About: Hypocapnia after traumatic brain injury: how does it affect the time constant of the cerebral circulation?

Facets (new session)
Description
Metadata
Settings
- owl:sameAs
- Inference Rule:

About: Hypocapnia after traumatic brain injury: how does it affect the time constant of the cerebral circulation? Goto Sponge NotDistinct Permalink

An Entity of Type : schema:ScholarlyArticle, within Data Space : wasabi.inria.fr associated with source document(s)

Attributes	Values
type	Academic Article research paper schema:ScholarlyArticle
isDefinedBy	Covid-on-the-Web dataset
has title	Hypocapnia after traumatic brain injury: how does it affect the time constant of the cerebral circulation?
Creator	Czosnyka, Marek Smielewski, Peter Ch, Bernardo Despina, · Kasprowicz, Magdalena Lalou, Afrodite Lalou, Despina Luzius, · Puppo, Corina Smielewski, · Steiner, A Steiner, Luzius Steiner@usb, Luzius Yelicich, Yelicich, Bernardo
Source	PMC
abstract	The time constant of the cerebral arterial bed (“tau”) estimates how fast the blood entering the brain fills the arterial vascular sector. Analogous to an electrical resistor–capacitor circuit, it is expressed as the product of arterial compliance (Ca) and cerebrovascular resistance (CVR). Hypocapnia increases the time constant in healthy volunteers and decreases arterial compliance in head trauma. How the combination of hyocapnia and trauma affects this parameter has yet to be studied. We hypothesized that in TBI patients the intense vasoconstrictive action of hypocapnia would dominate over the decrease in compliance seen after hyperventilation. The predominant vasoconstrictive response would maintain an incoming blood volume in the arterial circulation, thereby lengthening tau. We retrospectively analyzed recordings of intracranial pressure (ICP), arterial blood pressure (ABP), and blood flow velocity (FV) obtained from a cohort of 27 severe TBI patients [(39/30 years (median/IQR), 5 women; admission GCS 6/5 (median/IQR)] studied during a standard clinical CO(2) reactivity test. The reactivity test was performed by means of a 50-min increase in ventilation (20% increase in respiratory minute volume). CVR and Ca were estimated from these recordings, and their product calculated to find the time constant. CVR significantly increased [median CVR pre-hypocapnia/during hypocapnia: 1.05/1.35 mmHg/(cm(3)/s)]. Ca decreased (median Ca pre-hypocapnia/during hypocapnia: 0.130/0.124 arbitrary units) to statistical significance (p = 0.005). The product of these two parameters resulted in a significant prolongation of the time constant (median tau pre-hypocapnia/during hypocapnia: 0.136 s/0.152 s, p ˂ .001). Overall, the increase in CVR dominated over the decrease in compliance, hence tau was longer. We demonstrate a significant increase in the time constant of the cerebral circulation during hypocapnia after severe TBI, and attribute this to an increase in cerebrovascular resistance which outweighs the decrease in cerebral arterial bed compliance.
has issue date	2019-06-07(xsd:dateTime)
bibo:doi	10.1007/s10877-019-00331-x
bibo:pmid	31175502
has license	no-cc
sha1sum (hex)	27c8d9fccef4d85b13f6761171fcbfc8b1016e79
schema:url	https://doi.org/10.1007/s10877-019-00331-x
resource representing a document's title	Hypocapnia after traumatic brain injury: how does it affect the time constant of the cerebral circulation?
has PubMed Central identifier	PMC7223592
has PubMed identifier	31175502
schema:publication	J Clin Monit Comput
resource representing a document's body	covid:27c8d9fccef4d85b13f6761171fcbfc8b1016e79#body_text
is schema:about of	named entity 'calculated' named entity 'cerebral circulation' named entity 'time constant' named entity 'respiratory minute volume' named entity 'IQR' named entity 'GCS' named entity 'arbitrary' named entity 'intracranial pressure' named entity 'arterial blood pressure' named entity 'head trauma' named entity 'flow velocity' named entity 'ESTIMATED FROM' named entity 'HYPOCAPNIA' named entity 'HYPERVENTILATION' named entity '1.05' named entity 'CIRCUIT' named entity 'GCS' named entity 'PRE' named entity 'COMBINATION' named entity 'STATISTICAL SIGNIFICANCE' named entity 'MIN' named entity 'FAST' named entity 'DECREASE' named entity 'PERFORMED BY' named entity 'CEREBRAL CIRCULATION' named entity 'BLOOD FLOW VELOCITY' named entity '152' named entity 'SEVERE' named entity 'REACTIVITY' named entity 'RESPIRATORY MINUTE VOLUME' named entity 'TBI' named entity 'THE BRAIN' named entity '124' named entity 'THEIR' named entity 'CEREBRAL' named entity 'CEREBROVASCULAR' named entity 'THESE' named entity 'DECREASED' named entity 'arterial' named entity 'entering' named entity 'TBI' named entity 'dominate' named entity 'trauma' named entity 'circuit' named entity 'units' named entity 'time constant' named entity 'hyperventilation' named entity 'TBI' named entity 'hyperventilation' named entity 'capillary' named entity 'hyperventilation' named entity 'EtCO' named entity 'blood volume' named entity 'MCA' named entity 'Wilcoxon signed-rank test' named entity 'hyperventilated' named entity 'ABP' named entity 'CPP' named entity 'Fast Fourier transformation' named entity 'admission' named entity 'lengthening' named entity 'ABP' named entity 'arterial' named entity 'predominant' named entity 'intense' named entity 'vasoconstrictive' named entity 'severe'

Faceted Search & Find service v1.13.91 as of Mar 24 2020

Alternative Linked Data Documents: Sponger | ODE Content Formats:

RDF

ODATA

Microdata

About

OpenLink Virtuoso version 07.20.3229 as of Jul 10 2020, on Linux (x86_64-pc-linux-gnu), Single-Server Edition (94 GB total memory)
Data on this page belongs to its respective rights holders.
Virtuoso Faceted Browser Copyright © 2009-2024 OpenLink Software