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I am suppose to have a formal home sleep study this next week sometime. Waiting for them to call me to schedule it. The DME said it would be through virtuox(?) and they would send me everything along with instructions. I am hoping they call monday and do the sleep study tuesday or wednesday night so I can officially be on the right track.

I will leave the pressure at 10 and wait for my sleep study to make any adjustments unless 10 makes me feel like crap then I will back it down. Will using the cpap prior to the sleep study affect the results of the sleep study? The sleep study will be without cpap.

Can you explain to me how pressure affects CA's? And if the sleep study shows a large number of CA's then will I require a different machine?

Thanks for all your patience answering my questions Pugsy. You are awesome!!!!

Cpap and centrals.
There is a small percentage of people who have essentially no centrals during a sleep study without a machine that develop centrals as a response to cpap pressure. Small number though..10 to 15 %. Not everyone has it and it doesn't have to be high pressures that seem to precipitate the centrals. It can happen with as little at 6 o 7 cm pressure and it doesn't always happen with higher pressures either. I routinely will see upwards of 20 cm pressure on my auto adjusting machine and I don't have any more centrals than I do or did at lower pressures.

Even if someone does have some centrals pop up as a response to cpap pressures it isn't always a big deal. It depends on how many and how it impact oxygen levels and/or sleep in general and sometimes the centrals will subside as the body gets adjusted to cpap therapy.
Yes, sometimes a different machine is needed but not always. That chances of that happening are small. We cross that bridge if we need to. No sense in worrying about it right now.
So they may not pop up and even if they do it can sometimes be managed (if it needs management) by a simple bilevel machine and we don't always have to go to the high dollar bilevel machines.

A few centrals are normal. We all have them from time to time. Even people without a sleep apnea diagnosis.
They are only a problem if they create a problem.

The night before you do the home study...don't use the machine. Just in case there is any residual left over something that might affect the home study.

Hi Pugsy, a quick question re centrals, now many an hour are normal? I'm trying to worry less!
Thanks, Kathy

Thanks for the explanation Pugsy. It will be interesting to find out if I am having CA's. The more I learn, the more curious I get about exactly what type of sleep apnea I have and what the right treatment is for me.

I must say I feel pretty good today. Not yawning anywhere near as much as I have been or near as hard. My eyes haven't watered once today and I just started yawning which is huge. Normally I am yawing within 45 minutes of getting up and yawn the rest of the day. Even if 10 is not the right pressure, it is making a difference. I even flipped my king size mattress by myself.

I am still researching machines and masks so I will be knowledgeble when I go back to see the doctor after my sleep study. The mask I am using is a small but I think it is still a bit too big as I have to really tighten the straps so it doesn't leak. But time will tell.

mrsbongo1 wrote: a quick question re centrals, now many an hour are normal? I'm trying to worry less!

See my recent comments in this thread.
viewtopic/t88370/Clear-airway-events.html

It depends on how many, where they are placed in the night and are they causing a problem with awakenings or desats.

5 or more centrals per hour that we can't explain away as sleep/semi awake or awake "centrals" needs to be discussed with the doctor or any centrals if the person having them is bugging the heck out of them.

Generally my own personal thoughts are over 3 or 4 consistently...every night and every hour...need to discuss with a doctor. It may not be that big of a deal but doctor should be aware of it.
I once had 17 centrals get flagged in 17 minutes ...back to back minutes. Have no idea what happened but that was a very rare occurrence. Most of the time I see anywhere from maybe 0 to 20 centrals spread out through the night and the hourly central index or average is less than 1 to maybe 2.

If I remember correctly your were having a lot more than that...
Is the central index still pretty high or has it dropped down somewhat? How many are you having?
Average per hour and through the night.
Sometimes we have them all in a cluster like I did with 17 in 17 minutes and that was fluke.
If you are having more than 5 per hour...every hour, every night...you need to be talking to your doctor.

There are a couple of adjustments you can make to make your oximetry data a little more meaningful.

In your software window you should see a screwdriver or tool kit near the bottom left side. Click on that. I believe the default for scoring is a 3% drop in O2 over a period of 10 seconds. You can change that to a 4% drop and leave the 10 seconds as is.

Next you can adjust the pulse numbers from a change of 6 BBM over a period of 8 seconds to a change of 15 BPM over a period of 30 seconds.

Since you are above sea level you can also adjust the trigger point of 90% down to something like 86% (or 84%). We just had a thread on this and I listed some references to O2 levels at different elevations. A review of that thread should give you acceptable target levels to shoot for.

As Pugsy has indicated there is not a direct correlation between desaturation events, pulse events, and sleep apnea events. However it seems that the targets are similar. The number ranges I have listed for scoring come from my cardiologist as "real world" values and my goal is to have less than 5 desaturation events per hour and less than 5 pulse events per hour. If desaturation is triggering arousals this should show up in the data. The next step is to determine if obstructions are causing the desaturation and that is where the xPAP data comes in. Also keep in mind that sleep disordered breathing can involve more than just O2 desaturation.

If possible you should see if you can adjust the ramp starting pressure. With a xPAP pressure of 10 you would find it more comfortable starting the ramp at 8.

Hi Hosecrusher,

Thanks for the information. The scoring was already set to 4% per 10 seconds. I set the trigger point to <89% as that is what my doctor wanted. He doesn't want me lower than 89% for very long. Although I did turn off the alarms so they wouldn't wake me up. Where I live 89% is the cutoff. In fact for night O2 levels the doctors go by the medicare standards of <= 88% for 5 minutes or more accumulative during sleep and you are put on oxygen at night. My doctor is holding off on putting me on oxygen in the hopes that the cpap will resolve the low O2 levels at night although he is not optimistic. However, I am hopeful as the added expense of oxygen is not something I need right now.

Cr1kk1t

Glad to hear that you have figured out how to check this.

My next suggestion was to run the set points by a doctor for guidance and I see that you are one step ahead of me on that and have already done that.

Now all you have to do is sleep a few nights and see if any trends develop.

mrsbongo1 wrote:Hi Pugsy, a quick question re centrals, now many an hour are normal? I'm trying to worry less!
Thanks, Kathy

Less than 5 per hour. Centrals often occur when initiating sleep. (people without OSA still have centrals at sleep onset).