March 28, 2013
Q: What does the RDI, AHI and ODI represent on the Watch-PAT report?
Dr. Smith: RDI stands for the respiratory disturbance index, which includes apneas, hypopneas and RERAs. If the RDI is high and the AHI is low, this indicates Upper Airway Resistance Syndrome, and most sleep centers will not report this on studies. Oral appliances are great for this condition.
AHI stands for the Apnea-Hypopnea Index, and contains apneas and hypopneas. Put simply, although not exactly correct, this is the number of times you stop breathing for at least 10 seconds each hour.
ODI is the desaturation index, and it means the number of times each hour your hemoglobin (storage facility and transporter of O2 in your blood) lets go of at least 4% of the O2 it contains. This is what you measure with your pulse oximeters you use when sedating patients.