Document Detail

Effects of hypoxia on respiratory control in neonates at high altitude.
MedLine Citation:
PMID:  7380684     Owner:  NLM     Status:  MEDLINE    
The respiratory responses to acute hypoxia were investigated in 21 newborn infants in Leadville, CO. Time-related changes in pulmonary ventilation (VE) described four distinct phases to the hypoxic response characterized by an abrupt initial decrease (phase I), a transient subsequent increase (phase II) and decrease (phase III), and a further transient decrease upon termination of the hypoxic challenge (phase IV). Based on the degree of respiratory stimulation during phase II, the subjects were divided into two groups, "responders" and "nonresponders." In both groups in VE were attributed to variation in tidal volume (VT), inspiratory duration (TI), and breath duration being little affected. The latter indicated an absence of vagal volume-related modulation of respiratory pattern. In all subjects, a fixed linear function described the relationship between the mean inspiratory flows at 0.3 s after inspiratory onset (i.e., V0.3/0.3) ant at end inspiration (i.e., VT/TI). Thus, changes in respiratory output with hypoxia are attributed to variations in both the "gain" and "shape" of the inspiratory drive.
E K Cotton; M M Grunstein
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology: respiratory, environmental and exercise physiology     Volume:  48     ISSN:  0161-7567     ISO Abbreviation:  J Appl Physiol Respir Environ Exerc Physiol     Publication Date:  1980 Apr 
Date Detail:
Created Date:  1980-08-15     Completed Date:  1980-08-15     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  7801242     Medline TA:  J Appl Physiol Respir Environ Exerc Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  587-95     Citation Subset:  IM    
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MeSH Terms
Adaptation, Physiological
Anoxia / physiopathology*
Infant, Newborn*
Lung / physiology
Tidal Volume
Time Factors
Vagus Nerve / physiology

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

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