Persistence of Upper-Airway Symptoms During CPAP Compromises Adherence at 1 Year

The most common adverse effects of CPAP are related to the upper airways. We evaluated upper-airway symptoms before and after a CPAP trial as well as their effect on CPAP adherence. We also evaluated the effect of humidification added to CPAP therapy on upper-airway symptoms.

We followed for 1 y 536 subjects with obstructive sleep apnea scheduled consecutively for CPAP initiation. Subjects completed visual analog questionnaires on nasal stuffiness, rhinorrhea, and mouth dryness (0 = no symptoms, 100 = severe symptoms).

Before CPAP initiation, mean nasal stuffiness score was 29.6 ± 24.9, rhinorrhea score was 16.0 ± 21.7, and mouth dryness score was 43.8 ± 33.1. In subjects who quit CPAP treatment before the 1-y follow-up, the increase in rhinorrhea score during CPAP initiation was significant, 5.3 (95% CI 0.5-9.5, P = .02), and in those using CPAP at 1 y, nasal stuffiness score and mouth dryness score decreased significantly during initiation, -5.1 (95% CI -7.9 to -2.4, P < .001) and -21.2 (-25.5 to -17.4, P < .001). Mouth dryness score decreased significantly with CPAP regardless of humidification: change with humidification, -18.1 (95% CI -22.1 to -14.3), P < .001; change without, -10.5 (95% CI -16.9 to -4.1), P = .002. Humidification also prevented the aggravation of rhinorrhea (change, -0.4 [95% CI -2.6 to 1.9], P = .75) and alleviated nasal stuffiness (change -5.3 [95% CI -7.8 to -2.6], P < .001) with CPAP, whereas its absence induced a significant rise in symptom scores: change in rhinorrhea, 11.5 (95% CI 7.1-16.7), P < .001; change in nasal stuffiness, 8.5 (95% CI 3.9-13.5, P < .001).

The severity of upper-airway symptoms before CPAP does not predict CPAP use at 1 y, whereas CPAP non-users at 1 y had smaller or no alleviation in symptom scores during initiation compared with those who continued CPAP treatment.