弥散加权成像观察去甲肾上腺素诱导的高血压灌注对心搏骤停猪脑功能的影响

目的 观察高血压灌注心搏骤停猪自主循环恢复(ROSC)后脑功能的变化.方法 采用电刺激建立猪心室纤颤(室颤)模型,室颤4 min后给予标准心肺复苏(CPR),将ROSC猪按随机数字表法分为两组,每组5只.高血压灌注组立即给予去甲肾上腺素(NE)使平均动脉压(MAP)维持在室颤前血压的130％;正常灌注组给予NE维持MAP为室颤前水平;两组均监测4h观察血流动力学变化;于室颤前及ROSC后1h、3h用弥散加权成像(DWI)技术扫描大脑顶叶皮质,观察脑功能成像的动态变化;于复苏后24 h制备脑组织切片,观察顶叶的病理学变化.结果 与正常灌注组比较,高血压灌注组于ROSC后不同时间点心率(HR,次/min)、MAP(mm Hg,1 mm Hg=0.133 kPa)、心排血量(CO,L/min)、冠状动脉灌注压(CPP,mm Hg)均出现升高趋势(ROSC 30 min HR:167±8比140±15,ROSC 1 h MAP:131 ±9比108±10,ROSC 1 h CO:4.9±0.1比3.4±0.5,ROSC 2 h CPP:118±12比88±1,P＜0.05或P＜0.01).两组复苏前后DWI未见明显异常;复苏后大脑皮质表观弥散系数(ADC)均呈下降趋势,正常灌注组下降趋势较高血压灌注组明显.光镜下观察高血压灌注对脑的保护作用优于正常灌注组.结论 高血压灌注可引起心搏骤停猪复苏后血流动力学的改变,增加脑血流量,对脑具有保护作用,有利于促进神经功能的恢复.     

促红细胞生成素对心肺复苏后心肌功能的影响

目的 探讨促红细胞生成素(EPO)对窒息性心搏骤停大鼠心肺复苏(CPR)后心功能不全的心肌保护作用.方法 经夹闭气管8 min建立窒息性心搏骤停-CPR动物模型.按随机数字表法将24只SD大鼠分为3组,每组8只.CPR组窒息致心搏骤停后8 min予胸外按压和机械通气进行复苏;EPO组于自主循环恢复(ROSC)后3 min股静脉注射EPO 5 kU/kg;正常对照组不予任何处理.持续监测左心室收缩压(LVSP)、左心室舒张期末压(LVEDP)、左心室内压上升或下降最大速率(±dp/dt max)等血流动力学指标.于观察终点(ROSC后120 min)处死大鼠,采血测定血清心肌肌钙蛋白Ⅰ(cTnI)含量;光镜和透射电镜下观察心肌组织病理改变;原位末端缺刻标记法(TUNEL)检测心肌细胞凋亡.结果 CPR组和EPO组ROSC后30、60、90、120 min时LVSP、+dp/dt max和- dp/dt max绝对值均较基线水平明显下降.与正常对照组比较,CPR组和EPO组ROSC 30 min时LVSP(mm Hg,1 mm Hg=0.133 kPa)、+dp/dt max(mm Hg/s)、- dp/dt max绝对值(mm Hg/s)即明显下降(LVSP:119.52±12.68、134.32±15.78比165.82土7.05; +dp/dt max:4 457.14±826.22、6 019.85±1 192.19比10 325.93±773.09; - dp/dt max:-3 956.04±952.37、-4 957.22±838.60比-8 421.33±886.65,均P＜0.01),并持续至ROSC 120 min(LVSP:124.62±8.07、145.61±16.70比162.34±7.63; +dp/dt max:4 977.67±350.40、7 471.62±998.32比9 999.39±727.96;- dp/dt max:-4 145.51±729.77、-5 895.64±787.30比-8 089.75±981.52,均P＜0.01);经EPO处理后ROSC各时间点LVSP、+dp/dtmax和- dp/dtmax绝对值均较CPR组显著升高(均P＜0.05).CPR组和EPO组ROSC 120 min LVEDP(mm Hg/s)均较正常对照组明显升高(22.94±3.94、11.18±2.58比2.89±0.70,均P＜0.01),EPO组LVEDP则较CPR组明显下降(P＜0.05).光镜和电镜下观察,CPR组心肌细胞坏死、炎性细胞浸润,心肌细胞胞膜完整性丧失、线粒体肿胀,心肌细胞凋亡增加[凋亡细胞数(个):314.1±30.7比165.2±45.9,P＜0.01];经EPO干预后心肌病理损伤减轻,心肌细胞凋亡较CPR组减少(凋亡细胞数:242.1±20.0比314.1±30.7,P＜0.05).CPR组和EPO组ROSC 120 min血清cTnI (μg/L)均较正常对照组明显升高(20.70土5.96、16.98±3.81比2.60±0.86,均P＜0.01),而CPR组和EPO组比较无差异.结论 EPO可以改善窒息性心搏骤停大鼠CPR后的心功能,减轻心肌损伤,其机制可能与减少线粒体损伤和心肌细胞凋亡有关.     

心肺复苏持续胸外心脏按压时呼吸机潮气量与气道高压报警值设置的研究

目的 研究持续胸外心脏按压时设置呼吸机不同潮气量(VT)与气道高压报警值对心肺复苏(CPR)效果的影响.方法 将重症医学科中40例呼吸、心搏骤停患者按随机数字表法均分为小VT通气组与常规VT通气组.两组均采用容量控制模式,小VT通气组CPR开始后呼吸机VT设置为6～7 ml/kg,高压报警值由40 cm H2O(1 cm H2O=0.098 kPa)上调至60 cm H2O;常规VT通气组CPR开始后VT值和高压报警值均保持不变(VT8 ～ 12 ml/kg,高压报警值40 cm H2O).观察对比CPR过程中呼吸机实测VT、吸气峰压(PIP),10 min、30 min时血气分析和血乳酸,以及并发症发生情况.结果 CPR 10 min后小VT通气组动脉血气分析中的5项指标[pH值、血氧分压(PaO2,mm Hg,1 mm Hg=0.133 kPa)、血二氧化碳分压(PaCO2,mm Hg)、HCO3-(mmol/L)、血氧饱和度(SaO2)]及血乳酸(mmol/L)均优于常规VT通气组(pH值:7.21 ±0.09比7.13±0.07,PaO2:45.35±5.92比40.70±4.70,PaCO2:57.10±7.59比61.60±5.47,HCO3-:18.50±3.50比14.75±2.65,SaO2:0.796±0.069比0.699±0.066,乳酸:7.07±1.60比8.13±1.56,均P＜0.05).小VT通气组复苏成功率较常规VT通气组高(45％比15％,P＜0.05);PIP(cm H2O)较常规VT通气组低(37.25±7.99比42.70±7.40,P＜ 0.05);两组均未发现气压伤.结论 CPR时呼吸机设置小VT(6～7 ml/kg)并适当上调气道高压报警值比常规VT通气方法效果更好,且气压伤发生率未见明显增加.     

插入式腹主动脉按压对心搏骤停兔心肺脑复苏的实验研究

目的：探讨插入式腹主动脉按压心肺复苏（IAAC-CPR）对心搏骤停兔心肺脑复苏的效果。方法健康新西兰大白兔10只,雌雄不拘,按随机数字表法分为传统胸外按压心肺复苏（CC-CPR）组和IAAC-CPR组,每组5只。经颈静脉快速推注冰氯化钾并夹闭气管导管制备心搏骤停模型;心搏骤停3 min后开始实施心肺复苏（CPR）,CC-CPR组为呼吸机辅助通气+胸外按压;IAAC-CPR组为呼吸机辅助通气+胸外按压+腹主动脉按压。观察CPR过程中血流动力学和脑皮质血流的变化;记录自主循环恢复（ROSC）时间,观察动物24 h生存情况、24 h神经功能评分及腹部器官情况等。结果 IAAC-CPR组复苏后30、60、90、120 s时脑血流量（CBF,PU值）及平均动脉压（MAP,mmHg,1 mmHg＝0.133 kPa）均明显高于CC-CPR组（CBF 30 s：16.1±6.0比7.8±2.2,60 s：91.6±11.8比57.3±23.2,90 s：259.9±74.9比163.6±50.3,120 s：301.5±60.5比208.4±23.8;MAP 30 s：46.4±9.4比31.4±8.7,60 s：55.8±13.8比34.0±11.5,90 s：61.2±11.5比38.2±10.1,120 s：63.6±11.8比40.2±10.2;均P＜0.05）。与CC-CPR组比较,IAAC-CPR组ROSC所需时间明显缩短（s：182.0±59.0比312.6±86.6,t＝2.787,P＝0.024）,24 h神经功能评分明显下降（分：2.4±1.7比4.6±0.6,t＝2.974,P＝0.023）;而复苏成功率（80.0%比60.0%,χ2＝0.000,P＝1.000）、24 h存活率升高（80.0%比40.0%,χ2＝0.417,P＝0.519）,但差异无统计学意义。ROSC后24 h尸解动物均未发现肝脏损伤。结论在心搏骤停兔复苏早期,IAAC-CPR较CC-CPR取得了更好的脑血流灌注,明显减轻了心搏骤停兔的神经系统功能损伤,且无腹部器官损伤。     

胞二磷胆碱提高心肺复苏效果和减轻心肌损伤的作用研究

目的 探讨胞二磷胆碱在心肺复苏(CPR)中对于提高自主循环恢复(ROSC)率和减轻心脏损伤的作用.方法 按随机数字表法将SD大鼠分为对照组(未窒息,5只)、模型组(10只)、肾上腺素组(10只)、胞二磷胆碱组(10只),用窒息法复制心搏骤停(CA)动物模型并进行CPR,各组分别于复苏前5 min和复苏开始时给2次药,对照组和模型组给予等量生理盐水.各组于CPR期间及复苏成功后2h内测定血流动力学指标,然后处死大鼠取心脏组织,检测ATP酶、超氧化物歧化酶(SOD)、丙二醛(MDA)水平,评估大鼠心肌缺血/再灌注损伤情况.结果 胞二磷胆碱组和肾上腺素组ROSC率高于模型组(90％、80％比20％,均P＜0.01),平均复苏时间(s)显著短于模型组(53±10、55±9比95±7,均P＜0.01);复苏后2h末心率(HR,次/min)、平均动脉压(MAP,mm Hg,1 mm Hg=0.133 kPa)均显著高于模型组(HR:222.78±41.55、167.75±11.76比131.50±0.70,MAP:36.53±8.69、39.30±6.45比30.19±5.15,均P＜0.01).胞二磷胆碱组复苏后心功能[左室内压上升/下降最大速率(±dp/dt max)]逐渐平稳并显著高于模型组和肾上腺素组;肾上腺素组虽高于模型组,但下降趋势明显.胞二磷胆碱组Na+-K+-ATP酶(μmol· mg-1· h-1)和SOD活性(U/mg)显著高于模型组和肾上腺素组(Na+-K+-ATP酶:7.35±0.20比5.11 ±0.69、4.70±0.41,SOD活性:320.65±47.25比225.79±24.64、253.67±12.00,均P＜0.01),而MDA含量(mmol/mg)显著低于模型组和肾上腺素组(8.19±1.64比16.59±1.27、14.65±0.93,均P＜0.01),且上述指标与对照组比较无明显差异;模型组和肾上腺素组上述各指标也无明显差异.结论 胞二磷胆碱可提高CPR成功率,并且与肾上腺素相比可减轻心肌缺血/再灌注损伤,改善复苏后心功能.     

窒息法致心搏骤停家兔心肺复苏后多器官功能障碍模型的建立方法与评价指标

目的 探讨心搏骤停(CA)复苏后多器官功能障碍综合征(PR-MODS)家兔模型的建立方法和相关评价指标,为CA复苏后综合治疗研究提供具有实用价值的动物模型及评价方法.方法 将35只家兔按随机数字表法分成假手术组(5只)、窒息7 min组(15只)和窒息8min组(15只).以夹闭气管法复制CA模型,心肺复苏(CPR)后观察两个窒息组家兔自主循环恢复(ROSC)率、不同时间点死亡率和全身炎症反应综合征(SIRS)发生率;同时检测两个窒息组家兔复苏前和ROSC后12、24、48血中肌酸激酶同工酶(CK-MB)、丙氨酸转氨酶(ALT)、肌酐(Cr)、血糖(Glu)及动脉血氧分压(PaO2)水平;在ROSC后48 h处死存活家兔,光镜下观察心、脑、肺、肾、肝、小肠等器官的病理学变化;并根据主要器官功能及形态学变化判定是否发生CA后PR-MODS.结果 ①窒息7 min组和8 min组家兔ROSC率分别为100.0％和86.7％(P＞0.05).窒息8 min组家兔6h死亡率明显高于窒息7min组(46.7％比6.7％,P＜0.05),而12 ～ 48 h死亡率仅有升高趋势(均P＞0.05).②ROSC后存活家兔可出现球结膜水肿、呼吸窘迫、血压下降、腹胀和肠鸣音减弱或消失,以及少尿等不同程度器官功能受损的表现.③假手术组家兔未发生SIRS和主要器官功能受损相关指标的变化.两个窒息组家兔在ROSC后12～ 24 h均发生SIRS反应;存活家兔在ROSC后12 h CK-MB(U/L)即较窒息前明显升高(窒息7 min组:786.88±211.84比468.20±149.45,窒息8min组:894.88±248.80比462.11±115.15,均P＜0.05),24 h ALT(U/L)、Cr(,mol/L)、Glu(mmol/L)即明显升高(窒息7 min组ALT:174.25±36.28比50.27±9.37,Cr:144.25±41.64比67.71±16.47,Glu:11.21±1.14比5.59±1.10;窒息8 min组ALT:205.50±10.61比51.13±10.37,Cr:230.50±88.39比65.93±13.81,Glu:11.55±0.35比6.41±1.23,均P＜0.05),48 h PaO2(kPa)即明显下降(窒息7 min组:5.03±0.73比9.07±1.03,P＜ 0.05).④ROSC后存活48 h的家兔(仅窒息7 min组存活4只)主要器官发生明显的病理改变,多表现为炎性细胞浸润、部分细胞变性水肿及坏死、组织出血等病理特征.结论 CA家兔在ROSC后如若出现SIRS和2个或2个以上器官功能障碍的体征、生化指标和非特异性病理改变,可作为评价PR-MODS动物模型的参考指标.     

多巴胺对恢复自主循环猪氧代谢的影响

目的 对心搏骤停心肺复苏(CPR)后自主循环恢复(ROSC)模型猪采用多巴胺升压,观察不同灌注条件对氧代谢的影响及神经功能恢复结果.方法 心室纤颤(VF)前将猪右股静脉连接连续心排血量监测仪,左颈内静脉置管并放置电极到右心室,分别行主动脉、颈动脉置管,采用电击致12头实验猪心搏骤停,VF 4 min后进行CPR,达到ROSC,按随机数字表法均分为高灌注组和正常灌注组.两组在4 h内均给予15 ml·kg-1·h-1生理盐水补液;高灌注组同时给予多巴胺持续静脉泵入升压,使平均动脉压(MAP)维持在复苏后基础血压的130%左右.于ROSC基础状态(0 h)及ROSC后0.5、1、2、4 h记录各组动物血流动力学参数并计算氧代谢各指标;24 h进行神经系统功能评价.结果 与正常灌注组比较,高灌注组ROSC 0.5、1、2、4 h氧输送量(DO2)、氧消耗量(VO2)明显升高[DO2(ml/min):556±43比375±25、660±56比381±53、674±53比362±44、685±44比400±38,VO2(ml/min):288±35比191±13、260±37比204±38、223±27比169±21、212±19比163±15,P＜0.05或P＜0.01];ROSC 1、2、4 h氧摄取率(ERO 2)明显下降[(39±4)%比(53±3)%、(33±2)%比(47±1)%、(31±3)%比(41±3)%,均P＜0.05];颈动脉血氧分压(PaO2)明显升高,但颈动脉血氧饱和度(SaO2)无差异;ROSC 0.5、1、2、4 h混合静脉血氧分压(PvO2,mm Hg,1 mm Hg=0.133 kPa)明显升高(38±4比33±1、42±2比36±2、40±2比36±2、43±2比38±1,P＜0.05或P＜0.01);ROSC 1、2、4 h混合静脉血氧饱和度(SvO2)和混合静脉血-颈动脉血乳酸含量差(PCLac)均升高[SvO2:0.60±0.04比0.45±0.03、0.66±0.02比0.52±0.01、0.68±0.03比0.58±0.03,PCLac(mmol/L):1.2±0.2比0.7±0.4、1.0±0.3比0.6±0.2、1.1±0.2比0.5±0.2,P＜0.05或P＜0.01];颈动脉氧含量(CAO2)升高,颈动-静脉氧含量差(CAvO2)、脑组织氧摄取率(C-ERO2)下降,颈动-静脉血乳酸含量差(VALac)升高.ROSC 24 h高灌注组6头猪均达到脑功能评分(CPC)1级;正常灌注组存活4头,其中3头达到CPC 2级,1头达到CPC 1级(P＜0.05).结论 在VF致心搏骤停模型猪ROSC后应用多巴胺升压,可以提高主动脉灌注压,改善全身和大脑灌注,对氧代谢、早期脑复苏有益.     

插入式腹主动脉按压心搏骤停兔复苏效果

目的 通过比较插入式腹主动脉按压心肺复苏(IAAC-CPR)与传统胸外按压心肺复苏(CC-CPR)对心搏骤停(CA)兔复苏过程中血流动力学及神经系统改变情况,初步评价IAAC-CPR的心肺脑复苏效果及其影响脑灌注和复苏预后的机制.方法 健康新西兰大白兔28只,体质量在2.0～2.5 kg,雌雄不拘,按随机数字表法,分为CC-CPR组(实施传统胸外按压)和IAAC-CPR组(于胸外按压放松期,施行腹主动脉按压),每组14只.冰氯化钾联合气管夹闭建立CA模型,由建模前5 min开始持续监测动物心电图(ECG)、主动脉收缩压(SBP)、舒张压(DBP)、平均动脉压(MAP)、心率(HR)及脑皮质血流(CBF)情况直至实验结束;分别记录复苏前基础值(1次/min),复苏30 s、60 s、90 s及120 s的MAP与SBP及脑皮质血流;并于建模前基础时点、自主循环恢复(ROSC)后2h、6h留取血液标本.比较两组动物的平均动脉压(MAP)、收缩压(SBP)、脑皮质血流(CBF)、血清S100B蛋白含量、ROSC率、复苏成功率、24 h存活率及24 h神经功能评分的差异.比较两组间差异时,均数比较采用独立样本t检验,率的比较用x2检验确切概率法.结果 复苏30 s、60 s、90 s、120 s内,IAAC-CPR组MAP、SBP及CBF均高于CC-CPR组,其中MAP值(mm Hg,1 mm Hg =0.133 kPa)为[30 s:(46.4±9.4) vs.(31.4±8.7,60)s:(55.8±13.8)vs.(34.0±11.5); 90s:(61.2±11.5)vs.(38.2±10.1); 120 s:(63.6±11.8) vs.(40.2±10.2);95％ CI,30s:-21.73～-12.41,60 s:-28.03～-16.26,90s:-25.27～-14.87,120 s:-25.38～-13.19;t值2:30 s:-7.536,60 s:-7.734,90 s:-7.943,120s:-6.505; P＜0.05,P＜0.01];SBP值(mm Hg)为[30s:(62.6±9.2)vs.(43.4±15.1); 60s:(75.4±14.0)vs.(50.4±13.8); 90s:(78.4±12.6)vs.(59.4±16.2),120s:(82.8±10.3)vs.(64.3±15.9);95％ CI,30 s:-28.91～-9.51,60 s:-35.82～-14.18,90s:-30.28～-7.71,120s:-28.93～-8.07;t值2:30s:-4.071,60s:-4.751,90s:-3.460,120s:-3.647;P值,30s:P＜0.05,P＜0.01,60s:P＜0.05,P＜0.01,90s:P=0.02,P＜0.05,120s:P=0.01,P＜0.05]; CBF值为[30 s:(16.1±6.0)vs.(7.8±2.2); 60s:(91.6±11.8)vs.(57.3±23.2); 90s:(259.9±74.9) vs.(163.6±50.3); 120s:(301.5±60.5)vs.(208.4 ±23.8);95％ CI,30 s:-14.82～-1.70,60 s:-61.24～-7.49,90s:-189.45～-3.29,120s:-160.12 ～-26.03;t值2:30 s:-2.904,60 s:-2.948,90s:-2.387,120s:-3.201;P值,30 s:P=0.020,P＜0.05,60 s:P=0.018,P＜0.05,90 s:P =0.044,P＜0.05,120s:P=0.013,P＜0.05].两组基础点血清S100B蛋白水平差异无统计学意义(P =0.781,P＞0.05),ROSC后2h、6 h IAAC-CPR组血清S100B蛋白水平(pg/mL)低于CC-CPR组,分别为:[2h:(148.7±19.9)vs.(176.0±17.5);6 h:(237.7±17.7)vs.(267.0±14.8); 95％CI,2 h:4.53 ～50.05,6 h:9.29 ～49.26;t值,2 h:2.519,6 h:3.164;P值,2h:P =0.022,P＜0.05,6 h:P=0.007,P＜0.05).ROSC率及24 h生存率差异无统计学意义,复苏成功率及24 h神经功能评分IAAC-CPR组优于CC-CPR组(复苏成功率:80％vs.60％,x2值:5.250:P=0.022,P＜0.05; 24 h神经功能评分:(3.3±1.49)vs.(4.4±0.94);t值,t=2.429; 95％CI,0.18 ～2.11;P值:P=0.024,P＜0.05).所有动物实验后尸检未见腹腔内器官损伤.结论 在心搏骤停兔的复苏过程中,IAAC-CPR可产生较高的平均动脉压(MAP)、收缩压(SBP)及脑皮质血流(CBF),从而减轻了CA所致循环中断造成的脑组织等重要脏器损伤,提高复苏成功率及24 h动物神经功能评分,其心肺脑复苏效果优于CC-CPR.     

非气管插管静脉吸入复合全身麻醉在脑电双频指数指导下的应用研究

目的 通过脑电双频指数(BIS)监测,进一步研究非气管插管静脉吸入复合全身麻醉的方法和麻醉效果.方法 单侧上肢骨折患者60例,随机分成A、B 2组各30例.A组患者给予小剂量的静脉麻醉药诱导,吸入气体麻醉药加深和维持麻醉,并插入鼻咽通气道,进行紧闭循环自主呼吸;B组则进行气管插管、使用肌肉松弛药和机械通气,记录2组患者麻醉各时段吸入和呼出七氟醚浓度、呼吸和循环方面的参数、脑电双频指数、血气分析、术毕清醒时间、拔管时间、麻醉恢复时间.结果 A、B 2组患者麻醉过程平稳,A组与B组比较:插管(或插入鼻咽通气道)后5 min(T 1)呼吸频率(RR)分别为[(10±2)次/min、(14±2)次/min,t=7.746,P＜0.01],呼气末二氧化碳 (PETCO2) 分别为[(43±3)mm Hg、(27±2)mm Hg,t=24.306,P＜0.01],潮气量 (VT) 分别为[(290±30)ml、(480±20)ml,t=28.863,P＜0.01];切皮时(T 2),RR分别为[(16±2)次/min、(14±2)次/min,t=3.873,P＜0.01],PETCO2分别为[ (42±3)mm Hg、(29±3)mm Hg,t=16.783,P＜0.01],VT分别为[(522±35)ml与(480±20)ml,t=6.114,P＜0.01];术中强刺激时(T 3),心率(HR)分别为[(73±5)次/min、(93±10)次/min,t=9.798,P＜0.01],平均动脉压(MAP)分别为[(116±12)mm Hg、(135±11)mm Hg,t=6.393,P＜0.01],RR分别为[(17±3)次/min、(14±2)次/min,t=4.557,P＜0.01],PETCO2分别为[(41±2)mm Hg、(27±2)mm Hg,t=27.111,P＜0.01],VT分别为[(556±30)ml、(480±20)ml,t=11.545,P＜0.01];术毕缝皮时(T 4),RR分别为[(16±2)次/min、(14±2)次/min,t=3.873,P＜0.01],PETCO2分别为[(41±3)mm Hg、(30±2)mm Hg,t=16.710,P＜0.01],VT分别为[(515±25)ml、(480±20)ml,t=5.988,P＜0.01],差异均有统计学意义,但均在正常生理范围.停药后A组与B组比较,清醒时间分别为[(3.5±1.5)min、(8.5±4.4)min,t=5.891,P＜0.01],拔管时间分别为[(4.1±1.2)min、(10.5±2.6)min,t=12.241,P＜0.01],麻醉恢复时间分别为[(8.2±3.5)min、(13.3±5.2)min,t=4.456,P＜0.01],均明显短于B组,2组患者无上呼吸道梗阻、胃液反流、误吸等情况发生,对手术过程无知晓.结论 非气管插管静脉吸入复合全麻安全有效、患者苏醒迅速.     

心肺复苏后心功能障碍与心肌内质网Ca2＋调控蛋白表达关系的研究

目的探讨心肌内质网Ca2＋调控蛋白表达与心肺复苏（CPR）后心功能障碍的关系。方法38只SPF级雄性SD大鼠按随机数字表法分为对照组（12只）和心搏骤停组（26只）。静脉弹丸式注射氯化钾40μg/g诱导心搏骤停,8 min后进行CPR;对照组大鼠仅麻醉后置管并监测指标,不诱导心搏骤停。在复苏后进行有创血流动力学监测1 h,采用超声心动图测定心功能。分别于自主循环恢复（ROSC）后5 min和60 min时采集心肌标本,采用蛋白质免疫印迹试验（Western Blot）检测内质网Ca2＋ATP酶（SERCA2a）、磷酸化受磷蛋白（p-PLB）和兰尼定受体（RyR）水平。结果心搏骤停组ROSC率为92.3%（24/26）,平均复苏时间为（68±39）s。心搏骤停组复苏后1 h心功能明显下降,与对照组相比,射血分数、短轴缩短率（FS）、左室内压上升或下降最大速率（±dp/dt max）明显降低〔射血分数：0.548±0.060比0.809±0.043,F＝71.692,P＝0.000;FS：（34.4±4.4）%比（46.0±3.5）%,F＝55.443,P＝0.000;+dp/dt max （mmHg/s）：4718±743比7098±394,P＜0.01;-dp/dt max （mmHg/s）：-3824±612比-6187±473,P＜0.01〕。与对照组相比,心搏骤停组ROSC后5 min及60 min PLB磷酸化水平（灰度值）均显著降低（5 min：0.64±0.15比1.29±0.13,P＜0.01;60 min：0.95±0.08比1.30±0.09,P＜0.05）,而内质网SERCA2a活性（灰度值）和RyR水平（灰度值）差异均无统计学意义（SERCA2a 5 min：1.01±0.18比1.24±0.07,60 min：1.03±0.14比1.25±0.06;RyR 5 min：0.96±0.13比0.97±0.13,60 min：0.88±0.14比0.99±0.11,均P＞0.05）。结论内质网PLB磷酸化水平异常与CPR后心功能障碍密切相关。     

A comparative study of the cardiorespiratory effects of continuous positive airway pressure breathing and continuous positive pressure ventilation in acute respiratory failure

Positive end expiratory pressure (PEEP) produces cardiopulmonary effects whether administered by controlled positive pressure ventilation (CPPV) or continuous positive airway pressure (CPAP). In eight patients with acute respiratory failure, the effects of 20 cm PEEP administered via CPPV and CPAP were compared. An esophageal balloon was used to calculate the transmural vascular pressures. The control values under mechanical ventilation with no PEEP (IPPV) for PaO₂ and QS/QT (FiO₂ being 1.0) were respectively 132±15 mmHg and 31±3%; CPPV gave a PaO₂ of 369±27 mmHg and QS/QT fo 14±1.6%, CPAP 365±18 mmHg and 18±1.3% respectively. The two different modes of ventilation (CPPV and CPAP) gave identical blood gas improvement through the same level of end expiratory transpulmonary pressure despite marked differences between absolute mean airway and esophageal pressures. Conversely, hemodynamic tolerance was very different from one technique to the other: CPPV depressed cardiac index from 3.4±0.3 to 2.4±0.2 l/min/m² as well as decreasing transmural filling pressures, suggesting a reduction in venous return. Conversely, filling pressures maintained at control values during CPAP and cardiac indexes were unchanged.Abbreviations IPPV intermittent positive pressure ventilation; mechanical ventilation (controlled mode) with zero end expiratory pressure (ZEEP) - CPPV continuous positive pressure ventilation: mechanical ventilation (controlled mode) with a positive pressure during expiration - CPAP continuous positive airway pressure; spontaneous ventilation with a positive pressure maintained during expiration - PEEP positive end expiratory pressure, whatever the ventilatory mode; spontaneous (CPAP) or mechanical (CPPV) Presented in part at the 44 th annual meeting of American College of Chest Physicians, Washington DC, October 1978     

Intervention studies to reduce the prevalence and incidence of pressure sores: a literature review

Much has been written about the prevention of pressure sores. However, electronic and manual searches located only 10 studies within the literature in the UK that described interventions able to reduce either their incidence or prevalence. All the studies located contained serious methodological flaws. Apparent success in reducing the number or severity of pressure sores could have resulted because staff involved in data collection were aware that the study was being undertaken and thus took more interest in pressure area care. From the review findings it is apparent that there is a dearth of research evidence upon which to base practice in the sphere of pressure sore prevention and further research is urgently required.     

Influence of tissue pressure on central venous pressure/peripheral venous pressure correlation: An experimental report

BACKGROUND: Peripheral venous pressure (PVP) has been shown to correlate with central venous pressure (CVP) in a number of reports. Few studies, however, have explored the relationship between tissue pressure (TP) and PVP/CVP correlation.METHODS: PVP and CVP were simultaneously recorded in a bench-top model of the venous circulation of the upper limb and in a single human volunteer after undergoing graded manipulation of tissue pressure surrounding the intervening venous conduit. Measures of correlation were determined below and above a point wherein absolute CVP exceeded TP.RESULTS: Greater correlation was observed between PVP and CVP when CVP exceeded TP in both models. Linear regression slope was 0.975 (95% CI: 0.959-0.990); r² 0.998 above tissue pressure 10 cmH₂O vs. 0.393 (95% CI: 0.360-0.426); and r² 0.972 below 10 cmH₂O at a flow rate of 2000 mL/h in the in vitro model. Linear regression slope was 0.839 (95% CI: 0.754-0.925); r² 0.933 above tissue pressure 10 mmHg vs. slope 0.238 (95% CI: -0.052-0.528); and r²0.276 in the en vivo model.CONCLUSION: PVP more accurately reflects CVP when absolute CVP values exceed tissue pressure.     

组织压监测下治疗小腿骨筋膜室综合征30例报告

目的：探讨测定组织压与血压的差值在诊治小腿骨筋膜室综合征的临床意义。方法：应用穿刺法,通过测量30例筋膜室综合征患者组织压、血压,明确减压手术的客观指标。结果：30例中10例行保守治疗,20例行减压治疗,随访均未发生骨筋膜室后遗症。结论：组织压、收缩压、舒张压的结合测量对指导何时行减压术有重要临床意义。当差值为20mmHg时,需即刻减压。     

持续气道正压-比例压力支持-自动管道补偿与双水平气道正压-压力支持通气两种模式撤机方法的比较

目的 :比较持续气道正压比例压力支持自动管道补偿 (CPAP PPS ATC)与双水平气道正压压力支持通气 (BIPAP PSV)两种模式撤机方法的结果。方法 :CPAP PPS ATC组 42例 ,BIPAP PSV组 40例 ,采用对照研究方法 ,比较两种通气模式、起始参数的调节、解决通气机依赖特点及撤机成功率。结果 :两种模式的撤机成功率无明显差异 (P>0 .0 5 ) ,两种模式均无人机对抗 ,CPAP PPS ATC模式较 BIPAP PSV模式对通气机依赖患者有更大的自主性 ,更容易实现撤机。结论 :BIPAP PSV为压力控制与自主呼吸相结合模式 ,CPAP PPS ATC为自主模式 ,CPAP PPS ATC是一种更好的机械通气撤机模式     

有创血压监测值与无创血压监测值相关性分析

目的 探讨有创血压监测值与无创血压监测值之间的线性关系,为临床血压监测提供参考.方法 选取ICU监测无创血压与有创血压的患者32例,采取自身对照的方法,同时监测患者有创血压及无创血压值,采集数据资料进行比较,并进行线性关系分析.结果 采集有效数据98对,所得数据有创血压收缩压及舒张压值分别为(146.93±21.426),(71.32±13.152) mm Hg,均高于无创血压值的(124.02±19.417),(68.86±15.251)mmHg,差异均有统计学意义(t分别为15.301,3.363;P＜0.05);有创血压与无创血压存在线性关系(r =0.880,P＜0.05).结论 有创血压与无创血压所得监测值之间有差异,不可相互替代,可使用无创血压监测值推导计算有创血压监测值.     

Preventing heel pressure sores: a comparison of heel pressure relieving devices

• ? It has been widely recognized that elderly patients with an orthopaedic problem are predisposed to developing heel pressure sores.
• ? In this study four pressure-reducing devices, commonly used in the prevention of heel ulcers, were objectively compared for their ability to decrease or remove pressure on the heels of patients with fractured necks of femurs and fractured femurs.
• ? Forty-one patients were randomly allocated a pressure relieving device. The efficacy of the device was evaluated by continuously assessing the skin integrity of both heels on a daily basis over a period of 12 days. Data were collected over a 30 month period.
• ? The four devices were foam splints, eggshell foam, duoderm and heel protector boots. Foam splints and eggshell foam proved to be more effective devices in relieving pressure exerted on the heel.
• ? This study recognizes that meticulous nursing care remains the critical clement in prevention of heel ulcers; however, the use of eggshell foam and foam splints in conjuction with this enhances the maintenance of skin integrity.

     

A comparison of extradural and intraparenchymatous intracranial pressures in head injured patients

The reliability of extradural pressure measurements for the measure of intracranial pressure (ICP) is still controversial. This study was undertaken to assess the limits of agreement between extradural and intraparenchymatous pressures using respectively the Plastimed extradural sensor and the Camino fiberoptic system. The study took place in a neurosurgical intensive care unit. Ten head injured patients were included in the study, leading to the comparison of 1032 pairs of hourly ICP values. Although the measures were significantly correlated, there was no agreement between the two methods of ICP monitoring. Extradural pressure was higher than intraparenchymatous pressure (bias 9 mmHg; 95% confidence interval of bias-9.8 to 27.8 mmHg). The lack of agreement between the two methods is probably due to the unreliability of extradural pressure for the measurement of ICP.     

不同负压值吸痰对气管粘膜损伤的实验研究

负压吸引吸痰法是一项侵入性操作,为了减少其对气管粘膜的损伤,探索适宜的负压值,我们对不同负压值吸痰所致气管粘膜损伤的程度,进行了动物实验。作者将实验组36只犬随机分为1～6组,吸痰负压值分别定于5、10、15、20、25、30Kpa,按常规吸痰法吸痰10次后分别处死。切取损伤的全层气管组织两块,做普通光学及电子显微镜检查。结果表明:负压吸引吸痰的负压值与气管粘膜损伤程度成正比,其负压值应控制在5～20Kpa之间,吸痰器计量表应采用低负压Kpa负压表。以便于控制、调节负压值,减少由于吸痰所致气管粘膜损伤。     

Clinical evaluation of the Takeda Medical (A & D) TM 2420 ambulatory blood pressure monitor. Practical experience and comparison with direct and indirect measurements

Takeda Medical (A & D) TM 2420 is an automatic ambulatory blood pressure monitoring system employing the auscultatory technique. The device was used under stable conditions and compared to readings from the Hawksley randomzero sphygmomanometer using a double headset stethoscope and a Y-connection. We tested 85 subjects (aged 13–89 years, systolic blood pressure 85–212 mmHg, diastolic blood pressure 40–116 mmHg) and found a difference amounting to 1.6±6.7 mmHg (mean±SD) for systolic and 2.1±4.5 mmHg for diastolic readings (Hawksley-TM 2420). In 62 subjects a comparison with simultaneous measurement on the opposite arm with the Hawksley manometer showed similar results. When comparing intra-arterial readings from 10 subjects, a difference (intra-arterial-TM 2420) of -1.9±12.1 mmHg was found for systolic pressures, while the diastolic difference was -10.7±8.7 mmHg. Twenty-four hour monitoring was performed on 80 subjects; 70 of these yielded usable tracings. The proportion of successful recordings was acceptable, but the device was not suitable for bicycle stress testing. The quality of the accessories provided with the equipment could be improved, but in spite of this the monitoring system was found to be recommendable for clinical use.