Same leak rate, different AHI. Why?

tony22 · Post by **tony22** » Tue Jun 24, 2008 11:19 am

This morning I looked at my data and saw a total AHI of 16 with a leak rate of .10L/s. The previous night it was around 5 with the same leak rate. Additionally, to me the feeling of the Liberty throughout the evening's sleep was the same.

What factors come into play affecting the AHI if the leak rate - and the flow rate (which was also identical on both evenings) - don't change from one night to the next?

Hawthorne · Post by **Hawthorne** » Tue Jun 24, 2008 1:41 pm

Your profile says you have software. Did you get this information from the machine display or the software info on your computer? The AHI is the sum of the apneas and hypoapneas you had during the night. That is affected by leaks, snores, etc, but they not counted in the AHI number. It's just apneas and hypoapneas. This would appear when you downloaded your card. It looks like you have a Resmed so it does score hypoapneas more, I am told. That 16 was probably mostly hypoapneas. Many things can change our numbers, not just leaks and snores. You may have had a restless night. You may have eaten or drunk something yesterday that changed things. You may have been stressed about something. You may have been overtired. It happens to all of us once in a while (sleep apnea or not). There will be bad nights. You may not really know it but your data will show it. If you didn't change any settings or anything, tonight will be close to where you were the nights before last. If, after a few days (3 or4 or more-like a week), it is still high, you need to tell your doctor or DME or change your settings (if you dothat yourself) since they may not be right for you.

Slinky · Post by **Slinky** » Tue Jun 24, 2008 3:12 pm

Not necessarily! It might not indicate a need for a change in therapy settings. It might instead indicate something physically going on w/you. Some congestion, sinus irritatation, allergy, digestive upset, stress, sore abused muscles, arthritis, etc., etc. that is not just a one night or couple night happening.

Hawthorne · Post by **Hawthorne** » Tue Jun 24, 2008 3:46 pm

I think I said something similar in my posting, Slinky. I suggested a number of things it could be- you suggested a few more. ONLY after suggesting possible other causes, did I suggested a possible change in therapy and did say, ONLY if it continues like this for a while.

tony22 · Post by **tony22** » Tue Jun 24, 2008 4:44 pm

Hawthorne wrote:Your profile says you have software. Did you get this information from the machine display or the software info on your computer?

H, I haven't downloaded the card yet. This is from the readings on the Resmed display.

Slinky wrote:Not necessarily! It might not indicate a need for a change in therapy settings. It might instead indicate something physically going on w/you. Some congestion, sinus irritatation, allergy, digestive upset, stress, sore abused muscles, arthritis, etc., etc. that is not just a one night or couple night happening.

Hmm, well. If I had to say anything about last night it's that I did in fact feel a little sore in my right shoulder. That may have caused irregular movement in bed that I didn't have the previous night. Ah, the joys of getting old !

Slinky · Post by **Slinky** » Tue Jun 24, 2008 4:45 pm

I stand corrected, Hawthorne.

Hawthorne · Post by **Hawthorne** » Tue Jun 24, 2008 7:17 pm

Your shoulder bothering you may well have been the problem. As Slinky and I said, pain and many other things can do that to your data numbers. I have Rheumatoid Arthritis and it can affect my data on nights when it's bothering me. I'm sleeping but it's not a good sleep when that happens and my data shows it. As Slinky said, it may not mean there is a need to change your therapy settings. Only time will tell you that.
When you download your card, you will see about your apneas and hypoapneas but it was probably something that will not happen tonight. That is, unless your shoulder is acting up again!! It's going to happen once in a while for various reasons. The Resmed does detect more hypoapneas than other machines and they are not as bad as apneas. Their like part apneas.
You're right "the joys of getting old!!!!!!"
Have a good one tonight!

Nosey · Post by **Nosey** » Tue Jun 24, 2008 7:38 pm

Interesting thread as my wife and I came home last night and there was no power until 3am and I was only able to use CPAP for 3 hours before starting the daily grind. Didn't sleep well even with the mask and found that although my leak was low (0.22L/s), my AHI was 27 (has been 3-6 the past 2 weeks)...no rhyme or reason I can find for the numbers. Mask seemed to fit fine...but sleep was bad. One issue was the constant occasional chirpping or our fire alarms (power had gone out and the batteries were low). I'll see what tonight brings and report if there is an additional outlier night.

Nosey · Post by **Nosey** » Sun Jun 29, 2008 9:42 am

Grrrrr......had one night where my AHI was high, the next few nights were fine (AHI=5-7) and then last night I had an AHI of 20. Seemed to me that there was not much leaking (had data confirmation) and that overall, there was not much pressure built up in the mask and only heard air coming from the machine upon inhaling. Definitely need a breakdown of the numbers via computer (am currently only getting summary nightly numbers). Also, kind of odd but think the AHI number is high only with the FF (Quattro) but not the nasal. Frustrating. One weekend of bad sleep..

Slinky · Post by **Slinky** » Sun Jun 29, 2008 10:14 am

When you change masks are you changing the Mask Selection? That can make SOME difference but NOT that much.

Snoredog · Post by **Snoredog** » Sun Jun 29, 2008 1:02 pm

tony22 wrote:
Hawthorne wrote:Your profile says you have software. Did you get this information from the machine display or the software info on your computer?
H, I haven't downloaded the card yet. This is from the readings on the Resmed display.

Slinky wrote:Not necessarily! It might not indicate a need for a change in therapy settings. It might instead indicate something physically going on w/you. Some congestion, sinus irritatation, allergy, digestive upset, stress, sore abused muscles, arthritis, etc., etc. that is not just a one night or couple night happening.
Hmm, well. If I had to say anything about last night it's that I did in fact feel a little sore in my right shoulder. That may have caused irregular movement in bed that I didn't have the previous night. Ah, the joys of getting old !

Nosey · Post by **Nosey** » Sun Jun 29, 2008 1:04 pm

Slinky,

I always change the meask selection for the machine when changing masks but thanks for the suggestion as one possible problem. I think I'll need to wait for the ability to analyze the data in detail (still awaiting purchase approval for ResScan 3.5 software....the only way Resmed says they will give it out (need software that is Vista compatible).

Best,

Richard

Slinky · Post by **Slinky** » Sun Jun 29, 2008 2:42 pm

Try SnoreDog's suggestion. He can be a pretty savvy ole dog - on occasion.

Nosey · Post by **Nosey** » Sun Jun 29, 2008 4:52 pm

Slinky,

Had not even seen Snoredog's earlier post. Much thanks! I'm obviously not paying enough attention..

My high AHI scores are mainly from HI.

Friday- 0.18 L/S, 21 AHI, 1.5 AI and 19.5 HI

Last night- 0.12 L/S, 13.7 AHI, A! 2.2, HI 11.5 (the numbers were higher at 4am and then went down when I switched from the FF Quattro to Optilite. I assume that the use of allergy medication may have contributed to the high HI score last night.

I am supposed to set up an appointment with the doc soon. My guess is she may up the pressure a tad (am currently at 8cm). Is it safe to assume she won't put me on a different machine (would hate to finally get the software only to be switched to something else).

Best,

Richard

Slinky · Post by **Slinky** » Sun Jun 29, 2008 5:31 pm

Not likely that she would switch you to another brand of xPAP given that would mean the purchase of another integrated humidifier. That's not to say she might not switch you to a Resmed autoPAP or Resmed bi-level but they'd be good to go w/the same software as your Elite so no sweat. Don't misunderstand, I know of no reason why she would switch you from the Elite either. I'm just saying IF she did decide to switch you to another type of xPAP, it would most likely still be a Resmed to avoid having to purchase another integrated humidifier.

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