Document Detail

Bolus technique for assessing distribution of inspired gas during tidal breathing.
MedLine Citation:
PMID:  3372426     Owner:  NLM     Status:  MEDLINE    
The washout of an insoluble tracer from the lung may be represented by a model with two ventilatory compartments representing poorly and better-ventilated regions. Using boli of a second insoluble gas delivered at a given point during inspirations of a multibreath washout test, the proportions of labeled inspired ventilation reaching the poorly and well-ventilated regions may be determined by analyzing the kinetics of the exhaled tracer. We studied eight normal subjects breathing through large-bore solenoid valves controlled to maintain tidal volume at 600 or 900 ml. Boli consisting of 15 ml of 80% He-20% O2 were delivered over 75 ms; this labeled approximately 125 ml of inspired gas. Boli were delivered after 50 ml had been inspired to mark early inspiration and after 300 ml had been inspired to mark midinspiration. Using 900-ml tidal breaths, late inspiration was marked by boli delivered at 600 ml. Subjects were studied in the seated and the supine positions. In both positions, significantly more of the early breath went to the poorly ventilated compartment. Several possible physiological mechanisms, singly or in combination, could account for these observations, but differences in dead space path length are most likely involved.
K I Arita; S M Lewis; C Mittman
Related Documents :
3016196 - Myopathy with abnormal mitochondria, transient low electron transport capacity in the r...
6152616 - Ventilatory effects of nitrous oxide during continuous infusion of fentanyl or alfentanil.
2814026 - Frequency analysis of the acoustical respiratory response.
14555586 - Reduction in ventilatory response to co2 with relaxation feedback during co2 rebreathin...
15833756 - High intensity exercise increases expression of matrix metalloproteinases in fast skele...
8336426 - Muscular strength capacity and altitude response.
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  64     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1988 Feb 
Date Detail:
Created Date:  1988-06-27     Completed Date:  1988-06-27     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:  681-8     Citation Subset:  IM    
Respiratory Disease Department, City of Hope Medical Center, California, Duarte 91010.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Lung Volume Measurements*
Middle Aged
Respiratory Function Tests / methods*
Tidal Volume*
Grant Support

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

Previous Document:  Low-frequency diaphragmatic fatigue in spontaneously breathing humans.
Next Document:  Subcellular changes in capillary endothelial cells during repair of hyperoxic lung injury.