Positive expiratory pressure (PEP) as lung physiotherapy in cystic fibrosis: a pilot study.

Positive expiratory pressure (PEP) on a face mask was compared with conventional lung physiotherapy in 12 patients with cystic fibrosis. Residual volume (p less than 0.02) and functional residual capacity (NS) was reduced and vital capacity increased (NS) during 6-9 months of PEP treatment. The subjective sputum production was significantly greater during the PEP period. PEP is easy to administer and is inexpensive.