Sierra

If you are using low pressure settings, less than 7 cm, then the EPR is going to be limited in what it can do. The machine will not allow the pressure to go below 4 cm. Say for example your minimum pressure is set for 5 cm, even if you set EPR at 3, all it will do is give you 5 cm on inhale and 4 cm on exhale. If your minimum is 7 cm then an EPR of 3 will give you 7 cm on inhale and 4 cm on exhale. Many find that comfortable. Over time I have adjusted my Ramp Start pressure up from 7 cm to currently about 8.6 cm. My test to determine whether or not it is set right is to breathe normally when I first go to bed, and see if I can feel any restriction on inhale or exhale. It should almost feel as if there is no mask on your face at all. i.e. no restriction in air flow.

Unfortunately many machines are delivered to the user with the minimum at 4 cm, and the Ramp Start at 4 cm. That can easily result in a feeling of not enough air. EPR on or off when the minimum is set at 4 cm will make no difference, because it cannot do anything.

There are two basic types of apnea; obstructive and central. Obstructive is essentially when the airway collapses, and their can be many causes and aggravating contributors. The central apnea occurs when the body just decides to stop breathing. It is less well understood, and again there can be many contributing factors. A sleep study would certainly give you a very good idea whether or not you are actually having apnea, or if it is something totally different.

Anything below about 8 cm is low pressure in my opinion. The difference between 4 and 5 is pretty insignificant, and in fact both pressures are so low that it may feel like there is not enough air when you have the mask on. All machines should go as low as 4 cm, but it is not necessarily going to feel comfortable. Do you have any difficulty breathing? Does the mask feel like it is restricting air flow? It is possible you may need a little higher pressure.

First, if you already have not, you should read through the posts in this fairly recent thread.

https://myapnea.org/forum/not-understand-epr-setting

My thoughts on EPR are that it does provide some comfort benefits by reducing the pressure on the exhale. The disadvantage is it also reduces your treatment pressure on exhale and if you are susceptible to apnea during exhale (and many are), then turning it on when it was off, can reduce your treatment effectiveness. If you have an auto CPAP and the maximum pressure allows it, your machine will probably compensate for it by increasing your inhale pressure. When it increases, so does exhale pressure, so you kind of come full circle, and have not really accomplished anything. And with an increased inhale pressure you are likely to have more issues with mask leaks.

For these reasons, my preference is to use EPR but only during the Auto Ramp portion of the nightly cycle. With EPR set at 3 and the start pressure set at 7-8 cm, the pressure will cycle on inhale and exhale to provide maximum comfort while you are going to sleep. Then when you are asleep the EPR goes off and inhale/exhale pressure become the same. This maximizes treatment effectiveness, and results in a lower maximum pressure during treatment.

Flex is much the same as EPR but the pressure reduction is less than the nominal setting. It modifies the reduction based on flow and pressure, and the impact on treatment effectiveness probably is less. Not sure if you can set Flex to be used only during the ramp on a Dreamstation, but if you can, that is how I would use it.

Hope that helps some,

If you are talking about the sleep report displayed on the machine screen, the Pressure there is the average of the 95% pressure levels for each day in the window of time that is selected at the top of the report. The 95% means that 95% of the time pressures were at or below that value of 13.9 cm in your case.

I've not had the headache issue, but it may be just you adapting to the higher oxygen levels you should be getting with using a CPAP.

Is this the mask you are using? What is your maximum pressure? I'm on mask #5, and wondering if I should go for 6! It is all on my nickel, and this appears to be a fairly expensive option.

https://www.youtube.com/watch?v=BRgTBdNNlTU

In my opinion the airway is more likely to collapse when sleeping on your back, however I'm sure it can collapse when sleeping on your stomach as well. A sleep test is the way to find out.

I am diabetic and do a minimum of 5 injections of long and short acting insulin per day. Yes, it can be dangerous if you mess up, and it is definitely far more complicated than adjusting your own CPAP.

I think the most harmful issue with how CPAPs are set up is the minimum pressure settings. Quite often the machine is left at default settings which are 4 to 20. The 20 is not really a big problem at least initially. The machine will only go as high as it thinks you need. The minimum is an issue. 4 cm is too low for real comfort, both during the going to sleep period and after you are asleep. This leaves many people feeling short of air, or with that suffocating feeling. A more realistic initial setup would be an Auto Ramp, with a start pressure of 7 cm, a minimum pressure of 7 cm, and an EPR of 3 set for Ramp Only. Then as you gain experience with what pressures you really need, the minimum should be bumped up so at least about 25% of the night you are at minimum. That prevents the machine from letting the pressure slip too low and cause apnea events. Last some final comfort can usually be obtained by bringing the maximum pressure down so it limits the maximum pressure 5-10% of the time. This can improve comfort, and if you watch when events occur, may not even increase the AHI.

As I understand it, ResMed is not confident in their machine's ability to accurately detect apnea events during periods of major leakage, so they suppress the reporting of apnea events during major leakage periods. For that reason large and frequent leakage may result in inaccurate AHI readings.

There are a couple of different ways that the test is done. The more comprehensive test is done in a sleep lab where you go and sleep overnight with all kinds of wires and gadgets hooked up to you. The second method which is becoming more common in Canada is the at home overnight test, where you are given some equipment which you wear overnight while sleeping in your own bed at home. That is the system I was diagnosed with. The equipment is called the Phillips Alice NightOne, and the link below shows a video on how it is worn.

Phillips Alice NightOne Test

The test done in the sleep lab may be more appropriate for you as it seems more complicated than simple sleep apnea. However depending on insurance it may be expensive. Both will give you a count of the apnea events you experience, your oxygen levels, and what sleep position you were in when you had the apnea events.