Solved - Any ideas on why my AHI has suddenly jumped?

A week and a half ago I swapped out my little over a year old S9 Vpap Auto for a new one on warranty. Ever since I swapped I have noticed an increased AHI to an average of 5.7 half centrals and half obstructive. I used to average about 1.35 AHI. My leaks have gone up tremendously and I know them to be true because I wake up with a dry mouth in the middle of the night. Looking at the summary graphs it seemed to start a week before I changed machines. One thing that has been changing on me is that I have lost about 65 lbs in the last 5 months. Could the weight loss be causing me problems. I have never had central apneas other than one or two a night. Now Rescan is showing 20 centrals or so a night. This is weird. My pressure is EPAP 10.8cm and max IPAP at 25cm with an 8cm pressure spread. I wonderr if I should decrease my pressure support down to 6cm or 4cm to see if it helps with the centrals. Any ideas?

Thanks, Dale

With weight being such a critical factor associated to the severity of sleep apnea, I would say a 65 pound weight reduction could certainly impact how much pressure is necessary to keep your airway splinted open. Congratulations by the way on that, good for you!

The fact that you have an autoset device gives you a bit of safety in making pressure adjustments. An Epap of 10.8 plus PS of 8 cmH2O means you start at 10.8 and as you inhale your pressure goes to 18.8. That's a lot of pressure relatively speaking, so your thoughts of reducing the pressure support may very well help alleviate the centrals.

If your sleep doctor is available to give you her/his suggested pressures, I would go ahead and call to inquire. If you don't have that option, I would suggest posting a copy of your most recent downloads so that reasonable pressure changes can be advised. Rather than reducing pressure support, maybe it would be better for you to reduce your EPAP, or both. It will depend on what the machine thinks is optimal.

Good luck, I hope whatever you decide works out.

When you lose weight, it's lost all over, including your face, and it's very likely you've got new leaks going on... so think about what mask or masks you're using and how to adjust them.

If it were caused by the lost weight, you'd think he would've noticed a trend over the past 5 months, not just the last week or so.

deerhound wrote:A week and a half ago I swapped out my little over a year old S9 Vpap Auto for a new one on warranty. Ever since I swapped I have noticed an increased AHI to an average of 5.7 half centrals and half obstructive. I used to average about 1.35 AHI. My leaks have gone up tremendously and I know them to be true because I wake up with a dry mouth in the middle of the night. Looking at the summary graphs it seemed to start a week before I changed machines. One thing that has been changing on me is that I have lost about 65 lbs in the last 5 months. Could the weight loss be causing me problems. I have never had central apneas other than one or two a night. Now Rescan is showing 20 centrals or so a night. This is weird. My pressure is EPAP 10.8cm and max IPAP at 25cm with an 8cm pressure spread. I wonderr if I should decrease my pressure support down to 6cm or 4cm to see if it helps with the centrals. Any ideas?

Thanks, Dale

I've noticed my older Respironics machines can vary in their reporting. Some of it can depend on the firmware level.
So, my question is.......does your new machine have the same firmware level as your previous one? That may not account for the increased events happening before the change in machines, but thought I'd ask.

In hindsight, I saw an increase in AHI for a few months before I ended up in the hospital with pneumonia in late April of 2011. After I got that straightened out, my AHI promptly dropped again. That was on straight pressure - CPAP mode.

When you're dealing with variable pressures and ranges, it's a little harder to nail down causes.


Den

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Thanks for the replies. I'm going to lower my pressure support to 6cm and see how that works. I'll try it for a couple of days and get back.

Thanks, Dale

deerhound wrote:Thanks for the replies. I'm going to lower my pressure support to 6cm and see how that works. I'll try it for a couple of days and get back.

Thanks, Dale

Update??

I went in to see the RT at my Sleep Center Tuesday and got fitted for a new FF Mask. The Quattro Air. I'm now waiting for Carecentrix to store my mask request on their desk for 2 weeks before approving it. Then I will try FF mask again and see if it helps me. I think I am getting too many mouth leaks for my data to be really useful. I also ordered a F&P Simplus from our sponsors to try out. I hope between the 2 masks one becomes my new go to mask. I'm not getting good sleep because of mouth leaks and I need a fix. I don't know why I all of a sudden can't keep my mouth fro opening but it started happening at about the same time as my AHI jumping. I think maybe, since I lost 75# I only have 2 of my previous 4 chins left. Maybe I don't have enough fat on my neck to keep my mouth closed.

Dale

Deerhound,

There are lots of reason you are having problems. I'm an RT and sleep tech and have worked in the field for many years. The high pressures and mask leaks can cause the centrals. You don't just have an auto, you have a more sophisticated machine with additional settings. Also, you have posted your weight loss but skinny people have sleep apnea too. The main benefit of knowing your weight loss is your face has more than likely changed in proportions and you need to find a mask that works better for you. A download would give people adequate information to try to help you. Your underlying question really was, "Do you think it is the machine? Is the machine the problem?" yet not enough information is out there to properly answer that. I definitely think one machine is working better than the other but could not tell you which for lack of data / information. Or, the one machine has different settings so there is no real comparison.

Full face masks require higher pressures and often cause central apneas.

Mouth leaks can be a result of pressures being to high. Increased mask leaks is definitely a sign you have higher air flows and pressures with a mask that isn't sealing well.

If you have lost weight and never had centrals before, you might consider running a baseline on yourself. Set the machine to straight auto 5cmH20 to 20 cmH20 (or the lowest setting you can tolerate whatever that is). No pressure support. I think you might be pleasantly surprised with the results. Sometimes simple is the route to go. Besides, many physicians will reassess pressure needs especially after significant weight loss and the one way they do this is setting your machine to auto 5-20 for two weeks.

There is a book on Kindle and iTunes called "My Little CPAP Book" that answers a lot of questions. It is only $2.99 and even goes over what is on the downloads. Rarely are our problems caused by one thing only. Many times we need to do a couple of things together to get that good night sleep we are looking for.

Sleepy711
Why don't you try and stop trying to sell your book... we have had posters on here before that have said they were RTs and sleep techs, and all they did was steer us in the wrong direction.

I'm going to sleep with the Simplus mask FedEx delivered this morning. If I negate the mouth leaks, then I can really see what is going on. If I still have problems I will post data charts. Thanks everyone.

Dale

2nd night with the Simplus and I am starting to get a handle on the leaks. Since I am using a FF I dropped the Pressure Support to 4cm from 8 which cut down on leaks from the mask. With mouth leaks negated, my AHI is now back down to 1.1h with a couple of centrals which appear to be when I am awake. I hate going back to FF, but I guess my body changes with the weight loss have made me start mouth leaking with pillows. I am going to have bariatric surgery on the 24th this month. I'm having a gastric sleeve procedure. I aim to continue losing weight to become healthier and more able to do things. With more weight loss I expect many changes to come with my Pap therapy. I will see my sleep doctor in 4 -5 months to have him check up on any changes. Thanks again for the help guys.

Dale

Thanks for the update! PS=4 is the default setting which most people use so it was probably the right adjustment along with a new mask. Mike seems to do best with PS=3. Good luck with your surgery, hope you'll keep us posted.