Efficacy of temporary positive expiratory pressure (TPEP) in patients with lung diseases and chronic mucus hypersecretion. The UNIKO® project: a multicentre randomized controlled trial.

Objective
To evaluate whether temporary positive expiratory pressure provides benefit in patients with lung diseases and chronic hypersecretion.

Design
Single blind multicentre randomized trial.

Setting
Five Italian rehabilitation centres.

Participants
Ninety-eight patients with chronic obstructive pulmonary disease and/or chronic bronchitis (n=78), or bronchiectasis (n=20), with a peak cough expiratory flow >150 l/min and sputum production >30 ml/day, randomly included into two treatment groups.

Interventions
For 10 consecutive days, the active group performed twice a day 20-minute cycles of manually assisted breathing techniques in sequence with the addition of 15 minutes of temporary positive expiratory pressure, while the control group was treated by manually assisted breathing techniques alone.

Measures
Within and between group changes of arterial oxygenation index, lung volumes and respiratory muscles strength were recorded at enrolment and after 3 and 10 treatment sessions. Pre-to-post treatment change of sputum volume and bronchial encumbrance (Δ-visual analog scale), sputum density and purulence were compared daily within the study period.

Results
No significant changes were recorded for the oxygenation index, while dynamic lung volumes and respiratory muscle strength significantly (P <0.05) improved in the active group. The group comparison analysis of the pre-to-post change showed that inspiratory capacity was significantly higher in the active than in the control group (+19.5% and +2.2%, P=0.044) at day 10. A greater improvement in Δ-visual analog scale was recorded in the active group at day 3 and 8.

Conclusions
These preliminary data suggest that temporary positive expiratory pressure improves lung volumes and speeds up the improvement of bronchial encumbrance in patients with lung diseases and hypersecretion.