Short-term effects of physiotherapy on ventilation inhomogeneity in cystic fibrosis patients with a wide range of lung disease severity.

Background: Lung clearance index (LCI) is increasingly used as a study endpoint for therapeutic interventions in cystic fibrosis (CF) patients. We set out to assess the effect of chest physiotherapy on ventilation inhomogeneity in clinically stable patients with CF lung disease of varying severity.

Methods: In 29 CF patients (7.3-43.7 years) N2MBW (nitrogen multiple breath washout), plethysmography, and spirometry measurements were conducted, followed by 30 min of supervised PEP mask chest physiotherapy and repeated measurements 30 min after therapy.

Results: We observed a mean change in LCI after physiotherapy from 15.00 to 14.80 (range, -4.84 to 3.37; p=0.578). In seven patients, LCI decreased, and in ten patients, LCI increased by ≥1. For the whole group, statistically significant improvements were seen in Reff, FEV1, FVC, and MEF50.

Conclusions: By opening up previously poorly ventilated lung regions, physiotherapy may either increase or decrease ventilation inhomogeneity; the short-term effect of physiotherapy on LCI appears to be unpredictable.