These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Protocol to measure acute cerebrovascular and ventilatory responses to isocapnic hypoxia in humans.
    Author: Kolb JC, Ainslie PN, Ide K, Poulin MJ.
    Journal: Respir Physiol Neurobiol; 2004 Jul 20; 141(2):191-9. PubMed ID: 15239969.
    Abstract:
    This study describes a protocol to determine acute cerebrovascular and ventilatory (AHVR) responses to hypoxia. Thirteen subjects undertook a protocol twice, 5 days apart. The protocol started with 8 min of eucapnic euoxia (end-tidal P(CO2) (PET(CO2)= 1.5 Torr) above rest; end-tidal P(O2) (PET(O2)) = 88 Torr) followed by six descending 90 s hypoxic steps (PET(O2) = 75.2, 64.0, 57.0, 52.0, 48.2, 45.0 Torr). Then, PET(O2) was elevated to 300 Torr for 10 min while PET(O2) remained at eucapnia (5 min) then raised by 7.5 Torr (5 min). Peak blood flow velocity in the middle cerebral artery (MCA) and regional cerebral oxygen saturation (Sr(O2)) were measured with transcranial Doppler ultrasound and near-infrared spectroscopy, respectively, and indices of acute hypoxic sensitivity were calculated (AHR(CBF) and AHRSr(O2)). Values for AHR(CBF), AHRSr(O2) and AHVR were 0.43 cm s(-1) % desaturation(-1), 0.80% % desaturation(-1) and 1.24l min(-1) % desaturation(-1), respectively. Coefficients of variation for AHR(CBF), AHRSr(O2) and AHVR were small (range = 8.0-15.2%). This protocol appears suitable to quantify cerebrovascular and ventilatory responses to acute isocapnic hypoxia.
    [Abstract] [Full Text] [Related] [New Search]