Physiological changes during severe airflow obstruction in chronic obstructive pulmonary disease

G. Scano, M. Gorini, R. Duranti, G. Misuri, I. Iandelli, F. Gigliotti

Research output: Contribution to journalArticle

Abstract

Chronic expiratory flow limitation and hyperinflation are the mechanical hallmarks of chronic obstructive pulmonary disease (COPD). Although carbon dioxide retention is dependent on the severity of airflow limitation, there is considerable variability in the relationships between arterial carbon dioxide tension (Pa,CO2) and forced expiratory volume in one second (FEV1) or total lung resistance (RL). In stable COPD patients with severe airflow obstruction, shallow breathing and inspiratory muscle weakness are the main factors associated with CO2 retention. In stable COPD patients, the diaphragm is less effective than in normal subjects and, with increasing airflow obstruction and hyperinflation, the contribution to the generation of ventilatory pressure of the ribcage inspiratory muscles increased. Abdominal muscles are recruited during expiration in severe COPD patients and the expiratory rise in gastric pressure is directly related to intrinsic positive end-expiratory (alveolar) pressure (PEEPi). During acute bronchoconstriction, COPD patients with severe airflow obstruction recruited the rib cage inspiratory muscles proportionally more than the diaphragm. The associated recruitment of abdominal muscles results in a reduction in abdominal volume at end-expiration and contributes to a significant extent to PEEPi. Dynamic hyperinflation can be overestimated during chronic and acute airway obstruction if abdominal muscle function is not evaluated.

Original languageEnglish
Pages (from-to)413-416
Number of pages4
JournalMonaldi Archives for Chest Disease - Cardiac Series
Volume54
Issue number5
Publication statusPublished - 1999

Keywords

  • Acute bronchoconstriction
  • Hypercapnia
  • Intrinsic postivie end-expiratory pressure
  • Respiratory muscle recruitment

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Pulmonary and Respiratory Medicine

Fingerprint Dive into the research topics of 'Physiological changes during severe airflow obstruction in chronic obstructive pulmonary disease'. Together they form a unique fingerprint.

  • Cite this