Residual sleep-disordered breathing during autotitrating continuous positive airway pressure therapy.

Obstructive sleep apnoea (OSA) is often treated with autotitrating continuous positive airway pressure (autoCPAP) devices. Clinical and bench tests of these devices have suggested performance limitations. These studies do not indicate whether this is a failure to detect or a failure to respond to airway obstruction.

Dynamic changes in brain bioenergetics during obstructive sleep apnea.

Repetitive collapse of the upper airway during obstructive sleep apnea/hypopnea (OSA) exposes the brain of sufferers to frequent, transient, hypoxic episodes. The loss of cerebrovascular reactivity in sleep, and particularly in OSA, means that physiologic compensatory mechanisms may not ensure adequate brain oxygen levels. This (31)P magnetic resonance spectroscopy study, of 13 males with severe, untreated OSA undertaken after overnight sleep deprivation, represents the first, seconds time-scale analysis of human brain bioenergetics during transient hypoxia and demonstrates that a moderate degree of oxygen desaturation during sleep has significant effects on brain bioenergetic status.