Where A CPAP Newbie Should Start

I'm just past my first year, this is what I've learned. Knowledge is power.

It is the same as without knowledge you don't have a power.

Where to start? If you are here reading and doing your homework, you are there.
Additionally I would say,
---When you schedule the appointment for your titration, asks if you can get a copy of the initial sleep study. It will be the Dr's report and plenty of info for you at that point.
---When the sleep clinic calls you and asks where to fax your prescription....
Tell them that you will pick it up. It will include both sleep studies and your script.
--- Pick it up and go to your local library and make 2 copies of the whole thing. You keep the original and a copy to scribble on... because you will.
Hand carry the other copy to shop for a DME. They don't need the original, they would have taken a fax.
You can do this over the phone but having the script is like holding the checkbook.
Ask them what they can do for you, or tell them what you want...
When they say... "But your prescription only says....." You say, who do I need to call, my Ins company or the sleep doc? Just be prepared to wait if that's what it takes. I doubt that it will, or you may have another DME in line to want your business..

I tried to use 2 local DME's. One tried to snow me and the other was talking about scheduling appointments, ordering equipment, 2 weeks... bla bla bla. I went into an Apria office that was most convenient for me, and they were the most knowledgeable and helpful and had me on the machine I wanted in 3 days. Keep in mind that everybody in business, is in it to make money. Corporate drives their train. They have jobs. I'm glad I have a national DME in case I had issues while traveling. It's a personal thing. But you don't have to pick one before you get your script in your hand.

I got a new CPAP and this one tells me every morning how long time I used it last night and the AHI. But I don't understand the numbers. Last night it was used for 5.6 hours and AHI=0.3. How is it possible to get an AHI of 0.3?

Let's see now... If you had 2 machine scored apneas in 5.6 hours, and the machine rounds things off, you would end up with an average of 0.3 per hour.

HoseCrusher wrote:Let's see now... If you had 2 machine scored apneas in 5.6 hours, and the machine rounds things off, you would end up with an average of 0.3 per hour.

2/5.6 = 0.4 if you round it off and 1/5.6 = 0.2 so 0.3 should be an impossible value.

Actually 2/5.6 = 0.3571428. By "rounding" in this case they simply dropped the additional decimal places.

HoseCrusher wrote:Actually 2/5.6 = 0.3571428. By "rounding" in this case they simply dropped the additional decimal places.

Yes, that would be possible that the machine is programmed to truncate instead of round off and just keep the first decimal. But 3 nights ago I had used it for 6.0 hours and a AHI of 0.4. That was when I first start to think that something was wrong because 2/6 = 1/3 = 0.33333... and that will be 0.3 both if you round it off and if you truncate. And 3/6 = 1/2 = 0.5. So the observed AHI of 0.4 is also an impssosible result and I thougt maybe I was wrong about the definition of AHI. So I started to look for a defintion and found this discussion and thought maybe someone could explain the strange number.

Ah yes, truncate is a much better description than rounding. Sorry for any confusion.

You are forcing me to exercise my gray matter, but how about this...

What happens if the machine figures in minutes and reports in hours.

Initially, you have 5.6 hours = 336 minutes. If you had 100 apnea/hypopnea events during that time, you would end up with 100/336 = 0.297619 as an AHI, which rounded up would be 0.3.

In the second case you have 6 hours = 360 minutes. If you had 144 apnea/hypopnea events during that time you would end up with 144/360 = 0.4, with no rounding needed.

What do you think about that?

HoseCrusher wrote:Ah yes, truncate is a much better description than rounding. Sorry for any confusion.

You are forcing me to exercise my gray matter, but how about this...

What happens if the machine figures in minutes and reports in hours.

Initially, you have 5.6 hours = 336 minutes. If you had 100 apnea/hypopnea events during that time, you would end up with 100/336 = 0.297619 as an AHI, which rounded up would be 0.3.

In the second case you have 6 hours = 360 minutes. If you had 144 apnea/hypopnea events during that time you would end up with 144/360 = 0.4, with no rounding needed.

What do you think about that?

Thank you for spending time on my math. I am sure that AHI is per hour, not per minute. But I think the truncation is the solution to the problem.

1) 2/5.6 truncated gives 0.3
2) 6.0 hours means more than 5.95 and less than 6.05 if rounded off, and at least 6.0 and less than 6.1 if truncated. So assume 3 apnea/hypopnea and acutual time 6.02 (shown as 6.0 rounded off or truncated), then 3/6.02 = 0.4983.... and then it is truncated to 0.4.

I guess it should be enough that the CPAP helps me sleep well, but when someone programmed it to give me this information every morning I like to understand what the numbers tell me and how many apnea/hypopnea I had.

So if not anybody else have a better solution I think we can assume that it truncate the AHI (and maybe also the the time).

Have a nice sleep.

You are correct. AHI is give per hour.

I got the idea of playing with minutes by reviewing my sleep study information. They seem to record everything in minutes, then translate that to an AHI.

I am actually surprised that the minute calculations worked out as well as they did. Oh well, it looks like your approach is more realistic and the numbers seem to fit.

I hope you have 99.85273 years of restful sleep, and you can either round or truncate as you see fit...

thanks, that helped me a lot!
regards,
chantal

Please could someone tell me what a DME is? NB: I am in New Zealand

Mask2fit wrote:Please could someone tell me what a DME is? NB: I am in New Zealand

Durable Medical Equipment

DME used here is in reference to someone who operates a business that sells durable medical equipment.

Thanks so much, it makes so many posts more comprehensible. What a strange thing though.

Thanks for the information. Im very new to the whole cpap thing(but not new to heavy snoring, since I was told I did it from infancy) So I think initally Ill be doing more reading than replying.