took 4 months; AHI 1.4!

We use themocouples (oral/nasal). We are looking into pressure transducers.

If AHI normal is < 15, then what about the pt with very high REM AHI, but has night average of < 15. This pt would be miserable w/o CPAP therapy.

We have to prove EDS or other symptoms if AHI < 15.

It has something to do with the pressure sensors. I'll copy over some information when I go to work tomorrow

This is what is at the bottom of all our sleep reports:

Current versus historical RDI values. In accordance with recent internationally agreed recommendations2, the AISH
laboratories transferred in 2002 from using oronasal thermistors to using nasal pressure transducers to measure airflow
and at the same time adopted a new standard for scoring apneas and hypopnoeas2. Nasal pressure is a more sensitive
measure of airflow and as a consequence, average AISH reported RDI values are now higher for the same severity sleep
disordered breathing. The best estimate is that RDI has increased by approximately 40.%. This is relevant when
interpreting current patient results with respect to our earlier studies of normal subjects1 and other previous epidemiological
studies, which relied on thermistors to measure airflow.

Severity of sleep disordered breathing. Bearing in mind the above, AISH consultants have adopted the following
consensus classification of severity of sleep disordered breathing

RDI: <15 Normal (see above caveats)
>15 - <30 Mild
> 30 - <45 Moderate
> 45 Severe

I may be confused but your literature discusses RDI as apposed to AHI, our RDI is usually higher especially in the case of uars and reras.

Doesn't RDI and AHI measure the same thing?
_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): AHI, RDI

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): AHI, RDI

AHI is apnea-hypopnea index
RDI is respiratory disturbance index
If you have UARS or RERAS that dio not qualify (sa02 desat>4%) for AHI but ar creating arousals, they are counted into the RDI.
Where do you worK?

Anonymous wrote:AHI is apnea-hypopnea index
RDI is respiratory disturbance index
If you have UARS or RERAS that dio not qualify (sa02 desat>4%) for AHI but ar creating arousals, they are counted into the RDI.
Where do you worK?

Thanks for the information. I work in Australia. Our sleep reports state RDI as being the measurement of sleep disordered breathing. Our reports also have a section with the total number of arousal per hour, which is subdivided into arousals associated with respiratory events, limb movements and spontaneous arousals.

split_city wrote:This is what is at the bottom of all our sleep reports:

Current versus historical RDI values. In accordance with recent internationally agreed recommendations2, the AISH laboratories transferred in 2002 from using oronasal thermistors to using nasal pressure transducers to measure airflow and at the same time adopted a new standard for scoring apneas and hypopnoeas2. Nasal pressure is a more sensitive measure of airflow and as a consequence, average AISH reported RDI values are now higher for the same severity sleep disordered breathing. The best estimate is that RDI has increased by approximately 40.%. This is relevant when interpreting current patient results with respect to our earlier studies of normal subjects1 and other previous epidemiological studies, which relied on thermistors to measure airflow.

Severity of sleep disordered breathing. Bearing in mind the above, AISH consultants have adopted the following consensus classification of severity of sleep disordered breathing

RDI: <15 Normal (see above caveats)
>15 - <30 Mild
>30 - <45 Moderate
>45 Severe

Hmmm, now SAG is greatly confused. Regardless of the diagnostic airflow methodology used, during intervention the waveform from the PAP machine is used to score events, and that is a pressure transducer. Are you then saying that RDI during titration and APAP is normal as long as it is <15?

Also, what are your components of RDI? Are they apneas, hypopneas and RERAs? RERAs and hypopneas need to have an associated event, be it an arousal and/or a desaturation. And >5 events per hour of those events are abnormal.

Or put another way, the diagnostic device selected is really academic. Either device (thermistor or pressure transducer) will identify an apnea, but beyond that, a respiratory event without an associated desaturation or at least an arousal is nothing.
SAG