Sleep-disordered Breathing

Sleep-disordered breathing is an umbrella term for several chronic conditions in which partial or complete cessation of breathing occurs many times throughout the night, resulting in daytime sleepiness or fatigue that interferes with a person's ability to function and reduces quality of life. Symptoms may include snoring, pauses in breathing described by bed partners, and disturbed sleep. Obstructive sleep apnea (OSA), which is by far the most common form of sleep-disordered breathing, is associated with many other adverse health consequences, including an increased risk of death (1–3). To be properly diagnosed, patients with suspected sleep-disordered breathing must be evaluated by a polysomnogram (sleep test), which measures approximately a dozen physiologic parameters during sleep. One of the most important measurements is breathing and its cessation during sleep. A breathing pause of 10 seconds or more is termed an apnea. Not surprisingly, apneas may be associated with oxygen desaturation (a decrease in blood oxygen) and other bodily responses as the person struggles to breathe. These arousals may consist of flexing of muscles, including those of the airways, and change in the electrical activity of the brain as measured by an electroencephalogram (EEG). Arousals are complex phenomena that may involve discharges of brain chemicals of the adrenalin family, which may contribute to the health conditions associated with