对比观察脂质纳泡与微泡在高强度聚焦超声消融兔肝中的增效作用

目的观察正常兔肝中脂质纳泡与微泡对高强度聚焦超声(HIFU)消融效果的影响,探讨纳泡的应用价值。方法采用机械振荡法联合低速离心制备纳泡,观察和分析纳泡及微泡的形态、大小及分布。18只健康新西兰兔随机分为3组:HIFU+生理盐水组、HIFU+微泡组及HIFU+纳泡组,耳缘静脉注入各溶液15s后开始HIFU辐照,辐照功率为180 W,辐照时间5s,观察HIFU辐照前后回声变化,检测靶区组织的凝固性坏死体积以及微细结构变化,并作统计学分析。结果制备的脂质纳泡粒径均一,纳泡、微泡的平均粒径分别为(588.00±53.02)nm、(3058.00±545.20)nm;HIFU+微泡组与HIFU+纳泡组,靶区凝固性坏死体积[(124.26±16.72)mm3,(121.35±11.25)mm3]差异无统计学意义(P0.05),但均显著大于HIFU+生理盐水组(62.49±4.54)mm3(P均0.05);各组坏死组织微细结构均严重破坏。结论脂质纳泡具有与微泡相同的HIFU增效作用,为纳泡在HIFU技术中的深入研究提供实验依据。     

低强度聚焦超声靶向爆破微泡

目的 探讨自制低强度聚焦超声（LIFU）体外靶向爆破微泡范围、空间分布,及在兔肝脏组织中应用LIFU辐照载紫杉醇脂质微泡（PLM）的定位控释情况。方法 ①采用4种不同声强（0.3、0.6、0.9、1.2 W/cm2）LIFU（频率1 MHz,焦距160 mm,占空比50%）分别辐照含脂质微泡的水囊,同时从不同切面观察并记录水囊内微泡爆破范围及空间分布形态;②选取新西兰大白兔10只,随机平均分为聚焦超声组（A组）和非聚焦超声组（B组）;对实验兔静脉注射PLM后,对A、B组分别采用LIFU和非聚焦超声定位辐照肝脏2 min;辐照后1 h处死实验兔,取焦域中心及距离中心1 cm、2 cm、3 cm处的肝脏组织,采用反相高效液相色谱法测定各肝脏组织内的紫杉醇含量。结果 ①LIFU体外定位爆破微泡范围局限、形状规则,爆破范围随声强增高而增大;②A组辐照中心处紫杉醇浓度最大,距离中心处越远,紫杉醇浓度越低（F=201.81,P〈0.05）;B组中各位置紫杉醇浓度的差异无统计学意义（F=1.36,P〉0.05）;辐照中心处,A组紫杉醇浓度高于B组（t=5.28,P〈0.05）。结论 LIFU能够实现体内外靶向爆破微泡,其聚焦部位和微泡爆破范围可调。     

超声定位辐照载血卟啉微泡治疗兔肝VX2肿瘤的实验研究

目的探讨超声定位辐照载血卟啉微泡介导药物靶向释放技术治疗兔VX2肝移植瘤的效果。方法利用35只新西兰大白兔建立肝VX2移植瘤模型,并随机均分为超声定位辐照载血卟啉微泡组（US＋LMLH组）、超声定位辐照血卟啉组（US＋HP组）、超声定位辐照空白脂质微泡组（US＋MB组）、单纯载血卟啉微泡组（LMLH组）、单纯血卟啉组（HP组）、单纯超声辐照组（US组）和生理盐水对照组（C组）。治疗前后用二维超声、CDFI及CEUS观察肿瘤大小、回声及血流灌注情况,计算肿瘤体积大小及生长抑制率;同时观察不同处理组肝内转移及远处转移情况;并用透射电镜观察肿瘤细胞的超微结构。结果US＋LMLH组肿瘤内部呈混合回声,CDFI及超声造影显示肿瘤的滋养血管明显减少,生长抑制率高于其他各组;在肝内及远处转移方面,US＋LMLH组较少转移,明显优于其他各组;超微结构显示US＋LMLH组细胞膜破坏,线粒体明显肿胀。结论超声定位辐照载血卟啉微泡能有效激活血卟啉,具有较强的体内抑瘤效果。     

一种新型相变纳米微球增强高强度聚焦超声消融的实验研究

目的探讨脂质包裹1,1,2-三氯三氟乙烷相变纳米微球对高强度聚焦超声(HIFU)消融效果的影响。方法采用薄膜水化法制备脂质包裹1,1,2-三氯三氟乙烷相变纳米微球并检测其理化性质。通过离体及在体实验验证其对HIFU的增效作用。离体实验采用250 W、10s的连续波辐照离体牛肝组织。在体实验采用200 W、5s的连续波辐照活体新西兰大白兔的肝脏组织。测量、计算HIFU辐照后靶区的凝固性坏死体积、能效因子(EEF)及强回声区体积,并进行统计分析。结果相变纳米微球在溶液中呈球状、均匀分布,粒径均一。离体实验显示,注射有纳米微球的牛肝组织HIFU辐照后凝固性坏死体积、EEF及强回声区体积均大于未经处理的牛肝组织(t=28.80、19.55、14.30,P=0.01、0.02、0.02)。在体实验显示,注射有纳米微球的新西兰大白兔肝组织HIFU辐照后凝固性坏死体积、EEF及强回声区体积均大于对照组(t=9.41、13.52、15.67,P=0.02、0.01、0.01)。结论脂质包裹1,1,2-三氯三氟乙烷相变纳米微球可明显提高HIFU消融效率。     

超声辐照微泡介导双自杀基因转染对裸鼠乳腺癌杀伤作用的在体研究

目的：探讨超声辐照微泡介导CD/TK双自杀基因质粒转染对在体乳腺癌的杀伤效应。 方法：用人乳腺癌MCF-7细胞建立裸鼠移植瘤模型后,将荷瘤裸鼠随机分为对照组、质粒组、超声辐照组、超声辐照微泡组,每组5只。对照组仅给予CD与TK相应的前药（5-氟胞嘧啶与更昔洛韦）;质粒组注射质粒（含CD/TK基因）与前药;超声辐照组注射质粒与前药,并予超声辐照;超声辐照微泡组注射靶向超声造影剂（质粒与微泡混合物）与前药,并予超声辐照。实验期间记录裸鼠肿瘤生长情况;处理结束后5 d,剥除肿瘤,计算各组的抑瘤率;用倒置荧光显微镜观察目的基因瘤内转染情况,计算基因转染效率;RT-PCR法检测目的基因的表达;免疫组化法计数肿瘤的微血管密度（MVD）。 结果：与对照组比较,质粒组肿瘤的生长无统计学差异（P>0.05）,而超声辐照组与超声辐照微泡组肿瘤生长被明显抑制（均P<0.05）,质粒组、超声辐照组、超声辐照微泡组的抑瘤率分别为3.72%、21.40%、47.13%。质粒组、超声辐照组、超声辐照微泡组基因转染效率分别为0.78%、2.81%、23.87%,后者转染效率明显高于前两组（均P<0.05）。超声辐照组与超声辐照微泡组肿瘤组织中均出现CD/TK基因阳性片段,而对照组与质粒组的肿瘤组织中未见。超声辐照组与超声辐照微泡组肿瘤组织MVD计数均明显低于对照组,且超声辐照微泡组低于超声辐照组（均P<0.05）,质粒组MVD计数与对照组无统计学差异（P>0.05）。 结论：超声辐照微泡介导的双自杀基因系统能有效提高基因转染效率与表达,从而增强对肿瘤生长和肿瘤微血管的生成的抑制作用。     

低强度超声联合载HSV1-TK/GCV自杀基因阳离子微泡对高强度聚焦超声不完全消融后残余肝癌细胞的抑制作用

目的探讨载单纯疱疹病毒Ⅰ型胸苷激酶/更昔洛韦(HSV1-TK/GCV)自杀基因的阳离子微泡联合低强度超声对高强度聚焦超声(HIFU)辐照后残留肝癌SMCC-7721细胞的抑制作用。方法以低功率HIFU辐照肝癌SMCC-7721细胞,选取最佳残存细胞亚系并稳定培养。通过低强度超声辐照载TK基因的阳离子微泡转染细胞。分为对照组(残余癌)、残余癌+超声+TK/GCV组、残余癌+微泡+TK/GCV组及残余癌+微泡+超声+TK/GCV组。以Western Blot法检测TK基因是否成功转入并稳定表达。采用流式细胞仪观察并检测基因转染效率。筛选适宜前药GCV浓度,并检测各组别相同条件下细胞存活率。以流式细胞仪检测细胞周期及凋亡率。结果HIFU功率为5 W,频率为10.20 MHz,持续辐照40s,可获得残癌稳定模型。前药GCV的最适浓度为100μg/ml。相同条件下残余癌+微泡+超声+TK/GCV组癌细胞存活率最低(P0.05),仅为(43.16±3.18)%,且TK蛋白的表达明显高于其他各组(P均0.05)。结论低强度超声联合载HSV1-TK/GCV自杀基因阳离子微泡对高强度聚焦超声不完全消融肝癌细胞有明显抑制作用。     

超声靶向微泡破裂增强恩度凝胶抑制裸鼠乳腺癌移植瘤血管生成

目的探讨超声靶向微泡破裂对瘤体内注射恩度凝胶抑制裸鼠乳腺癌移植瘤血管生成作用的影响。方法制备载恩度的PLGA-PEG-PLGA温度敏感型凝胶,检测恩度凝胶体外释放及超声辐照对药物释放的影响;建立荷人乳腺癌裸鼠移植瘤模型,分为模型组、恩度凝胶瘤体内注射组、超声靶向微泡破裂组、恩度凝胶联合超声靶向微泡破裂组,每7天治疗1次,连续3次后行肿瘤CEUS,测定肿瘤组织微血管密度,评价各种处理对肿瘤血管生成的抑制作用。结果恩度凝胶在体外平稳释放约1周,超声辐照可提高恩度凝胶的释放速率;恩度凝胶瘤体内注射联合超声靶向微泡破裂处理具有明显的抑制肿瘤血管生成作用,肿瘤CEUS峰值强度及微血管密度均明显低于模型组及恩度凝胶治疗组(P0.05)。结论超声靶向微泡破裂可阻断荷人乳腺癌裸鼠移植瘤微循环,并有效控制恩度凝胶的药物释放速率,使之释放更多药物作用于血管内皮细胞,具有明显的抑制肿瘤血管生成作用。     

离体大鼠心肌缺氧/复氧不同时间点心肌组织中TNF-α水平的动态变化及意义

目的探讨离体大鼠心肌缺氧/复氧在不同时间点心肌组织中肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)表达的变化及其意义。方法采用Langendorff方法制备离体大鼠心肌缺氧/复氧模型。48只雄性SD大鼠随机分为4组:对照组(sham组)、缺氧/复氧组(H/R,分为0.5 h组、1h组、2 h组3个组)。比较每组左心室发展压(LVDP)、左心室发展压最大上升/下降速率(±dp/dtmax)和心率(heart rate,HR)的变化,检测各组大鼠心肌中TNF-α和肌酸激酶同工酶(CK-MB)的浓度和TNF-αm RNA的表达水平,观察心肌结构的变化。结果与对照组相比,缺氧/复氧各组(H/R 0.5 h组、1 h组、2 h组)大鼠LVDP、±dp/dtmax、HR的值均降低(P0.05),心肌中TNF-α和CK-MB水平均上升(P0.05),TNF-αm RNA的表达明显升高(P0.05),随缺氧/复氧时间的延长,以上指标变化更明显,H/R 0.5 h组、1 h组、2 h组间两两比较,差异均有统计学意义(P0.05),复氧2 h组心肌中的TNF-α和CK-MB的浓度为最高,TNF-αm RNA的表达达到峰值。结论缺氧/复氧期间,大鼠心肌组织中TNF-α水平逐渐升高,与心肌组织的损伤程度相关,可能是引起心肌缺氧/复氧损伤的机制之一。     

微泡超声增强庆大霉素对大肠杆菌抗菌作用的机制研究

目的 观察微泡超声对庆大霉素抑制大肠杆菌的增强效果,并探讨其可能机制.方法 配制1×107 CFU/ml大肠杆菌(ATCC 25922)悬液,分为空白对照组、微泡(Sonovue)组、超声组和微泡超声组,每组按照庆大霉素浓度进一步分为0、1、2 μg/ml三个浓度组(n=8).微泡浓度为体积分数10％.超声辐照强度为300 mW/cm2,频率为46.5 kHz,占空比为33％,辐照时间为12 h.平板计数法比较各组残留活菌密度,取对数(log10 CFU/ml)行统计学分析.每组另取少量菌液行透射电镜扫描,观察残留菌的微观形态.结果 未添加庆大霉素时,四组残留菌量的差异无统计学意义;庆大霉素1 μg/ml时,微泡超声组(5.44±0.49 log10 CFU/ml)与空白对照组(7.44±0.64 log10 CFU/ml)、微泡组(7.19±0.38 log10 CFU/ml)、超声组(6.86±0.29 log10 CFU/ml)的差异均有统计学意义;庆大霉素浓度为2μg/ml时,微泡超声组(2.87±0.28 logl0 CFU/ml)与空白对照组(4.45±0.43 log10 CFU/ml)、微泡组(4.33±0.40 log10 CFU/ml)、超声组(3.89±0.37 log10 CFU/ml)的差异仍均有统计学意义.上述药物浓度下超声组与空白对照组菌量的差异均无统计学意义.透射电镜扫描提示,与单纯超声辐照相比,微泡超声辐照可迸一步改变细菌胞膜的形态,胞膜皱褶更明显,存在较多不连续.结论 与单纯超声辐照相比,微泡超声可以进一步提高庆大霉素对大肠杆菌的抗菌效果,可能与微泡增强超声的“声孔效应”有关.     

20 kHz超声联合微泡诱导人前列腺癌PC3细胞的细胞自噬及早期凋亡

目的探讨低频、低功率超声联合微泡造影剂诱导人雄激素非依赖性前列腺癌PC3细胞早期细胞凋亡及自噬。方法以频率20kHz、声功率80mW超声连续波辐照人前列腺癌PC3细胞悬液60s,之后分为单纯微泡组(A)、单纯超声组(B)、超声联合微泡组(C)、空白对照组(D),分别给予相应处理。辐照后继续培养24h,以流式细胞仪检测细胞早期凋亡情况,吖啶橙染色荧光显微镜观察细胞胞浆内酸性囊泡,透射电镜观察细胞自噬泡。结果 4组细胞早期凋亡率差异有统计学意义(P0.01);两两比较,除A组与D组差异无统计学意义(P0.05)外,余差异均有统计学意义(P0.01)。C组细胞核基本正常,胞浆内可见大量发红色荧光的酸性囊泡及大量由双层膜包裹的自噬泡或自噬体。D组细胞形态基本正常,胞浆内未见到明显自噬泡形成。结论低频低功率超声联合微泡造影剂能明显提高人雄激素非依赖型前列腺癌PC3细胞的早期凋亡率,并可促进细胞自噬。     

经导管注射微泡介导的体外超声溶栓实验

目的探讨经导管血栓内注射微泡对体外超声溶栓的增强作用。方法取新鲜人血血栓40份分为4组,每组10份,实验1组:血栓内注射尿激酶和微泡+超声,对照1组:血栓内注射尿激酶和微泡+超声假照;实验2组:经外周循环注射尿激酶和微泡+超声;对照2组:经外周循环注射尿激酶和微泡+超声假照,比较4组的溶栓率。超声频率1.0MHz,声压512kPa。另用超声激励MBDiO释放,观察治疗后血栓内荧光分布与强度。结果实验1组的溶栓率(37.70%±3.17%)显著高于实验2组(11.67%±1.13%)、对照1组(14.37%±2.22%)及对照2组(7.90%±0.68%,P0.05)。血栓内注射微泡后,内可见大片强回声后伴声影,治疗后强回声区在血栓内有扩散。激光共聚焦显微镜观察实验1组治疗后血栓内可见大量明亮荧光信号分布,而实验2组治疗后的血栓内部基本无荧光信号。结论血栓内注射微泡和尿激酶介导的超声溶栓率显著高于经静脉给药方法。     

载多西紫杉醇脂质微泡联合超声靶向微泡破裂对兔VX2肝癌微血管的作用

目的探讨载多西紫杉醇脂质微泡（DLLM）联合超声靶向微泡破裂（UTMD）对兔VX2肝癌微血管的抑制作用。方法建立60只兔VX2肝癌动物模型,将其随机分为6组（n=10）：单纯药物组（Doc组）、单纯载药微泡组（DLLM组）、药物＋超声组（Doc＋US组）、单纯微泡＋超声组（PLM＋US组）、载药微泡＋超声组（DLLM＋US组）及对照组,比较各组动物肿瘤组织的血管密度（MVD）、CD34及VEGF的表达。结果处理后DLLM＋US组的CD34表达水平低于其他各组,MVD明显降低,与其他各组相比差异有统计学意义（P〈0.01）;DLLM＋US组的VEGF表达水平明显低于其他各组（P〈0.01）。结论 DLLM联合UTMD能抑制兔VX2肝癌的微血管生成,从而抑制兔VX2肝癌的生长。     

携Sialyl Lewisx多聚体微泡超声造影评价小鼠腹主动脉的炎症反应

目的探讨采用携Sialyl Lewisx多聚体（PSLex）微泡靶向CEUS评价动脉系统血管炎症反应的可行性。方法构建分别携P-Sialyl Lewisx（MB-S）、抗P-选择素单抗（MB-P）和同型对照单抗（MB-C）的3种微泡,应用流式细胞仪分析其配体结合率,利用平行板流动腔和Image-Pro Plus图像分析软件,分析3种微泡在0.5、2.0和4.0dyn/cm2剪切应力下的靶向结合数目。对急性腹主动脉炎症模型（炎症组）和假手术模型（对照组）小鼠各9只,采用弹丸式注入以上微泡,6min后行CEUS检查,测量腹主动脉显影的声强度（VI）。结果 MB-P、MB-S的配体结合率比较差异无统计学意义（P〉0.05）。在3种剪切应力下,MB-S和MB-P的全程（6min）结合数目均高于MB-C（P均〈0.05）;在0.5dyn/cm2时,MB-S的全程结合数目与MB-P的差异无统计学意义（P〉0.05）,而在2.0和4.0dyn/cm2时,MB-S的全程结合数目明显多于MB-P（P均〈0.05）;各种微泡的全程结合数目均随剪切应力提高而减少（P均〈0.05）。在炎症组中,MB-S、MB-P和MB-C的VI值依次降低（P均〈0.05）;除MB-C外,MB-S和MB-P在炎症组的VI值均分别高于对照组（P均〈0.05）。结论在高剪切应力下MB-S的结合能力明显优于MB-P,可用于评价动脉血管内皮炎症反应。     

超声针联合微泡干预尿激酶溶解体外血凝块

目的 观察超声针联合微泡干预尿激酶溶解体外血凝块的效果。方法 以10 ml牛全血制备体外血凝块,将40个血凝块随机分为5组（每组8个）：对单纯超声组以超声针治疗8 min;对单纯尿激酶组注射2 ml尿激酶溶液（5 000 IU/ml）;对超声针+尿激酶组予以超声针治疗8 min+注射2 ml尿激酶溶液;对超声+生理盐水组予超声针治疗8 min+注射2 ml生理盐水;对超声针+尿激酶+微泡组于超声针+尿激酶组基础上向尿激酶溶液中加入0.01 ml自制微泡。以称重法计算各组血凝块溶解质量（W₀）及溶解率;观察大体标本溶解情况,并于扫描电镜下观察血凝块微观变化。另取9个血凝块随机分为3组（每组3个）：对照组,仅注入2 ml细胞膜特异性橙红色荧光染料1,1''-双十八烷基-3,3,3'',3''-四甲基吲哚羰花青高氯酸盐（DiI）溶液;超声组,超声针治疗8 min,同时注射2 ml DiI溶液;超声+微泡组,在超声组基础上于DiI溶液中额外加入0.01 ml自制微泡。于荧光显微镜下观察DiI渗透情况。结果 干预前各组血凝块质量（W_before）差异无统计学意义（P>0.05）;干预后各组血凝块溶解质量（W₀）及溶解率差异均有统计学意义（P均<0.01）,超声+尿激酶组与超声+尿激酶+微泡组W₀及溶解率均显著高于其余3组（P均<0.05）,但该2组间差异均无统计学意义（P均>0.05）。相比单纯超声组和单纯尿激酶组,超声+尿激酶组和超声+尿激酶+微泡组血凝块明显破坏,后者更为显著。超声组和超声+微泡组血凝块组织疏松,DiI渗透深远,满视野荧光,针道扩大,表面破坏,以超声+微泡组更显著。结论 超声针能显著提高尿激酶对体外血凝块的溶解能力;联合应用微泡后溶解质量未见显著增加。     

Immediate alterations in intestinal oxygen saturation and blood flow after massive small bowel resection as measured by photoacoustic microscopy

PurposeMassive small bowel resection (SBR) results in villus angiogenesis and a critical adaptation response within the remnant bowel. Previous ex vivo studies of intestinal blood flow after SBR are conflicting. We sought to determine the effect of SBR on intestinal hemodynamics using photoacoustic microscopy, a noninvasive, label-free, high-resolution in vivo hybrid imaging modality.MethodsPhotoacoustic microscopy was used to image the intestine microvascular system and measure blood flow and oxygen saturation (So₂) of the terminal mesenteric arteriole and accompanying vein in C57BL6 mice (n = 7) before and immediately after a 50% proximal SBR. A P value of less than .05 was considered significant.ResultsBefore SBR, arterial and venous So₂ were similar. Immediately after SBR, the venous So₂ decreased with an increase in the oxygen extraction fraction. In addition, the arterial and venous blood flow significantly decreased.ConclusionMassive SBR results in an immediate reduction in intestinal blood flow and increase in tissue oxygen utilization. These physiologic changes are observed throughout the remnant small intestine. The contribution of these early hemodynamic alterations may contribute to the induction of villus angiogenesis and the pathogenesis of normal intestinal adaptation responses.     

Cyclosporine, an immunosuppressant, attenuates phorbol-induced lung injury in rats

Objective

White cell activation in the lung plays a critical role to induce lung injury and lymphocytes in the thoracic duct system may also participate. We evaluated the effect of cyclosporine on phorbol myristate acetate (PMA)-induced lung injury.

Materials and Methods

We used an in situ isolated, blood perfused rat lung model to measure pulmonary arterial pressure (PAP) and lung weight gain (LWG; g) for 50 minutes after a bolus injection of PMA (0.05 μg/mL). Oxygen radical release was estimated by an LKB 1251 luminometer and by nitric oxide (NO) release as measured by an ENO-20 NO analyzer.

Results

In the group exposed to PMA alone, the mean PAP increased from 16.53 ± 1.28 to 43.33 ± 3.40 mm Hg (P < .001), and lung weight increased by 4.35 ± 0.67 g during the 50-minute perfusion after PMA challenge (P < .001). In vitro measurement showed that PMA induced a significant increase in oxygen radical release (P < .001). PMA attenuated NO release (P < .001) into the perfusion system. Pretreatment with cyclosporine (3 mg/kg) for 3 days prevented the increases in both PAP (P < .01) and LWG (P < .001). NO release was maintained in cyclosporine-pretreated rats. Cyclosporine also showed dose-dependent attenuation of oxygen radical release by PMA-activated white blood cells.

Conclusion

The mechanisms responsible for the protective effect of cyclosporine on the lung injury induced by phorbol may be related to an attenuation of oxygen radical production with maintenance of NO release.     

Assessment of postoperative risk factors for EEG abnormalities in routine clinical management after paediatric cardiopulmonary bypass

Open in a separate window OBJECTIVESThe postoperative risk factors for electroencephalogram(EEG) abnormalities after paediatric cardiopulmonary bypass (CPB) remain to be identified. We investigated the characteristics of EEG abnormalities and risk factors in routine clinical management post-CPB.METHODSEEG and cerebral oxygen saturation (ScO₂) were monitored in 96 patients (aged 3 days, 37 months, median 5 months) for 72 h post-CPB. Clinical measurements included 4-hourly arterial and central venous pressure, arterial blood gases, doses of inotropic and vasoactive drugs, daily C-reactive protein (CRP) and NT-proB-type Natriuretic Peptide (NT-proBNP). Demographics, STAT categories and outcomes (duration of mechanical ventilation,CICU stay) were recorded. UnRESULTSSeizures occurred in 20 patients (20.8%) beginning at 0–48 hand lasting 10 min–31 h; background abnormalities occurred in 67 (69.8%) beginning at 0–8 h and lasting 4–48 h. Patients with EEG abnormalities had worse outcomes. In univariable regression, seizures positively correlated with STAT categories, CPB time, temperature, blood pressure, central venous pressure, NT-proBNP, CRP, lactate and epinephrine, negatively with ScO₂ and PaCO₂ (P < 0.001 for lactate and epinephrine, P < 0.1 for the remaining). The degree of background abnormalities positively correlated with STAT categories, CPB time, operative time, central venous pressure, milrinone, negatively with blood pressure (P = 0.0003–0.087); it negatively correlated with lower dose of epinephrine (P < 0.001) and positively with higher dose (P = 0.03l). In multivariable regression, seizures positively correlated with epinephrine, lactate and temperature; the background abnormality correlations remain significant except for milrinone and operative time (P < 0.001 for epinephrine, P < 0.05 for the remaining).CONCLUSIONSNumerous perioperative risk factors are associated with EEG abnormalities post-CPB. The most significant and consistent risk factor is epinephrine.     

Gastric intramucosal pH and hepatic venous oximetry after cardiopulmonary bypass in valve replacement patients

To determine splanchnic perfusion after cardiopulmonary bypass, gastric intramucosal pH (pH_i) and hepatic venous oxygen saturation (S_HVO₂) were measured in 14 patients with cardiac valve replacement. Blood samples were analysed at 6, 12 and 24 h after admission to an intensive care unit. Gastric pH_i increased significantly (P <0.01) from 7.21 at 6h to 7.31 at 12 h and increased to 7.37 at 24 h while S_HVO₂ increased significantly (P <0.05) from 48% at 6 h to 57% at 12 h and 24 h. Cardiac index was >41/min per m² and mixed venous oxygen saturation >70%. Despite sufficient cardiac output, splanchnic perfusion decreased after cardiopulmonary bypass and recovered within 24 h after admission to the intensive care unit. It is concluded that gastric pH_i and S_HVO₂ are useful parameters for monitoring postoperative splanchnic perfusion in patients with open-heart surgery.     

Butorphanol in combination with dexmedetomidine provides efficient pain management in adult burn patients

ObjectiveThis study aimed to compare the sedation and analgesic effects of butorphanol alone and butorphanol in combination with dexmedetomidine on dressing changes in adult burn patients.MethodFrom June 2016 to May 2019, 44 adult burn patients from our department were enrolled in this prospective, double-blinded study. Their total burn surface area (TBSA) varied from 10% to 30%; and the depth of burn injury ranged from second degree to third degree. The patients were randomized into two groups. In the control group, butorphanol combined with saline was injected into the body via venous route during dressing change. In the observation group, butorphanol in combination with dexmedetomidine was injected. The variation in mean blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation were recorded at various time-points of the procedure. Visual Analogue Scale (VAS) of pain and Ramsay Sedation Scores (RSS) were also recorded at different time points. Consumption of butorphanol and adverse events in these two groups were compared.ResultsThe mean blood pressure and heart rate were significantly decreased in the observation group before butorphanol injection (P < 0.05) and before the dressing change (P < 0.05). The respiratory rates and peripheral oxygen saturation of these two groups showed no significant differences at all time points (P > 0.05). Patients in the observation group had lower VAS scores during dressing change (P < 0.05). The RSS Scores in the observation group were higher than those in the control group during (P < 0.05) and after the dressing change (P < 0.05). The consumption of butorphanol was more in the control group (P < 0.05), and the adverse events recorded in the control group were higher (P < 0.05).ConclusionButorphanol combined with dexmedetomidine can reduce analgesic use of butorphanol during dressing change. This combination resulted in a higher sedation score and fewer adverse effects.