Pressure efficacy for side vs back sleeping

I typically sleep on my side but have noticed that if I do fall asleep on my back I will awaken gasping for air. This happened last night even with good seal on mask. I knew from sleep study my OSA was severe on my back but only moderate on my side. Still, I would have thought the CPAP would provide at least a modicum of therapy for back sleeping. Otherwise therapy is going good. Do I just need to be mindful to stay off my back? I know I cannot do the tennis ball thing.

IMHO you need to consider treating for the worst case, back sleeping. That may include increasing your pressures.

What you are experiencing is the exact argument for using an APAP. That the machine can adjust pressures depending on how you are positioned.

BeanMeScot wrote:What you are experiencing is the exact argument for using an APAP. That the machine can adjust pressures depending on how you are positioned.

How can the machine know how I am positioned?

I would agree. Sleep studies are usually done on your back (worst case scenerio) if, for some reason - medical, injury- you may have to sleep on your back even for a short period of time.

I have to sleep on my back. I have Rheumatoid Arthritis, and while back sleeping is not the recommended position for people with sleep anpea, I have no choice if I want to sleep.

I'm glad I was titrated on my back for that reason and besides, I wouldn't have been able to get through the titration any other way.

I assume I could get by with a lower pressure if I did not sleep on my back but that's how it is. I have the software and reader and auto machine set at a narrow range. I know from my data, that I am at a good setting with AHI below 1 most of the time and I never am wakened gasping for breath. Both these things tells me that my settings are doing the job.

If you were titrated on your back, the data may not be accurate given the strange circumstances of a sleep study (wires, machine, mask etc). Now that you have settled into therapy at home, this gasping for breath while on your back, to me, is a good indication that, either your titrated pressure was not adequate or your needs have changed and you need a higher pressure.

As I recall, you have an M Series Plus so no data except compliance. You will have to go with how you feel and raise your pressure slowly (.5 cm at a time) raising it another .5 every week or so, until you are no longer gasping while on your back.

Just my experience and thoughts.

Jason S. wrote:How can the machine know how I am positioned?

It can't, but it can sense when you are having difficulty breathing and compensate by increasing pressure, and back off when you are not.

On your back, the airway closes more because of gravity and, therefore, the machine senses that your airway is closing when you are on your back. It doesn't know you are on your back. It knows your airway is closing.

I see you have a DS100 M Series. That machine gives no detailed data either.

BeanMeScot wrote:What you are experiencing is the exact argument for using an APAP. That the machine can adjust pressures depending on how you are positioned.

I just read about APAP and it sounds like the overall pressure one might receive in a night could be up to 40% less than CPAP. That's because even people with OSA breathe normally at times and the machine would back off the pressure when its not needed. If APAP actually works, its sounds like it could be a good thing. I wonder how accurate the sensor is that detects what pressure is needed.

In response to other poster, I was tested on both back and side, because the report noted I was much worse on my back. I do not think its a good idea to incrementally up my pressure until I no longer have apneas while back sleeping. That would just give me extra unwanted pressure and the associated side effects for my 95% side-sleeping on the off-chance that I might roll onto my back.

Finally, I wonder how I would go about changing my machine? Should I return to my internist and tell him the current therapy is not adequate for back sleeping in hopes he can prescribe me for APAP?

Yeah, the APAP is set up to a range of pressure. You might need 9cm on your side so your CPAP is set at 9cm. But maybe you need 11cm on your back. The CPAP can't do anything about it. If you have an APAP set from 9-13, for example, the machine could change the pressure depending on the pressure needed to open your airway.

I think talking to your internist about it would be a great idea. Tell him your experience of not being able to breath well on your back and the fact that your sleep study showed worse AHI on your back. An APAP would be a natural solution to the issue.

Jason S. wrote:If APAP actually works, its sounds like it could be a good thing. I wonder how accurate the sensor is that detects what pressure is needed.

APAP does work. Look at some of the reports I have posted. My initial titrated pressure was given at 8 cm but while it did help and data wasn't hugely bad (AHI 7-9 rande), I felt like crap still. I changed my minimum to 10 cm and got much better results. Now experimenting with 11 cm minimum just to tweak it a bit more. The auto pressure function responds slowly to what it perceives as the beginnings of an apnea event (either flow limitation, snores, hypopnea, etc) and will raise pressure trying to stop the event. I am not sure how "slow" is slow but it doesn't make a huge leap from 8 cm to 14 cm. It gently "feels" out pressure needs by small increases. For this reason the minimum needs to be set to prevent the common majority of events and leave the upper range open to deal with those random events that need more pressure. I am content with leaving the ceiling open. The pressure changes that might be needed do not wake me or bother me.

I am much worse in REM staged sleep. I don't see any sense in keep a constant, much higher pressure just for those REM related events. I am not in REM all night. APAP works for me.

I can't put into words all the technical jargon on how the APAP does its thing. If you haven't read this, it might explain things better.
http://sleepapnea.respironics.com/techn ... logic.aspx

Jason S. wrote: I just read about APAP and it sounds like the overall pressure one might receive in a night could be up to 40% less than CPAP. That's because even people with OSA breathe normally at times and the machine would back off the pressure when its not needed. If APAP actually works, its sounds like it could be a good thing. I wonder how accurate the sensor is that detects what pressure is needed.

Most of us here have found APAP to work best when you set the minimum pressure to a cm or two less than your titrated CPAP pressure. APAPs make pressure changes very slowly, so if you set the minimum too low, you can have events (and poor sleep) before the machine ups the pressure into the correct range. APAPs work by detecting not just apneas and hypopneas but also the precursors (e.g. snoring, flow limitations) that precede them. As long as leaks are under control, the APAP algorithms work extremely well for most people.

Finally, I wonder how I would go about changing my machine? Should I return to my internist and tell him the current therapy is not adequate for back sleeping in hopes he can prescribe me for APAP?

If you pay for your own equipment, you can get an APAP from our forum sponsor (CPAP.COM) with your existing CPAP prescription. If you use insurance, you'll need a prescription that specifies APAP. Depending on how recently insurance bought your current CPAP machine and the details of your insurance, you may have a battle on your hands trying to get a new one.

Jason S. wrote:How can the machine know how I am positioned?

Jason, ResMed has a great video on their autopap technology:
http://www.resmed.com/us/patients_and_f ... c=patients
Click on the swf file in the middle of the screen. If fully explains how these machines work. I was impressed with how effective it is in delivering this complex information.

Cheers!