Effects of Continuous Airway Pressure on the Ability to Heat and Humidify Air

We hypothesize that continuous positive pressure applied to the airway will decrease the ability of the nose to warm and humidify inspired air compared to zero or negative pressure. We will use continuous positive airway pressure (CPAP), a device commonly used to treat patients with sleep apnea, to vary the pressure in the airway and determine if increased pressure decreases the ability to warm and humidify inspired air. If our hypothesis is correct, it may explain the reason why CPAP is poorly tolerated in patients with sleep apnea; i.e., less ability to warm and humidify air leading to more nasal mucosal irritation.