Cerebrovascular pressure reactivity and brain tissue oxygen monitoring provide complementary information regarding the lower and upper limits of cerebral blood flow control in traumatic brain injury: a CAnadian High Resolution-TBI (CAHR-TBI) cohort study.
Creators: name: Gomez, Alwyn
name: Sekhon, Mypinder
name: Griesdale, Donald
name: Froese, Logan
name: Yang, Eleen
name: Thelin, Eric P
name: Raj, Rahul
name: Aries, Marcel
name: Gallagher, Clare
name: Bernard, Francis
name: Kramer, Andreas H
name: Zeiler, Frederick A
Publisher: name: Apollo - University of Cambridge Repository
Year: 2022
Subjects: Research Articles
Traumatic brain injury
Brain tissue oxygen tension
Cerebrovascular reactivity
Multi-modal monitoring
Cerebrovascular physiology

description: Funder: Canadian Institutes of Health Research; doi: http://dx.doi.org/10.13039/501100000024
description: Funder: Manitoba Public Insurance (MPI) Neuroscience Research Operating Fund
description: Funder: Health Sciences Centre Foundation Winnipeg
description: Funder: Canada Foundation for Innovation; doi: http://dx.doi.org/10.13039/501100000196; Grant(s): Project #: 38583
description: Funder: Research Manitoba; doi: http://dx.doi.org/10.13039/100008794; Grant(s): Grant #: 3906
description: Funder: University of Manitoba VPRI Research Investment Fund
description: Funder: University of Manitoba MPI Professorship in Neuroscience
description: Funder: University of Manitoba Dean’s Fellowship
description: Funder: Manitoba Medical Service Foundation; doi: http://dx.doi.org/10.13039/100008795
description: Funder: R. Samuel McLaughlin Research Fellowship
description: Funder: Institute of Neurosciences, Mental Health and Addiction; doi: http://dx.doi.org/10.13039/501100000034; Grant(s): Grant #: 472286
description: Funder: University of Manitoba - Biomedical Engineering (BME) Fellowship Grant
description: Funder: University of Manitoba Graduate Enhancement of Tri-Agency Stipend
description: Funder: Strategic Research Area Neuroscience (StratNeuro, Karolinska Institutet
description: Funder: Svenska Kulturfonden, Medicinska Understödsföreningen Liv &amp; Hälsa
description: Funder: Finska Läkaresällskapet; doi: http://dx.doi.org/10.13039/100010135
description: BACKGROUND: Brain tissue oxygen tension (PbtO2) and cerebrovascular pressure reactivity monitoring have emerged as potential modalities to individualize care in moderate and severe traumatic brain injury (TBI). The relationship between these modalities has had limited exploration. The aim of this study was to examine the relationship between PbtO2 and cerebral perfusion pressure (CPP) and how this relationship is modified by the state of cerebrovascular pressure reactivity. METHODS: A retrospective multi-institution cohort study utilizing prospectively collected high-resolution physiologic data from the CAnadian High Resolution-TBI (CAHR-TBI) Research Collaborative database collected between 2011 and 2021 was performed. Included in the study were critically ill TBI patients with intracranial pressure (ICP), arterial blood pressure (ABP), and PbtO2 monitoring treated in any one of three CAHR-TBI affiliated adult intensive care units (ICU). The outcome of interest was how PbtO2 and CPP are related over a cohort of TBI patients and how this relationship is modified by the state of cerebrovascular reactivity, as determined using the pressure reactivity index (PRx). RESULTS: A total of 77 patients met the study inclusion criteria with a total of 377,744 min of physiologic data available for the analysis. PbtO2 produced a triphasic curve when plotted against CPP like previous population-based plots of cerebral blood flow (CBF) versus CPP. The triphasic curve included a plateau region flanked by regions of relative ischemia (hypoxia) and hyperemia (hyperoxia). The plateau region shortened when cerebrovascular pressure reactivity was disrupted compared to when it was intact. CONCLUSIONS: In this exploratory analysis of a multi-institution high-resolution physiology TBI database, PbtO2 seems to have a triphasic relationship with CPP, over the entire cohort. The CPP range over which the plateau exists is modified by the state of cerebrovascular reactivity. This indicates that in critically ill TBI patients admitted to ICU, PbtO2 may be reflective of CBF.