[Diagnosis] Help Interpreting Data

[aehjr]

Good morning,
Was hoping someone here can help me understand the data I'm seeing. Unfortunately, I did not run the CPAP for a few days before making a pressure setting change so I don't know how much variation occurs normally.

On 12/3, I changed the settings on my CPAP so I could see the system leaks and AHI info. I also changed my pressure setting from 6.0 cm to 6.5 cm/H2O.
Here are the settings:
Date - 7 day AHI -30 day AHI
12/3 - 6.4 - 9.1
12/4 - 7.6 - 8.9
12/5 - 8.4 - 8.8
12/6 - 8.4 - 8.8

System Leak 37.0(7 day) - 31(30 day)

A couple of things don't make sense to me. Between 12/3 and 12/4, the 7 day average went up while the 30 day average went down. I did the math and the numbers don't work. The increase to 7.6 on Tuesday would mean an AHI that night of 14+ while the 30 day average decrease would have required a drop in AHI to about 4.

The leak numbers seem crazy; I've checked and rechecked the mask. No leaks around the seal. The only air "leaking" is the vent in the CPAP hose. Is this a measurement of how much air is bleeding off through the mask vent?

As an additional data point, my wife said I was sleeping on my back last night (after foot surgery and haven taken a pain killer) and she said I was "gurgling like crazy."

My machine is a 2008 vintage Respironics so SleepyHead is not an option. Would appreciate any insight anyone could provide.

Thanks

[PaulaO2]

First, you've only had the change for a handful of days. You need much more before things settle down and you can see if anything helped or hindered.

You can only see the averages, not the AHI for that day?

As for the leaks, is that total leak or leak over intentional? Intentional leak is that air you mentioned that comes out the exhaust port. You'll need to know you mask's intentional leak (usually found on the manufacturer's website). And leaks can happen while you sleep, not just when you are checking. A pillow can push against it and move it just enough to slightly break the seal. Or you move onto your back and the hose pull the mask.

The gurgling might have been water in the hose (rainout).

[aehjr]

You can only see the averages, not the AHI for that day?

As for the leaks, is that total leak or leak over intentional? Intentional leak is that air you mentioned that comes out the exhaust port.

The gurgling might have been water in the hose (rainout).

Thanks, Paula. My larger issue with the data was that one was going up while the other was going down. I knew that the numbers won't have settled out in three days. If at the end of a week of monitoring the numbers, my AHI is still higher than it was when I made the pressure change, should I drop the pressure back to 6.0? Or should I try going up another increment? I have scheduled an appointment next week with a pulmonology specialist who is also board certified in sleep medicine. Going to shoot for replacement of my nearly five year old RemStar ProM with a ResMed S9 AutoSet unit so the issues with understanding my Respironics data may become a moot point.

I cannot see the daily data; just the 7 and 30 day averages.

I found the intentional leak data on the Respironics web site as you described. The intentional leak should be around 20 so the unintentional leak is around 17. What s a "reasonable" unintentional leak figure? I find myself adjusting the mask in my sleep but I didn't think I was doing it too often each night.

[zonk]

What s a "reasonable" unintentional leak figure? I find myself adjusting the mask in my sleep but I didn't think I was doing it too often each night.

its more likely after 5 years pressure need to be adjusted and would guess your doctor might refer you for a sleep study
some people get higher AHI in supine position than sleeping on their sides

for ResMed machines acceptable unintentional leak around 24 L/min but lower is better
leaks should be not a problem for you at such low pressure ... how long since cushion been replaced
unintentional leak made up of mask leak and mouth leak ... a chinstrap would helps if you suspect some mouth leak

[aehjr]

Thanks. The cushion and mask are new. They have only been in use since Monday (three nights).

I don't wake up with dry mouth and my wife has never mentioned the mouth issue but I'll check that.

[aehjr]

On 12/3, I changed the settings on my CPAP so I could see the system leaks and AHI info. I also changed my pressure setting from 6.0 cm to 6.5 cm/H2O.
Here are the settings:
Date - 7 day AHI -30 day AHI
12/3 - 6.4 - 9.1
12/4 - 7.6 - 8.9
12/5 - 8.4 - 8.8
12/6 - 8.4 - 8.8

My AHI keeps going up. On 12/7, I reset the pressure back to 6.0 cm/ H2O (original pressure).
12/7 - 10.6 (7 day average)
12/8 - 12.0

Thankfully, I have an appointment with a pulmonologist on Friday. Any thoughts as to what might be going on to cause my AHI to keep going up? Mask leak numbers are consistent through the period. I'm averaging 9+ hours of sleep per day and don't feel terrible but also don't feel particularly rested.

[PaulaO2]

Stop changing the pressure setting.

If you want to make changes, go ahead. But do so knowing you will need to wait a long time between changes. For one, no two nights are the same. For two, your body and brain need time to adjust. Make a change, wait a week or more, then look at the data as a whole.

[zonk]

Hi aehjr ... Good luck with the doc appointment
everyone is different. at times feel like crap even with good numbers and other times feel fantastic with not so good numbers
play with exhalation pressure relief (Flex) see if it makes any difference
some people seem do better set off and vice versa
as you don,t use any software, you don,t have any idea if any events flagged while you were awake or duration of events

[aehjr]

Stop changing the pressure setting.

If you want to make changes, go ahead. But do so knowing you will need to wait a long time between changes. For one, no two nights are the same. For two, your body and brain need time to adjust. Make a change, wait a week or more, then look at the data as a whole.

Paula - Understand no two nights are the same but is it normal for 7-day averages of AHI to double in six days? Is that much variation normal?

[vsheline]

Good morning,
Was hoping someone here can help me understand the data I'm seeing. Unfortunately, I did not run the CPAP for a few days before making a pressure setting change so I don't know how much variation occurs normally.

On 12/3, I changed the settings on my CPAP so I could see the system leaks and AHI info. I also changed my pressure setting from 6.0 cm to 6.5 cm/H2O.
Here are the settings:
Date - 7 day AHI -30 day AHI
12/3 - 6.4 - 9.1
12/4 - 7.6 - 8.9
12/5 - 8.4 - 8.8
12/6 - 8.4 - 8.8

System Leak 37.0(7 day) - 31(30 day)

A couple of things don't make sense to me. Between 12/3 and 12/4, the 7 day average went up while the 30 day average went down. I did the math and the numbers don't work. The increase to 7.6 on Tuesday would mean an AHI that night of 14+ while the 30 day average decrease would have required a drop in AHI to about 4.

The leak numbers seem crazy; I've checked and rechecked the mask. No leaks around the seal. The only air "leaking" is the vent in the CPAP hose. Is this a measurement of how much air is bleeding off through the mask vent?

As an additional data point, my wife said I was sleeping on my back last night (after foot surgery and haven taken a pain killer) and she said I was "gurgling like crazy."

My AHI keeps going up. On 12/7, I reset the pressure back to 6.0 cm/ H2O (original pressure).
12/7 - 10.6 (7 day average)
12/8 - 12.0

Thankfully, I have an appointment with a pulmonologist on Friday. Any thoughts as to what might be going on to cause my AHI to keep going up? Mask leak numbers are consistent through the period. I'm averaging 9+ hours of sleep per day and don't feel terrible but also don't feel particularly rested.

Hi aehjr,

Welcome to the forum!!

I am not familiar with Respironics reports. Do you know whether System Leak is an average for 1 night, or the max or 95 percentile for one night, or what?

Regarding what may be making your 7 day average AHI continue to get worse, if lately you have been sleeping more often on your back, that could explain it. Maybe when sleeping on your back you need more than 6.5 cm H2O.

Also, your pain medication may be making your AHI worse.

The pressure we need to stop obstructive apneas can change a lot with position and with medication and with when and what we eat before going to bed. Even if we have an Auto PAP machine, the AHI will fluxuate day to day, and it is more likely to fluxuate when we only have a non-Auto CPAP machine, especially if we start sleeping on our back more than before, or if we have a change in medication.

You asked about the changes in average AHI between 12/3 and 12/4.

The increase of 1.2 in the 7-day average means the AHI on 12/4 was 1.2x7=8.4 higher than the AHI on the one day a week earlier which dropped out of the 7-day window.

The decrease of 0.2 in the 30-day average means the AHI on 12/4 was 0.2x30=6 lower than the AHI on the one day a month earlier which dropped out of the 30-day window.

Both of these things could have happened. They do not neccessarily contradict each other. Your AHI might have been changing quite a lot from one day to the next, but because your machine hides the daily AHI from you (so you won't over-react to daily fluxuations, I guess), you only see long term averages and it may seem unreasonable for the AHI on 12/4 to be 8.4 worse than one night a week earlier while also being 6 better than one night a month earlier, but this might easily have been the case, especially if your pressure is too low.

Let us know how you are doing, and what your doc says.

Take good care of yourself,
--- Vaughn