Measurements and results: Sputum was collected on an hourly basis for a total of 6 consecutive hours.
During the first and the last hour, patients collected sputum without having any treatment and
underwent pulmonary function tests (PFTs). Oxygen saturation was measured at 30-min intervals
during hours 1 to 6. For the first 20 min of the second to the fifth hour, patients received one of the
treatments. To assess the effect of the intervention, the weight of expectorated sputum during hours
2 to 6 was averaged and expressed as percentage of the weight expectorated during the first hour
(baseline). For the five treatment modalities, mean sputum dry and wet weights ranged between
122% and 185% of baseline. There was no statistically significant difference among the treatment
modalities. As measured by sputum wet weight, all oscillatory devices tended to be less effective than
CPT (p=0.15). As measured by dry weight, oral airway oscillation at 8 Hz with an LE ratio of 9:1 and
CPT tended to be more effective than the other treatment modalities (p=0.57). None ofthe treatment
modalities had an effect on PFTs and oxygen saturation and all were well tolerated.
Conclusion: In outpatients with stable CF, high-frequency oscillation applied via the airway opening
or via the chest wall and CPT have comparable augmenting effects on expectorated sputum weight
without changing PFTs or oxygen saturation. In contrast to CPT, high-frequency oral airway and
chest wall oscillations are self-administered, thereby containing health-care expenses.