Apnea-hypopnea index
Encyclopedia
The apnea-hypopnea index (AHI) is an index of sleep apnea
severity that combines apnea
s and hypopneas. The apneas (pauses in breathing) must last for at least 10 seconds and are associated with a decrease in blood oxygenation. Combining these gives an overall sleep apnea severity score that evaluates both number sleep disruptions and degree of oxygen desaturation (low blood level).
The AHI, as with the separate apnea index and hypopnea index, is calculated by dividing the number of events by the number of hours of sleep. (AHI values are typically categorized as 5-15/hr = Mild; 15-30/hr = Moderate; and > 30/h = Severe.)
Sleep apnea
Sleep apnea is a sleep disorder characterized by abnormal pauses in breathing or instances of abnormally low breathing, during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour. Similarly, each abnormally low...
severity that combines apnea
Apnea
Apnea, apnoea, or apnœa is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged...
s and hypopneas. The apneas (pauses in breathing) must last for at least 10 seconds and are associated with a decrease in blood oxygenation. Combining these gives an overall sleep apnea severity score that evaluates both number sleep disruptions and degree of oxygen desaturation (low blood level).
The AHI, as with the separate apnea index and hypopnea index, is calculated by dividing the number of events by the number of hours of sleep. (AHI values are typically categorized as 5-15/hr = Mild; 15-30/hr = Moderate; and > 30/h = Severe.)