Can AHI be 0?

The following was my last night record:

AHI 0, Usage 4 hours, Mask fit 100%

(My 14-Day Average AHI 1.5, Usage 8.37 hours, Mask Fit 100%)

Can you explain to me why my AHI 0? Can AHI be 0?

Hi Wong,

Yes, if you don't have any Apneas or Hypopneas during your time on the machine, the reading will be zero. I've had nights like that.

If it becomes a pattern several days in a row, you are either doing great (congrats!!) or your machine is "stuck" (I've heard this about S9 machines) and needs to be unplugged briefly, then plugged back in to reboot.

--SleepyCPAP

Wong wrote:The following was my last night record:

AHI 0, Usage 4 hours, Mask fit 100%

(My 14-Day Average AHI 1.5, Usage 8.37 hours, Mask Fit 100%)

Can you explain to me why my AHI 0? Can AHI be 0?

Hi Wong,

It is definitely possible.

However, have you downloaded sleepyhead software because if not, you might want to use the link in my signature to do so. Having it would enable you to make sure you don't have excessive leaks that could have caused the 0 AHI because when that happens, the machine can't accurately evaluate whether you are experiencing any apneas/hypopneas. As a result, the AHI of 0 might be a deceptive figure.

49er

If SleepyHead software is to be believed, then the answer is absolutely yes. I "pitch a perfect game" approximately 25-30% of nights.

RobertS975 wrote:If SleepyHead software is to be believed, then the answer is absolutely yes. I "pitch a perfect game" approximately 25-30% of nights.

SleepyHead just reports what the machine gathers and reports.
ResScan software from ResMed does the same thing...reports what the machine reports.
The software doesn't do the evaluation...the machine does.

That said....there has been a history of a few S9 machines getting "stuck" on reporting 0.0 AHI or leak or whatever...night after night a person sees 0.0 and while that is not totally impossible to have happen it does sort of make someone raise their eyebrows a bit. To "unstick" the S9s we just tell people to unplug the machine from the electric source for a couple minutes and then plug back in. This forces the machine's internal software to reboot sort of like when we have to reboot a computer to clear out some funky cobwebs.
It is something that can be done that doesn't hurt a thing to do and sometimes is needed.

I have had it happen on a couple of occasions with my S9 machine. While I often have really low AHIs and a lot of 0.0s.....It would be unusual for me to have a week of 0.0 all in a row.

When someone has AHI of 0.0 I hate to rain on their parade and tell them it might not be true so I don't usually say anything until they report several days in a row with 0.0 because then I wonder if the S9 is "stuck".

While this behavior is known with the S9 machines I do not know if the same sort of thing might happen with the new AirSense models. I haven't heard of it yet though.

Interesting points, Pugsy. I assume that my "perfect nights" are real... never get more than 2 or 3 in a row at most, and even when not perfect, my AHI numbers are quite low. One thing that I have noticed is that if I lie there awake for any length of time with the CPAP on and running, there is a higher incidence of events in that situation. I have posted about this phenomenon previously in a separate thread.

Almost without exceptions, any events recorded are either hypopnea or central apnea. But like I said, since starting CPAP in Feb 2014, the numbers have been excellent. And since I starting using the P10, the overall AHI is minuscule and there are frequent perfect nights.

I get an "0" 2 or 3 times a month. It ain't stuck. Sheriff

I average "a few" in most months. Not every month and some months are more than others. I think the most I've had in any calendar month so far this year is seven. Many, many nights were just "close" ( like 0.1 ).


Den

.

My average for the last 6 months has been 0.6. I am a happy camper!

When I have a horrible night's sleep (which is most nights), I usually have an AHI of 0.0, probably because I didn't sleep well; i.e., mask leaking into face, straps too tight, too loose, air coming out of my pursed lips, and hence, did not have any sleep apneas. I guess I need to sleep to get sleep apnea.

Wong wrote:The following was my last night record:

AHI 0, Usage 4 hours, Mask fit 100%

(My 14-Day Average AHI 1.5, Usage 8.37 hours, Mask Fit 100%)

Can you explain to me why my AHI 0? Can AHI be 0?

I would think the 100% mask fit is more unlikely than the AHI=0. Both of them together is suspicious.

On a slight tangent: Only four hours? Why?
If you need to show compliance, remember that 4 on the display
just might round DOWN on the compliance report, meaning NOT ENOUGH!
Shoot for more, especially for your health and well-being.
7 or 8 hours is best for most folks.

Luthie2006 wrote:When I have a horrible night's sleep (which is most nights), I usually have an AHI of 0.0, probably because I didn't sleep well; i.e., mask leaking into face, straps too tight, too loose, air coming out of my pursed lips, and hence, did not have any sleep apneas. I guess I need to sleep to get sleep apnea.

With what you are telling us, the chances of having an AHI of 0 is very low. S9 machines have occasionally needed a reboot. Pull the plug on the machine and after a few seconds replug it. By the way...you CAN get apneas while you are awake. The machine cannot tell if you are asleep or awake.