ABSTRACT
Sleep-disordered breathing is a generic term covering ob-
structive sleep apnea, central sleep apnea with periodic
breathing, and nocturnal hypoventilation.
Obstructive sleep apnea (OSA) is characterized by recur-
rent episodes of upper airway collapse during sleep, usually
associated with sleep fragmentation, with fluctuations in
blood pressure, heart rate and cardiac output. Partial
episodes are called hypopneas. By contrast, in central sleep
apnea the respiratory irregularity is most commonly asso-
ciated with chronic heart failure or cerebral insult, such as
neurosarcoid, and caused by unstable ventilatory drive.
Nocturnal hypoventilation oocurs in individuals with venti-
latory insufficiency and if unaddressed may lead to daytime
ventilatory failure. It occurs in those with severe restrictive
ventilatory defects, such as secondary to respiratory muscle
weakness, morbid obesity or reduced ventilatory drive.
