A PHP Error was encountered

Severity: Warning

Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests

Filename: helpers/my_audit_helper.php

Line Number: 176

Backtrace:

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 1034
Function: getPubMedXML

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3152
Function: GetPubMedArticleOutput_2016

File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global

File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword

File: /var/www/html/index.php
Line: 316
Function: require_once

Airway-parenchyma uncoupling in nocturnal asthma. | LitMetric

Airway-parenchyma uncoupling in nocturnal asthma.

Am J Respir Crit Care Med

Pulmonary Disease and Critical Care Medicine, Molecular Physiology and Biophysics, University of Vermont, Colchester, Vermont 05446, USA.

Published: January 2000

AI Article Synopsis

  • The study investigates how lung volume affects airway resistance in patients with nocturnal asthma, finding that increased lung volume typically reduces airway resistance.
  • During sleep, however, functional residual capacity (FRC) decreases leading to an unexpected increase in airway resistance, which doesn't improve when FRC is restored.
  • The research suggests that when sleeping, the lungs become less flexible, disrupting the connection between lung tissue and airways, which may exacerbate asthma symptoms.

Article Abstract

Airway flow resistance is well known to be dependent upon lung volume. The rise in lung volume that occurs in asthma is therefore thought to be an important mechanism that defends airway patency. The purpose of the current study was to investigate the interdependence or mechanical coupling between airways and lung parenchyma during the inflammatory processes that occur in the patient with nocturnal asthma. Five patients with documented nocturnal asthma were studied in both a vertical and a horizontal body plethysmograph. Lung volume was altered with continuous negative pressure as applied to the chest wall with a poncho cuirass in different postures and during sleep. We found during the awake phase that an increase in lung volume decreased lower pulmonary resistance (Rlp); however, within 30 min of sleep onset, functional residual capacity (FRC) fell and Rlp rose more than would be expected for the fall in FRC. Restoring FRC to presleep values either at an early (half-hour) or a late (3-h) time point did not cause Rlp to significantly fall. A second phase of the study showed that the loss of Rlp dependence on lung volume was not due to the assumption of the supine posture. Indirect measurements of lung compliance were consistent with a stiffening of the lung. We conclude that with sleep there is an immediate uncoupling of the parenchyma to the airway, resulting in a loss of interdependence that persists throughout sleep and may contribute to the morbidity and mortality associated with nocturnal asthma.

Download full-text PDF

Source
http://dx.doi.org/10.1164/ajrccm.161.1.9804053DOI Listing

Publication Analysis

Top Keywords

lung volume
20
nocturnal asthma
16
lung
8
asthma
5
volume
5
airway-parenchyma uncoupling
4
nocturnal
4
uncoupling nocturnal
4
asthma airway
4
airway flow
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!