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Continuous Measurement in Neurocritical Care of Cerebral Blood Flow (CBF) Calculated from ICP and Central Venous Pressure

Ryding, Erik LU (2025) In Neurology International 17(4).
Abstract

Background/Objectives: In neurocritical care, usually, the only continuous measurement of brain pathophysiology is intracranial pressure (ICP). The objective of this study was to find the relationship between cerebral blood flow (CBF) and parameters usually measured in neurocritical care, mainly central venous pressure and ICP. Methods: If the venous outflow of the CBF is considered, the CBF is controlled only by two parameters, the rICP (the ICP minus the venous blood pressure in the venous sinus at its outflow) and the Rv (the flow resistance of the soft-walled veins). For the rICP, the sinus blood pressure can be calculated from the central venous pressure (measured at the same horizontal level as the ICP) and the cervical venous... (More)

Background/Objectives: In neurocritical care, usually, the only continuous measurement of brain pathophysiology is intracranial pressure (ICP). The objective of this study was to find the relationship between cerebral blood flow (CBF) and parameters usually measured in neurocritical care, mainly central venous pressure and ICP. Methods: If the venous outflow of the CBF is considered, the CBF is controlled only by two parameters, the rICP (the ICP minus the venous blood pressure in the venous sinus at its outflow) and the Rv (the flow resistance of the soft-walled veins). For the rICP, the sinus blood pressure can be calculated from the central venous pressure (measured at the same horizontal level as the ICP) and the cervical venous flow resistance. For the Rv, the systolic ICP increase indicates the systolic arterial inflow volume, which then flows out before the diastole. The mean ICP increase divided by the mean outflow of the increased blood volume gives the Rv. This method of calculating the CBF by dividing the rICP by the Rv was named CBF(1). For validation of CBF(1), data from nine subjects in an open study were used. The data were ICP and MR blood flow measurements of arterial inflow and jugular vein outflow. Since the rICP, Rv, and CBF were unknown, an iterative method was needed to calculate these parameters. Results: The observed Rv and rICP values showed a close correlation, which indicated that CBF was dependant on the rICP only. Consequently, the comparison between the data in the study of the nine subjects, and the calculated values from CBF(1), boiled down to a comparison between the supine ICP values and the calculated rICP. The comparison showed that the rICP and supine ICP had highly significant similarity, and that the CBF(1) method was validated. Conclusions: A method for CBF measurement from ICP data in neurocritical care was found.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
CBF, central venous pressure, ICP, rICP, venous resistance
in
Neurology International
volume
17
issue
4
article number
49
publisher
MDPI AG
external identifiers
  • scopus:105003502057
  • pmid:40278420
ISSN
2035-8385
DOI
10.3390/neurolint17040049
language
English
LU publication?
yes
id
7c4de7cf-98f6-4668-a21e-1c5df9f1ecfd
date added to LUP
2025-08-12 10:47:29
date last changed
2025-08-13 03:00:09
@misc{7c4de7cf-98f6-4668-a21e-1c5df9f1ecfd,
  abstract     = {{<p>Background/Objectives: In neurocritical care, usually, the only continuous measurement of brain pathophysiology is intracranial pressure (ICP). The objective of this study was to find the relationship between cerebral blood flow (CBF) and parameters usually measured in neurocritical care, mainly central venous pressure and ICP. Methods: If the venous outflow of the CBF is considered, the CBF is controlled only by two parameters, the rICP (the ICP minus the venous blood pressure in the venous sinus at its outflow) and the Rv (the flow resistance of the soft-walled veins). For the rICP, the sinus blood pressure can be calculated from the central venous pressure (measured at the same horizontal level as the ICP) and the cervical venous flow resistance. For the Rv, the systolic ICP increase indicates the systolic arterial inflow volume, which then flows out before the diastole. The mean ICP increase divided by the mean outflow of the increased blood volume gives the Rv. This method of calculating the CBF by dividing the rICP by the Rv was named CBF(1). For validation of CBF(1), data from nine subjects in an open study were used. The data were ICP and MR blood flow measurements of arterial inflow and jugular vein outflow. Since the rICP, Rv, and CBF were unknown, an iterative method was needed to calculate these parameters. Results: The observed Rv and rICP values showed a close correlation, which indicated that CBF was dependant on the rICP only. Consequently, the comparison between the data in the study of the nine subjects, and the calculated values from CBF(1), boiled down to a comparison between the supine ICP values and the calculated rICP. The comparison showed that the rICP and supine ICP had highly significant similarity, and that the CBF(1) method was validated. Conclusions: A method for CBF measurement from ICP data in neurocritical care was found.</p>}},
  author       = {{Ryding, Erik}},
  issn         = {{2035-8385}},
  keywords     = {{CBF; central venous pressure; ICP; rICP; venous resistance}},
  language     = {{eng}},
  number       = {{4}},
  publisher    = {{MDPI AG}},
  series       = {{Neurology International}},
  title        = {{Continuous Measurement in Neurocritical Care of Cerebral Blood Flow (CBF) Calculated from ICP and Central Venous Pressure}},
  url          = {{http://dx.doi.org/10.3390/neurolint17040049}},
  doi          = {{10.3390/neurolint17040049}},
  volume       = {{17}},
  year         = {{2025}},
}