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- Samuel J.E. Lucas
- From the Department of Physiology (S.J.E.L., K.N.T.), School of Physical Education (S.J.E.L.), University of Otago, Dunedin, New Zealand; Physiological Rhythms Unit (C.T.), Department of Surgery and Anesthesia, University of Otago, Wellington, New Zealand; Department of Cardiothoracic Surgery (S.D.G.), Section of Surgery, University of Otago and Dunedin Hospital, Dunedin, New Zealand; Department of Biomedical Engineering (S.O.), Toyo University, Kawagoe-Shi, Saitama, Japan; Department of Human...
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- Yu Chieh Tzeng
- From the Department of Physiology (S.J.E.L., K.N.T.), School of Physical Education (S.J.E.L.), University of Otago, Dunedin, New Zealand; Physiological Rhythms Unit (C.T.), Department of Surgery and Anesthesia, University of Otago, Wellington, New Zealand; Department of Cardiothoracic Surgery (S.D.G.), Section of Surgery, University of Otago and Dunedin Hospital, Dunedin, New Zealand; Department of Biomedical Engineering (S.O.), Toyo University, Kawagoe-Shi, Saitama, Japan; Department of Human...
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- Sean D. Galvin
- From the Department of Physiology (S.J.E.L., K.N.T.), School of Physical Education (S.J.E.L.), University of Otago, Dunedin, New Zealand; Physiological Rhythms Unit (C.T.), Department of Surgery and Anesthesia, University of Otago, Wellington, New Zealand; Department of Cardiothoracic Surgery (S.D.G.), Section of Surgery, University of Otago and Dunedin Hospital, Dunedin, New Zealand; Department of Biomedical Engineering (S.O.), Toyo University, Kawagoe-Shi, Saitama, Japan; Department of Human...
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- Kate N. Thomas
- From the Department of Physiology (S.J.E.L., K.N.T.), School of Physical Education (S.J.E.L.), University of Otago, Dunedin, New Zealand; Physiological Rhythms Unit (C.T.), Department of Surgery and Anesthesia, University of Otago, Wellington, New Zealand; Department of Cardiothoracic Surgery (S.D.G.), Section of Surgery, University of Otago and Dunedin Hospital, Dunedin, New Zealand; Department of Biomedical Engineering (S.O.), Toyo University, Kawagoe-Shi, Saitama, Japan; Department of Human...
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- Shigehiko Ogoh
- From the Department of Physiology (S.J.E.L., K.N.T.), School of Physical Education (S.J.E.L.), University of Otago, Dunedin, New Zealand; Physiological Rhythms Unit (C.T.), Department of Surgery and Anesthesia, University of Otago, Wellington, New Zealand; Department of Cardiothoracic Surgery (S.D.G.), Section of Surgery, University of Otago and Dunedin Hospital, Dunedin, New Zealand; Department of Biomedical Engineering (S.O.), Toyo University, Kawagoe-Shi, Saitama, Japan; Department of Human...
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- Philip N. Ainslie
- From the Department of Physiology (S.J.E.L., K.N.T.), School of Physical Education (S.J.E.L.), University of Otago, Dunedin, New Zealand; Physiological Rhythms Unit (C.T.), Department of Surgery and Anesthesia, University of Otago, Wellington, New Zealand; Department of Cardiothoracic Surgery (S.D.G.), Section of Surgery, University of Otago and Dunedin Hospital, Dunedin, New Zealand; Department of Biomedical Engineering (S.O.), Toyo University, Kawagoe-Shi, Saitama, Japan; Department of Human...
説明
<jats:p> Cerebral autoregulation (CA) is a critical process for the maintenance of cerebral blood flow and oxygenation. Assessment of CA is frequently used for experimental research and in the diagnosis, monitoring, or prognosis of cerebrovascular disease; however, despite the extensive use and reference to static CA, a valid quantification of “normal” CA has not been clearly identified. While controlling for the influence of arterial P <jats:sc>co</jats:sc> <jats:sub>2</jats:sub> , we provide the first clear examination of static CA in healthy humans over a wide range of blood pressure. In 11 healthy humans, beat-to-beat blood pressure (radial arterial), middle cerebral artery blood velocity (MCAv; transcranial Doppler ultrasound), end-tidal P <jats:sc>co</jats:sc> <jats:sub>2</jats:sub> , and cerebral oxygenation (near infrared spectroscopy) were recorded continuously during pharmacological-induced changes in mean blood pressure. In a randomized order, steady-state decreases and increases in mean blood pressure (8 to 14 levels; range: ≈40 to ≈125 mm Hg) were achieved using intravenous infusions of sodium nitroprusside or phenylephrine, respectively. MCAv <jats:sub>mean</jats:sub> was altered by 0.82±0.35% per millimeter of mercury change in mean blood pressure ( <jats:italic>R</jats:italic> <jats:sup>2</jats:sup> =0.82). Changes in cortical oxygenation index were inversely related to changes in mean blood pressure (slope=−0.18%/mm Hg; <jats:italic>R</jats:italic> <jats:sup>2</jats:sup> =0.60) and MCAv <jats:sub>mean</jats:sub> (slope=−0.26%/cm · s <jats:sup>−1</jats:sup> ; <jats:italic>R</jats:italic> <jats:sup>2</jats:sup> =0.54). There was a progressive increase in MCAv pulsatility with hypotension. These findings indicate that cerebral blood flow closely follows pharmacological-induced changes in blood pressure in otherwise healthy humans. Thus, a finite slope of the plateau region does not necessarily imply a defective CA. Moreover, with progressive hypotension and hypertension there are differential changes in cerebral oxygenation and MCAv <jats:sub>mean</jats:sub> . </jats:p>
収録刊行物
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- Hypertension
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Hypertension 55 (3), 698-705, 2010-03
Ovid Technologies (Wolters Kluwer Health)
