Effects of humidification on nasal symptoms and compliance in sleep apnea patients using continuous positive airway pressure

Study objectives: To evaluate the effects of humidification on nasal sympto ms and compliance in sleep apnea patients using continuous positive airway pressure (CPAP). Design: A randomized, crossover design was employed. Setting:The study was conducted at two suburban community-based hospital sl eep laboratories. Patients: Data were collected on 38 obstructive sleep apnea patients (mean age, 44.1 years) in whom CPAP was a novel treatment. Interventions: The interventions were heated humidity, cold passover humidi ty, and a washout period without humidity. Measurements and results: Patients were titrated with heated humidity or co ld passover humidity in the laboratory and subsequently initiated on humidi ty. Objective compliance, self-report of factors affecting CPAP use, satisf action with CPAP, feeling upon awakening, and daytime sleepiness were asses sed at the completion of each 3-week treatment period and a S-week washout period. Outcome measures were assessed with one-way analysis of variance fo llowed by Scheffe post hoc comparisons. Significant main effects were obser ved for compliance (F-2,F-37 = 5.2; p = 0.008), satisfaction with CPAP (F-2 ,F-37 = 4.5; p = 0.01), and feeling refreshed on a awakening (F-2,F-37 = 4. 4; p = 0.02). A significant decrease in daytime sleepiness was observed bet ween baseline and each of the conditions (F-3,F-37 = 55.5; p < 0.0001), but Epworth sleepiness scale scores did not differ between conditions (all p v alues > 0.56). CPAP use with heated humidity (5.52 +/- 2.1 h/night) was gre ater than CPAP use without humidity(4.93 +/- 2.2 h/night; p = 0.008). Compl iance differences were not observed between CPAP use with cold passover hum idity and CPAP use without humidity. Patients were more satisfied with CPAP when it was used with heated or cold passover humidity (p less than or equ al to 0.05), However, only heated humidity resulted in feeling more refresh ed on awakening (p < 0.05). No significant differences were observed among the three groups on the global adverse side effect score (F-2,F-37 = 2.5; p = 0.09). Specific side effects such as dry mouth or throat and dry nose we re reported less frequently when CPAP was used with heated humidity compare d to CPAP use without humidity (p < 0.001), Conclusions: Compliance with CPAP is enhanced when heated humidification is employed, This is likely due to a reduction in side effects associated wit h upper airway symptoms and a more refreshed feeling upon awakening. Compli ance gains may be realized sooner if patients are started with heated humid ity at CPAP initiation.