Document Detail

Mechanical response to methacholine and deep inspiration in supine men.
MedLine Citation:
PMID:  16959912     Owner:  NLM     Status:  MEDLINE    
The effects of supine posture on airway responses to inhaled methacholine and deep inspiration (DI) were studied in seven male volunteers. On a control day, subjects were in a seated position during both methacholine inhalation and lung function measurements. On a second occasion, the whole procedure was repeated with the subjects lying supine for the entire duration of the study. On a third occasion, methacholine was inhaled from the seated position and measurements were taken in a supine position. Finally, on a fourth occasion, methacholine was inhaled from the supine position and measurements were taken in the seated position. Going from sitting to supine position, the functional residual capacity decreased by approximately 1 liter in all subjects. When lung function measurements (pulmonary resistance, dynamic elastance, residual volume, and maximal flows) were taken in supine position, the response to methacholine was greater than at control, and this was associated with a greater dyspnea and a faster recovery of dynamic elastance after DI. By contrast, when methacholine was inhaled in supine position but measurements were taken in sitting position, the response to methacholine was similar to control day. These findings document the potential of the decrease in the operational lung volumes in eliciting or sustaining airflow obstruction in nocturnal asthma. It is speculated that the exaggerated response to methacholine in the supine posture may variably contribute to airway smooth muscle adaptation to short length, airway wall edema, and faster airway renarrowing after a large inflation.
Maurizio Meinero; Giuseppe Coletta; Luca Dutto; Manlio Milanese; Giorgio Nova; Andrea Sciolla; Riccardo Pellegrino; Vito Brusasco
Publication Detail:
Type:  Clinical Trial; Journal Article     Date:  2006-09-07
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  102     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2007 Jan 
Date Detail:
Created Date:  2007-01-08     Completed Date:  2007-03-13     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:  269-75     Citation Subset:  IM    
Anestesia, Rianimazione e Medicina d'Urgenza, Azienda Ospedaliera S. Croce e Carle, Università di Genova, Genova, Italy.
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MeSH Terms
Airway Resistance / drug effects,  physiology
Bronchoconstriction / drug effects,  physiology
Bronchoconstrictor Agents / pharmacology*
Elasticity / drug effects
Inhalation / drug effects*,  physiology
Methacholine Chloride / pharmacology*
Middle Aged
Muscle Contraction / drug effects,  physiology
Muscle, Smooth / drug effects,  physiology
Respiratory Function Tests
Respiratory Mechanics / drug effects*,  physiology
Supine Position / physiology
Total Lung Capacity / drug effects,  physiology
Reg. No./Substance:
0/Bronchoconstrictor Agents; 62-51-1/Methacholine Chloride

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

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