(12-06-2012, 11:07 AM)aehjr Wrote: 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."
(12-08-2012, 08:17 PM)aehjr Wrote: 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.
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,