sleeptech

As you fall asleep, it is quite common for your breathing to become a little irregular for a short period as you pass from wake to sleep. This will result in a number of events that could be either central or obstructive. These events are called onset events because they happen at sleep onset but disappear quickly once sheep is properly established.

The number of events you describe is very low and could easily be explained by onset events as you get back to sleep. Also, toward the end of the night your sleep drive is reduced and your sleep is more likely to be disturbed. When your sleep is disturbed you can have another small cluster of onset events as you settle back to sleep. This could account for why you have more at the end of the night - simply because you are a little more retless after your toilet break.

This is all guess work of course. Whatever the cause, the number of events is so small it is almost certainly no cause for concern.

The number of 5 was chosen partly because many years ago, before there was much research to go by, someone thought it sounded good. There is more than that. The likelihood of measurable, negative outcomes is very low at an AHI of 5 or below, so it's also based upon raw statistics. However, there's a lot of variation in the way individuals respond. Some people may have a low AHI because their events are isolated to their REM sleep, and those few events can be very severe. In other cases and AHI 5 is enough to make some one highly symptomatic (e.g. very tired). Really, AHI is a useful measurement but, like anything, it is only a guide and needs to be considered in light of other factors. I always think an AHI of 5 sounds pretty bad still.

There is further wrinkle in that an AHI reported by a CPAP machine is not necessarily the same as an AHI reported by a sleep study. Your CPAP machine con only estimate AHI based upon changes in air pressure (i.e. changes in your breathing). Sometimes these will be due to genuine apnoeas or hypopnoeas, but sometimes they will be something else that would be ruled out in a full sleep study. For this reason the AHI reported by your CPAP machine should always be considered a likely overestimation. It is also common for some medical devices to err on the side of a false positive rather than a false negative. This is because it is usually better to be alerted to a possible problem and, upon further investigation, find that it is not real, rather than for a real problem to be missed.

Do you have nay data from your machine? It could be useful in understanding this. Also, what kind of machine do you have? Different machines have some slightly different features like autoramp which may not be helping.

When you say doubled, from what to what?

Hmm. That sounds familiar... ;-)

I believe that any effective treatment has a role to play. I also know, from perusing scientific data, going to conferences etc., that the reason CPAP is considered the "gold standard" is that the success rate is way higher than other available options. It certainly is not for everybody, but it is by far and away the best bet for most people, based upon the available research as a whole. I would expect that many of your patients, Dr Luisi, have tried CPAP and dislike it, which is the very reason they are seeing you. I have had many patients who tried oral appliances and were unable to tolerate them or found them ineffective. I also have had many patients who tried CPAP and disliked it, swapped to an oral appliance and then wound up back on CPAP because they found the oral appliance even worse. You say that "In the real world compliance issues with CPAP make it suboptimal or useless for a large percentage of patients" but I suspect that is an anecdotal perspective because the objective research clearly bears out the effectiveness of CPAP in terms of both effectiveness AND compliance. It is certainly "suboptimal or useless" for some patients but the proportion is small rather than large. I would hate for people reading this forum to start casting their CPAP machines aside based upon your comments, thus endangering their health, just as I would not suggest that they throw away their oral appliances which have been demonstrated effective.

The bottom line is that the best treatment is the one which achieves the best outcome for the patient, whatever that may be. There is no one-size-fits-all approach. Every person is an individual and must be treated as such. Only by everyone involved investing the time required to meet the needs of each individual patient will the best results be achieved.

All I can say is that is SOME cases the people who do do the test do also make money from selling the treatment, both in Australia and the US. That is not the case where I work as we don't charge for anything, which is nice because my only interest is in helping people not making money. However it is a BIG problem in the industry that a number of service providers that perform sleep studies have a vested financial interest in the outcome. I see the effects of money-centred healthcare all the time and it bothers me a lot. People who need CPAP therapy should be able to trust that the advice they get from doctors and techs is given in the best interest of the patient, rather than a desire to make more money. This is why it is important to educate yourself and be involved in your therapy, because YOU need to be the judge of whether you are being given the right advice or not.

Have you tried a full face mask? It would seem to be the simplest option.

What your data is telling me is that your breathing is good and you use your CPAP well every night. Good job. It also says that you only have a large leak 1% of the time, however, I happen to know that there threshold for a leak to register as large leak on your particular machine is quite high, and even though your leak may not be high enough to count as "large leak" it may well still be enough to be waking you. Are you aware of any leaks? Is your mask especially uncomfortable?

The difference between lying on your back and front is quite unusual. If you have tried both in the last month it has had no effect on your AHI which, as I referred to before, is very low. It is probably worth while practising sleeping on your back as it can only help. Just keep and eye on your AHI and make sure it doesn't go up much if you are spending more time on your back.

I just realised that I missed a question on your original post "is there a better machine out there that can sense I am awake and will automatically lowers the pressure?". To answer the first part, all CPAP machines are the same in regard to how well they treat your OSA. All that separates them is the secondary features. On that note, the answer to the second part of your questions is yes, there is a machine that senses when you are awake and automatically drops the pressure for you. The Icon series CPAP machines from Fisher & Paykel, and their new Sleep Style range, both have a feature called Sense Awake which does exactly that. If it thinks you have woken it will automatically drop the pressure back to a pre set level. I have seen it work very well and I have seen instances where it gets thoroughly confused and fails utterly (activating 30 or more times/night when it shouldn't be). It would be far cheaper to try getting used to sleeping on your back as much as possible before shelling out on a new machine.

Out of curiosity, do you know if you have C-Flex turned on?

The primary fitting landmark for an Amara View is how far out the tip of your nose is from your face (the length of your nose if you like). The size of the rest of you is mostly irrelevant. So you may well find that a small fits you well, even if you are a large fellow.