SLEEP-DISORDERED BREATHING

Sleep-disordered breathing includes snoring, upper airway resistance s yndrome, sleep hypopneas and apneas, and is a borderline pathology bet ween several disciplines (neurology, pneumology, cardiology, oto-rhino -laryngology, etc.). The common element is an abnormal increase in upp er airway resistance during sleep. In mild cases, this increase accele rates airflrow and induces vibrations of the pharyngeal structures (sn oring); in severe cases the airway is occluded and airflow ceases (obs tructive apnea). Sleep apnea syndrome (SAS) is present in 4% of males and 2% of females in the general population. The risk factors are an a ge above 50, male sex, weight excess, presence of respiratory symptoms , tobacco smoking, alcohol consumption, use of hypnotic drugs... Snori ng is much more frequent than sleep apnea, present in up to 50 % of ma les aged 50 yr or more; most snorers do not have apneas (''simple'' sn orers). Apneas end with a micro-arousal; this sleep disruption explain s the excess daytime sleepiness of patients with SAS. The daytime slee piness is responsible for the increased rate of accidents (traffic, do mestic, work...) in SAS patients. The second effect of apneas is desat uration, leading to heart rhythm abnormalities, coronary or cerebrovas cular accidents, pulmonary vasoconstriction, systemic hypertension, et c. Screening for SAS is justified by its prevalence, by the potentiall y severe consequences and by the existence of an efficacious treatment : continuous positive airway pressure.