NIRS监测新生儿缺氧缺血性脑病脑氧合代谢和脑血流量的临？…

目的 观察缺缺血性脑病（ＨＩＥ）的脑氧合代谢和脑血流量变化,早期判定不同程度缺氧缺血性脑病的脑功能状态。方法 采用近红外光谱仪监测２４例ＨＩＥ患儿音乐刺激（ＭＳ）前后脑前额皮质区域氧合血红蛋白（ＨｂＯ２）,还原血红蛋白（Ｈｂ）,总血红蛋白（ｔＨｂ）的变化,并与对照组（３０例）作比较。结果 对照组ＨｂＯ２、Ｈｂ、ｔＨｂ明显上升。ＨＩＥ组：轻度组ＨｂＯ２、ｔＨｂ变化差异无显著性（Ｐ〉０．０５）,Ｈｂ明     

围产期窒息缺氧后脑氧合和脑血液动力学改变及其与心脏损害的关系

围产期窒息缺氧可致新生儿多脏器损伤 ,由于脑损伤可致神经系统后遗症而受到人们的关注。目前认为有多种机制参与脑损伤的病理过程 ,其中脑血液动力学改变与脑氧合密切相关 ,与脑损伤有直接的关系 ,而脑血流和脑血容量又受到心功能和全身血液动力学的影响。现就围产期窒息缺氧后脑氧合状态、脑血液动力学与心脏损害的关系作一综述。一、缺氧后脑氧合及脑血液动力学的变化脑组织的新陈代谢率高 ,其代谢耗能几乎全部依赖于血液供氧。脑循环取决于动脉压、静脉压、颅内压、脑血管的收缩和舒张。脑血管自动调节机制使脑的灌注和血流在一定范围内…     

NIRS监测新生儿缺氧缺血性脑病脑氧合代谢和脑血流量的临床研究

目的 观察缺氧缺血性脑病(HIE)的脑氧合代谢和脑血流量变化,早期判定不同程度缺氧缺血性脑病的脑功能状态.方法 采用近红外光谱仪监测24例HIE患儿音乐刺激(MS)前后脑前额皮质区域氧合血红蛋白(HbO2),还原血红蛋白(Hb),总血红蛋白(tHb)的变化,并与对照组(30例 )作比较.结果 对照组HbO2、Hb、tHb明显上升.HIE组:轻度组HbO 2、tHb变化差异无显著性(P＞0.05),Hb明显增加[MS前:(-0.10±0.24)μmol/L, MS后(0.50±0.33)μmol/L,P＜0.05];中度组HbO2、tHb明显减少[MS前:(0.0 7±0.44)μmol/L,( 0.48±0.43)μmol/L,MS后:(-1.72±0.59)μmol/L,(-0.98±0.55)μmol/L,P＜0.05],Hb明显增加[MS前:(0.41±0.28)μmol/L,MS后:(0.74 ±0.36 μmol/L,P＜0.05],重度组三项均降低[MS前:(0.35±0.80)μmol/L,(0.22 ±0.47)μmol/L,(0.57±0.98)μmol/L,MS后:(-3.24±1.37)μmol/L,(0.15±0.51)μm ol/L,(-3.09±1.39)μmol/L,P＜0.05].将HIE的病情程度与MS前后tHb的变化差值进行直线相关分析,结果二者呈显著负相关关系(r=-0.64, P＜0.001).结论 NI RS可以早期监测HIE的脑功能,判定不同程度缺氧缺血性脑病的脑功能状态.     

新生儿缺氧的脑氧合功能变化及其与脑损伤程度的关系

目的 了解新生儿缺氧后脑氧合功能状态.方法 应用近红外光谱测定技术(NIRS)对39例有围产期缺氧史和42例无缺氧史的新生儿在安静状态下和声音刺激后脑的氧合功能进行了检测,并与脑电图和影像学检查进行了比较.结果 正常新生儿在安静状态下脑氧合状态稳定,声音刺激后脑氧合增强,然而在有缺氧史的新生儿,显示出脑活动抑制,对声音刺激所产生的脑氧合反应性变化减弱.13例病例在监测过程中出现发作性脑氧合降低.结论 在围产期缺氧性脑损伤后,脑氧合功能在一段时间内仍可能是异常的,这种变化与脑损伤程度有关.     

选择性头部亚低温治疗新生儿缺氧缺血性脑损伤对脑血流和氧合代谢的影响

目的探讨新生儿缺氧缺血性脑损伤(hypoxic-ischemicbraindamage,HIBD)选择性头部亚低温治疗期间脑血流和脑氧合代谢的变化。方法38例中、重度HIBD新生儿随机分为常温组和低温组;7例相对正常的新生儿作为对照组。生后6h以内开始治疗,常温组维持体温在36℃,低温组维持鼻咽温度在34℃,低温持续72h,然后自然复温,其它治疗方法两组相同。三组均持续观察84h。三组患儿分别在生后6、12、24、48、72和84h,采用经颅多普勒血流诊断仪测定大脑中动脉的血流速率的变化,采用近红外光谱分析技术测定细胞色素aa3(cytochromeaa3,Cytaa3)的变化。结果低温组新生儿生后6h内收缩期血流速率(Vs)[(250．5±7．69)cm／s],平均血流速率(Vs)[(15．67±5．97)cm／s]、舒张末期血流速率(Vd)[(7．27±5．06)cm／s]和△Cytaa3均较对照组降低,阻力指数(RI)(0．81±0．15)较对照组(0．67±0．09)增加(P均<0．05);低温组Vs和Vm在生后12-48h较常温组增加(P均<0．05),RI降低(P<0．05),且与对照组无差别。与常温组比较,低温组△Cytaa3在生后36-60h显著增加(P<0．05或0．01)。结论中重度新生儿HIBD脑血速率明显降低,存在明显的脑氧合障碍;选择性头部亚低温治疗新生儿HIBD可以改善脑血流动力学和脑氧合代谢状态。     

Cerebral blood flow distribution and hypoxic-ischemic brain damage in newborn rats

OBJECTIVE: Our purpose was to assess the cerebral blood flow distribution and resulting grade of hypoxicischemic brain damage in newborn rats. METHODS: Seven-day-old Wistar rats (n = 75) underwent left common carotid artery ligation followed by 2 hours hypoxia (8% oxygen in nitrogen) at 33 degrees C. The control animals were exposed to hypoxia without ligation (n = 8). Colored microspheres of 15 microm in diameter were administered into the left cardiac ventricle percutaneously at the end of hypoxia. They were killed 24 hours after induced injury. Brain sections 2 mm in thickness were removed for microtubule-associated protein 2 (MAP-2) staining, and remaining parts were separated into left and right hemispheres for counting the microspheres. The blood flow distribution to the ligated side was expressed as the difference from the non-ligated control side. Severity of MAP-2 disappearance was ranked as normal, mild or severe. RESULTS: In the control rats, there was no loss of MAP-2 staining. The blood flow equally distributed into both cerebral hemispheres. The cerebral blood flow distribution on the side of carotid artery ligation decreased by 44.7 +/- 21.9% in the mildly damaged group and 65.8 +/- 16.8% in the severely damaged group. CONCLUSION: The greater the percentage difference of blood flow distribution from the non-ligated side, the more severe the brain damage.     

Increased cerebral blood flow in preeclampsia with magnetic resonance imaging

OBJECTIVE: The purpose of this study was to compare third trimester and nonpregnant cerebral blood flow of women with preeclampsia to normotensive control subjects with the use of magnetic resonance imaging techniques. STUDY DESIGN: Nine normotensive pregnant women and 12 untreated women with preeclampsia underwent velocity-encoded phase contrast magnetic resonance imaging of the bilateral middle and posterior cerebral arteries in the third trimester and at 6 to 8 weeks after delivery. The Student t test was used for comparison, with a probability value of <.05 considered significant. RESULTS: Third-trimester large cerebral artery blood flow was significantly higher in preeclampsia. Mean vessel diameter was unchanged, except for the left posterior cerebral artery. There was no difference in mean vessel diameter or cerebral blood flow between the 2 groups while the women were not pregnant. CONCLUSION: Cerebral blood flow is increased significantly in preeclampsia. We hypothesize that increased cerebral blood flow ultimately could lead to eclampsia through hyperperfusion and the development of vasogenic edema.     

Effects of recombinant human superoxide dismutase during reoxygenation with 21% or 100% oxygen after cerebral asphyxia in newborn piglets

Objective: Superoxide radicals (O₂^-) are generated during reoxygenation following asphyxia, possibly more when higher concentrations of O₂ are used during resuscitation. Superoxide dismutase (SOD) is an antioxidant enzyme, which scavenges O₂^-. We tested the hypothesis that a single intravenous dose of recombinant human Cu,Zn SOD (rhSOD) could influence microcirculation and biochemical markers of asphyxia in piglets reoxygenated with 21% or 100% O₂ after combined cerebral hypoxemia-ischemia-hypercapnia. Methods: Anesthetized newborn piglets were randomized to asphyxia (n = 40) or control (n = 3). Asphyxia was induced by ventilation with 8% O₂, adding CO₂, and temporary occlusion of both common carotid arteries. After 20 min, 16 piglets received rhSOD 5 mg/kg intravenously and reoxygenation with 21% O₂ (rhSOD, 21%; n = 8) or 100% O₂ (rhSOD, 100%; n = 8), and 24 piglets received saline and reoxygenation with 21% O₂ (21%, n = 13) or 100% O₂ (100%, n = 11). The cortical microcirculation was assessed by laser Doppler flowmetry, and glutamate in the striatum and hypoxanthine in the cortex were measured by in vivo microdialysis. Results and conclusion: rhSOD peaked in plasma after 5 min. No rhSOD was detected in brain tissue. There were no significant differences between rhSOD and non-rhSOD groups in any measured variable.     

新生儿窒息后肾血流与尿微量蛋白关系的研究

目的　探讨新生儿窒息后肾血流参数与尿微量蛋白的关系。方法　测定分析2004年1月至2007年12月甘肃省人民医院71例窒息新生儿及20名正常新生儿新鲜 尿液中尿αl-微球蛋白 （αl-MG）、微量白蛋白（MA）、转铁蛋白（TRF）、免疫球蛋白（IgG）水平,同时抽取全部新生儿静脉血测血尿素氮 （BUN）、肌酐（ Cr）、二氧化碳结合力（CO2-CP）、Ca2+、 K+ 、Na+、 Cl- ,并分别在出生后第1、3、7天测定肾动脉血流参数,包括收缩期峰值流速（PSFV）、阻力指数（RI ）、舒张末血流速度（EDFV）、时间平均流速（TAMX）、搏动指数（PI）。结果　（1）窒息新生儿尿中αl-MG、TRF、MA 、IgG均明显高于正常组（P < 0.05） ,重度窒息组TRF、αl-MG明显高于轻度窒息组（ P < 0.01）。（2）窒息组肾动脉EDFV在第1、3、7天均低于正常组,差异有统计学意义 （ P < 0.05）,各日 龄组肾动脉RI和PI均高于正常组,差异有统计学意义（ P < 0.05）。（3）肾血流参数EDFV与MA、TRF、αl-MG 、IgG呈负相关（P <0.01）,RI、PI与MA、TRF、 αl-MG、 IgG呈正相关性 （P < 0.01）。结论　通过肾血流检测可估计尿微量蛋白的高低,肾血流检测具有省时、方便、外界影响因素少、可连续观察等优点; 通过尿微量蛋白的高低评估患儿肾血流,判断有无肾血管痉挛、肾缺血及早期肾损害,可为早期使用肾血管扩张药物提供依据。     

氨茶碱对早产儿脑血流的影响

目的　研究不同胎龄早产儿脑血流(cerebral blood flow,CBF)特点及氨茶碱对早产儿CBF的影响. 方法　 46例早产儿分为早产Ⅰ组和早产Ⅱ组.早产Ⅰ组胎龄≤32周,24例;早产Ⅱ组32周<胎龄<36周,22例.使用彩色多普勒超声诊断仪动态监测早产儿(出生3 d内)在输注氨茶碱前0.5 h,输注完后1、2和6 h双侧大脑前动脉(anterior cerebal artery,ACA)及大脑中动脉(media cerebal artery,MCA)的三项脑血流速度(cerebral blood flow velocity,CBFV)参数即收缩期峰值流速(peak-systolic velocity,PSV)、舒张期末峰值流速(end-diastolic velocity,EDV)和时间平均血流速度(time-mean flow velocity,TMFV)及搏动指数(pulsatility index,PI)、阻力指数(resistance index,RI).同时测量肱动脉平均动脉压(mean arterial blood pressure,MABP)变化.并与20例正常足月儿(对照组)的脑血流参数进行比较. 结果 左侧ACA(L-ACA)、MCA(L-MAC)和右侧ACA(R-ACA)、MCA(R-MAC)的PSV、EDV、TMFV在早产Ⅰ组低于早产Ⅱ组,这两组又分别低于对照组,差异均有统计学意义(P<0.05);而PI和RI在三组间差异无统计学意义(P＞0.05);三组中同侧MCA的CBFV高于ACA,差异有统计学意义(P<0.05),但三组左右两侧MCA和ACA的差异无统计学意义(P＞0.05).静脉输注完氨茶碱后1和2 h,早产儿ACA和MCA的CBFV均显著下降,与用药前比较差异有统计学意义(P<0.05),输注完后6 h CBFV回升至用药前水平,用药前后ACA和MCA的PI或RI无明显改变(P＞0.05).输注完后1、2或6 h两组早产儿左侧ACA或MCA的CBFV分别与右侧ACA或MCA的CBFV比较,组内及组问差异均无统计学意义(P＞0.05).两组早产儿用药前后各时间点肱动脉MABP差异无统计学意义(P＞0.05),各组不同时间点的MABP与双侧ACA、MCA-TMFV之间均不存在直线相关关系(P＞0.05). 结论 早产儿CBFV明显低于正常足月儿,CBFV随胎龄增长而增加;早产儿双侧MCA的CBFV显著高于ACA;使用氨茶碱早期可能引起早产儿脑血流波动,临床上应合理用药,加强监护.     

围生期窒息新生儿二氧化碳分压和pH值改变与神经系统损害的关系

目的 探讨围生期窒息新生儿PaCO2及pH快速变化及其与神经系统损害之间的关系。 方法 2002年1月至2003年12月南华大学第一附属医院将55例足月窒息新生儿分为3组：组Ⅰ，pH>7.00，无神经系统异常，无需呼吸支持；组Ⅱ，pH≤7.00，余同组Ⅰ；组Ⅲ，pH≤7.00，神经系统异常，需辅助呼吸支持。采集脐动脉血、产后1h和2h桡动脉血进行血气分析并观察Apgar评分和临床经过。 结果 脐动脉血pH值和PaCO2各组间差异有显著性；产后1h动脉血pH组Ⅰ、Ⅲ间和组Ⅱ、Ⅲ间差异有显著性；产后1h动脉血pH、PaCO2分别和脐动脉血pH、PaCO2比较，差异有显著性；三组间有不同的神经系统表现；Apgar评分组Ⅲ较低。 结论 在严重酸中毒时，胎儿出生后pH、PaCO2会发生显著改变，需持续辅助机械通气的患儿有不良的神经系统预后。 Abstract Objective To explore the relationship between the rapid changes in CO2 and pH value and neurologic injury in asphyxia infants in presence of severe academia. Methods Umbilical arterial blood and radial arterial blood at postnatal 1,2h were checked in 55 infants.These infants were categortized in three groups:Ⅰ,pH>7.00,normal neurologic examination without respiration support;Ⅱ,identification to Ⅰexcept pH≤7.00;Ⅲ,pH≤7.00,abnormal neurologic examination with mechanical ventilation. Results Umbilical arterial blood pH was significantly different in Ⅲ vs Ⅰ and in Ⅱ vs Ⅲ.PaCO2 was significantly different in Ⅲ vs Ⅱ vs Ⅰ.At postnatal 1h pH increased and PaCO2 decreased in all groups,significant differences in three group remained.At postnatal 2h,no differences were observed for pH and PaCO2 in Ⅱand Ⅲ,there was different neurologic prognosis among groups.Apgar score was lower in Ⅲ. Conclusion After delivery pH and PaCO2 have rapid changes in presence of severe academia.Lower pH and Apgar score with mechanical ventilation are poor prognosis factors of neurologic result. Key words Asphyxia;Acidosis;Blood gas;Newborn infants     

Maternal cerebral blood flow changes in pregnancy

OBJECTIVE: This study was undertaken to determine blood flow changes in the large cerebral arteries during normal pregnancy. STUDY DESIGN: Ten healthy pregnant volunteers underwent velocity-encoded phase contrast magnetic resonance imaging at 4 time intervals: 14 to 16, 28 to 32, and 36 to 38 weeks' gestation, and at 6 to 8 weeks' postpartum. Analysis consisted of serial paired Student t tests, with P<.05 considered significant. RESULTS: By using postpartum values for comparison, cerebral blood flow decreased by 14 to 16 weeks in the middle cerebral artery (P<.001), but was not significantly changed in the posterior cerebral artery. Significant decreases occurred in both the middle (P<.0001) and posterior (P=.002) cerebral arteries in late pregnancy. CONCLUSION: An approximately 20% reduction in large artery cerebral blood flow occurs during normal pregnancy, secondary to changes in velocity, whereas the area of these vessels remains unchanged. These findings may represent generalized vasodilatation of downstream resistance arterioles, assuming constant blood flow at the tissue level.     

早产儿早期心功能改变对脑血流影响的研究

探讨心功能改变对早产儿早期脑血流的影响。方法　2007年1—7月在暨南大学第二附属医院深圳市人民医院新生儿科住院的261例胎龄为29～36+6周 的早产儿于生后不同日龄根据左心室射血分数（EF）各分为3组。应用经颅多普勒监测早产儿生后1、3、7 d的大脑中动脉血流速度指标及血管弹性指标。应用彩 色多普勒超声心动图监测早产儿心功能指标及主动脉瓣口峰值流速。记录生后1 d早产儿胎龄及出生体重,并监测体温、血气、血糖、血压及红细胞比积。结果　 生后1、3、7 d早产儿的脑血流速度均随EF增加而加快;EF与大脑中动脉收缩期峰值流速、舒张期末血流速度、平均血流速度均呈正相关（r分别为0.70、0.41、 0.61,P 均<0.01）,而EF与血管阻力指数及弹性指数未见明显相关性。结论　早产儿早期脑血流速度受左室泵血功能的影响,而胎龄及出生体重是影响早产儿早 期左室泵血功能的重要因素。     

雌激素替代治疗对绝经后妇女血清一氧化氮和脑血流的影响

目的 :探讨雌激素替代治疗对绝经后妇女大脑中动脉血流的影响及其作用机制。方法 :接受结合型雌激素 0 .6 2 5mg d治疗 3个月的绝经后妇女 2 5例 ,于治疗前后对比观察血清雌二醇 (E2 )、一氧化氮 (NO)及大脑中动脉搏动指数 (PI)变化。结果 :ERT治疗3个月后血清E2 、NO浓度较治疗前明显升高 (P <0 .0 1) ,而大脑中动脉PI明显降低 (P<0 .0 1)。同时 ,服药前后NO升高与PI降低有显著相关性 (r =0 .56 ,P <0 .0 5)。结论 :ERT可增加脑血流量 ,其机制可能与NO水平升高有关