Document Detail

Phase locking of the respiratory rhythm in cats to a mechanical ventilator.
MedLine Citation:
PMID:  6576843     Owner:  NLM     Status:  MEDLINE    
Mechanical ventilation of paralyzed, pentobarbital-anesthetized adult cats was performed while recording phrenic nerve activity. The periodic changes in lung volume owing to mechanical ventilation affected the rhythm of central respiratory activity, resulting in a variety of regular and irregular patterns of coupling between respiratory system output, monitored by phrenic activity, and the mechanical ventilator. Phase-locked patterns, in which phrenic burst onset occurred at specific and repetitive phase(s) of the mechanical ventilator, with ratios of ventilator frequency: phrenic burst frequency of 1:2, 1:1, 3:2, 2:1, and 3:1 were observed. Regular and irregular patterns occurred over specific ranges of frequency and volume of the mechanical ventilator. A careful study was made of the 1:1 phase locking as the frequency and inflation volume of the mechanical ventilator were changed. The inspiratory time (TI) was defined as the interval between the time when phrenic activity began to rise and the onset of its rapid decline, and the expiratory time (TE) as the time between inspirations. In the 1:1 phase-locking region, as the frequency of the ventilator was increased both TI and TE decreased, and the phase of phrenic onset in the ventilator cycle changed. During ventilation with frequencies higher than the intrinsic phrenic frequency (initial burst frequency of phrenic activity with the ventilator turned off) inspiratory activity was prematurely terminated by lung inflation (Hering-Breuer inspiratory inhibitory reflex). During ventilation with frequencies lower than the intrinsic phrenic frequency, the onset of phrenic activity was delayed (TE was prolonged) by lung inflation (Hering-Breuer expiratory promoting reflex).
G A Petrillo; L Glass; T Trippenbach
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Canadian journal of physiology and pharmacology     Volume:  61     ISSN:  0008-4212     ISO Abbreviation:  Can. J. Physiol. Pharmacol.     Publication Date:  1983 Jun 
Date Detail:
Created Date:  1983-10-21     Completed Date:  1983-10-21     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372712     Medline TA:  Can J Physiol Pharmacol     Country:  CANADA    
Other Details:
Languages:  eng     Pagination:  599-607     Citation Subset:  IM    
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MeSH Terms
Lung Volume Measurements
Phrenic Nerve / physiology
Respiration, Artificial*
Respiratory Function Tests
Ventilators, Mechanical

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

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