Sleep disordered breathing: OSA, CSA, Pathophysiology and Diagnosis.

ABSTRACT

Obstructive sleep apnea syndrome (OSAS) is a prevalent disorder that has been reported to occur in 2 to 4% of middle-aged adults. A similar prevalence of OSAS has been reported from India as well. However, this condition is frequently unrecognized and underdiagnosed. Important pathophysiological changes in patients with obstructive sleep apnea (OSA) is an alteration in human upper airway leading to a reduction in cross-sectional area of the upper airway contributing to the easy collapsibility of upper airway during sleep. Other pathophysiological changes in OSA are oxidative stress, systemic inflammation, sympathetic nerve activation, endothelial dysfunction, procoagulant activity, intrathoracic pressure changes and metabolic dysregulation. The gold standard for diagnosis of OSA is full polysomnography.