The Sleep Apnea Syndrome

Sleep apnea is defined as a lack of detectable nasal or oral breathing for at least 10 seconds. A hypopnea is defined as a reduction of normal nasal breathing up to 50% or less accompanied by sleep arousal. Apnea and hypopnea are not, however, differentiated in clinical routine. The severity of an apnea is therefore measured using the Apnea-Hypopnea-Index (AHI).

The AHI distinguishes between three levels of severity: a mild sleep apnea is up to 15 breathing reductions/pauses per hour, a moderate apnea is 16-30 breathing reductions/pauses per hour and a severe sleep apnea is more than 30 breathing reductions/pauses per hour.
Attacks of sleep during the day often correlate with these levels of severity at night.

• With a mild sleep apnea a patient is likely to fall asleep during passive periods (ex. watching television).
• With a moderate sleep apnea a patient is likely to fall asleep during activities with a low level of concentration as concerts or meetings.
• With a severe sleep apnea a patient is likely to fall asleep during highly concentrated activities, while driving, eating or even speaking.