丙泊酚对内毒素性急性肺损伤大鼠血清TNF-α、IL-1β及IL-10的影响

目的探讨内毒素性急性肺损伤(ALI)大鼠用丙泊酚后处理对血清肿瘤坏死因子(TNF)-α、白细胞介素(IL)-1β和IL-10影响。方法雄性SD大鼠96只,随机均分为四组,每组24只。脂多糖(LPS)致伤组(B组)、丙泊酚低剂量治疗组(C组)和丙泊酚高剂量治疗组(D组)经尾静脉注射LPS 5 mg/kg制作ALI模型;之后生理盐水对照组(A组)和B组泵入生理盐水,C、D组分别注射丙泊酚2、4 mg/kg后再分别泵入4、8 mg.kg-1.h-1。分别在制模后1、2、3、4 h抽取动脉血测定TNF-α、IL-1β及IL-10的水平。结果制模后各时点A组大鼠TNF-α、IL-1β和IL-10含量均明显低于其它三组(P<0.05或P<0.01)。制模后1、2 h B组TNF-α、IL-1β和IL-10含量明显高于C、D组(P<0.01),C组IL-1β和IL-10含量明显高于D组(P<0.05或P<0.01)。制模后3、4 h B组IL-1β和IL-10含量仍明显高于C、D组(P<0.01),C组显著高于D组(P<0.01)。结论丙泊酚可以显著抑制ALI大鼠血清TNF-α、IL-1β及IL-10上升的程度。     

肺保护性通气在老年患者腹腔镜子宫内膜癌根治术中的应用

目的探讨肺保护性通气在老年患者腹腔镜子宫内膜癌根治术中的应用效果。方法选择2019年6月至2020年6月择期行腹腔镜子宫内膜癌根治术的老年女性患者60例,年龄65～80岁,BMI 20～28 kg/m~2,ASAⅠ或Ⅱ级。采用随机数字表法将患者分为两组:肺保护性通气组(P组)和常规机械通气组(R组),每组30例。P组设置V_T 7 ml/kg、呼气末正压通气(PEEP) 7 cmH_2O、每30分钟规律手法肺复张一次;R组仅设置V_T 9 ml/kg,未采用PEEP和肺复张。记录气腹前即刻、气腹后2 h、手术结束即刻的气道峰压(Ppeak)、气道平台压(Pplat)、肺动态顺应性(Cdyn)及血清IL-6、IL-8、TNF-α浓度。记录气腹前即刻和出复苏室即刻的氧合指数(PaO_2/FiO_2)。结果与气腹前即刻比较,气腹后2 h、手术结束即刻两组Pplat、Ppeak及血清IL-6、IL-8、TNF-α浓度均明显升高(P0.05),Cdyn明显降低(P0.05);出复苏室即刻两组PaO_2/FiO_2明显降低(P0.05)。与R组比较,P组气腹后2 h、手术结束即刻Pplat、Ppeak及血清IL-6、IL-8、TNF-α浓度明显降低(P0.05),Cdyn明显升高(P0.05);出复苏室即刻PaO_2/FiO_2明显升高(P0.05)。结论肺保护性通气可以减轻老年患者腹腔镜子宫内膜癌根治术围术期呼吸功能损伤和炎症反应,可安全用于老年患者腹腔镜子宫内膜癌根治术。     

氨溴索预先给药对兔单肺通气时肺损伤的影响

目的 评价氨溴索预先给药对兔单肺通气时肺损伤的影响.方法 家兔67只随机分为4组,麻醉下气管插管,机械通气,A组(n=18)持续双肺通气4 h,B组(n=16)、C组(n=15)和D组(n=18)单肺通气2 h后恢复双肺通气2 h,C组和D组在单肺通气前分别静脉注射氨溴索5、15 mg/kg(生理盐水稀释至20 ml),B组给予等容量生理盐水.分别于麻醉前(基础状态)、单肺通气1、2 h、恢复双肺通气1、2 h时采集静脉血样,测定血清超氧化物歧化酶(SOD)活性、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和IL-8浓度,进行白细胞(WBC)计数和中性粒细胞计数,最后一次采集血样后,处死动物,取双侧肺组织,光镜下观察肺组织病理学.结果 与A组比较,B组、C组和D组SOD活性降低,TNF-α、IL-6、IL-8、WBC计数和中性粒细胞计数升高(P<0.05或0.01).与B组比较,C组和D组SOD活性升高,TNF-α、IL-6、IL-8、WBC计数和中性粒细胞计数降低(P<0.05或0.01).C组和D组间上述指标差异无统计学意义(P>0.05).A组双侧肺组织未见明显损伤;C组和D组非通气侧肺组织损伤轻于B组.结论 静脉注射氨溴索5、15 mg/kg可减轻单肺通气诱发兔肺损伤,其机制与抑制炎性反应及脂质过氧化反应有关.     

盐酸戊乙奎醚对心肺转流后肺损伤的保护作用

目的探讨盐酸戊乙奎醚对心肺转流(CPB)后肺损伤的保护作用。方法 40例二尖瓣置换手术患者随机均分为盐酸戊乙奎醚组(P组)和对照组(C组),两组麻醉方法相同。P组在麻醉诱导后和升主动脉开放前分别缓慢静注盐酸戊乙奎醚0.02mg/kg;C组在同时点给予等容量的生理盐水。手术开始前(T1)和升主动脉开放后30min(鱼精蛋白中和后,T2)分别进行右肺中叶灌洗。测定肺灌洗液(BALF)中细胞因子白细胞介素-8(IL-8)和肿瘤坏死因子α(TNF-α)浓度;行血气分析计算肺泡-动脉氧分压差(PA-aDO2)。结果 T2时C组BALF中IL-8、TNF-α和PA-aDO2明显高于T1时和P组(P0.05或P0.01)。结论盐酸戊乙奎醚通过抑制炎性细胞因子释放IL-8和TNF-α,减轻CPB后的肺损伤。     

术前雾化吸入布地奈德对开胸手术患者单肺通气时炎性反应的影响

目的 评价术前雾化吸入布地奈德对开胸手术患者单肺通气时炎性反应的影响.方法 肺叶切除术患者50例,年龄20 ～ 60岁,体重50 ～ 80 kg,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将其分为2组(n=25):对照组(C组)和布地奈德组(B组).术前C组雾化吸入生理盐水20 min;B组雾化吸入布地奈德1 mg 20 min.分别于单肺通气前(T1)、单肺通气结束后30 min(T2)、术后24 h(T3)和48 h(T4)时采集动脉血样,进行血气分析；采集静脉血样,采用ELISA法测定血清TNF-α、IL-1、IL-6、IL-8和IL-10的浓度.分别于T1和T2时,记录气道峰压、气道平台压和肺顺应性,采用ELISA测定支气管肺泡灌洗液TNF-α、IL-1、IL-6、IL-8和IL-10浓度.结果 与C组比较,B组T1和T2时气道峰压和气道平台压降低,肺顺应性升高,T2时支气管肺泡灌洗液中TNF-α、IL-1、IL-6和IL-8的浓度降低,T2-4时氧合指数升高,血清TNF-α、IL-1、IL-6和IL-8的浓度降低(P＜0.05),各时点PaCO2比较差异无统计学意义(P＞0.05).结论 术前雾化吸入布地奈德可抑制开胸手术患者单肺通气时的炎性反应,有助于改善肺功能.     

核因子-κB在体外循环后肺损伤发病机制中的作用

目的探讨核因子-κB(NF-κB)在体外循环后肺损伤发病机制中的作用和甲基强的松龙预处理对肺损伤的防治作用。方法健康雄性家犬12条,随机均分为两组:甲基强的松龙组(M组)和对照组(C组)。持续检测ECG、MAP和平均肺动脉压(MPAP),体外循环前(T0)、主动脉开放30 min(T2)9、0 min(T3)分别测定CVP、肺动脉楔压(PCWP)、心排出量(CO)、肺顺应性和动脉血气并计算肺血管阻力(PVR)、心脏指数(CI)和肺泡-动脉氧分压差(PA-aDO2)。T0、主动脉开放前(T1)、T2、T3分别:(1)采取动脉血测定肿瘤坏死引子α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、白细胞介素-8(IL-8);(2)取适量右上肺组织测定肺组织湿干重比(W/D)、髓过氧化物酶活性(MPO)变化、细胞核内NF-κB p65亚单位的活性变化及肺病理学改变。结果(1)两组T1、T2、T3和T0相比,NF-κB活性、TNF-α、IL-1β、IL-6、IL-8、MPO和W/D均显著增加(P<0.01),T1、T2、T3M组和C组相比NF-κB活性、TNF-αI、L-1βI、L-6I、L-8、MPO和W/D均显著降低(P<0.01);(2)病理学改变:T1、T2、T3和T0相比两组均出现肺间质中性粒细胞浸润,肺间隔增宽,肺泡腔有渗出并且C组较M组改变明显;(3)血液动力学改变:MAP、CI在组内及两组之间各时点均无显著变化,T2、T3C组PVR较T0明显升高(P<0.05),而M组无显著变化;(4)肺功能:两组T2、T3较T0PA-aDO2显著增加(P<0.01),M组T2、T3较C组PA-aDO2明显降低(P<0.05);C组T2、T3肺顺应性较T0明显降低(P<0.05),而M组无明显变化,PaCO2无明显变化。结论体外循环可引起肺组织NF-κB的活化和细胞因子的显著增加,发生肺损伤;甲基强的松龙可抑制NF-κB的活性,减轻肺损伤。     

戊乙奎醚对肢体缺血再灌注诱发大鼠肺损伤的影响

目的 探讨戊乙奎醚对肢体缺血再灌注诱发大鼠肺损伤的影响.方法 雄性Wistar大鼠36只,体重250～300 g,随机分为4组(n=9):对照组(Ⅰ组)、肢体缺血再灌注诱发肺损伤组(Ⅱ组)、小剂量盐酸戊乙奎醚组(Ⅲ组)和大剂量盐酸戊乙奎醚组(Ⅳ组).Ⅱ组、Ⅲ组和Ⅳ组麻醉后双后肢缺血3 h,Ⅲ组和Ⅳ组分别于股动脉开放前10 min肌肉注射盐酸戊乙奎醚2、9 mg/kg,再灌注4 h快速取肺,计算肺组织湿/干重比(W/D),透射电镜下观察肺组织超微结构,酶联免疫吸附法测定肺组织肿瘤坏死因子-α(TNF-α)和白细胞介素(IL)-10含量.结果 与Ⅰ组比较,Ⅱ组肺组织W/D及TNF-α、IL-10含量升高(P<0.01);与Ⅱ组比较,Ⅲ组肺组织W/D及TNDF-α含量降低、IL-10含量升高(P<0.01);与Ⅲ组比较,Ⅳ组肺组织W/D及TNF-α含量降低、IL-10含量升高(P<0.01).结论 戊乙奎醚可减轻肢体缺血再灌注诱发大鼠肺损伤,且呈剂量依赖性,其机制与降低肺组织炎性反应有关.     

吸入一氧化氮对内毒素性急性呼吸窘迫综合征犬肺炎性反应的影响

目的 通过观察吸入一氧化氮(NO)对内毒素性急性呼吸窘迫综合征(ARDS)犬肺组织中肿瘤坏死因子-α(TNF-α)、白细胞介素-8(IL-8)及CD11b mRNA表达的影响,从分子水平探讨吸入NO治疗ARDS的机制。方法 12条毕格犬静脉输注内毒素达ARDS后,随机分成两组,单纯机械通气组(C组,n=6),机械通气 吸入NO组(NO组,n=6),NO吸入浓度分别为10、20、40、80 ppm,按顺序各吸入1 h后,降至10 ppm吸6 h。无菌条件下取肺组织,提取肺组织总RNA,采用逆转录-多聚酶链反应技术检测TNF-α、IL-8、CD11b mRNA表达的水平。结果 C组肺组织中的TNF-α、IL-8及CD11b mRNA表达水平高于NO组(P<0.05)。结论 NO抑制炎性反应可能是其对ARDS产生治疗作用的一个方面。     

不同剂量瘦素对大鼠机械通气肺损伤的影响

目的评价不同剂量瘦素对大鼠机械通气肺损伤的影响。方法健康清洁级SD雄性大鼠48只,6～8周龄,采用随机数字表法分为四组:气管切开保留自主呼吸的假手术组(A组)、机械通气模型组(B组)、瘦素10μg/kg组(C组)和瘦素50μg/kg组(D组),每组12只。采用10%水合氯醛3.5 ml/kg麻醉大鼠,疼痛反射消失后C组腹腔注射瘦素10μg/kg,D组腹腔注射瘦素50μg/kg,A、B组腹腔注射等容量生理盐水,注射后即刻进行气管切开,插管机械通气。A组气管插管后保留自主呼吸,B、C、D组机械通气建立VILI模型,参数设置:V_T 20 ml/kg,RR 80次/分,I∶E 1∶1,FiO_2 21%,PEEP 0 mmHg,通气时间4 h。分别于基础状态、通气结束时抽取股动脉血进行血气分析。通气结束后放血处死大鼠,在4℃下取肺组织并收集支气管肺泡灌洗液(bronchoalveolar lavage fluid, BALF),光镜下进行中性粒细胞计数,采用ELISA法测定TNF-α、IL-6、IL-1β浓度;取肺组织称重,计算肺湿干重比(W/D);观察肺组织病理改变并进行病理评分;采用Western blot检测肺组织研磨液中NF-κB p65含量。结果与A组比较,B、C、D组W/D、肺损伤评分、BALF中性粒细胞计数、TNF-α、IL-6、IL-1β浓度及肺组织NF-κB p65含量明显升高(P0.01)。与B组比较,C、D组BALF中性粒细胞计数、TNF-α、IL-6、IL-1β浓度及肺组织肺损伤评分、NF-κB p65含量明显降低(P0.05)。与C组比较,D组BALF中性粒细胞计数、TNF-α、IL-6、IL-1β浓度及肺组织肺损伤评分、NF-κB p65含量明显降低(P0.05)。结论瘦素可降低大鼠机械通气肺损伤中炎性因子的表达水平,减轻肺损伤,50μg/kg较10μg/kg作用明显。     

吸入不同浓度一氧化碳对大鼠脑死亡致肺损伤的影响

目的 评价吸入不同浓度一氧化碳(CO)对大鼠脑死亡(BD)致肺损伤的影响.方法 成年雄性Wistar大鼠32只,随机分为4组(n=8),假手术组(S组)向大鼠颅内置入Fogarty导管,吸入40%O2 150 min;BD组、C1组和C2组向大鼠颅内置入Fogarty导管,通过膨胀导管前端球囊诱导BD,膨胀球囊30 min后确认BD情况.发生BD后BD组吸入40%O2 120min,C1组和C2组分别吸入40%O2+0.025%CO和40%O2+0.050%CO混合气120 min.于麻醉前(基础状态)、吸入CO前即刻、吸入CO 30、60、90和120 min时采集动脉血样,进行动脉血气分析.吸入CO 120 min时采集动脉血样,测定血浆IL-6和TNF-α浓度;采集血样后,处死大鼠,取肺组织,测定髓过氧化物酶(MPO)活性;计算肺组织湿/干重比(W/D比),并进行肺组织损伤评分(LIS评分).结果 与S组比较,BD组、C1组和C2组PaO2/FiO2、BE和pH值降低,血浆IL-6和TNF-α的浓度、MPO活性、肺组织W/D比和LIS评分升高(P＜0.05);与BD组比较,C1组和C2组PaO2/FiO2、BE和pH值升高,血浆IL-6和TNF-α的浓度、MPO活性、肺组织W/D比和LIS评分降低(P＜0.05);与C1组比较,C2组血浆IL-6和TNF-α的浓度降低(P＜0.05),血气分析指标、MPO活性、肺组织W/D比和LIS评分差异无统计学意义(P＞0.05).结论 吸入0.025%和0.050%CO减轻大鼠BD致肺损伤的效应无差异.     

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.