AHI is 0.0 on a ResMed S9 AutoSet with EPR

[infntyx2]

As a recently diganosed OSA sufferer and ResMed S9 AutoSet user, I've just set the Sleep Quality to ON to get a little more info displayed. I was surprised to see that last night resulted in the following: Leak 22.8L/min, AHI 0.0, Total AI 0.0, Central AI 0.0. I was expecting to see numbers other than 0. Is this possible to get 0's or is something not right? I've only had Sleep Quality set to ON for a couple days. The readings for the week were: Leak 10.8L/min, AHI .1, Total AI .1, Central AI 0.0. When I had gone through the sleep clinic I was told during light sleep I was light to Moderate, 12-16 events/hour, and during REM I was Servere, 73 events/hour. Is it possible to get an AHI of 0.0 under normal circumstances?

[PST]

Yes, it is possible for some people to get an AHI of 0.0 under normal circumstances. I've never done it myself, but others have. Great success story. Don't worry if you don't do it every night.

[DreamOn]

Yes, 0.0 AHI is possible. I've been using my S9 Autoset for 28 days now, and I've had two 0.0 AHI nights. I've had six nights that were 0.1 AHI, and all nights have been less than 1.0 AHI. I've only had one obstructive apnea in 28 days too.

Your Leak Rate, at 22.8 L/min is quite high. On the ResMed machines, a Leak Rate above 24.0 L/min is the level where your therapy can be affected, as the machine can't compensate for leaks above that level. AHI may also be inaccurate when the leak rate exceeds that level. With the ResMed machines, there is a Mask setting on the machine. When that's set correctly, a zero leak rate is "ideal". If you're using the Swift FX mask, the Mask setting should be "Pillows."

You're probably losing therapy air from your mouth, perhaps when you're deep asleep (we don't always wake up). If your mouth is dry in the morning, that's one clue of mouth-leaking. You may want to try another size of nasal pillows, in case yours aren't fitting well. Some of us need to sleep close to the edge of the bed pillow, with face hanging off, so the nasal pillows don't get displaced. They make special bed pillows too. You could try a chin strap and/or mouth-taping, but you may need to consider a full-face mask if the excessive leaks continue to be a problem. Make sure your hose doesn't have any holes and the connections are good too.

[infntyx2]

Thanks DreamOn... I haven't been a back sleeper in years. Based on the doc's two cents, I was under the impression that I was a side-sleeper and ultimately a stomach sleeper in order to breath (breathing as the result of gravity). I haven't had tonsils or adenoids since I was 5 but the doc said I was at high risk due to a larger toungue and small soft pallete. I hate sleeping on my stomach; it just became typical in the past few years. I know I started feeling sleep deprived at least 1.5 to 2 years ago. Anyway... I think the leaking is occurring as I turn my head to the side at night and the nasal pillows shift, leak, and wake me up until I adjust it. I'm using a medium set of nasal pillow which seem to fit fine if I just sleep on my back. My respiratory therapist said that I should start on my side at night if that's my intent. That way its fitting well before I catch some Zzzz's. I don't know... I'm still a newbie so I guess I need to gain some experience. On the bright side (in one week), I am feeling much less tired, have no sleep headaches, and feel much less lethargic (especially in the early morning and late afternoon).

[DreamOn]

It's wonderful that you're feeling better during the day! That's what matters most. And your AHI results are excellent too. Just thought I'd mention about the leak rate, since that night you cited it was pretty high. Mouth-leaking can sneak up on you, so watch for that. It wasn't a problem for me during the first few weeks. I think it began when I started sleeping more deeply. I would hear the air escaping occasionally, but most of the time I slept through it. I started getting dry mouth.

There are some good threads regarding the Swift FX. This one may have a few tips that'll help you: viewtopic.php?f=1&t=53011. I think that headgear adjustment is especially important.

I have positional apnea -- many more apneas when I sleep on my back. A lot of people do. The tongue tends to fall back in that position, which can block the airway. The mouth also tends to open more in the supine position, which allows therapy air to escape. So I do try to sleep on my side. I usually use nasal pillows or nasal mask with a chin strap.

It does take a while to get used to this new way of sleeping. Sounds like you're off to a great start though!

[torontoCPAPguy]

I had a median leak rate of 0.0 last night and a max of 22.8 as well .... and you need to check out the graph! I took a look and the max leak rate was at 5:45 a.m. approximately; when I awoke and removed the mask before turning off the blower! The rest of the night shows zip.

Apnea index of 0.1 and AHI of 0.6 and when I look at the graphs... it all happens around the time I wake up at 5:45 a.m. I think it has to do with my taking off the mask. Or in the alternative it may be the cause for me waking up early. I don't know. But it seems to be a regular thing time wise.

More later. Stay tuned. Or tooned.

[Physician]

With my S9, my AHI = 0.0 to 0.1

[torontoCPAPguy]

Now I'm curious as heck. Is it me taking the mask off before shutting down the blower? Or is it the 'event' waking me up and I then take the mask off? This AM I am going to turn the blower off before removing the mask. Comments?

[DreamOn]

I always turn off the blower before removing my mask.

[jabman]

With my S9, my leek rate has been between 3.00 - 7.00 L/m. My AHI's are between 1.00-3.00 never going much higher then 3.00. (I have to double check that number).
I shut my machine off before taking the mask off.

[Roman Hokie]

I always turn off the blower before removing my mask.

Me, too. Not that taking off the mask first should affect much on the ResMed. That's the advantage of having leak rate measured at 95 percentile.

Figure if you sleep 480 minutes (8 hours) a night, then 95th percentile means that 24 minutes the leak was above the reported leak rate. Taking your mask off before hitting the switch (or using SmartOn/Off like I do) won't affect your reported leak rate.

Now... if we were on machines that report "average" or "mean" leak rates, then removing the mask before shutting off the flow will alter the reported numbers.