Objective: To identify potential risk factors for the need for an additional cold or heated humidifier in nasal continuous positive airway pressure (nCPAP) circuitry.
Design: A prospective cohort study.
Setting: University hospital sleep-disorders center.
Patients: Eighty-two consecutive patients with obstructive sleep apnea syndrome were followed up for a median of 347 days (range, 3 to 530 days) after the initiation of nCPAP therapy.
Measurements and results: In 46 patients (56%), the occurrence of upper-airway symptoms led to the addition of a cold humidifier after a median time of 39 days (range, 2 to 94 days). In 23 of the 46 patients, the persistence of the symptoms indicated the secondary use of a heated humidifier after a median time of 28 days (range, 5 to 70 days). nCPAP use (mean +/- SD) was not influenced by cold humidification (4.58 +/- 2.05 h/d vs 4.7 +/- 2.48 h/d; p = 0.75), but it increased significantly with heated humidification (5.38 +/- 2.26 h/d vs 3.51 +/- 2.53 h/d; p < 0.01). Anthropometric characteristics, drying medications, clinical findings such as deformity of the nasal septum, symptoms of a chronic mucosa disease (CMD), a previous uvulopalatopharyngoplasty (UPPP), and polysomnographic parameters had no significant effect on the need for a cold humidifier. Age > 60 years (odds ratio [OR], 5.58; 95% confidence interval [CI], 1.69 to 18.43), drying medications (OR, 6.59; 95% CI, 1.29 to 33.51), presence of CMD (OR, 4.11; 95% CI, 1.24 to 13.58), and previous UPPP (OR, 4.56; 95% CI, 1.18 to 17.6) were found as significant risk factors for the addition of a heated humidifier.
Conclusion: Our results demonstrate that heated humidification significantly improves the nCPAP daily rate of use and that its need may be predicted.