Tidal expiratory flow patterns in airflow obstruction.

• DOI: 10.1136/thx.36.2.135
• Publication Date: 2008-12-13T03:15:45Z
• Authors: M J Morris; D J Lane
• Keywords: Expiration; Airway obstruction; Elastic recoil

Tidal expiratory flow pattern was analysed in 99 subjects with a view to assessing it as quantitative measurement of airflow obstruction. Fifteen normal volunteers, nine patients dyspnoea referred for investigation whom airway resistance within limits, 24 restrictive lung disorders, and 51 obstruction were studied. The against time had quadrilateral configuration obstruction, which differed from the more sinusoidal form that is seen without rapid rise tidal peak two ways, percentage volume expired at (delta V/V) t/t). Both these indices correlated significantly conventional measurements during quiet breathing resembles forced maneuver similar volumes. In some cases this may be caused by dynamic compression occurring breathing. others, result static recoil being permitted drive freely expiration, rather than braked postinspiratory contraction inspiratory musculature.