sleeptech

I can't imagine why CPAP pressure would have anything to do with back pain, nor have I ever heard of it happening. However, what could be happening is that the increase of pressure has stabilised your breathing better which has lead to your sleep being less disturbed. This could mean that you are moving a lot less in your sleep which is thus causing the back pain. This could still be true if it was just REM sleep that is improved because in REM sleep most of your muscles are super relaxed to stop you acting out your dreams. It's a bit like you body anaesthetising itself. If you had not been having solid REM and now you are, causing you to be more still, then this might have an effect. I'm really just guessing here. Unfortunately I have no great ideas for fixing it. Just be careful about medicating for it, because if you take muscle relaxants for your back they may also relax your airway making your OSA worse, and then you need more than 17 cmH2O to keep you breathing properly.

I use ResScan all the time (and hate it because it is unstable and unreliable, but that's neither here nor there). As Wiredgeorge said, the main statistic is the AHI. This measures the number of changes in breathing that occurred per hour of operation (not sleep mind you because the machine doesn't know when you are sleeping). Generally speaking, anything 5 or below is good. The hours of use is also important. The most useful figure is average usage per night (this is what is used for assessing compliance). ResScan also supplies median usage, which is a bit obscure and not terribly useful. Mask leak can also be handy, which ResScan can show as median leak, 95% leak and max leak. median leak is similar to the average level and should probably be below about 15, but this is rather variable depending on the patient and the mask used. Max leak level is a bit useless because it is the maximum leak level recorded at any point in the period of the report, which may only last for 2 seconds and is therefore not relevant. 95% leak is more useful because it is the highest leak rate reached if you leave out the worst 5%. This is handy because, combined with the median leak rate, you can tell if fit is usually good but gets worse in patches or if it is good all the time.

ResScan is highly configurable and can display all sorts of statistics and graphs. Most of it is totally useless. Stick to the basics. Also remember that the data should always be taken in the context of the patient's real world experiences. If there is a high leak rate but the patient is happy, the AHI is low and their symptoms are well controlled, why bother about it? Likewise, just because the leak reading is great that doesn't mean you can simply ignore the patient telling you that their mask leak is bothering them.

As usual, Wiredgeorge is on the ball.

Your ResMed machine should be able to detect the central apnoeas if they develop, so you're probably fine. I'm glad it's helpful for you. For most people EPR is probably harmless, it's just that there are risks, and the number of people for whom it is a problem, albeit the minority, is still pretty significant. Even a small proportion of sufferers from a condition as common as OSA can be tens of thousands of people (possibly even hundreds). This is exacerbated by the fact that the manufacturers tell everyone that it's completely harmless and everyone should use it, so most CPAP machines have it turned on by default. As usual, proper education is the key here, along with healthcare professionals who are prepared to put in all of the work required to do the job properly.

Yes, an EPR of one should drop the pressure by approximately 1 cmH2O. EPR of 2 drops the pressure by 2 cmH2O and so on. Sorry that explanation was confusing.

With regard to asthma being related to OSA - it is true that they both involve narrowed airways. However, asthma (as I understand it - this is not my field) involves a narrowing of the bronchioles which are small tubes that spread out throughout your lungs connecting the alveoli to the trachea. OSA is a collapse of the airway at the back of your throat, a completely different part of your airway. Therefore I doubt that they are directly connected. However, because both hinder your breathing, it would seem possible that they could interact. For example, if your asthma was narrowing your bronchioles due to some environmental cause (like pollen), then you add OSA on top your oxygen levels could start lower and drop lower. This may also cause an increased arousal response. In short, the symptoms of your your OSA would get worse. This doesn't mean that the 2 are connected, they just affect the same area.

I can also confirm that there is no surgical procedure demonstrated repeatedly effective for the treatment of OSA. While there are plenty of doctors who will perform surgery for OSA, there is not a surgery which is officially approved as an effective treatment. In all of the cases of surgery which I have seen or heard about, there is a very low rate of success, and those surgeries which are successful often only reduced the severity of OSA, eg from an AHI of 100 to 50, which is still a big problem. Also, if they are successful to any degree, there is a high chance of surgeries reverting so that you wind up as bad as or worse than before. Add to this the fact that most surgeries are very painful, have a long post-operative recovery time and have a high rate of post-operative infection, and the picture is pretty bleak. every doctor I know (including all the good ones) won't touch surgery with a barge pole for the reasons given above. As stated before, I am not a doctor, and medical science changes rapidly, so an effective surgery may be developed. Just be very wary if your doctor starts talking surgery because they often don't mention, or just plain don't know, the things I wrote above. Do your research and know exactly what you are getting into.

In relation to your question about exercise mdavis, I concur that you should start with CPAP. It will only help increase your ability to exercise. If you can lose weight and thus cure your OSA you can stop the CPAP. Also, it is very likely that you can rent a machine in the short term (we do that where I work).

CPAP use usually relieves oedema, rather than making it worse. If your sleep specialist cannot come up with any better answers, I'd seek the opinion of a cardiologist. It may be a sign of something else going wrong. I can assure you that it's almost certainly nothing to do with your humidifier.

Sage advice, Wiredgeorge.

I'm glad you asked. This is one of my favourite topics to bend people's ears about. EPR stands for Expiratory Pressure Relief. It is a function that ResMed introduced in their S8 and later models and it is the the same as C-Flex on Respironics machines, which they have had since the M series (although I'm sure both companies would swear blind they're totally different). The idea is to drop the pressure slightly on expiration in order to make the pressure more tolerable. Sounds reasonable but it is, in fact, a huge problem and should be avoided in almost every instance. "Why?", I hear you ask. I'll try not to get into too much detail explaining this.

The first problem is that EPR (and C-FLEX) lower your effective CPAP pressure. For example, if you need a CPAP 12 to breathe properly, but have EPR set on 3, you will only be getting an effective CPAP pressure of somewhere between 9 and 10, and because this is lower than is required you will obstruct. What will often happen next is that the patient will complain of persistent symptoms (because their OSA is not being adequately treated) and their download will show a higher than desirable AHI, so the pressure will be turned up making it less tolerable, increasing leak problems and leading to overall lower compliance with therapy. I have had to deal with this on more than one occasion.

The second problem is that by raising and lowering the pressure as you breathe, EPR actually increases the amount of air that you are breathing. With standard CPAP the pressure is constant, and the movement of air in and out of you lungs is done purely by your own respiratory muscles, so the amount of air you breathe is the normal amount that you should be breathing. All CPAP does is hold your airway open so that you can breathe normally. EPR works like low level BiPAP. As you breathe in the pressure increases and as you breathe out it decreases, which means that more air is moving in and out of your lungs than normal - the EPR is slightly augmenting your respiratory effort. This may sound all well and good, but there is a reason that you breathe the amount you do. Too little is a problem, we all know that, but too much can be a problem too. The extra breathing work done by EPR can be enough to hyperventilate you, sending your CO2 level too low which, in turn, causes central events. Again, I have recorded evidence of this happening.

Where I work, we only ever allow our patients to use EPR or C-Flex if they have had a sleep study with it and we can verify that it is not causing any harm. Otherwise we do not use it at all. I can think of fewer than 5 people who have actually had some benefit from using EPR/C-Flex in all my years of being a sleep tech. The people who sell the machines and the reps for the companies who make them will extol the virtues of EPR/C-Flex and tell you that it is perfectly safe. IT IS NOT. One of the engineers who designed the system admitted as much to another tech I work with.

So, to sum up, do not use EPR/C-Flex unless you have had a sleep study with it to make sure it's OK. It's not worth the risk. On ResMed machines EPR can be set to ramp only which is much less risky. Otherwise, if you think you really need it, get a study done while using it. As always, consult with your doctor, but you will probably find that they know nothing about this, as most of them don't in my experience.

If my long winded ramble above did not make this clear, don't worry. Central sleep apnoea can be treated too, and from your end there would be little difference in the treatment. So relax, there is every chance that you will fixed up better than before without too much fuss. And remember, keep asking questions until you get the answers you need. Especially of your doctors. They are paid very well to answer you questions.

Did you have a study with the CPAP on, or were you just given an autoset and a pat on the back? If you have had a study to confirm that the treatment is actually working, and it showed that it is, you probably have something else as well OSA. There are oodles of medical problems which make you tired. If you have not had a study with CPAP on, get one. It's the best was to be sure of the efficacy of your treatment.