1
|
Sayin ES, Duffin J, Poublanc J, Venkatraghavan L, Mikulis DJ, Fisher JA, Sobczyk O. Determining the effects of elevated partial pressure of oxygen on hypercapnia-induced cerebrovascular reactivity. J Cereb Blood Flow Metab 2023; 43:2085-2095. [PMID: 37632334 PMCID: PMC10925865 DOI: 10.1177/0271678x231197000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 08/28/2023]
Abstract
Evaluation of cerebrovascular reactivity (CVR) to hypo- and hypercapnia is a valuable test for the assessment of vasodilatory reserve. While hypercapnia-induced CVR testing is usually performed at normoxia, mild hyperoxia may increase tolerability of hypercapnia by reducing the ventilatory distress. However, the effects of mild hyperoxia on CVR was unknown. We therefore recruited 21 patients with a range of steno-occlusive diseases and 12 healthy participants who underwent a standardized 13-minute step plus ramp CVR test with a carbon dioxide gas challenge at the subject's resting end-tidal partial pressure of oxygen or at mild hyperoxia (PetO2 = 150 mmHg) depending on to which group they were assigned. In 11 patients, the second CVR test was at normoxia to examine test-retest differences. CVR was defined as % Δ Signal/ΔPetCO2. We found that there was no significant difference between CVR test results conducted at normoxia and at mild hyperoxia for participants in Groups 1 and 2 for the step and ramp portion. We also found no difference between test and retest CVR at normoxia for patients with cerebrovascular pathology (Group 3) for step and ramp portion. We concluded normoxic CVR is repeatable, and that mild hyperoxia does not affect CVR.
Collapse
Affiliation(s)
- Ece Su Sayin
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - James Duffin
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada
| | - Lashmikumar Venkatraghavan
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, ON, Canada
| | - David John Mikulis
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada
| | - Joseph Arnold Fisher
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Olivia Sobczyk
- Department of Anaesthesia and Pain Management, University Health Network, University of Toronto, Toronto, ON, Canada
- Joint Department of Medical Imaging and the Functional Neuroimaging Lab, University Health Network, Toronto, ON, Canada
| |
Collapse
|
2
|
Cowdrick KR, Akbar M, Boodooram T, Harris LH, Bai S, Brothers RO, Arrington M, Lee SY, Khemani K, Gee B, Buckley EM. Impaired cerebrovascular reactivity in pediatric sickle cell disease using diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2023; 14:5696-5708. [PMID: 38021121 PMCID: PMC10659811 DOI: 10.1364/boe.499274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 12/01/2023]
Abstract
Cerebrovascular reactivity (CVR), defined as the ability of cerebral vasculature to dilate in response to a vasodilatory stimulus, is an integral mechanism in brain homeostasis that is thought to be impaired in sickle cell disease (SCD). This study used diffuse correlation spectroscopy and a simple breath-hold stimulus to quantify CVR non-invasively in a cohort of 12 children with SCD and 14 controls. Median [interquartile range] CVR was significantly decreased in SCD compared to controls (2.03 [1.31, 2.44] versus 3.49 [3.00, 4.11] %/mmHg, p = 0.028). These results suggest DCS may provide a feasible means to routinely monitor CVR impairments in pediatric SCD.
Collapse
Affiliation(s)
- Kyle R. Cowdrick
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Drive NE, Atlanta, GA 30322, USA
| | - Mariam Akbar
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Drive NE, Atlanta, GA 30322, USA
| | - Tisha Boodooram
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Drive NE, Atlanta, GA 30322, USA
| | - LaBeausha H. Harris
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Drive NE, Atlanta, GA 30322, USA
| | - Shasha Bai
- Pediatric Biostatistics Core, Emory University School of Medicine, 1405 Clifton Road NE, Atlanta, GA 30322, USA
| | - Rowan O. Brothers
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Drive NE, Atlanta, GA 30322, USA
| | - Michael Arrington
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Drive NE, Atlanta, GA 30322, USA
| | - Seung Yup Lee
- Department of Electrical and Computer Engineering, Kennesaw State University, 840 Polytechnic Lane, Marietta, GA 30060, USA
| | - Kirsma Khemani
- Aflac Cancer and Blood Disorders Center, Division of Pediatric Hematology/Oncology, Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA 30322, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Beatrice Gee
- Aflac Cancer and Blood Disorders Center, Division of Pediatric Hematology/Oncology, Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA 30322, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Erin M. Buckley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Drive NE, Atlanta, GA 30322, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
- Children's Research Scholar, Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA 30322, USA
| |
Collapse
|
3
|
Sayin ES, Sobczyk O, Poublanc J, Mikulis DJ, Fisher JA, Kuo KHM, Duffin J. Assessment of cerebrovascular function in patients with sickle cell disease using transfer function analysis. Physiol Rep 2022; 10:e15472. [PMID: 36200271 PMCID: PMC9535348 DOI: 10.14814/phy2.15472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/29/2022] [Accepted: 09/01/2022] [Indexed: 11/07/2022] Open
Abstract
In patients with sickle cell disease (SCD), the delivery of oxygen to the brain is compromised by anemia, abnormal rheology, and steno‐occlusive vascular disease. Successful compensation depends on an increase in oxygen supply such as that provided by an increase in cerebral blood flow (CBF). We used magnetic resonance imaging to provide a high‐resolution assessment of the ability of SCD patients to respond to a vasoactive stimulus in middle, anterior, and posterior cerebral artery territories for both white and gray matter. Cerebrovascular reactivity (CVR) was measured as the blood oxygen level dependent signal (a surrogate for CBF) response to an increase in the end tidal partial pressure of CO2 (PETCO2). The dynamic aspect of the response was measured as the time constant of the first order response kinetics (tau). To confirm and support these findings we used an alternative examination of the response, transfer function analysis (TFA), to measure the responsiveness (gain), the speed of response (phase), and the consistency of the response over time (coherence). We tested 34 patients with SCD and compared the results to those of 24 healthy controls participants. The results from a three‐way ANOVA showed that patients with SCD have reduced CVR (p < 0.001) and lower coherence (p < 0.001) in gray matter and white matter and reduced gain in gray matter only (p < 0.001). In terms of the speed of the response to CO2, tau (p < 0.001) and TFA phase (p < 0.001) were increased in SCD patients compared to healthy control subjects. These findings show that the cerebrovascular responsiveness to CO2 in patients with SCD is both decreased and slowed compared to healthy controls.
Collapse
Affiliation(s)
- Ece Su Sayin
- Department of PhysiologyUniversity of TorontoTorontoCanada,Departments of Anaesthesia and Pain ManagementUniversity Health NetworkTorontoCanada
| | - Olivia Sobczyk
- Department of PhysiologyUniversity of TorontoTorontoCanada,Departments of Anaesthesia and Pain ManagementUniversity Health NetworkTorontoCanada,Joint Department of Medical Imaging and the Functional Neuroimaging LaboratoryUniversity Health NetworkTorontoCanada
| | - Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging LaboratoryUniversity Health NetworkTorontoCanada
| | - David J. Mikulis
- Joint Department of Medical Imaging and the Functional Neuroimaging LaboratoryUniversity Health NetworkTorontoCanada,Institute of Medical SciencesUniversity of TorontoTorontoCanada
| | - Joseph A. Fisher
- Department of PhysiologyUniversity of TorontoTorontoCanada,Departments of Anaesthesia and Pain ManagementUniversity Health NetworkTorontoCanada
| | - Kevin H. M. Kuo
- Division of Medical Oncology and Hematology, Department of MedicineUniversity of TorontoTorontoOntarioCanada
| | - James Duffin
- Department of PhysiologyUniversity of TorontoTorontoCanada,Departments of Anaesthesia and Pain ManagementUniversity Health NetworkTorontoCanada
| |
Collapse
|