What Does Flow Limitation Index Mean?
A flow limitation index is a metric used to measure the average number of flow limitation events that occur when someone is sleeping. A flow limitation index may be derived from a specific sleep study or from information gathered by an automatic positive airway pressure (APAP) device used for the treatment of sleep apnea.
A flow limitation event is recorded when an airway pressure measurement device detects what is known as a flow limitation. A flow limitation occurs when the sleeper's airway becomes partially obstructed, altering the airflow pressure.
The flow limitation index is calculated by dividing the total number of flow limitation events which occur by the number of hours over which events were recorded. This information may then be used to diagnose disorders including obstructive sleep apnea or to assess the effectiveness of an individual's treatment for an obstructive airway disorder.