NASAL RESISTANCE IN SNORERS WITH OR WITHOUT SLEEP-APNEA - EFFECT OF POSTURE AND NASAL VENTILATION WITH CONTINUOUS POSITIVE AIRWAY PRESSURE

We investigated the effects of posture and nasal ventilation with cont inuous airway pressure (CPAP) on nasal resistance in snorers with or w ithout obstructive sleep apnea (OSA). Posterior rhinomanometry was per formed in 70 snorers referred for polysomnography and in 11 nonsnoring volunteers, (1) in the seated posture; (2) and (3) after 10 minutes i n the supine position, before and after inhalation of oxymetazoline; a nd (4) 10 minutes after return to the seated position. The effect of C PAP on posterior rhinomanometry was also examined in the nonsnorers an d in 12 of the snorers. Changing from the seated to the supine positio n resulted in an increase in resistance in snorers and nonsnorers (res istance supine 182+/-10.9% and 128+/-6.7% respectively of seated value , p<0.05). After oxymetazoline instillation, resistance in the supine position decreased but remained higher in snorers than baseline value in the seated position. Effects of posture and oxymetazoline were simi lar in snorers with or without sleep apnea. During nasal ventilation w ith CPAP, resistance was 30+/-3.8 and 45+/-4.4% of value before CPAP i n snorers and nonsnorers, respectively (p<0.05). These effects of post ure and CPAP were also observed when resistance was measured with ante rior rhinomanometry. In conclusion, nasal resistance measured with pos terior rhinomanometry in the supine position is not predictive for OSA . Nasal ventilation with CPAP resulted in an acute and marked decrease in nasal resistance.