RDI
Also written as: RDI — Respiratory Disturbance Index
Comprehensive measure of sleep-disordered breathing including apneas, hypopneas, and respiratory effort-related arousals per hour.
Full Definition
The Respiratory Disturbance Index (RDI) is a comprehensive polysomnographic measure that quantifies the frequency of respiratory events during sleep by calculating the total number of apneas, hypopneas, and respiratory effort-related arousals (RERAs) per hour of sleep. Unlike the apnea-hypopnea index which only counts apneas and hypopneas, the RDI includes RERAs, which are sequences of breaths characterized by increasing respiratory effort leading to arousal without meeting criteria for apnea or hypopnea. This makes the RDI a more sensitive measure for detecting subtle forms of sleep-disordered breathing, particularly upper airway resistance syndrome. The RDI is particularly useful when standard AHI values appear normal but patients continue to experience symptoms suggesting sleep-disordered breathing.
Usage
Usage note: Always use capitals for the acronym.
In Context
- "The RDI of 22 events per hour was elevated despite a normal AHI, suggesting upper airway resistance." — Sleep apnea evaluation
- "Insurance coverage was approved based on the elevated RDI meeting treatment criteria." — Prior authorization documentation