Sleep Study Results

[vsheline]

can you give me a better understanding of RERA's?

Hi Phil,

RERA's are arousals from sleep that do not technically meet the definitions of apneas or hypopneas, but do disrupt sleep. They are abrupt transitions from a deeper stage of sleep to a shallower.

A RERA is characterized by increasing respiratory effort for 10 seconds or more leading to an arousal from sleep, but one that does not fulfill the criteria for a hypopnea or apnea. Therefore RERA's are not counted in the Apnea Hypopnea Index (AHI), which is the sum of the apneas and hypopneas per hour.

Apnea is at least 80% or 90% reduction in airflow lasting at least 10 seconds. (Standards vary.)

Hypopnea is at least 30% or 40% or 50% reduction in airflow lasting at least 10 seconds. (Standards vary.)

RERA's cause arousal but either the reduction in airflow was less than 30% or 40% or 50%, or the duration was less than 10 seconds.

There is an index (number of events per hour) which includes RERA's. It is called the respiratory disturbance index (RDI) — or respiratory distress index. The RDI is the AHI plus the number of RERA's per hour.

Here again is the link to the fantastic article "Flow Limitation/UARS and BiPAP" written by Dr Barry Krakow:
http://www.apneaboard.com/forums/Thread-...rry+krakow

[zonk]

From PRS1 manual:
RERA (Respiratory effort-related arousal) is defined as an arousal from sleep that follows a 10 second or longer sequence of breaths that are characterized by increasing respiratory effort, but which does not meet criteria for an apnea or hypopnea. Snoring, though usually associated with this condition need not be present. The RERA algorithm monitors for a sequence of breaths that exhibit both a subtle reduction in airflow and progressive flow limitation. If this breath sequence is terminated by a sudden increase in airflow along with the absence of flow limitation, and the event does not meet the conditions for an apnea or hypopnea, a RERA is indicated.

The manual available via Email (section three)
http://www.apneaboard.com/adjust-cpap-pr...tup-manual

[vsheline]

From PRS1 manual:
... The RERA algorithm monitors for a sequence of breaths that exhibit both a subtle reduction in airflow and progressive flow limitation. If this breath sequence is terminated by a sudden increase in airflow along with the absence of flow limitation, and the event does not meet the conditions for an apnea or hypopnea, a RERA is indicated.

ResMed bi-level machines currently do not attempt to detect/report RERA's. This is an area in which Philips Respironics machines appear to have detection and reporting which is more advanced than ResMed machines.

Unless electrodes are used to monitor brain waves and muscle effort (like is done during a sleep study), in any RERA detection algorithm there will be some chance that a RERA occurred but was not recognized (a RERA was missed, not reported), and there will be some chance that an unusual breathing pattern may be mistaken for a RERA (a RERA was falsely reported).

The PRS1 algorithm for RERA detection seems very conservative, with a fairly elaborate set of criteria to be met before a RERA is scored. I think the PRS1 algorithm for RERA detection may miss a few RERA's but is quite unlikely to falsely report a RERA event by mistake.

If the PRS1 RERA detection algorithm says a certain number of RERA events occurred, very likely at least that many did occur.

[zonk]

Hi vsheline, thank you for clarification
I only wanted to tell Philipg33 about the manual as he got new swanky "System One" machine today

[Philipg33]

Thanks guys for further explaining. Much to learn here for sure! I am having problems with the humidifier of this new "swanky" machine. I'll start a new thread on it as someone else may need that in the future.


Thank you again!