Hemodynamic effects of pressures applied to the upper airway during sleep

P. R. Eastwood, A. K. Curran, C. A. Smith, J. A. Dempsey

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The increase in systemic blood pressure after an obstructive apnea is due, in part, to sympathetically mediated vasoconstriction. We questioned whether upper airway (UA) receptors could contribute reflexly to this vasoconstriction. Four unanesthetized dogs were studied during wakefulness and non-rapid-eye-movement (NREM) sleep. The dogs breathed via a fenestrated tracheostomy tube sealed around the tracheal stoma. The snout was sealed with an airtight mask, thereby isolating the UA when the fenestration was closed and exposing the UA to negative inspiratory intrathoracic pressure when it was open. The blood pressure response to three UA perturbations was studied: 1) square-wave negative pressures sufficient to cause UA collapse with the fenestration closed during a mechanical hyperventilation-induced central apnea; 2) tracheal occlusion with the fenestration open vs. closed; and 3) high-frequency pressure oscillations (HFPO) with the fenestration closed. During NREM sleep, 1) blood pressure response to tracheal occlusion was similar with the fenestration open or closed; 2) collapsing the UA with negative pressures failed to alter blood pressure during a central apnea; and 3) application of HFPO to the UA during eupnea and resistive-loaded breaths increased heart rate and blood pressure. However, these changes were likely to be secondary to the effects of HFPO-induced reflex changes on prolonging expiratory time. These findings suggest that activation of UA pressure-sensitive receptors does not contribute directly to the pressor response associated with sleep-disordered breathing events.

Original languageEnglish
Pages (from-to)537-548
Number of pages12
JournalJournal of Applied Physiology
Volume89
Issue number2
DOIs
Publication statusPublished - Aug 2000
Externally publishedYes

Bibliographical note

Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.

Keywords

  • Dog
  • Fenestrated tracheostomy tube
  • High-frequency oscillating pressure
  • Sleep apnea
  • Upper airway reflexes

Fingerprint Dive into the research topics of 'Hemodynamic effects of pressures applied to the upper airway during sleep'. Together they form a unique fingerprint.

Cite this