Local cerebral perfusion pressure （CPP） is a primary factor controlling cerebral circulation and previous studies have indicated that the ratio of cerebral blood flow （CBF） to cerebral blood volume （CBV） can be ...Local cerebral perfusion pressure （CPP） is a primary factor controlling cerebral circulation and previous studies have indicated that the ratio of cerebral blood flow （CBF） to cerebral blood volume （CBV） can be used as an index of the local CPP. In this study, we investigated whether the CBF/CBV ratio differs among different brain structures under physiological conditions, by means of （15）O positron emission tomography. Nine healthy volunteers （5 men and 4 women; mean age, 47.0 ± 1.2 years） were studied by H2（15）O bolus injection for CBF measurement and by C（15）O inhalation for CBV measurement. The CBF/CBV ratio maps were created by dividing the CBF images by the CBV images after anatomical normalization. Regions of interest were placed on the CBF/CBV maps and comparing the regions. The mean CBF/ CBV ratio was highest in the cerebellum （19.3 ＋ 5.2/ min）, followed by the putamen （18.2 ± 3.9）, pons （16.4 ±4.6）, thalamus （14.5：1： 3.3）, cerebral cortices （13.2 ±2.4）, and centrum semiovale （1115 ± 2.1）. The cerebellum and putamen showed significantly higher CBF/CBV ratios than the cerebral cortices and centrum semiovale. We created maps of the CBF/ CBV ratio in normal volunteers and demonstrated higher CBF/CBV ratios in the cerebellum and putamen than in the cerebral cortices and deep cerebral white matter. The CBF/CBV may reflect the local CPP and should be studied in hemodynamicallycompromised patients and in patients with risk factors for small-artery diseases of the brain. Keywords： cerebral perfusion pressure; cerebra blood flow; cerebral blood volume; H2（15）O; C（15）O展开更多
Ohjectire To examine the hypothesis of normal perjusion pressure breakthrough (NPPB). Methods A modified Spetzler carotid -jugular (CJ) fistula model was created to imitate NPPB. In 9 male adult Sprague- Dawley rats, ...Ohjectire To examine the hypothesis of normal perjusion pressure breakthrough (NPPB). Methods A modified Spetzler carotid -jugular (CJ) fistula model was created to imitate NPPB. In 9 male adult Sprague- Dawley rats, the ipsilateral vertebral artery and bilateral external carotid arteries were occluded. The period of hypoperfusion CJ fistula was extended to 14 weeks, as a modofcation of Spetzler model. The histological change were examtned under transmission electron microscope 14 weeks after creation of the listula. Results Ischemic histological changes such as increased pinocytosis, increased lucency of the basal lamina, and frank necrosis of the cerebral capillary were found in rats of CJ fistula group. Conclusion The findings in this study suggest that blood - braln barrier (BBB) was impaired by chronic hypoperfusion. The impaired BBB mny be one of the important causes of the NPPB phenomenon.展开更多
目的探讨血压水平对急性缺血性脑卒中血管内治疗后脑灌注的影响。方法80例急性缺血性脑卒中合并高血压接受血管内治疗患者,随机分为积极降压组和指南降压组,每组40例。积极降压组在血管再通后1 h内将血压降至110~140/60~90 mm Hg(1 mm H...目的探讨血压水平对急性缺血性脑卒中血管内治疗后脑灌注的影响。方法80例急性缺血性脑卒中合并高血压接受血管内治疗患者,随机分为积极降压组和指南降压组,每组40例。积极降压组在血管再通后1 h内将血压降至110~140/60~90 mm Hg(1 mm Hg=0.133 kPa)并至少维持72 h;指南降压组按照指南推荐将血压降至<180/110 mm Hg。比较两组患者性别、年龄、卒中部位、入院时的血压(收缩压/舒张压)情况、头颅影像学检查结果[脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)]、再通术后90 d美国国立卫生研究院卒中量表(NIHSS)评分、改良Rankin量表(mRS)评分、吸烟史、饮酒史、糖尿病史、既往脑梗死病史和冠心病病史情况、病死率,分析脑灌注情况与血压、机械开通成功率、MTT、CBF的相关性。结果两组性别、年龄、卒中部位、病程、入院时血压(收缩压/舒张压)、吸烟史、饮酒史、糖尿病史、既往脑梗死病史和冠心病病史、病死率比较无差异(P>0.05)。积极降压组的机械开通成功率90.0%高于指南降压组的70.0%,头颅影像学检查结果MTT(35.12±2.63)s短于指南降压组的(41.99±2.56)s,CBF(65.72±3.50)ml/(100 g·min)、CBV(4.92±1.03)ml/100 g均大于指南降压组的(50.69±3.49)ml/(100 g·min)、(4.39±1.13)ml/100 g,再通术后90 d NIHSS评分(10.72±3.48)分低于指南降压组的(15.69±3.27)分,预后良好占比87.5%高于指南降压组的67.5%(P<0.05)。急性缺血性脑卒中患者脑灌注充分与否与血压水平呈负相关,与机械开通成功率、MTT、CBF呈正相关(P<0.05)。结论血压水平的控制范围会对急性缺血性脑卒中血管内治疗后脑灌注产生一定影响,而使用积极降压干预有助于改善患者预后,提高机械开通效果。展开更多
Background:Dysfunction of cerebral autoregulation is one of the pathophysiological mechanisms that causes delayed cerebral ischemia(DCI)after subarachnoid hemorrhage(SAH).Pressure reactivity index(PRx)have been confir...Background:Dysfunction of cerebral autoregulation is one of the pathophysiological mechanisms that causes delayed cerebral ischemia(DCI)after subarachnoid hemorrhage(SAH).Pressure reactivity index(PRx)have been confirmed to reflect the level of cerebral autoregulation and used to derive optimal cerebral perfusion pressure(CPPopt).The goal of this study is to explore the associations between autoregulation,CPPopt,PRx,and DCI.Methods:Continuous intracranial pressure(ICP),arterial blood pressure(ABP),and cerebral perfusion pressure(CPP)signals acquired from 61 aSAH patients were retrospectively analyzed.PRx was calculated and collected by Pneumatic computer system.The CPP at the lowest PRx was determined as the CPPopt.The duration of a hypoperfusion event(dHP)was defined as the cumulative time that the PRx was>0.3 and the CPP was<CPPopt.The duration of CPP more than 10 mmHg below CPPopt(ΔCPPopt<−10 mmHg)was also used to assess hypoperfusion.The percent of the time of hypoperfusion by dHP andΔCPPopt<−10 mmHg(%dHP and%ΔCPPopt)were compared between DCI group and control group,utilizing univariate and multivariable logistic regression.It was the clinical prognosis at 3 months after hemorrhage that was assessed with the modified Rankin Scale,and logistic regression and ROC analysis were used for predictive power for unfavorable outcomes(mRs 3–5).Results:Data from 52 patients were included in the final analysis of 61 patients.The mean%dHP in DCI was 29.23%and 10.66%in control.The mean%ΔCPPopt<−10 mmHg was 22.28%,and 5.90%in control.The%dHP(p<0.001)and the%ΔCPPopt<−10mmHg(p<0.001)was significantly longer in the DCI group.In multivariate logistic regression model,%ΔCPPopt<−10 mmHg(p<0.001)and%dHP(p<0.001)were independent risk factor for predicting DCI,and%ΔCPPopt<−10 mmHg(p=0.010)and%dHP(p=0.026)were independent risk factor for predicting unfavorable outcomes.Conclusions:The increase of duration of hypoperfusion events and duration of CPP below CPPopt over 10 mmHg,evaluated as time of lowered CPP,is highly indicative of DCI and unfavorable outcomes.展开更多
Acute neurologic injuries represent a common cause of morbidity and mortality in children presenting to the pediatric intensive care unit.After primary neurologic insults,there may be cerebral brain tissue that remain...Acute neurologic injuries represent a common cause of morbidity and mortality in children presenting to the pediatric intensive care unit.After primary neurologic insults,there may be cerebral brain tissue that remains at risk of secondary insults,which can lead to worsening neurologic injury and unfavorable outcomes.A fundamental goal of pediatric neurocritical care is to mitigate the impact of secondary neurologic injury and improve neurologic outcomes for critically ill children.This review describes the physiologic framework by which strategies in pediatric neurocritical care are designed to reduce the impact of secondary brain injury and improve functional outcomes.Here,we present current and emerging strategies for optimizing neuroprotective strategies in critically ill children.展开更多
目的:探讨不同呼气末正压通气(Positive end expiratory pressure,PEEP)水平对慢性阻塞性肺疾病急性加重期(Acute exacerbation of chronic obstructive pulmonary disease,AECOPD)伴肺动脉高压患者的影响。方法:选取2020年6月至2022年...目的:探讨不同呼气末正压通气(Positive end expiratory pressure,PEEP)水平对慢性阻塞性肺疾病急性加重期(Acute exacerbation of chronic obstructive pulmonary disease,AECOPD)伴肺动脉高压患者的影响。方法:选取2020年6月至2022年5月期间我院收治的103例AECOPD伴肺动脉高压患者作为研究对象,所有患者按照随机数字表法分为常规组(n=51)和高水平组(n=52)。常规组采用常规PEEP,高水平组采用高水平PEEP,两组患者均持续治疗3 d。观察两组氧利用率、血清炎性因子、脑血流灌注以及肺功能。结果:治疗3 d后,高水平组氧利用率(Ratio of oxygen utilization,O_(2)UC)高于常规组(P<0.05);高水平组超敏C-反应蛋白(High sensitivity C-reactive protein,hs-CRP)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白-细胞介素-6(Interleukin-6,IL-6)以及降钙素原(Procalcitonin,PCT)水平低于常规组(P<0.05);高水平组阻力指数(Resistance Index,RI)、搏动指数(Pulsatility index,PI)和平均血流速度(Mean velocity,Vm)和常规组无明显差异(P>0.05);高水平组肺用力肺活量占预计值百分比(Percentage of forced vital capacity to the expected value,FVC%pred)、第一秒用力呼气容积占预计值百分比(Percentage of forced expiratory volume in the first second to the expected value,FEV1%pred)、第一秒用力呼气容积占用力肺活量百分比(Percentage of forced expiratory volume in the first second to forced vital capacity,FEV1/FVC)均高于常规组(P<0.05)。结论:相比较于常规PEEP,将高水平PEEP用于AECOPD伴肺动脉高压患者中可提高氧利用率,促进肺功能恢复,减轻机体炎症反应,且不影响脑血流灌注。展开更多
基金partly supported by the Molecular Imaging Program,a grant(21591561) from the Ministry of Education,Culture,Sports,Science,and Technology and the Japan Science and Technology Agency,Japanby the Research Promotion Program on Health from the National Institute of Biomedical Innovation,Japana Grant-in-Aid(H21-019 and H21-5) from the Ministry of Health,Welfare,and Labour,Japan
文摘Local cerebral perfusion pressure （CPP） is a primary factor controlling cerebral circulation and previous studies have indicated that the ratio of cerebral blood flow （CBF） to cerebral blood volume （CBV） can be used as an index of the local CPP. In this study, we investigated whether the CBF/CBV ratio differs among different brain structures under physiological conditions, by means of （15）O positron emission tomography. Nine healthy volunteers （5 men and 4 women; mean age, 47.0 ± 1.2 years） were studied by H2（15）O bolus injection for CBF measurement and by C（15）O inhalation for CBV measurement. The CBF/CBV ratio maps were created by dividing the CBF images by the CBV images after anatomical normalization. Regions of interest were placed on the CBF/CBV maps and comparing the regions. The mean CBF/ CBV ratio was highest in the cerebellum （19.3 ＋ 5.2/ min）, followed by the putamen （18.2 ± 3.9）, pons （16.4 ±4.6）, thalamus （14.5：1： 3.3）, cerebral cortices （13.2 ±2.4）, and centrum semiovale （1115 ± 2.1）. The cerebellum and putamen showed significantly higher CBF/CBV ratios than the cerebral cortices and centrum semiovale. We created maps of the CBF/ CBV ratio in normal volunteers and demonstrated higher CBF/CBV ratios in the cerebellum and putamen than in the cerebral cortices and deep cerebral white matter. The CBF/CBV may reflect the local CPP and should be studied in hemodynamicallycompromised patients and in patients with risk factors for small-artery diseases of the brain. Keywords： cerebral perfusion pressure; cerebra blood flow; cerebral blood volume; H2（15）O; C（15）O
文摘Ohjectire To examine the hypothesis of normal perjusion pressure breakthrough (NPPB). Methods A modified Spetzler carotid -jugular (CJ) fistula model was created to imitate NPPB. In 9 male adult Sprague- Dawley rats, the ipsilateral vertebral artery and bilateral external carotid arteries were occluded. The period of hypoperfusion CJ fistula was extended to 14 weeks, as a modofcation of Spetzler model. The histological change were examtned under transmission electron microscope 14 weeks after creation of the listula. Results Ischemic histological changes such as increased pinocytosis, increased lucency of the basal lamina, and frank necrosis of the cerebral capillary were found in rats of CJ fistula group. Conclusion The findings in this study suggest that blood - braln barrier (BBB) was impaired by chronic hypoperfusion. The impaired BBB mny be one of the important causes of the NPPB phenomenon.
文摘目的探讨血压水平对急性缺血性脑卒中血管内治疗后脑灌注的影响。方法80例急性缺血性脑卒中合并高血压接受血管内治疗患者,随机分为积极降压组和指南降压组,每组40例。积极降压组在血管再通后1 h内将血压降至110~140/60~90 mm Hg(1 mm Hg=0.133 kPa)并至少维持72 h;指南降压组按照指南推荐将血压降至<180/110 mm Hg。比较两组患者性别、年龄、卒中部位、入院时的血压(收缩压/舒张压)情况、头颅影像学检查结果[脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)]、再通术后90 d美国国立卫生研究院卒中量表(NIHSS)评分、改良Rankin量表(mRS)评分、吸烟史、饮酒史、糖尿病史、既往脑梗死病史和冠心病病史情况、病死率,分析脑灌注情况与血压、机械开通成功率、MTT、CBF的相关性。结果两组性别、年龄、卒中部位、病程、入院时血压(收缩压/舒张压)、吸烟史、饮酒史、糖尿病史、既往脑梗死病史和冠心病病史、病死率比较无差异(P>0.05)。积极降压组的机械开通成功率90.0%高于指南降压组的70.0%,头颅影像学检查结果MTT(35.12±2.63)s短于指南降压组的(41.99±2.56)s,CBF(65.72±3.50)ml/(100 g·min)、CBV(4.92±1.03)ml/100 g均大于指南降压组的(50.69±3.49)ml/(100 g·min)、(4.39±1.13)ml/100 g,再通术后90 d NIHSS评分(10.72±3.48)分低于指南降压组的(15.69±3.27)分,预后良好占比87.5%高于指南降压组的67.5%(P<0.05)。急性缺血性脑卒中患者脑灌注充分与否与血压水平呈负相关,与机械开通成功率、MTT、CBF呈正相关(P<0.05)。结论血压水平的控制范围会对急性缺血性脑卒中血管内治疗后脑灌注产生一定影响,而使用积极降压干预有助于改善患者预后,提高机械开通效果。
文摘Background:Dysfunction of cerebral autoregulation is one of the pathophysiological mechanisms that causes delayed cerebral ischemia(DCI)after subarachnoid hemorrhage(SAH).Pressure reactivity index(PRx)have been confirmed to reflect the level of cerebral autoregulation and used to derive optimal cerebral perfusion pressure(CPPopt).The goal of this study is to explore the associations between autoregulation,CPPopt,PRx,and DCI.Methods:Continuous intracranial pressure(ICP),arterial blood pressure(ABP),and cerebral perfusion pressure(CPP)signals acquired from 61 aSAH patients were retrospectively analyzed.PRx was calculated and collected by Pneumatic computer system.The CPP at the lowest PRx was determined as the CPPopt.The duration of a hypoperfusion event(dHP)was defined as the cumulative time that the PRx was>0.3 and the CPP was<CPPopt.The duration of CPP more than 10 mmHg below CPPopt(ΔCPPopt<−10 mmHg)was also used to assess hypoperfusion.The percent of the time of hypoperfusion by dHP andΔCPPopt<−10 mmHg(%dHP and%ΔCPPopt)were compared between DCI group and control group,utilizing univariate and multivariable logistic regression.It was the clinical prognosis at 3 months after hemorrhage that was assessed with the modified Rankin Scale,and logistic regression and ROC analysis were used for predictive power for unfavorable outcomes(mRs 3–5).Results:Data from 52 patients were included in the final analysis of 61 patients.The mean%dHP in DCI was 29.23%and 10.66%in control.The mean%ΔCPPopt<−10 mmHg was 22.28%,and 5.90%in control.The%dHP(p<0.001)and the%ΔCPPopt<−10mmHg(p<0.001)was significantly longer in the DCI group.In multivariate logistic regression model,%ΔCPPopt<−10 mmHg(p<0.001)and%dHP(p<0.001)were independent risk factor for predicting DCI,and%ΔCPPopt<−10 mmHg(p=0.010)and%dHP(p=0.026)were independent risk factor for predicting unfavorable outcomes.Conclusions:The increase of duration of hypoperfusion events and duration of CPP below CPPopt over 10 mmHg,evaluated as time of lowered CPP,is highly indicative of DCI and unfavorable outcomes.
文摘Acute neurologic injuries represent a common cause of morbidity and mortality in children presenting to the pediatric intensive care unit.After primary neurologic insults,there may be cerebral brain tissue that remains at risk of secondary insults,which can lead to worsening neurologic injury and unfavorable outcomes.A fundamental goal of pediatric neurocritical care is to mitigate the impact of secondary neurologic injury and improve neurologic outcomes for critically ill children.This review describes the physiologic framework by which strategies in pediatric neurocritical care are designed to reduce the impact of secondary brain injury and improve functional outcomes.Here,we present current and emerging strategies for optimizing neuroprotective strategies in critically ill children.
文摘目的:探讨不同呼气末正压通气(Positive end expiratory pressure,PEEP)水平对慢性阻塞性肺疾病急性加重期(Acute exacerbation of chronic obstructive pulmonary disease,AECOPD)伴肺动脉高压患者的影响。方法:选取2020年6月至2022年5月期间我院收治的103例AECOPD伴肺动脉高压患者作为研究对象,所有患者按照随机数字表法分为常规组(n=51)和高水平组(n=52)。常规组采用常规PEEP,高水平组采用高水平PEEP,两组患者均持续治疗3 d。观察两组氧利用率、血清炎性因子、脑血流灌注以及肺功能。结果:治疗3 d后,高水平组氧利用率(Ratio of oxygen utilization,O_(2)UC)高于常规组(P<0.05);高水平组超敏C-反应蛋白(High sensitivity C-reactive protein,hs-CRP)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白-细胞介素-6(Interleukin-6,IL-6)以及降钙素原(Procalcitonin,PCT)水平低于常规组(P<0.05);高水平组阻力指数(Resistance Index,RI)、搏动指数(Pulsatility index,PI)和平均血流速度(Mean velocity,Vm)和常规组无明显差异(P>0.05);高水平组肺用力肺活量占预计值百分比(Percentage of forced vital capacity to the expected value,FVC%pred)、第一秒用力呼气容积占预计值百分比(Percentage of forced expiratory volume in the first second to the expected value,FEV1%pred)、第一秒用力呼气容积占用力肺活量百分比(Percentage of forced expiratory volume in the first second to forced vital capacity,FEV1/FVC)均高于常规组(P<0.05)。结论:相比较于常规PEEP,将高水平PEEP用于AECOPD伴肺动脉高压患者中可提高氧利用率,促进肺功能恢复,减轻机体炎症反应,且不影响脑血流灌注。
