New user would be grateful for help in reading graphs!

[Gillian]

Hi
I have spent the last few weeks reading as many of the posts about the Resmed 9 Auto, trying to understand the explanations given for the various graphs, as well as why the masks leak! What a huge amount to absorb especially after the shock of finding out about the apnea.

I guess I'm now at the stage where I would dearly love some personal explanation particularly about the graphs. I realize that having the central apnea complicates things. Some nights the OA comes down to between 2-3 but then the CA can still be 13. As I am still having problems with mask leaks (which to me look as if they are connected to the pressure getting high?) I am not sure whether this is a mask problem or CA. It always seems to be worse between 1-4 pm, sometimes later. I can't figure out if I am having a CA which sends the flow high and the pressure higher and then more Ca's etc. OR is it than the leaks are causing CA's? As you can see I am becoming more confused the longer I look at it.

Fortunately I don't have any issues in being compliant and use the machine between 5 and 8 hours a night.

I'll stop waffling on now and post these graphs in the hopes that someone will take pity on me. In anticipation, thank you!
Following are my stats for 12th. (11th in brackets).

AHI Index 9.15 (11th - 12.72)
Hypopnea 0.34 (11th - .12)
Unspecified Apnea 0.17 (.12)
Obstructive Apnea 3.73 (2.74)
Clear Airway Apnea 4.91 (9.73)




Thanks so much for all the time you spend reading all these messages and trying to help everyone!

Gillian

[Burkebang]

Your event flag graph is too cluttered to make much sense of it at this view. If you could post a 2 hour view from 00:00 - 02:00, I'm sure we could see more. Also turn off the AHI graph and switch on the snore graph.

Another option is to switch to the Sleepyhead software, it has a much better event flag graph and automatically scales the timeline for the best possible view of the graphs.

[archangle]

Welcome, Gillian.

At least your individual apneas aren't very long. And your AHI isn't that high.

How long have you been using the AutoSet?

Zoom in on the area where you're having lots of apneas and post that, please.

Looks like you woke up at 1:40 or so. Do you remember anything about why you woke up? Did you feel like you were choking?

[Gillian]

Hope these are better.

I don't remember being awake but I know that around that time I am very restless and aware of something happening. My husband thinks that he can hear the higher pressure.

Thanks

Gillian.

PS Not used to navigating this forum so am a bit slow, sorry.

[Gillian]

Sorry Archangel

Meant to tell you that I was diagnosed in August, did a 6 home trial using various machines (Fand P, Respironics) and then decided to purchase the Resmed. What really annoyed me was that at no time during the trial was I given anything other than very basic info such as AHI. Always told leaks were negligible so bought the same mask I had been using thinking it was perfect.

Gillian

[Burkebang]

I got a much better view of your graph now

I think your machine needs a head start on treating those clusters of obstructive apneas. I think you should try increasing your minimum pressure to 8 and record some more data for a few nights. If you want to go to sleep at lower pressure, just set the ramp time to longer than it takes you to go to sleep and ramp pressure to 5. Remember to set ramp both in the clinical menu and patient menu.

I think the head start this increase in pressure gives the machine may prevent more obstructive apneas from happening, this may reduce the need for the machine to go to those very high pressures. This in turn may reduce the number of centrals you are having.

[archangle]

See that gap in your data at 2:00? It looks like the apneas woke you up, and you turned off the machine for a few minutes. Note the pressure immediately drops back to 5.

Zoom in on a few minutes around 1:50 where you can see the actual airflow waveform and see what your apneas actually look like. You should see gaps where your airflow stops for 10 seconds or so.

How long have you been on the current machine and settings?

Watch your data for a few more days. It looks a little bit like your apnea may actually be worse at higher pressure. It may be that apneas are causing your machine to increase pressure, but it may be that pressure actually makes you worse. It might be worth experimenting with reducing your max pressure temporarily to see what happens to your AHI.

As for leaks, see the red line at 24? That's the magic number where ResMed assumes your leaks are too high and you may not be getting the right pressure in your airway. It's not a disaster, but it may make your therapy less effective. It may also affect the accuracy of your AHI.

[avi123]

IMO, the nasal pillows mask is causing your leaks. Those leaks would cause the S9 machine to flag events as "Unknown", the yellow flag at 1:50. But notice that the S9 machine is quite robust and did diagnose events even when the leaks were above 37.5 L/min (between 1:40 and 1:50).
But the rise in pressure was caused by the rise in Obstructive events between 1:00 to 1:40 a.m. The rise in pressure probably caused the rise in leaks. The S9 Autoset (or S9 Elite) does NOT raise pressure b/c of leaks.







To get a clear picture of my treatment I usually look at the nightly Stats and graphs of pressure, events, leak, snore, and flow limitation:

[Pugsy]

Leaks didn't really become an issue until roughly 1:20 or so. Up till then you were well below the 24 L/min line.
There is a good chance that the leaks were disruptive to your sleep...allowing more events which also are likely disruptive to sleep. More sleep disruptions allow more awake/semi awake stuff to happen and a good chance that those centrals are sleep stage transition or sleep onset or simply semi awake centrals getting flagged. It's really hard to tell for sure at this point.

I agree with Burkebang...a little more minimum pressure to give the machine a better head start.
With a little more baseline pressure the pressure variations very well could stabilize. While these new machines don't go chasing the leaks like the older machine did it is possible that the leaks and pressure started feeding each other or at least the leaks may have reduced the effectiveness of the therapy pressure to a point that events start to increase and they for sure will feed the pressure.

Avi tells everyone that nasal pillow masks are the problem and thinks everyone should do what he does....over the nose mask and chin strap. He seems to think that nasal pillow masks are inferior for whatever reason he can come up with.
Take his ideas with a grain of salt if you wish.

The leaks definitely need work during that time frame where you went over 24 L/min though. I suspect that your minimum is right at the lowest level to prevent the events sort of effectively and when you have the leaks, even if not hugely above the 24 L/min mark, then the effectiveness of the pressure is compromised more quickly than it would likely be if your minimum pressure was a bit higher. You likely are sitting on the minimum edge and it doesn't take much leak to push you over the edge to less than optimal pressure due to leaks.

Of course the usual APAP comments can be made also. If pressure changes are disruptive to sleep then a tighter range or change to cpap mode might be indicated. Straight cpap mode or a very tight APAP range might also lessen the chance for leaks if the increased pressure is feeding the leak monster.

If it were me I would increase the minimum 1 cm.
BTW your machine will NOT respond to centrals with an increase in pressure but if you see a pressure increase in the neighborhood of a flagged central then you know that there was some sort of obstructive event warning sign happening behind the scenes. The machine only responds to obstructive stuff....won't respond to central stuff.

If you are indeed having centrals that are cpap induced then APAP mode may not be the best choice because of the pressure increases that can go along with flow limitations and snores which the machine will try to fix with increased pressure. In other words the machine might be trying to prevent something based on some snores or flow limitations with increased pressure and in turn causes a central event...trading a maybe not so bad event precursor for a full blown central. Using straight cpap or apap at a very tight range might be the best way to go if these centrals are pressure related.

Did you have centrals during your diagnostic sleep study or did they just show up with the addition of cpap pressure?

[DoriC]

Gillian is using a nasal mask according to her profile.

[Gillian]

Hi everyone, thanks for all the replies. First of all, I have been on this machine for about 2 months now. Started pressure at 5 to 16. Then changed it to 4 to.15 Because I thought the high pressure was perhaps causing the leaks. Now I will do as suggested and raise the min pressure again.

I do know that anything over 24 l/min is getting bad but don't know what else I can do to stop the leaks which spike with high pressure. Am using a nasal mask already with a liner and also have unsuccessfully tried the ear plugs. All seems great until that high pressure shows its ugly head!

When I had the Polysom. It showed AHI 54.6 with OA 92 CA 144 mixed 26. Evidently my centrals are more than likely caused by my pain meds, I have Complex Reg. Pain Syndrome as well as Rheumatoid Arth. And fibromyalgia. My RA specialist is going to help me try to lower the pain meds but not terribly hopeful. The sleep doc said that because after my 6 week trial the OA was down to 5.7 although the CA was still 13.7 (AHI 25.4) that he felt the machine was worth using just to keep the OA under control. Didn't want to discuss the bilevel machines because according to him there is no real research proving that they actually work!! What do you think? The centrals freak me out!

The numbers seem to jump all over the place. I have just downloaded the last 2 nights to give you and they were OA 3.6 and 1.9 And CA 4.8 and 12.3. That the 13th and 14th. The events are clustered around the same time of night and the leaks as well.


Well I am going to change the machine right now and hopefully I will have good news for next time.
Hope you all have as good a day as you can.

Regards

Gillian

[Pugsy]

When I had the Polysom. It showed AHI 54.6 with OA 92 CA 144 mixed 26. Evidently my centrals are more than likely caused by my pain meds, I have Complex Reg. Pain Syndrome as well as Rheumatoid Arth. And fibromyalgia. My RA specialist is going to help me try to lower the pain meds but not terribly hopeful. The sleep doc said that because after my 6 week trial the OA was down to 5.7 although the CA was still 13.7 (AHI 25.4) that he felt the machine was worth using just to keep the OA under control. Didn't want to discuss the bilevel machines because according to him there is no real research proving that they actually work!! What do you think? The centrals freak me out!

There are indeed bilevel machines that do work treating centrals. They would be the ASV models.
I don't know where your doctor got his thinking that there is no proof that they work unless he is thinking the regular bilevel machines that don't have the ASV type of functions.

[nanwilson]

[quote="avi123"]IMO, the nasal pillows mask is causing your leaks. Those leaks would cause the S9 machine to flag events as "Unknown", the yellow flag at 1:50. But notice that the S9 machine is quite robust and did diagnose events even when the leaks were above 37.5 L/min (between 1:40 and 1:50).
But the rise in pressure was caused by the rise in Obstructive events between 1:00 to 1:40 a.m. The rise in pressure probably caused the rise in leaks. The S9 Autoset (or S9 Elite) does NOT raise pressure b/c of leaks.


[Avi...did you not read her post...she is NOT using pillows but has a NASAL mask. You "assumed" AGAIN!!

[DoriC]

You might do better with a tighter range like 8-12 or even straight cpap at 9 or 10 if you find it comfortable. Keep us posted.

[Lizistired]

Gillian, I think you are sensitve to the xpap pressure. You have an event, your pressure increases, then your leaks increase.... you have more events, more pressure increases, more leaks.... it's a vicious cycle... you had no flow limitations during this period.
Since you didn't get a titration pressure, I would suggest you go to cpap pressure of 8 to 10, whatever you pick, and adjust from there. It might only take one night to give you an idea. If you chase numbers on apap, you could be doing it for weeks.
Also consider that your EPR setting is also a pressure change. You have to decide whether the EPR provides comfort and what level is most comfortable for you.