Statistical properties of cerebral near infrared and intracranial pressure-based cerebrovascular reactivity metrics in moderate and severe neural injury: a machine learning and time-series analysis.

Aug 28, 2023

Contributors: Alwyn Gomez,Amanjyot Singh Sainbhi,Kevin Y Stein,Nuray Vakitbilir,Logan Froese,Frederick A Zeiler

Cerebrovascular reactivity has been identified as a key contributor to secondary injury following traumatic brain injury (TBI). Prevalent intracranial pressure (ICP) based indices of cerebrovascular reactivity are limited by their invasive nature and poor spatial resolution. Fortunately, interest has been building around near infrared spectroscopy (NIRS) based measures of cerebrovascular reactivity that utilize regional cerebral oxygen saturation (rSO) as a surrogate for pulsatile cerebral blood volume (CBV). In this study, the relationship between ICP- and rSO-based indices of cerebrovascular reactivity, in a cohort of critically ill TBI patients, is explored using classical machine learning clustering techniques and multivariate time-series analysis.
High-resolution physiologic data were collected in a cohort of adult moderate to severe TBI patients at a single quaternary care site. From this data both ICP- and rSO-based indices of cerebrovascular reactivity were derived. Utilizing agglomerative hierarchical clustering and principal component analysis, the relationship between these indices in higher dimensional physiologic space was examined. Additionally, using vector autoregressive modeling, the response of change in ICP and rSO (ΔICP and ΔrSO, respectively) to an impulse in change in arterial blood pressure (ΔABP) was also examined for similarities.
A total of 83 patients with 428,775 min of unique and complete physiologic data were obtained. Through agglomerative hierarchical clustering and principal component analysis, there was higher order clustering between rSO- and ICP-based indices, separate from other physiologic parameters. Additionally, modeled responses of ΔICP and ΔrSO to impulses in ΔABP were similar, indicating that ΔrSO may be a valid surrogate for pulsatile CBV.
rSO- and ICP-based indices of cerebrovascular reactivity relate to one another in higher dimensional physiologic space. ΔICP and ΔrSO behave similar in modeled responses to impulses in ΔABP. This work strengthens the body of evidence supporting the similarities between ICP-based and rSO-based indices of cerebrovascular reactivity and opens the door to cerebrovascular reactivity monitoring in settings where invasive ICP monitoring is not feasible.

© 2023. European Society of Intensive Care Medicine and Springer Nature Switzerland AG.

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ABOUT THE CONTRIBUTORS

Alwyn Gomez,Amanjyot Singh Sainbhi,Kevin Y Stein,Nuray Vakitbilir,Logan Froese,Frederick A Zeiler
Alwyn Gomez

Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada. gomeza35@myumanitoba.ca.

Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada. gomeza35@myumanitoba.ca.

Amanjyot Singh Sainbhi

Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada.

Kevin Y Stein

Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada.

Nuray Vakitbilir

Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada.

Logan Froese

Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada.

Frederick A Zeiler

Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.

Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.

Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada.

Centre on Aging, University of Manitoba, Winnipeg, Canada.

Division of Anaesthesia, Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Cambridge, UK.

Department of Clinical Neurosciences, Karolinksa Institutet, Stockholm, Sweden.