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Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury

Introduction: Traumatic brain injury (TBI) contributes to worldwide death and disability more than any other traumatic event, but it is of particular concern in children in developing resource-scarce countries. Cerebral autoregulation (CA) is a homeostatic mechanism that aims to maintain constant ce...

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Main Author: Smith, Claudia Ann
Other Authors: Figaji, Anthony
Format: Thesis
Language:English
Published: Department of Human Biology 2022
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access_status_str Open Access
author Smith, Claudia Ann
author2 Figaji, Anthony
author_browse Figaji, Anthony
Smith, Claudia Ann
author_facet Figaji, Anthony
Smith, Claudia Ann
author_sort Smith, Claudia Ann
collection Thesis
description Introduction: Traumatic brain injury (TBI) contributes to worldwide death and disability more than any other traumatic event, but it is of particular concern in children in developing resource-scarce countries. Cerebral autoregulation (CA) is a homeostatic mechanism that aims to maintain constant cerebral blood flow within a range of systemic blood pressures, and the loss of this mechanism has been associated with mortality and worse outcomes in adult TBI. Paediatric studies of CA disturbance are few and consist of small cohorts. Given the differences between adult and paediatric TBI pathophysiology, CA needs examination in a larger cohort of paediatric TBI. This study aimed to describe the profile of PRx, a mathematical indicator of cerebrovascular pressure reactivity, in a large cohort of children with severe TBI. The specific aims were to 1) describe the characteristics of PRx; 2) examine associations between PRx, clinical and physiological variables, and 3) examine associations between PRx and mortality at 6 months, and PRx and dichotomized outcome (as well as survivors only) at ≥ 6 months post-injury. Methods: Patient demographics, clinical and monitoring data were recorded, and the temporal profile of median PRx was plotted by outcome groups. The associations between PRx, Glasgow Coma Score (GCS), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) were examined with both summary measures and correlation analysis using high frequency data. Associations between PRx and mortality/outcome were examined with multiple regression analysis, and the prognostic ability of PRx, ICP and CPP was investigated with receiver operating curve analysis. Results: We examined 196 children with severe TBI. Mortality rate was 10.7%, and 70.4% of the cohort had unfavourable outcome. PRx was consistently higher in patients with poor outcome when examined by various summary statistics and over time. Hourly analysis showed that PRx had a moderate positive correlation with ICP (r = 0.35; p < 0.001) and a weak negative correlation with MAP (r = -0.10; p < 0.001) and CPP (r = -0.27; p < 0.001). PRx had a strong and independent association with mortality. Conclusion: This study calculated, described, and analysed PRx in the largest known cohort of children with severe TBI. PRx had a strong association with outcome (particularly mortality) that was independent of ICP, CPP and GCS. However, a combination of several PRx and ICP-related variables will likely be important for overall prognostication in paediatric severe TBI. Whether CA should be incorporated into clinical care, and if so, how, requires separate investigation.
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spelling oai:open.uct.ac.za:11427/36081 Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury Smith, Claudia Ann Figaji, Anthony Rohlwink, Ursula Medicine Introduction: Traumatic brain injury (TBI) contributes to worldwide death and disability more than any other traumatic event, but it is of particular concern in children in developing resource-scarce countries. Cerebral autoregulation (CA) is a homeostatic mechanism that aims to maintain constant cerebral blood flow within a range of systemic blood pressures, and the loss of this mechanism has been associated with mortality and worse outcomes in adult TBI. Paediatric studies of CA disturbance are few and consist of small cohorts. Given the differences between adult and paediatric TBI pathophysiology, CA needs examination in a larger cohort of paediatric TBI. This study aimed to describe the profile of PRx, a mathematical indicator of cerebrovascular pressure reactivity, in a large cohort of children with severe TBI. The specific aims were to 1) describe the characteristics of PRx; 2) examine associations between PRx, clinical and physiological variables, and 3) examine associations between PRx and mortality at 6 months, and PRx and dichotomized outcome (as well as survivors only) at ≥ 6 months post-injury. Methods: Patient demographics, clinical and monitoring data were recorded, and the temporal profile of median PRx was plotted by outcome groups. The associations between PRx, Glasgow Coma Score (GCS), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) were examined with both summary measures and correlation analysis using high frequency data. Associations between PRx and mortality/outcome were examined with multiple regression analysis, and the prognostic ability of PRx, ICP and CPP was investigated with receiver operating curve analysis. Results: We examined 196 children with severe TBI. Mortality rate was 10.7%, and 70.4% of the cohort had unfavourable outcome. PRx was consistently higher in patients with poor outcome when examined by various summary statistics and over time. Hourly analysis showed that PRx had a moderate positive correlation with ICP (r = 0.35; p < 0.001) and a weak negative correlation with MAP (r = -0.10; p < 0.001) and CPP (r = -0.27; p < 0.001). PRx had a strong and independent association with mortality. Conclusion: This study calculated, described, and analysed PRx in the largest known cohort of children with severe TBI. PRx had a strong association with outcome (particularly mortality) that was independent of ICP, CPP and GCS. However, a combination of several PRx and ICP-related variables will likely be important for overall prognostication in paediatric severe TBI. Whether CA should be incorporated into clinical care, and if so, how, requires separate investigation. 2022-03-15T10:13:42Z 2022-03-15T10:13:42Z 2021 2022-03-15T08:06:49Z Master Thesis Masters MSc http://hdl.handle.net/11427/36081 eng application/pdf Department of Human Biology Faculty of Health Sciences
spellingShingle Medicine
Smith, Claudia Ann
Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury
thesis_degree_str Master's
title Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury
title_full Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury
title_fullStr Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury
title_full_unstemmed Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury
title_short Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury
title_sort investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury
topic Medicine
url http://hdl.handle.net/11427/36081
work_keys_str_mv AT smithclaudiaann investigatingcerebrovascularpressurereactivityinalargecohortofchildrenwithseveretraumaticbraininjury