明分离得到外泌体。缺氧对肾小管上皮细胞分泌的外泌体形态、粒径分布比例无明显影响,但提高了外泌体的分泌量。（2）缺氧外泌体相比于常氧外泌体促进了LPS诱导的M1型巨噬细胞IL-6、TNF-α、iNOS 的表达和分泌（均P＜0.01）,同时提高STAT的磷酸化水平并减少SOCS1的蛋白表达（均P＜0.01）;对炎性反应相关microRNA检测发现缺氧外泌体中miR-155、miR-27a表达量较常氧外泌体明显升高（P＜0.05）。 结论    缺氧可改变外泌体的生物学功能,表现为协同促进LPS诱导的M1型巨噬细胞的表型转化,这可能是慢性肾脏病微炎性反应状态持续的原因之一。     

In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis

Abstract While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.     

Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy: A controlled randomised trial

Background: Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV). Methods: Thirty-eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre-and intra-operative arterial blood gases and O₂ flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions. Results: Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 ± 1.8 (μg · kg^?1· h^?1 vs. 6.6 ± 4.8 μg · kg^?1· h^?1), a lower O₂ supply (3.3 ± 2.8 1/min vs. 11.6 ± 3.4 1/min), a shorter recovery time (5.4 ± 2.9 min vs. 9.8 ± 7.1 min) and no manually assisted ventilation (0 ± 0 vs. 1 ± 1.1 nd?/procedure). Intraoperative PaCO₂ was higher in the SAV (8.1 ± 1.3 kPa) than in the INPV group (5.0 ± 1.6 kPa) and intraoperative pH differed in the two groups (7.26 ± 0.05, SAV vs. 7.47 ± 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3). Conclusions: As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces 02 need and affords optimal surgical conditions. INPV appears a safe, non-invasive and effective ventilatory management during IRB.