Determinants of Early Cystic Fibrosis Lung Disease

Assessed through the raised volume rapid thoracoabdominal compression technique and plethysmography

The Lung Clearance Index is derived from the Multiple Breath Washout test. It is the cumulative exhaled volume (the volume of gas needed to wash out resident gas mixture out of the lungs) divided by the FRC. The FRC is the amount of air left in the lungs after normal exhalation.

During quiet sleep, tidal breathing flow-volume curves are obtained. The tPEF/tE is calculated by taking the time it takes to reach peak expiratory flow divided by the total peak expiratory time.