ResMed Efficacy Results

Can anyone help me to understand the meanings of the Daily Pressure & AHI results? Are these averages for the session or peaks? Are the AI's reported actual interventions or residuals i.e. AI' s not overcome? Same questiOn for HI's?

ehreesejr wrote:Are the AI's reported actual interventions or residuals i.e. AI' s not overcome? Same questiOn for HI's?

The reported apneas and hypopneas in Efficacy results are the ones that were not prevented. They are the ones that sneaked through despite treatment.

Generally, an overall AHI of less than 5.0 (while doing "cpap" treatment) is considered effective treatment.

Using a Respironics or Puritan Bennett machine, I personally like to see my AHI be below 3.0

If I'm using a ResMed S8 machine, however, I don't worry if my total AHI is 5.0 or 6.0, as long as the Apnea Index (AI) is miniscule and the AHI is made up mostly of hypopneas (the HI number.) I mentally cut the HI number in half when using a ResMed S8 machine...but that's just me.

Each manufacturer uses their own definition of how "limited" a limited flow (our breathing) has to get before they christen it a "hypopnea" on the data. Doesn't mean that one manufacturer's machines are spotting hypopneas better (higher HI numbers) than another's. And doesn't mean that one manufacturer's machines prevent hypopneas (lower HI numbers) better than others. The difference in the "Hypopnea" numbers a person might see if switching machine brands every night is simply a reflection of the different definitions for "hypopnea" the various manufacturers use in their machines' algorithms.

My edit: Added "S8" to all my references to ResMed machines in this old post, since the definition of hypopnea was changed by ResMed in the later S9 series machines.

Thanks to RestedGal for the response. I've been on the machine since June and I feel fine but then again I never felt bad and only went to the sleep study because my wife observed the breathing cessations. My typical nubers are pressuure=12,AHI=17 and AI =2
The sleep Doc said the study said I was moderate and AHI was 12. I'm confused by the worse numbers . The Doc also said that maybe I should be on Bipap but did not have a physiological reason; only experience with improvement when adaptive did not reduce AHI. Any thoughts or suggestions are welcome.

I don't think the AHI produced by our machines can be directly compared to the AHI that comes out of a diagnostic PSG sleep study.

A sleep study uses different rules for scoring apneas and hypopneas. Oversimplifying, the sleep study's definition for a hypopnea involves a certain percentage of drop in O2 levels as well as a certain percentage of reduction in air flow before the event is scored as an "hypopnea."

Our treatment machines don't measure O2, however. Our treatment machines measure just a degree of air flow reduction for a certain amount of time, and call that an hypopnea.

What I'm getting at is that it would be like comparing apples and oranges...well, maybe more like tangerines to oranges... lol.... since a sleep study and the machines are not using the same definition for "hypopnea."

To make it even more confusing (regarding our treatment machines) one brand of autopap might call an event an hypopnea, while another brand might still label that particular amount of reduction in air flow a "flow limitation."

Another thing to consider is that the sleep study is looking for other evidence of sleep disordered breathing ... arousals. Think of arousals as getting kicked up out of whatever stage of sleep you're in, but not really waking up to an alert enough state to be aware of the disturbance.

Our machines can't see "arousals" at all. The sleep study sees them.

Arousals can be caused by apneas, hypopneas, periodic limb movements (a different kind of sleep disorder) and by something that reflects lessening air flow but that doesn't meet the sleep study definition for apnea or hypopnea... RERAs (Respiratory Effort Related Arousal.) Perhaps the throat is collapsing somewhat...enough to cause the brain to issue a micro arousal to get you breathing a little better, but without the drop in O2 tha's required to score it as an hypopnea. Bingo... a RERA... which puts another dent in your sleep architecture, messing up your sleep cycles.

I wouldn't worry about comparing your machine's AHI (especially the hypopneas reported by the machine) with the AHI that came out of your sleep study. The two are different animals...not calculated the same.

All that said, I can understand why you'd be concerned that you're getting as high an AHI while using your machine as what you got during the diagnostic sleep study. If it were me, I'd mentally cut in half the "HI" (hypopnea index) that your ResMed machine is reporting. Any time I used a ResMed machine, it recorded 2 or 3 times as many "hypopneas" as other brands of machines (Respironics, Puritan Bennett) did.

That doesn't mean one brand of machine is letting hypopneas through while another brand is preventing them. Nor does it mean that one brand is mistakenly not identifying "all" the hypopneas that sneak through, while another brand is seeing them. It's just a difference in the manufacturers' definitions of how much flow reduction (and for how long) there has to be, in order for our machines to call something an hypopnea instead of just a flow limitation. But none of our machines use the higher threshold (because of the drop in O2 requirement) that sleep labs use when they identify an event as an hypopnea.

All that said, it can always be interesting to try other machines, so if your doctor will agree to having you at least try another brand, and the DME will agree to the swap, you might want to do that. Perhaps the Respironics REMstar Auto|A-flex, or the Respironics BiPAP Auto if the doctor will prescribe a bilevel machine.

Or you might want to try just cpap mode in your current machine for awhile, with EPR turned on for pressure relief during exhalation. Your S8 Vantage has EPR available in cpap mode, but not in auto mode. You might want to try setting it for cpap mode, setting the pressure at 12 or 13, and try the EPR out at all three "relief" settings.

RestedGal, Thank you for the detailed information. This is a great help to my understanding. Could you tell me what the pressure reading means? I get between 11 and 12.5 on the daily report. By the way, I read somewhere on this site ,that the ResMed does not attempt to deal with apneas above a pressue of 10. What does that mean?

What are your settings? I have now used my new autoset II for three nights. I began to tweak my settings as soon as I got the machine - except for the first night, when I just collapsed into bed too tired to even do anything, even clean my mask (I know, shame on me). As those on this forum have said repeatedly, don't change but one thing at a time, and then look at the data the next morning. Well, I finally figured out how to find the data on this new Resmed (I had been using a m-series with c-flex before).

I first changed my min pressure to 6 (they had set it to 4). I already knew my pressure was 9, so I made sure it was set on that. I'll probably up the min to 8 soon. On the m-series that I had used for about 6 weeks, my AHI had gone up to 3.8, and I didn't know why. But my average night's usage had dipped below 3 hours. I'm trying to improve on that now. For 3 nights, I now have an average of 3.5 hours. Its still a problem for me to keep my mask on - but I will keep trying. I still have to take one Temazopam pill before bedtime.

However, this morning when I checked the data, my AHI and HI were both .5, and my AI was zero! I am amazed. My leak is .08 (ave. for 3 nights), so I must be doing something right. I am not sure what "settling" means. Maybe someone can explain that to me. My max settling is set at 30 (whatever the heck that is)

I can't believe it. I'm in love. (with this new autoset II) Now, if it would love me back and stay on my face, the mask, that is.
Good luck,
Jay

ehreesejr wrote:Thanks to RestedGal for the response. I've been on the machine since June and I feel fine but then again I never felt bad and only went to the sleep study because my wife observed the breathing cessations. My typical nubers are pressuure=12,AHI=17 and AI =2
The sleep Doc said the study said I was moderate and AHI was 12. I'm confused by the worse numbers . The Doc also said that maybe I should be on Bipap but did not have a physiological reason; only experience with improvement when adaptive did not reduce AHI. Any thoughts or suggestions are welcome.

What is the current settings on your Vantage?

AHI= Apnea/Hypopnea Index, it is the SUM of both Apnea and Hypopnea seen per hour (avg.), broken down they are:

AI=Apnea Index, number of apnea seen per hour.
HI=Hypopnea Index, number of Hypopnea seen per hour.
SUM together they are AHI index.

If your CPAP titration was 12 cm, on that machine you would set it:

Mode=AutoSet
Min Pressure=12
Max Pressure=15 or default 20

Your goal should be to first look at leak, make sure it is under control for your mask/pressure combination,
Next, increase Min pressure until AI=1 (or if you can get it lower like .8 or .6), then observe HI and get it
below 5 by fine tuning in smaller .5 cm pressure increases to Minimum pressure. Right now you could probably
bump Minimum to 13 cm and lower AI from 2 and the overall AHI seen. If AI goes up put it back to 12 cm.

Thanks for the replies. I cannot contol my pressure. The default settings are 5to 20. My leakage is typically 0.00l/s according to the LED efficacy results, The pressure last night was 12.2 ,usage was 7.5 hours and the AHI=19.5 with an AI of 1.5.
As I have said, I feel fine. However having been cardioverted from atrial fibrillation therefore I am concerned about the fact that my numbers stay up albiet the ai is only 1.5 . How would centrals show up? Does anyone know?

Packitin,
I beieve the settling number is a pediod in which only your low pressure is used for the time selected, 0-45, to allow you to move into sleep more easily. During the time set I believe that they do not account AHI.

Hello Jay,

Thanks for your post.

My name is Garrett,

I just got the Resmed Vantage Auto Set 2 and I love it, but I need to set the unit at one specific pressure number on one particular day. How do I do that. My supplier sent me the Rescan Data card. When I insert it, I go to menu on the display, but only get USAGE and MASK TYPE and some other option. Could you tell me specifically what I need to do to set minimum and maximum air pressures. Please e-mail me at garrettcoan@gmail.com or, better yet, give me a quick call on my cell phone which is 201-303-4303.

Thanks so much.

I really appreciate it,
Garrett

packitin wrote:What are your settings? I have now used my new autoset II for three nights. I began to tweak my settings as soon as I got the machine - except for the first night, when I just collapsed into bed too tired to even do anything, even clean my mask (I know, shame on me). As those on this forum have said repeatedly, don't change but one thing at a time, and then look at the data the next morning. Well, I finally figured out how to find the data on this new Resmed (I had been using a m-series with c-flex before).

I first changed my min pressure to 6 (they had set it to 4). I already knew my pressure was 9, so I made sure it was set on that. I'll probably up the min to 8 soon. On the m-series that I had used for about 6 weeks, my AHI had gone up to 3.8, and I didn't know why. But my average night's usage had dipped below 3 hours. I'm trying to improve on that now. For 3 nights, I now have an average of 3.5 hours. Its still a problem for me to keep my mask on - but I will keep trying. I still have to take one Temazopam pill before bedtime.

However, this morning when I checked the data, my AHI and HI were both .5, and my AI was zero! I am amazed. My leak is .08 (ave. for 3 nights), so I must be doing something right. I am not sure what "settling" means. Maybe someone can explain that to me. My max settling is set at 30 (whatever the heck that is)

I can't believe it. I'm in love. (with this new autoset II) Now, if it would love me back and stay on my face, the mask, that is.
Good luck,
Jay

Garrett, to avoid having to post your e-mail address and/or cell phone number or other personal information publicly in this forum go to the top left of the page and click on User Control Panel. Then click on Profile. Fill in as much as you want to. Save it. Return to User Control Panel, click on Edit Equipment and fill in that information so you don't have to keep repeating yourself and we don't have to keep asking what device or mask you are using, select Text and Submit. Return to User Control Panel, click on Board Preferences, select allowing others to send you an e-mail and/or Private Messages. The PMs are excellent for sharing your e-mail address or phone privately w/just selected individuals. You can send others PMs by looking at the bottom of their posts to see if the PM avatar is there and if so clicking on it. Or by checking their Profile and clicking on PM Me if they have allowed that option.

If you are going to change your therapy settings you should only make ONE change at a time and STAY at that one change for a full 7 nights before deciding, based on the week's accumulated data, what ONE more change you want to make. Make NO MORE than one change at a time, whether therapy setting or mask change, before making any ONE other change at which you would also stay one full week BEFORE making any one other change. One night's data just does NOT tell the entire story. We do not necessarily sleep the same each night.

With the Resmeds you should make sure that you are using the correct Mask Selection in order to have reliable data. If you are using other than a Resmed mask then the Mask Selection should be set to Standard. With the Standard Mask selection the Resmeds automatically substract .4 L/s or 24 L/M from the Reported Leak Rate and you must then do the math yourself based on what the allowed vent rate for the mask you are using is for your set Pressure. You can find that table in your mask's literature. If you are using a Resmed mask and have selected the correct Mask Selection your Resmed will do the math for you and report the correct Leak rate.