Document Detail

Neurocirculatory consequences of intermittent asphyxia in humans.
MedLine Citation:
PMID:  11007566     Owner:  NLM     Status:  MEDLINE    
We examined the neurocirculatory and ventilatory responses to intermittent asphyxia (arterial O(2) saturation = 79-85%, end-tidal PCO(2) =3-5 Torr above eupnea) in seven healthy humans during wakefulness. The intermittent asphyxia intervention consisted of 20-s asphyxic exposures alternating with 40-s periods of room-air breathing for a total of 20 min. Minute ventilation increased during the intermittent asphyxia period (14.2 +/- 2.0 l/min in the final 5 min of asphyxia vs. 7.5 +/- 0.4 l/min in baseline) but returned to the baseline level within 2 min after completion of the series of asphyxic exposures. Muscle sympathetic nerve activity increased progressively, reaching 175 +/- 12% of baseline in the final 5 min of the intervention. Unlike ventilation, sympathetic activity remained elevated for at least 20 min after removal of the chemical stimuli (150 +/- 10% of baseline in the last 5 min of the recovery period). Intermittent asphyxia caused a small, but statistically significant, increase in heart rate (64 +/- 4 beats/min in the final 5 min of asphyxia vs. 61 +/- 4 beats/min in baseline); however, this increase was not sustained after the return to room-air breathing. These data demonstrate that relatively short-term exposure to intermittent asphyxia causes sympathetic activation that persists after removal of the chemical stimuli. This carryover effect provides a potential mechanism whereby intermittent asphyxia during sleep could lead to chronic sympathetic activation in patients with sleep apnea syndrome.
A Xie; J B Skatrud; D C Crabtree; D S Puleo; B M Goodman; B J Morgan
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  89     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2000 Oct 
Date Detail:
Created Date:  2000-10-25     Completed Date:  2000-11-09     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1333-9     Citation Subset:  IM    
Department of Medicine, University of Wisconsin, Madison 53705, USA.
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MeSH Terms
Anoxia / physiopathology*
Asphyxia / physiopathology*
Blood Pressure
Heart Rate
Hemodynamics / physiology*
Microcirculation / physiopathology*
Muscle, Skeletal / blood supply,  innervation,  physiopathology*
Peroneal Nerve / physiopathology*
Respiratory Mechanics
Skin / innervation
Tidal Volume
Time Factors

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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