scholarly journals Variation in cerebral blood flow velocity with cerebral perfusion pressure >40 mm Hg in 42 children with severe traumatic brain injury

2009 ◽  
Vol 37 (11) ◽  
pp. 2973-2978 ◽  
Author(s):  
Shaji Philip ◽  
Onuma Chaiwat ◽  
Yuthana Udomphorn ◽  
Anne Moore ◽  
Jerry J. Zimmerman ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Injury ◽  
Flow Velocity ◽  
Severe Traumatic Brain Injury ◽  
Blood Flow Velocity ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Cerebral Blood Flow Velocity

Traumatic brain injury: Increasing ICP attenuates respiratory modulations of cerebral blood flow velocity

2015 ◽  
Vol 37 (2) ◽  
pp. 175-179 ◽  
Author(s):  
Christina Haubrich ◽  
Rolf R. Diehl ◽  
Magdalena Kasprowicz ◽  
Jennifer Diedler ◽  
Enrico Sorrentino ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Injury ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity

Cerebral pressure-flow relations in hypertensive elderly humans: transfer gain in different frequency domains

2005 ◽  
Vol 98 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Jorge M. Serrador ◽  
Farzaneh A. Sorond ◽  
Mitul Vyas ◽  
Margaret Gagnon ◽  
Ikechukwu D. Iloputaife ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Transfer Function ◽  
Flow Velocity ◽  
Elderly People ◽  
Blood Flow Velocity ◽  
Perfusion Pressure ◽  
Cerebral Blood Flow Velocity ◽  
Pressure Changes

The dynamics of the cerebral vascular response to blood pressure changes in hypertensive humans is poorly understood. Because cerebral blood flow is dependent on adequate perfusion pressure, it is important to understand the effect of hypertension on the transfer of pressure to flow in the cerebrovascular system of elderly people. Therefore, we examined the effect of spontaneous and induced blood pressure changes on beat-to-beat and within-beat cerebral blood flow in three groups of elderly people: normotensive, controlled hypertensive, and uncontrolled hypertensive subjects. Cerebral blood flow velocity (transcranial Doppler), blood pressure (Finapres), heart rate, and end-tidal CO2 were measured during the transition from a sit to stand position. Transfer function gains relating blood pressure to cerebral blood flow velocity were assessed during steady-state sitting and standing. Cerebral blood flow regulation was preserved in all three groups by using changes in cerebrovascular resistance, transfer function gains, and the autoregulatory index as indexes of cerebral autoregulation. Hypertensive subjects demonstrated better attenuation of cerebral blood flow fluctuations in response to blood pressure changes both within the beat (i.e., lower gain at the cardiac frequency) and in the low-frequency range (autoregulatory, 0.03–0.07 Hz). Despite a better pressure autoregulatory response, hypertensive subjects demonstrated reduced reactivity to CO2. Thus otherwise healthy hypertensive elderly subjects, whether controlled or uncontrolled with antihypertensive medication, retain the ability to maintain cerebral blood flow in the face of acute changes in perfusion pressure. Pressure regulation of cerebral blood flow is unrelated to cerebrovascular reactivity to CO2.

Cerebral Blood Flow Velocity in the Human Newborn: The Value of Its Determination

PEDIATRICS ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 147-152
Author(s):  
Joseph J. Volpe ◽  
Jeffrey M. Perlman ◽  
Alan Hill ◽  
Joseph B. McMenamin
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Injury ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Circulation ◽  
Cerebral Blood Flow Velocity ◽  
Doppler Frequency ◽  
Systemic Hemodynamic ◽  
Human Newborn

An ultrasonic technique based on measurement of the Doppler frequency shift produced by the movement of red blood cells in an insonated vessel has been useful for measurement of cerebral blood flow velocity in the newborn. When the transducer is applied to the anterior fontanel, flow velocity in each anterior cerebral artery can be determined noninvasively. Reliable application ofthe technique requires utilization of both the audible and visible signals produced by the instrument. Experience and awareness of the anatomy are also important in interpretation. Serial measurements of cerebral blood flow velocity have provided useful information concerning changes in the cerebral circulation under important neonatal circumstances. Examples of the latter include PDA, pneumothorax, hydrocephalus, and hyperviscosity. Most of the changes in the cerebral circulation appear to reflect directly systemic hemodynamic changes. This relation between cerebral and systemic hemodynamic events is compatible with other observations, indicating that in the human newborn—particularly the infant most at risk for hypoxic-ischemic and/or hemorrhagic brain injury—the cerebral circulation is pressure passive. Indeed, the changes in the cerebral circulation observed so far with the Doppler technique may have important implications for the genesis of neonatal ischemic and hemorrhagic brain injury.

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