How Effective is APAP in Setting Optimal Air Pressure to Reduce AHI ?

Ok, I had my cpap set, fixed at 14 cm and I started seeing AHI pretty close to 5.

After being told by nurse to set apap to 10 - 14 cm I am seeing AHI trending up.

I know how to change the air pressure or the pressure range.

I am pretty aggressive about my health care goals and do not need to follow the health providers guidance if their "bar is set too low" for success.

thanks for any insights ! dmypub

What I see is:

• the machine was set to a fixed CPAP pressure of about 8 cm from Oct 29 to Dec 6, with pretty poor AHI results averaging about 20-22
• From Dec 7 to Dec 11 it was in Auto mode with a minimum of 8 cm and max of 14 cm. Results were much improved. Averaging perhaps about 12?
• From Dec 13 to 17 it was in CPAP mode with increased fixed pressures each day from about 10 to 14. Results did not improve each day in step, but that is not unusual.
• From Dec 18 to Jan 6 it was in fixed CPAP mode at 14 cm. Results are the best you have had to date, but still not great. Average about 10 for AHI?
• From Jan 7 on it seems to be in Auto mode with a minimum of 10 to a max of 14. Results to my eye are about the same as the fixed 14 cm, and perhaps even a bit better.

You can get a more accurate read of the average AHI for each mode from the SleepyHead Statistics page. Each time you change the treatment settings it should start a new line, with the start and end date, the average AHI, and what the settings were. That would let you compare the modes tried to date more accurately. A duration of one night at a certain setting is fairly meaningless though. I think a minimum of 7 days is required to give the mode a fair evaluation, and a month is better still.

If you can post a daily Detail page it would be much more helpful. January 7th would be a good night to post. Are you using the Flex setting on the machine? If so, one possible quick improvement could be to turn it off or set it to zero.

Going with that range over the fixed pressure could reduce Central events when not at max pressure. I do not know this users history so this is a generalization. BTW, that technique does not always work or it will only seem to work because Central elements on a CPAP are usually consistently inconsistent.

Fred

I have actually found benefit in raising the minimum pressure while leaving the maximum pressure fixed. I only like to raise maximum pressure as a last resort. Raising minimum pressure often eliminates the trigger events which the auto machine needs to be prompted to raise the pressure.

However in this case, with a fixed 14 cm not achieving <5 AHI kind of indicates max pressure will have to be increased at some point. If Flex is being used, I would discontinue that first though.

Yes, in my non medical professional opinion, that looks to me like Cheyne-Stokes Respiration. I have experienced events that look quite similar. Certainly the 5000 foot elevation is not helping. I was taking a minimal dose of a beta blocker, bisoprolol, and I convinced my GP doctor to cut the dose in half. I think he was a bit skeptical about it, but said my blood pressure was fine with the lower dose, and went along with it. With central apnea it is hard to attribute cause and effect, but I think it has reduced my frequency of CSR. Beta blockers not only reduce blood pressure but they mainly do it by reducing the pulse rate. I think in turn that reduces blood flow which can aggravate central apnea. The literature reports an association of CRS with atrial fibrillation to.

There is a good blog here by an MD, Robert Thomas, on Complex Sleep Apnea that you may be interested in reading. He mentions that there is some indication a drug intended to treat elevation sickness, acetazolamide, can reduce central sleep apnea. Perhaps something to have a discussion with your doctor about. I believe it is basically a diuretic which is considered a safe drug to treat blood pressure long term.

You may find this study abstract of interest:

Acetazolamide reduces blood pressure and sleep disordered breathing in hypertensive obstructive sleep apnoea patients – a randomized controlled trial

I think what I would try next is a tighter range. You are still getting quite a few events where the machine seems to be getting caught with not enough pressure. At the maximum pressure end it is not even going up to full pressure, and you would not lose much by restricting the max pressure. It is always a bit of a guess, but I think I would try 14.5 min and 16 max. Your minimum pressure is getting up there, so you may want to use the DreamStation SmartRamp feature. You should be able to select it and then choose a ramp start pressure. I would suggest a ramp start of 7-8 cm, whatever feels comfortable to you. It should hold the pressure at that value until it detects you are sleeping, thus making it easier to go to sleep. When you go to sleep it should then ramp up to your minimum treatment pressure.

On the mask farts issue, some people report getting a better seal and better comfort by using a layer of old cotton T-shirt material as a liner. You would have to cut it out in the shape of your mask seal plus a bit extra. Remzzzs is one commercial brand. I have no personal experience though.

That looks better. Your CA event frequency is very low and the residual is mainly OA and H. The machine did not attempt to go over 15 cm even though you had the max at 16 cm. What seems to be happening is that the machine algorithm is getting caught with the pressure too low, events happen, and it jumps up, and then fairly quickly the machine wants to reduce pressure. The set minimum of 14 cm is likely preventing it from going even lower and making things worse. Unfortunately this quick spiking up and down is a characteristic of the Respironics algorithm. My first thought would be bump the minimum pressure up to 14.5 and try that. If that helps, but there is still high OA, then the next step may be to go to a fixed 15 cm. I wouldn't jump into that yet, as you want to see where the machine wants to take pressure in limited auto control.

On the CSR I would not get too hung up on whether it is or it isn't. I think there is enough there to say there is an issue that should be raised with your GP doctor or cardiologist. Remember that Respironics does not say it is CSR, they just report periodic breathing probably on a basis that may be unique to Respironics. ResMed does report CSR, but again they are probably not all that transparent as to how they do it. This periodic breathing issue may have been there before you went on PAP treatment, and now the only difference is that you have a PAP machine reporting it to you, compliments of SleepyHead. Or, it may not have been there before, and the PAP treatment in the pressure range you have of about 15 cm is causing it, or aggravating it. That is of bigger concern, and again I would recommend discussion with the appropriate medical professional, like a cardiologist.

If they feel it is something that should be addressed, then that drug (Acetazolamide) I mentioned before may be of some help. Another approach that is used is to switch machines from the standard APAP you are using now to an ASV machine. There are risks associated with that too, and while it probably will reduce CSR and central apnea, it may or may not improve outcomes. That is something to be discussed fully with your health care professionals. Here is another reference you may find of interest.

Cheyne Stokes Respirations

This all said I would think that your elevation of 5000 feet is a factor in this, and it may not be fair to assume this is a heart issue. There can be other causes, and that drug for elevation sickness may have some benefits. And, I also think with a few more tweaks you may be able to get your AHI under the treatment guideline of 5.

Keep posting. I think you are making good progress.

Well the good news in this one is that your Periodic Breathing seems to be down, and there were zero central apnea events even though the pressure was higher. If you were disturbed with leaks all night that is probably the reason for feeling bad. Simply not enough sleep is the most likely problem.

I see from an earlier post you have a new mask (F30) on order. What mask are you using now? I don't have a lot of experience with full face masks but others here may. Perhaps they may have some suggestions on how to address leaks. From what I can see your mask leaks were much better later in the night, so perhaps you were making progress.

Probably about half of the obstructive events were happening at the 14.5 cm minimum. The next step would be to try a 15 cm minimum while leaving the max at 16. Probably going to make it harder from the leaks perspective though, so sooner or later you will have to solve that one. Perhaps the new mask will be better...

The other issue is that the obstructive events (not so much with the hypopnea) look like they are occurring in clusters. Bonjour has mentioned in another thread that sometimes it is a head positional issue that can be reduced by using a soft cervical collar. They are not too expensive, so at some point that may be worth a try.