Experiments on RemStar Snore Detection...

[jdacal]

Snoring often occurs before obstruction of the airway. Typically, by responding early to snoring, AutoSet Spirit can help prevent apneas.

Only problem with that logic is that some of us snore pretty constantly so adjusting pressure based on snoring alone makes my pressure jump to anywhere from 17 - 20. Needless to say, those pressures are so uncomfortable and leaky that the frequent awakening is worse than the apnea.

I've managed to drop my AHI to 4.6 by setting pressure to 10 - 15. At this pressure my snores are inaudible (to my wife anyway, not to the APAP). As opposed to wall shaking snores without the APAP. I'm feeling pretty rested in the morning as well.

I think the algorithm should do a better job of looking at past AHI's and try to set a limit on how far it should increase pressure to reduce snoring, yet maintain a reasonable AHI. I don't see this happening now. It appears to just increase pressure based on the current snore, without any analyzing of prior data.

[loonlvr]

My snore index is usually below 3, but AHi is between 8-15. My auto is set between 10 and 16 most of the time. I still am unable to prevent a barrage of apneas about two hrs into sleep that lasts about and hour. They usually include some centrals. But the rest of the nite isn"t so bad. That barrage sends my AHI into double digits. At least I don t snore.

[biggziff]

Just talking to Tridens and he was speculating that rainout could cause a noise that would be interpreted as a snore or two. I'd have to agree especially after reading this post. If a ruler on the hose can create a "snore" then gurgling could well be another culprit.

[dkeat]

This activity had a strong effect on the APAP pressure, raising it from 5.5 cm to 10.5 cm

I have the same machine and have had some fairly unpleasant experiences with pressure rising due to events unrelated to apneas. Unattractive as it may sound, when phlegm collects at the back of the throat I sometime do a backwards snort to clear it. This is usually enough to change the pressure. Snorting to clear the nose will also have an effect.

I finally turned down the top pressure from 15 to 9 as I was having escalating pressure right up to 15 and the higher it got the worse my AHI was getting. This was the right thing to do and my AHI has come down nicely to under 3.

Today I decided to see what the numbers will look like on straight CPAP set to 8.

[rested gal]

Interesting. Neither of my REMstar Autos (one before C-Flex was added, one with it) ran the pressure up for me, yet "snores" (no audible ones, so I'm told) are tick marked with great regularity all the way across the chart all night long.

After playing around with raising the lower pressure up as much as 9 in a vain attempt to get rid of the snore tick marks, I finally stopped even looking at the snore marks on the Encore data. Didn't seem to affect the way the REMstars operated for me. Weren't running the pressure up.

My autopap pressure setting range is 8 - 14. By far most of the night, every night, is spent at 8. Rarely has any autopap I've used gone to 12 for very brief periods. The multitude of "snores", or whatever the machine is interpreting as snores and marking as a lot of snoring throughout the night, wasn't causing either of my REMstar Autos to increase the pressure. Go figure.

Mouth air leaks, on the other hand...those can sure run the pressure up for me...with any autopap. Nights that I notice an edge of tape has worked loose, I might as well get up and put on fresh tape. Can see the difference the next morning -- the machine using the low pressure consistently the remainder of the securely-taped night.

Possibly some (not all, of course) people who are seeing snores recorded on their Encore data accompanied by pressure rise are also leaking treatment air from the mouth. Unless a person who has lip leaks or mouth leaks unbeknownst to them pays close attention to the leak line too, it would be easy to think it was snores (real or something misinterpreted by the machine as snores) running the pressure up and never think of the leaks themselves as being the reason for pressure to rise. Mouth air leaks could also cause snoring if treatment air is detouring out instead of doing its job.

For me, the many snore marks on Encore are "simply there" to be ignored, since I know that with tape and a rock bottom leak line, there's no problem. Leaks are what make my machine really have to go to work.

The PB 420E autopaps (two of them) I've used haven't toted up more than a few snores on some nights, none on many nights. Same range 8 - 14, with the 420E I currently use.

[littlebaddow]

A random observation to throw into this interesting discussion.

Using the remstar auto with c-flex & heated humidifier, setting 6cm-10cm I've had pretty consistent results for nearly a year. Machine typically runs at 6cm for 80% to 90% of the night and 7cm for the rest, very rarely rising to higher values for a few minutes. (Incidentally, this compares with a proposed setting of 10cm for cpap in my original sleep study).

Headline results:
Average AHI around 1
Average snore index around 3.3, evenly spread through the night
More importantly, a long suffering wife delighted that she is no longer able to hear me snoring

I have travelled with the machine before but recently spent 2 nights away from home and for the first time I didn't bother taking the humidifier with me. For those 2 nights the snore index scores were 14.5 and 10, values I've never before recorded. The pressure ranges for the 2 nights were also a little higher, with 9% and 20.6% at 8cm or higher respectively. AHI was in the normal range. My guess is my throat was dryer so sounded different!

I'm not sure what this may mean in the context of the more detailed analysis in this thread and I have sympathy for those of you still trying to find the optimum treatment, but for myself I conclude that, as long as I feel I'm getting a decent nights sleep and feel in good health, I shouldn't get too hung up on the snore index.

[loonlvr]

I guess since this thread has been restarted, I will repeat what many ppl and myself have said. UNLESS snoring is disturbing ones bedpartner, I find my snore index irrelevant. My main concern is my AHI. As long as its low, I'm a happy guy!

[IWannaSleep]

I totally agree with loonlvr. I monitor all my data closely, but primarily make adjustments to lower AHI. I have run experiments trying to find a pressure where I can keep AHI to a minimum while lowering my SI, but without success. So, other than curiosity, I ignore the snore line.

On the other hand, once on treatment, the only data my sleep docs are interested in has been the results of overnight oximetry testing. They were happy finding my blood oxygen was not dropping below about 93% saturation at any time. I agree as far as overall serious health issues, but I still believe all the rest impacts the quality of sleep.