输血对贫血早产儿脑血流动力学及脑损伤的影响研究

目的 初步探讨输血对贫血早产儿脑血流动力学及脑损伤的影响.方法 采用前瞻性队列研究方法,以2012年10月至2013年9月入住我院新生儿重症监护病房、胎龄≤34周且出生1周后接受输血治疗的贫血早产儿为研究对象,运用便携式超声诊断仪测定输血前与输血后各24 h内大脑前动脉（ACA）、大脑中动脉（MCA）的5个血流动力学参数,包括收缩期峰流速（Vs）、舒张末期血流速度（Vd）、平均血流速度（Vm）、搏动指数（PI）、阻力指数（RI）.运用二维超声观察输血前24 h及输血后1周内头颅超声变化.结果 本研究共纳入40例早产儿,输血后ACA的Vs、RI较输血前降低[Vs：（46.0＆#177;10.8） cm/s比（50.6＆#177;10.9） cm/s,RI：（0.79＆#177;0.10）比（0.84 ＆#177;0.13）,P＜0.05],Vm、PI、Vd输血前后差异无统计学意义（P＞0.05）;MCA各血流动力学参数与ACA血流动力学变化趋势基本一致,但差异无统计学意义（P＞0.05）;输血后89.3％的早产儿脑损伤较前无变化或减轻,10.7％的早产儿输血后出现脑室周围-脑室内出血或出血程度较前加重.结论 输血可影响早产儿大脑血流动力学,以ACA最为显著.输血可能对早产儿脑损伤产生影响.     

偏头痛患儿间歇期脑血流动力学变化的意义

目的 研究儿童偏头痛发作间歇期脑血流动力学变化，判断脑血管功能状态，为临床提供可靠依据。方法择偏头疼患儿78例为观察组，同期其他疾病患儿40例为对照组。采用经颅多普勒超声（TCD）技术，常规检测两组患儿双侧大脑中动脉（MCA）、大脑前动脉（ACA）、大脑后动脉（PCA），观察收缩峰的血流速度（Vs）、血流频谱形态及声频变化。结果观察组患儿TCD检测脑血流动力学变化异常率为794％，其中高流速型32例、双侧流速不对称型21例及流速不稳定型9例、40例对照组TCD检测血流动力学变化异常率为47．5％。其中高流速型9例，双侧流速不对称型7例、流速不稳定型3例，哺组异常率比较差异有显著性（X^2=12．653 P〈0.01）。结论头颅多普勒检查对儿童偏头痛的诊断和治疗有重要价值。     

新生儿脑血流速度正常值检测

125例正常足月新生儿，按不同日龄分为5组，以经颅多谱勒超声（TCD）测量其大脑前动脉（ACA）、大脑中动脉（MCA），颈内动脉（ICA）的收缩峰流速VS，舒张峰流速Vd，平均流速Vm及收缩、舒张流速比（S／D），搏动指数（PI），阻力指数（RI）。统计各参数左右两侧的平均值及标准差。统计结果指示：新生儿期脑内各血管各期血流速度（s，Va，Vm）均较成人及年长儿低。各期血流速度均随日龄增加而加快。S／D，PI，RI也随日龄增加而增加。     

新生儿缺氧缺血性脑病血浆内皮素-1及脑血流动力学变化

探讨新生儿缺氧缺血性脑病（HIE）血浆内皮素-1（ET-1）及脑血流变化的规律。方法采用放射免疫法检测92例HIE血浆ET-1浓度,与对照组对较,应用经颅彩色多谱勒（TCD）对32例HIE脑血流参数及结构形态进行了检测。结果HIE急性期血浆ET－1均有增高,重度增高显著,与对照组有显著差异,恢复期降低;TCD与对照组比较显示脑内各血管血流减低,阻力及搏动指数增高。结论HIE损伤大脑血管内皮细胞,使ET-1释放增加,与HIE损伤程度呈正相关。严重HIE时脑血管痉挛、阻力增加,应用TCD检测脑血流也有助于指导治疗及评估预后。     

东莨菪碱改善新生儿缺氧缺血性脑病血流动力学的探讨

目的　研究新生儿缺氧缺血性脑病 (HIE)的发病机制及脑血流动力学的变化 ,并对东莨菪碱在治疗HIE的作用机制进行探讨。方法　用超声多普勒方法测定 5 1例使用东莨菪碱的HIE患儿 (HIE观察组 )和 4 8例非HIE患儿 (非HIE对照组 )在生后 3日龄和 7日龄双侧大脑前动脉 (ACA)、大脑中动脉 (MCA)和大脑后动脉(PCA)的血流动力学指标 ;同时测定 6 0例未使用东莨菪碱的HIE患儿 (HIE对照组 )的各动脉血流动力学参数。结果　 3日龄时HIE观察组脑血流速度较非HIE对照组普遍降低 ,以双侧ACA(P <0 0 5 )和左侧PCA(P <0 0 1)的降低最为明显 ,7日龄时HIE观察组双侧ACA流速恢复 ,仅左侧PCA血流速度仍明显低于非HIE对照组 (P <0 0 5 ) ;7日龄时HIE观察组双侧ACA、MCA和PCA各血流参数均较HIE对照组有明显的改善。结论　HIE患儿的ACA、MCA、PCA流速普遍降低 ,以ACA和PCA最甚 ,且与HIE损伤的部位相一致 ;东莨菪碱可明显改善HIE患儿的脑血流动力学 ,从而阻断了脑细胞缺氧性损伤与脑血流动力异常之间的恶性循环。     

经颅多普勒超声检测血管迷走性晕厥患儿脑血流动力学变化分析

目的 采用经颅多普勒超声（TCD）分析血管迷走性晕厥（VVS）的脑血流动力学特点,并探讨TCD对VVS的临床应用价值。方法 对2011年12月至2013年8月于兰州大学第二医院小儿心血管科就诊的38例血管迷走性晕厥患儿,及20名体检健康儿童行直立倾斜试验,并应用TCD进行监测。结果 基础状态下,观察组与对照组比较,左右大脑中动脉的收缩期血流速度（Vs）、舒张末期血流速度（Vd）、平均血流速度（Vm）差异无统计学意义（P＞0.05）,脉冲指数（PI）值差异无统计学意义（P＞0.05）;对照组行直立倾斜试验后与基础状态时比较,左右大脑中动脉的Vs、Vd、Vm差异无统计学意义（P＞0.05）,PI值差异无统计学意义（P＞0.05）;观察组通过直立倾斜试验诱发血管迷走性晕厥阳性反应时与基础状态时比较,左右大脑中动脉的Vs、Vd、Vm明显加快（P＜0.05）,PI值明显升高（P＜0.05）。结论 VVS发生时,脑血管阻力增加,脑血流调节障碍;TCD检查对于判断VVS患儿脑血流状态具有重要价值。     

脑功能损害危重患儿经颅多普勒超声监测的临床研究

目的 应用经颅多普勒超声(transcranial Doppler ultrasonography,TCD)观察脑功能损害患儿脑血流动力学变化,探讨TCD在监测与评估脑损害患儿预后中的价值.方法 以大脑中动脉为靶血管,检测脑功能损害组20例及无脑损害组(对照组)20例患儿的脑血流动力学参数[收缩期峰流速(Vs)、平均血流速度(Vm)、舒张期流速(Vd)、搏动指数(PI)、阻力指数(RI),对比两组患儿各参数间的差异.脑功能损害组患儿按Glasgow评分、预后再分组,比较不同Glasgow评分(≤6分组和7~13分组)、不同预后患儿的TCD各参数的差异.每日动态监测脑功能损害组患儿的TCD直至TCD参数正常,将TCD参数达正常时间与Glasgow评分、意识障碍持续时间进行相关分析.对比脑功能损害组不同Glasgow评分、不同预后患儿TCD达正常时间的差异.结果 (1)脑功能损害组大脑中动脉的Vs、PI、RI均较对照组高,Vd较对照组低,差异均有统计学意义(P均<0.05).(2)脑功能损害组Glasgow评分≤6分患儿的PI(0.91±0.21)高于Glasgow评分7~13分患儿(0.83±0.14),两组比较差异有统计学意义(P<0.05);而Vs、Vd、RI两组比较差异均无统计学意义(P均>0.05).脑功能损害组不同预后患儿间的大脑中动脉血流动力学各参数比较差异均无统计学意义(P均>0.05).(3)脑功能损害组患儿TCD参数达正常时间与入院当日Glasgow评分呈负相关(r=-0.653,P<0.01);TCD参数达正常时间与意识障碍持续时间呈正相关(r=0.923,P<0.01).不同Glasgow评分、不同预后患儿的TCD参数达正常时间差异均有统计学意义,Glasgow评分≤6分、预后差患儿的TCD达正常时间更长(P均<0.05).结论 脑功能损害患儿的脑血流动力学异常,脑损害程度越重者,PI越高,TCD参数恢复正常的时间越长;动态监测TCD可反映脑血流变化,对评估病情和预后有一定价值.     

健康足月新生儿脑血流速度及搏动指数检测的意义

目的探讨健康足月新生儿脑血流动力学变化。方法应用经颅多普勒(TCD)检测健康足月新生儿50名大脑中动脉、大脑前动脉和颈内动脉血流速及搏动指数。结果生后24h内检测血流速度最低,以后随生后天数的增加呈直线上升,1个月时血流速较出生时增加1倍(t=3.98P<0.01)。大脑中动脉收缩期峰流速与生后天数相关性最好(r=0.88)。搏动指数在新生儿期呈渐增趋势。结论TCD可了解新生儿期脑血流动力学变化,为诊断新生儿脑血管疾病提供可靠的定量依据。     

新生儿缺氧缺血性脑病时脑血流动力学变化

目的 研究新生儿缺氧缺血性脑病(hypoxic ischemic encephalopathy:HIE)对脑血流动力学的影响 方 法 应用美国惠普8500-GP型彩色超声诊断仪对新生儿HIE患儿脑血流动力学变化进行有对照组的前瞻性研究 结果 新生儿HIE患儿大脑中动脉收缩期峰值流速(PSFV)、搏动指数(PI)及阻力指数(RI)均显著低于对照组相应值 (P<0.01);患儿舒张末期血流速度(EDFV)低于对照组舒张末期血流速度(P>0.05) 结论 脑血流动力学紊乱是新生 儿窒息致缺氧缺血性脑损伤的重要原因。应用无损伤性彩色超声诊断仪监测大脑中动脉血流动力学变化有助于早期 评估其预后并指导临床治疗。     

多普勒超声检测围产窒息儿心脑肾血流参数的临床价值

由于新生儿窒息缺氧后可导致全身多器官受损，于1993年1月～1994年3月对我院住院新生儿中有围产窒息史者3O例应用彩色多普勒超声检测治疗前后的心功能S．V（每搏排出量），E．F（射血分数）．VS（肾动脉血流收缩期峰值速度）及Vd（舒张期速度）．M．CA（大脑中动脉），AC．A（前动脉），P．C．A（后动脉），BA（基底动脉）的VS（收缩期血流），Vd（舒张期血流），V（平均血流），RI（阻力指数），PI（搏动指数）。直观的了解到新生儿窒息缺氧后心、脑、肾血流参数变化，为临床诊断，指导治疗提供了依据。对象和方法1．对象：男18…     

经颅多普勒超声观察甘露醇对心肺复苏后患儿脑血流的影响

目的　应用经颅多普勒超声 (TCD)观察甘露醇对复苏后患儿脑血流动力学的影响。方法　以大脑中动脉(MCA)和颈内动脉颅外段 (EICA)为靶血管,观察 21例复苏后患儿脑血流变化的趋势及应用首剂甘露醇前后各指标的变化。据舒张期血流将患儿分为 2组:Ⅰ组为舒张期血流消失或反流(9例);Ⅱ组为舒张期血流正向(12例)。结果　Ⅰ组静注甘露醇前后MCA和EICA的收缩期峰流速(Vp)、舒张期流速(Vd)、平均流速(Vm)、脉动指数(PI)无明显改变 (P>0.05), Glasgow评分最高值明显低于Ⅱ组(P<0.05 ),随病程TCD频谱形态无改善,预后极差。Ⅱ组用药后MCA的Vd、Vm、Vp增加,PI降低 (P<0 05 );EICA的Vd增加 (P<0.05 ),Vp、Vm、PI无明显变化 (P>0.05),随病程TCD频谱形态渐趋正常,患儿全部存活。结论　脑损害较轻的患儿应用甘露醇可改善脑灌注,舒张期血流消失或反向频谱提示预后不良,与严重脑损伤密切相关,甘露醇对此类患儿难以发挥调节脑血流作用。     

Detection of cerebrovascular disease in patients with sickle cell disease using transcranial Doppler sonography: correlation with MRI,MRA and conventional angiography

A prospective study of 58 patients with sickle cell disease (SCD) by transcranial Doppler sonography (TCD) included both MRI and MRA in patients over 7 years of age and those with abnormal TCD. Arteriography was performed in cases where a stenosis was suspected on TCD. Middle cerebral artery (MCA) and basilar artery (BA) velocities were significantly higher in the sickle cell hemoglobin SS group than in the hemoglobin SC group. Patients with a MCA mean velocity of over 1.90 m/s had stenoses found by arteriography. Patients with unilaterally undetectable MCA flow had experienced a stroke and MCA thrombosis was confirmed at MRA and arteriography. We concluded that TCD is valuable in detecting arterial stenosis in SCD and will lead to consideration of these patients for intensive therapy, such as bone marrow transplantation (BMT) or transfusion regimes.

     

经颅多普勒超声对脑功能受损危重症患儿脑功能及预后评估的应用

目的：探讨在儿童危重症患者使用经颅多普勒超声( transcranial Doppler sonography, TCD)判断脑损伤情况的应用价值。方法对2014年11月至2015年3月期间所有入住本院重症医学科的首次格拉斯哥昏迷评分( GCS)小于13分并且明确存在脑损伤患儿进行TCD检查,根据脑血流频谱形态、血流速度分为低灌注组、基本正常组及相对异常组。收集第1、3、7天TCD检查大脑中动脉及颈内动脉颅内段的脑血流频谱形态、血流速度以及患儿第1、7天GCS评分,观察经治疗后脑灌注改善情况对GCS评分及预后的影响。结果共收集病例65例,低灌注组21例,脑灌注改善6例、未改善15例;相对异常组42例,脑灌注改善28例,未改善14例;基本正常组2例,脑灌注均改善。低灌注组脑灌注改善患儿第7天GCS评分明显大于未改善的患儿(12.33±4.63 vs.3.00±0.00,P<0.05);相对异常组其脑灌注改善患儿第7天GCS评分明显大于未改善的患儿(13.42±2.72 vs.3.50±1.09,P<0.05)。TCD监测提示脑灌注改善的患儿存活比例(34/36例)显著大于未改善的患儿(2/29例)(χ2＝49.82, P<0.05)。结论 TCD检查能够较准确评估脑功能、意识状态,在治疗脑功能受损患儿的过程中具有指导意义。     

Intracerebral regional distribution of blood flow in response to uterine contractions in growth-restricted human fetuses

OBJECTIVE: To explore middle cerebral artery (MCA) and anterior cerebral artery (ACA) blood flow responses to superimposed acute hypoxemia in growth-restricted fetuses with and without established brain-sparing flow during basal conditions. MATERIAL AND METHODS: 47 term fetuses suspected of growth restriction were exposed to an oxytocin challenge test with simultaneous cardiotocography and Doppler velocimetry in the umbilical artery, MCA and ACA. The MCA-to-ACA pulsatility index (PI) ratio was calculated during basal conditions, contractions and relaxations. Basal brain-sparing flow was defined as an MCA-to-umbilical artery PI ratio of<1.08, de novo brain-sparing flow in the MCA as an MCA PI decrease with> or =1 standard deviation during uterine contractions or relaxations compared with basal measurements, and de novo brain-sparing flow in the ACA as an ACA PI decrease with > or =1 standard deviation. Non-parametric statistical tests were used with P<0.05 considered significant. RESULTS: MCA and ACA PI were both significantly lower in the brain-sparing flow group (N=8) during basal conditions (P< or =0.01). During the oxytocin challenge test, MCA and ACA PI both decreased in the non-brain-sparing flow group (N=39) (P< or =0.02) but not in the brain-sparing flow group (P> or =0.4). The MCA-to-ACA PI ratio remained unchanged in both groups. de novo brain-sparing flow calculations revealed no preferential flow to any cerebral artery. CONCLUSION: Cerebral circulatory responses to acute hypoxemia are synchronized in the middle and anterior cerebral arteries without any preferential regional flow distribution.     

发作间隙期脑血流动力学改变对偏头痛预防性治疗效果的影响

目的　部分偏头痛发作间隙期存在脑血流动力学改变 ,但其对偏头痛治疗效果的影响尚不清楚 ,该文旨在探讨发作间隙期脑血流动力学改变与偏头痛预防性治疗效果的关系。方法　 5 2例偏头痛患者在发作间隙期先进行经颅多普勒 (TCD)检查 ,分为TCD正常组与异常组 ,各组再随机给予西比灵或赛庚啶预防治疗 ,采用Bussone头痛评分评估治疗效果。结果　TCD异常患儿治疗 4个月后西比灵组头痛指数低于赛庚啶组 5 .6 9± 4 .15vs 15 .92± 10 .5 2 ,差异有显著性 (P <0 .0 5 ) ;而TCD正常的患儿治疗 4个月后赛庚啶组头痛指数低于西比灵组 6 .4 3± 6 .6 2vs 17.4 6± 11.6 2 ,差异有极显著性 (P <0 .0 1)。结论　针对发作间隙期脑血流动力学改变选用不同药物预防偏头痛 ,可能起到提高疗效、减少副反应、降低成本的作用。     

Transcranial Doppler, MRA, and MRI as a screening examination for cerebrovascular disease in patients with sickle cell anemia: an 8-year study

Objective. The authors previously reported five transcranial Doppler ultrasonography (TCD) findings as significant in detecting clinical cerebrovascular disease in a 4-year study in patients with sickle cell disease. This is a follow-up to evaluate the validity of the original findings over another 4-year period during which the study population doubled. A clinical follow-up of the original asymptomatic sickle cell patients with positive TCD, MRA, and MRI was also made. Materials and methods. Over an 8-year period TCD, MRI, and MRA were prospectively performed in 90 sickle cell patients who were clinically asymptomatic for stroke and in 27 sickle cell patients with clinical stroke. Results. Of the 4 out of original 46 control patients in 1992 who had positive MRA and TCD, 3 have subsequently had clinical stroke. None of the 9 original patients with positive TCD and positive MRI but negative MRA have developed stroke. All five original TCD indicators of disease were still significant (P < 0.05) for detecting clinical disease: maximum velocity in ophthalmic artery (OA) > 35 cm/s, mean velocity in middle cerebral artery (MCA) > 170 cm/s, resistive index (RI) in OA < 50, velocity in OA greater than in MCA, and velocity in posterior cerebral (PCA), vertebral, or basilar arteries greater than in MCA. Four additional factors were also significant: turbulence, PCA or ACA without MCA, RI < 30, and maximum velocity in MCA > 200 cm/s. Conclusion. Positive MRA with a positive TCD in an asymptomatic patient in long-term follow-up suggests a trend for developing clinical stroke. A 4- to 8-year follow-up of nine patients with positive TCD, positive MRI, but not positive MRA did not show development of clinical stroke. Nine Doppler findings are significant in screening for clinically symptomatic vascular disease in sickle cell patients. It is recommended that children with sickle cell disease be screened for cerebrovascular disease with TCD. If one or two indicators of abnormality are present, MRA is recommended. If the MRA is positive, the patient may be considered for transfusion therapy or other treatment for prevention of stroke. Received: 17 April 1997 Accepted: 7 July 1997     

Transcranial Doppler in hemoglobin SC disease

Background: Stroke is a severe clinical disorder in sickle cell disease (SCD), and few studies have evaluated transcranial Doppler (TCD) flow velocities in hemoglobin SC disease (HbSC). The guidelines for stroke risk are based on evaluations in sickle cell anemia (SCA) or HbS/β thalassemia. Procedure: In this study, we compare cerebral blood flow in patients with SCD stratified by genotypes. A total of 1,664 pediatric patients with SCD underwent TCD velocity screening, and the time‐averaged maximum mean velocity (TAMM) was determined in the middle cerebral artery (MCA), anterior cerebral artery (ACA), and distal intracranial internal carotid artery (ICA). Results: Abnormal velocities were not identified in the ACA; therefore, we only use ICA and MCA velocities. TAMM from the left and right in the ICA and MCA was 134.3 ± 32.0 and 134.4 ± 32.6 cm/s in patients with SCA, and 105.2 ± 20.6 and 104.7 ± 20.0 cm/s in the patients with HbSC, respectively. Mean TAMM between right and left ICA/MCA was 134.5 ± 30.5 cm/s in the SCA group, and 104.9 ± 19.3 cm/s in the HbSC group. Notably, our data show that TCD velocities were significantly lower among the patients with HbSC compared to SCA. TAMM was negatively correlated with hemoglobin and hematocrit in both genotypes. Conclusion: These results suggest that a different cut‐off value for abnormal TCD velocities could be considered for patients with HbSC. Additional studies are warranted to determine the actual risk of stroke in HbSC genotype associated with this possible TCD risk value.     

Cerebral perfusion during major cardiac surgery in children

Summary Six children undergoing major cardiac surgery had extensive cerebral monitoring during cardiopulmonary bypass (CPB). The monitoring included continuous recording of arterial blood pressure (BP), central venous pressure (CVP), cerebral electrical activity by a cerebral function monitor (CFM), and middle cerebral artery (MCA) flow velocity by the transcranial pulsed Doppler (TCD) technique.Introduction of the precooled blood containing priming solution resulted in rapid fall in BP as well as MCA velocities in these children at the start of CPB. During steady-state CPB at 20°C, MCA flow velocities were reduced in five of six children, range 45%–105% of pre-bypass value. These flow velocity values were recorded at cerebral perfusion pressures (CPP=BP–CVP) in the range of 14–26 mmHg. This reduced cerebral perfusion during steady-state CPB appears to be more than sufficient to meet the cerebral metabolic demands at the particular temperature. The reduced cerebral perfusion is in contrast to the enhanced perfusion found in adults during moderately hypothermic (28°–30°C) low-flow, low-pressure CPB previously reported. It was presumably due to the reduced temperature, reduced perfusion pressure, and less hemodilution.During periods of constant temperature, hematocrit, and partial pressure of carbon dioxide (PaCO ₂), MCA flow velocities varied passively with changes in CPP, demonstrating that cerebral autoregulation was not operative. Transcranial Doppler appears to be a suitable tool for investigating CPB techniques optimal with respect to cerebral circulation.