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

dc.contributor.advisorFigaji, Anthony
dc.contributor.advisorRohlwink, Ursula
dc.contributor.authorSmith, Claudia Ann
dc.date.accessioned2022-03-15T10:13:42Z
dc.date.available2022-03-15T10:13:42Z
dc.date.issued2021
dc.date.updated2022-03-15T08:06:49Z
dc.description.abstractIntroduction: 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.
dc.identifier.apacitationSmith, C. A. (2021). <i>Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury</i>. (). ,Faculty of Health Sciences ,Department of Human Biology. Retrieved from http://hdl.handle.net/11427/36081en_ZA
dc.identifier.chicagocitationSmith, Claudia Ann. <i>"Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury."</i> ., ,Faculty of Health Sciences ,Department of Human Biology, 2021. http://hdl.handle.net/11427/36081en_ZA
dc.identifier.citationSmith, C.A. 2021. Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury. . ,Faculty of Health Sciences ,Department of Human Biology. http://hdl.handle.net/11427/36081en_ZA
dc.identifier.ris TY - Master Thesis AU - Smith, Claudia Ann AB - 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. DA - 2021 DB - OpenUCT DP - University of Cape Town KW - Medicine LK - https://open.uct.ac.za PY - 2021 T1 - Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury TI - Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury UR - http://hdl.handle.net/11427/36081 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/36081
dc.identifier.vancouvercitationSmith CA. Investigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury. []. ,Faculty of Health Sciences ,Department of Human Biology, 2021 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/36081en_ZA
dc.language.rfc3066eng
dc.publisher.departmentDepartment of Human Biology
dc.publisher.facultyFaculty of Health Sciences
dc.subjectMedicine
dc.titleInvestigating cerebrovascular pressure reactivity in a large cohort of children with severe traumatic brain injury
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationlevelMSc
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