{
    "abstract": "What is the central question of this study? Is cerebrovascular reactivity affected by isocapnic changes in breathing pattern? What is the main finding and its importance? Cerebrovascular reactivity does not change with isocapnic variations in tidal volume and frequency.\nDeviations of arterial carbon dioxide tension from resting values affect cerebral blood vessel tone and thereby cerebral blood flow. Arterial carbon dioxide tension also affects central respiratory chemoreceptors, adjusting respiratory drive. This coincidence raises the question: does respiratory drive also affect the cerebral blood flow response to carbon dioxide? A change in cerebral blood flow for a given change in the arterial carbon dioxide tension is defined as cerebrovascular reactivity (CVR). Two studies have reached conflicting conclusions on this question, using voluntary control of breathing as a disturbing factor during measurements of CVR. Here, we address some of the methodological limitations of both studies by using sequential gas delivery and targeted control of carbon dioxide and oxygen to enable a separation of the effects of carbon dioxide on CVR from breathing vigour. We confirm that there is no detectable superimposed effect of breathing efforts on CVR.",
    "authors": [
        {
            "affiliation": "Department of Anaesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada.\nDepartment of Physiology, University of Toronto, Toronto, Ontario, Canada.",
            "firstname": "Ece Su",
            "initials": "ES",
            "lastname": "Sayin"
        },
        {
            "affiliation": "Department of Physiology, University of Toronto, Toronto, Ontario, Canada.",
            "firstname": "Anahis",
            "initials": "A",
            "lastname": "Davidian"
        },
        {
            "affiliation": "Department of Anaesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada.\nDepartment of Physiology, University of Toronto, Toronto, Ontario, Canada.",
            "firstname": "Harrison",
            "initials": "H",
            "lastname": "Levine"
        },
        {
            "affiliation": "Department of Anaesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada.\nDepartment of Physiology, University of Toronto, Toronto, Ontario, Canada.",
            "firstname": "Lashmi",
            "initials": "L",
            "lastname": "Venkatraghavan"
        },
        {
            "affiliation": "Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.\nJoint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, Ontario, Canada.",
            "firstname": "David J",
            "initials": "DJ",
            "lastname": "Mikulis"
        },
        {
            "affiliation": "Department of Anaesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada.\nDepartment of Physiology, University of Toronto, Toronto, Ontario, Canada.\nInstitute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.",
            "firstname": "Joseph A",
            "initials": "JA",
            "lastname": "Fisher"
        },
        {
            "affiliation": "Department of Anaesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada.\nJoint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, Ontario, Canada.",
            "firstname": "Olivia",
            "initials": "O",
            "lastname": "Sobczyk"
        },
        {
            "affiliation": "Department of Anaesthesia and Pain Management, University Health Network, Toronto, Ontario, Canada.\nDepartment of Physiology, University of Toronto, Toronto, Ontario, Canada.",
            "firstname": "James",
            "initials": "J",
            "lastname": "Duffin"
        }
    ],
    "conclusions": null,
    "copyrights": "\u00a9 2021 The Authors. Experimental Physiology \u00a9 2021 The Physiological Society.",
    "doi": "10.1113/EP090122",
    "journal": "Experimental physiology",
    "keywords": [
        "breathing pattern",
        "cerebral blood flow",
        "cerebrovascular reactivity",
        "trans cranial Doppler"
    ],
    "methods": null,
    "publication_date": "2021-12-29",
    "pubmed_id": "34961983",
    "results": null,
    "title": "Does breathing pattern affect cerebrovascular reactivity?",
    "xml": "<Element 'PubmedArticle' at 0x78850350ba10>"
}