EFFECT OF HIGH-FREQUENCY ORAL AIRWAY AND CHEST-WALL OSCILLATION AND CONVENTIONAL CHEST PHYSICAL THERAPY ON EXPECTORATION IN PATIENTS WITH STABLE CYSTIC-FIBROSIS

Study objective: To compare the effect of high-frequency oral airway o scillation, high-frequency chest wall oscillation, and conventional ch est physical therapy (CPT) on weight of expectorated sputum, pulmonary function, and oxygen saturation in outpatients with stable cystic fib rosis (CF). Design: Prospective randomized trial. Setting: Pediatric p ulmonary division of a tertiary care center. Patients: Fourteen outpat ients with stable CF recruited from the CF center. Interventions: Two modes of oral airway oscillation (1: frequency 8 Hz; inspiratory to ex piratory [I:E] ratio 9:1; 2: frequency 14 Hz; I:E ratio 8:1), two mode s of chest wall oscillation (1: frequency 3 Hz; I:E ratio 4:1; 2: freq uency 16 Hz; I:E ratio 1:1, alternating with frequency 1.5 Hz, I:E rat io 6:1), and CPT (clapping, vibration, postural drainage, and encourag ed coughing) were applied during the first 20 min of 4 consecutive hou rs. 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 dur ing hours 2 to 6 was averaged and expressed as percentage of the weigh t expectorated during the first hour (baseline). For the five treatmen t modalities, mean sputum dry and wet weights ranged between 122% and 185% of baseline. There was no statistically significant difference am ong. the treatment modalities. As measured by sputum wet weight, all o scillatory devices tended to be less effective than CPT (p=0.15). As m easured by dry weight, oral airway oscillation at 8 Hz with an I:E rat io of 9:1 and CPT tended to be more effective than the other treatment modalities (p=0.57). None of the treatment modalities had an effect o n 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 CPI have comparable augme nting effects on expectorated sputum weight without changing PFTs or o xygen saturation. In contrast to CPT, high-frequency oral airway and c hest wall oscillations are self-administered, thereby containing healt h-care expenses.