Low AHI but higher pressure??

cortez356 · Post by **cortez356** » Mon Apr 25, 2011 2:30 pm

HI; I havent posted in awhile as I thought my therapy was OK. I have not really seen much change in my strength but I am not as tired as before APAP. I use an S9 Autoset and was using a Swift FX from November until right around Jan.1. I switched to an Activa LT nasal mask and really like it . However I noticed that my AHI has dropped to where it is often .5 or less. That is great. But my results in Rescan have me perplexed. My pressure settings have been 6.8 to 14. Last year typical results were Pressure 7.5,9,12(median,95th and max). Now my pressures are more like 9.8,12,13. When I would look at the graphs last year my pressure lines were near the bottom range. Now they are mostly higher. It is as if my OSA has gotten worse and the machine is adjusting to the change. Can this be correct. I mostly sleep on my back and do not remeber if I did the same previously. I started taking a Claritin every night in March and that has really helped with the time I am asleep. My leaks run from 5 to 9 median and other than a few really bad ones when the mask was almost off the max is usually under 12. I guess I am sleping right through the leaks. Should I be worried? Any suggestions?

Thanks

Bob

cortez356 · Post by **cortez356** » Tue Apr 26, 2011 6:45 pm

Some help please.

Bob

NightMonkey · Post by **NightMonkey** » Tue Apr 26, 2011 6:50 pm

Can you post a typical night's graph? Just that one page time line.

Right off the bat I don't like your min pressure. Needs to be higher.

avi123 · Post by **avi123** » Tue Apr 26, 2011 7:15 pm

cortez356 wrote:HI; I havent posted in awhile as I thought my therapy was OK. I have not really seen much change in my strength but I am not as tired as before APAP. I use an S9 Autoset and was using a Swift FX from November until right around Jan.1. I switched to an Activa LT nasal mask and really like it .

However I noticed that my AHI has dropped to where it is often .5 or less. That is great. But my results in Rescan have me perplexed. My pressure settings have been 6.8 to 14. Last year typical results were Pressure 7.5,9,12(median,95th and max). Now my pressures are more like 9.8,12,13. When I would look at the graphs last year my pressure lines were near the bottom range. Now they are mostly higher. It is as if my OSA has gotten worse and the machine is adjusting to the change. Can this be correct.

Reply:

In my opinion, you can't trust the CPAP with setting pressures. Only PSG sleep study can do it reliably b/c there are other body organs affected by it. Especially the heart. Once I get my S 9 Autoset (soon) I'll make sure that any pressure above 10 cm (up to 13) does open up most of the Obstructive Apneas and does not create more Central Apneas. I'll do it via the ResScan traces. In no way am I going to boost pressure above 13 cm without verifying it by a new PSG.

I mostly sleep on my back and do not remeber if I did the same previously. I started taking a Claritin every night in March and that has really helped with the time I am asleep. My leaks run from 5 to 9 median and other than a few really bad ones when the mask was almost off the max is usually under 12. I guess I am sleping right through the leaks. Should I be worried? Any suggestions?

Thanks

Bob

the S 9 Resmed Autoset and Elite can't detect events correctly if the leak is above 30 L/Min.

DreamDiver · Post by **DreamDiver** » Tue Apr 26, 2011 8:00 pm

cortez356 wrote:HI; I havent posted in awhile as I thought my therapy was OK. I have not really seen much change in my strength but I am not as tired as before APAP. I use an S9 Autoset and was using a Swift FX from November until right around Jan.1. I switched to an Activa LT nasal mask and really like it . However I noticed that my AHI has dropped to where it is often .5 or less. That is great. But my results in Rescan have me perplexed. My pressure settings have been 6.8 to 14. Last year typical results were Pressure 7.5,9,12(median,95th and max). Now my pressures are more like 9.8,12,13. When I would look at the graphs last year my pressure lines were near the bottom range. Now they are mostly higher. It is as if my OSA has gotten worse and the machine is adjusting to the change. Can this be correct. I mostly sleep on my back and do not remeber if I did the same previously. I started taking a Claritin every night in March and that has really helped with the time I am asleep. My leaks run from 5 to 9 median and other than a few really bad ones when the mask was almost off the max is usually under 12. I guess I am sleping right through the leaks. Should I be worried? Any suggestions?

Thanks

Bob

Bob,
I wouldn't worry about the pressure readings changing if my AHI is so reasonably low, like 0.5, and I could easily handle the current pressure regime. I might be curious about why my pressure pressure is higher, as you are. When your readings were at 7.5,9,12, what was your AHI? Has your AHI correspondingly gone down as the pressure readings have ranged up? To me that sounds like a good sign, if it has. I wonder if your body is just getting used to using the machine. Keeping in mind that I'm not a doctor, I'd call that successful auto-titration.

If my current pressures readings were hovering around 9.8/12/13, and my min pressure were set at 6.8, I might set my min pressure to 9.5 and see how I do at that pressure regime.

In the end - do you feel better?

deerslayer · Post by **deerslayer** » Tue Apr 26, 2011 8:09 pm

if i understand you correctly , when your machine was set to lower pressures, your AHI was higher ?
now with your S9 adjusting to head off events, your AHI is better ?...Sounds like your getting dialed in & therapy is working for you .
i recently bumped my min. up 1 from 11 to 12 & 17 max from 16. 90% has been 13 last week for 8hr. + . have noticed a significant drop in events, with max pressure hitting ceiling a couple times. however noticed am dreaming more and getting through the day with more energy.

cortez356 · Post by **cortez356** » Tue Apr 26, 2011 9:01 pm

Thanks for the replies. I have attached last night's results. Where I see the difference is in the pressure. Before my machine would be doing what I call idling. Just coasting along with the graph showing much of the night at or near the bottom and some spikes. That does not happen anymore. Some nights the event graph show none or a few low events. Last night I was on my back for maybe 60% of the time. I havent used my oximeter for awhile but I had no desats below 92 the last time I checked. I am not as tired as I used to be and feel that I can think better but muscle strength is very bad. Just an hour of any kind of lifting my arms overhead( like painting) leaves me with sore muscles. Even laying on my side at night hurts my shoulder. I was quite active until 30 months ago. After emergency gall bladder surgery have never been the same. However about 20 years ago I was diagnosed as having mild CFS. That went away about 10 years ago. Any help appreciated. I dont see my family doc for 3 weeks. I may try and get the hospital in Canada with the sleep lab to get me in line for an overnight sleep test. If I am lucky they may squeeze me in in 5 months!! The lab is not run by a neurologist but a lung Dr. Is that normal? Some days I tyhink I am like anold used car. Falling apart. I have had high BP for many yuears. I was on Cozaar and Aldactazide. I also reduced my salt intake and lost some weight. My BP was great for 6 months. about 125to130 over 80 to 85. Now for some reason it started to drop. A few days ago it was around 110 over 75. I stopped taking the Aladactazide and it is still 107 over 70. I havent had lower readings for more than 15 years. I am thinking of stopping my Cozaar but would really like to see my Dr. first. Like is sometimes say; " It's always something" Thanks again.

Bob

avi123 · Post by **avi123** » Wed Apr 27, 2011 9:08 am

Bob, I don't understand why you are using such a high maximum inspiration pressure, would not a lower pressure such as 10 cm to 12 cm take care of your Obstructive apneas?

You also posted: "However about 20 years ago I was diagnosed as having mild CFS {Chronic fatigue syndrome}, that went away about 10 years ago" . Nowhere do you give your age but I would be very careful, given your past situation, to follow medical advice from non MDs.

Your muscle problems are typical with CFS. See it here:

http://en.wikipedia.org/wiki/Chronic_fa ... ome#Pacing

You also posted: "I have had high BP for many yuears. I was on Cozaar and Aldactazide. I also reduced my salt intake and lost some weight. My BP was great for 6 months. about 125to130 over 80 to 85. Now for some reason it started to drop. A few days ago it was around 110 over 75. I stopped taking the Aladactazide and it is still 107 over 70. I havent had lower readings for more than 15 years. I am thinking of stopping my Cozaar but would really like to see my Dr. first."

I also take anti blood pressure Rx and have my BP down to 110/65. My Doc thinks that it is fine.

Bob, see here on the Flow graph that the 9.6 cmH20 that I set on my S9 Elite CPAP did not open the 35 second long Obstructive Apnea. If I raise the pressure to 10 cm and above then it would be bad during Central Apneas. So I plan to upgrade my S9 Elite with S9 Autoset. Then I'll set it at a range of 8 to 11 and see if it works. I doubt it b/c as I said before that you can't trust CPAPs for reliable info. So said my Doc MD. If not I'll go back and do another PSG and let my sleep doc advice me.

If you're are interested, you can see here my self titration log done over the recent three months. Apparently there is not a trend showing up. This is why I posted above that CPAP devices are too crude to deal with OSA events, b/c they depend on flow only.

ozij · Post by **ozij** » Wed Apr 27, 2011 9:56 am

There's mild snoring and flow limitations driving the pressure up.
They seem to be very sudden, so my guess is they happen when you're dreamning, and I think you need the pressure up there for those short periods. I wouldn't worry about the change.

DoriC · Post by **DoriC** » Wed Apr 27, 2011 10:11 am

It could be because you're sleeping supine which you weren't doing before. Ozij said not to worry so not to worry! My husband is doing lots of dreaming lately and his AHI is increasing although he sleeps on his side, so he probably needs a pressure increase which I'm tweaking now.

Avi, you're having lots of events so you're not getting optimum therapy at your current setting.

radaddict · Post by **radaddict** » Wed Apr 27, 2011 10:28 am

Your Rescan results could also be due to changing your mask (from Swift FX to Activa LT). I know that pressure is pressure, but each mask has it's own dynamics. I see similar results myself when I use a Swift FX vs. Activa LT. My results are even more dramatic if I change to a full face mask (Quattro). Try switching back to the Swift FX for a night and see if your results revert to what your were seeing last year.

cortez356 · Post by **cortez356** » Wed Apr 27, 2011 1:17 pm

Avi: THanks for the reply. My pressure is set @6.8 and 14. I need the higher # as many times the machine is running at those high pressures. Wouldnt reducing the pressure increase the AHI as the pressure would not be high enough to overcome the obstruction?? Or am I misunderstanding something. I am considering raising the 6.8 to maybe8 or 9 just to see what happens.

Bob

avi123 · Post by **avi123** » Wed Apr 27, 2011 2:16 pm

cortez356 wrote:Avi: THanks for the reply. My pressure is set @6.8 and 14. I need the higher # as many times the machine is running at those high pressures. Wouldnt reducing the pressure increase the AHI as the pressure would not be high enough to overcome the obstruction?? Or am I misunderstanding something. I am considering raising the 6.8 to maybe8 or 9 just to see what happens.

Bob

Bob, as I understand it if you set your APAP at 6.8 cm and 14 cm it would run at 6.8 cm until it hit an Obstructive Apnea and then it will raise the pressure up to 14 cm to open up the next Obstruction. However, if the FOT tells it that the airway is open which could mean a Central Apnea it will not raise the pressure above 10 cm (I need to double check that it is not above 6.8 cm). Before, I been talking about the 14 cm and not the 6.8 cm.

Were these pressures set by the sleep test or by a Sleep Doc?

Going again over your post: "Last year typical results were Pressure 7.5,9,12 (median,95th and max). Now my pressures are more like 9.8,12,13. When I would look at the graphs last year my pressure lines were near the bottom range." I now realize that I was wrong about my question. As a matter of fact if I go by my last sleep study Rx of 6 cm I myself should be using pressures almost like your, once I get my S9 Autoset. But, imo, I'll need higher pressure b/c as I you seein my above graph a pressure of 9.6 cm did not open an Obstructive apnea that I had. Once I get the S9 Autoset I'll set it at 8 cm and 12 cm and then check the ResScan's Flow graph at low speed (set the lower split screen at 2 min scale) and scan the Flow graph to see if there are any Obstruction Apneas that were not opened (as I did in the graph in my above post). If yes, then I might need to raise the upper pressure some what. But I'll be protected by the Autoset to drop the pressure if it ecounters Central events.

cortez356 · Post by **cortez356** » Wed Apr 27, 2011 2:27 pm

I must apologize as I forgot to thank the other posters for their input. I have been very pleased with my results. Getting AHI's that are 0.4 and 0.6 are like winning a lottery. My only concern was why did my pressure results suddenly change. Some of the erplies suggest dreaming . I am thinking maybe I have nasal obstructions? Sinus? I will continue to watch my results and post if I see anything that answers my question. It will be interesting to see what my Pulmonologist says.

Thanks

Bob

roster · Post by **roster** » Sat Apr 30, 2011 12:24 pm

avi, You need to do more studying before you give detailed advice on how the machines work.

avi123 wrote: Bob, as I understand it if you set your APAP at 6.8 cm and 14 cm it would run at 6.8 cm until it hit an Obstructive Apnea and then it will raise the pressure up to 14 cm to open up the next Obstruction.

Two mistakes in this statement. First, the machine raises pressure in response to flow limitations and snores in addition to apneas. Second, the machine will not "hit an apnea" and raise the pressure to 14. The machine will gradually raise the pressure in response to events. If the events continue to happen the pressure will eventually get to 14.

avi123 wrote: ... to open up the next Obstruction. ... But, imo, I'll need higher pressure b/c as I you seein my above graph a pressure of 9.6 cm did not open an Obstructive apnea that I had.

The machine will not "open an apnea". Once an apnea occurs it is only opened by the patient arousing to flex the airway muscles.

Be careful about what you are commenting on.

Good luck when your S9 Autoset arrives and may you become a leading expert on how it works.

Low AHI but higher pressure??

Low AHI but higher pressure??

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Machine	Mask

Additional Comments: straight cpap 12.20 AHI avg.0.79