RERAs and UARs are often used interchangeably, though RERA is the correct term. UARS stands for Upper Airway Resistance Syndrome. RERA stands for Respiratory Effort Related Arousal. If you have several RERAs per night that disrupt your sleep, then your sleep doctor would diagnost you with Upper Airway Resistance Syndrome, or UARS.
A RERA is the exact same as an Obstructive Hypopnea except for two differences. A RERA has an SpO2 (blood oxygen level) desaturaton of only 3% or less where a Hypopnea is of 4% or more. A RERA must have an arousal associated (it must cause you to wake up). A hypopnea doesn’t have to result in an arousal. The breathing that is allowed is so low that it results it an awakening that often isn’t remembered.
Like other types of sleep disordered breathing events, RERA’s are very disruptive to sleep. RERA’s can be successfully treated with CPAP or possibly an Oral Appliance Therapy (OAT device).
Below is one example of a RERA. The belts that are around the chest and abdomen are still moving indicating they are trying to breathe. “Flow” is the sensor that shows breathing. You can see that this patient is still breathing, but that it is less that periods where the patient wakes. The F3,C4,C3, and O2 signals speed up when the airflow increases (outlined in red). The breathing also resumes at this point. The oxygen level drops by 3% or less.
The unfortunate thing about RERAs is that they don’t count toward the overall AHI. The AHI only counts Apneas and Hypopneas that occur per hour of sleep.
The RDI counts Apneas, Hypopneas, and RERAs. The problem is that Medicare doesn’t use the RDI to approve, and pay for, CPAP. Medicare only uses the AHI. The problem with this is that many insurance companies just copy Medicare guidelines.
For example, a person could have one RERA per minute of sleep causing an RDI of 60.0. That’s 60 times waking up per hour. You can imagine how exhausted you’d be waking up. The AHI would be 0.0 and nothing would be done about it from a treatment standpoint.
In situations like this it is important to be working with a Board Certified Sleep Disorders Physician. A doctor with these credentials will know ways to get you approved for Positive Pressure therapy. It is often just them knowing what coding to use and how to word the report. This can make the difference between you getting treated or not.
Hopefully you now know the difference between the terms RERAs and UARS.