hypopnée

Hypopnea refers to a condition characterized by abnormally shallow breathing or a slow respiratory rate. It is often associated with sleep-disordered breathing, specifically obstructive sleep apnea (OSA) and central sleep apnea (CSA). In the context of sleep, a hypopneic event is typically defined by a significant reduction in airflow during sleep, usually by at least 30%, lasting for 10 seconds or longer, and accompanied by a decrease in blood oxygen saturation by at least 3% or an arousal from sleep. This reduction in airflow is less severe than a complete cessation of breathing, which is termed an apnea.

The causes of hypopnea can vary. In OSA, it often results from a temporary collapse or narrowing of the upper airway during sleep, leading to restricted airflow. In CSA, the brain fails to send the proper signals to the muscles that control breathing, causing periods of shallow breathing. Symptoms of hypopnea can include daytime sleepiness, loud snoring, morning headaches, and difficulty concentrating. Diagnosis typically involves a sleep study, also known as polysomnography, which monitors breathing patterns, oxygen levels, and brain activity during sleep. Treatment strategies depend on the underlying cause and severity and may include lifestyle modifications, positive airway pressure (PAP) therapy, or other medical interventions.