ABSTRACT
There is evidence that while obstructive sleep apnea is primarily related to obstruction of the upper airway, changes in the control of breathing are also important determinants of the propensity for airway collapse during sleep. Studies have investigated the differences in hypercapnic and hypoxic ventilatory response, as well as differences in loop gain, between subjects with and without sleep apnea and whether continuous positive airway pressure (CPAP) has an effect on these measures. This chapter will discuss this literature in more detail, showing that there are no clear observed effects of sleep apnea or CPAP on hypercapnic response or loop gain. In contrast, there may be differences in hypoxic ventilatory response that may improve with the use of CPAP. Future research needs to focus on control of breathing during sleep, include patients more clearly naïve of CPAP, and control for other differences such as obesity and method for measuring ventilatory control.
