(04-21-2013, 11:21 AM)tekis Wrote: I just got the SD card in a couple nights ago. Should I wait for more data to be collected? Seems like it's still too early to tell anything. Though my AHI was 3.0 (for 3 hours...). Thanks.
(04-21-2013, 12:40 PM)Sleepster Wrote: The only other thing you need to pay attention to is your leak rate. If you have an acceptable leak rate and an acceptable AHI then that's the limit of what your data can do to help you with your therapy. The rest is up to you.
I suggest also keeping an eye on the length of time your events are lasting and on the breakdown of the Obstructive Apnea Index (OAI = average number of OA events per hour) versus the Central Apnea Index (CAI = average number of CA events per hour).
Your Apnea Hypopnea Index (AHI = average number of apneas per hour plus average number of hypopneas per hour) is the sum of your OAI plus CAI plus the averages per hour of unknown type apneas and hypopneas:
AHI = OAI + CAI + UAI + HI
All these numbers will fluxuate greatly from one night to the next, so it is important to pay attention only to the average over a week or month.
much of your AHI is made up of CAI, please keep in mind it is not unusual for the CAI to improve (on average becoming lower) during the first few months of treatment as your body adjusts to treatment.
Also keep in mind that it is not unusual for central apneas or hypopneas to occur while we are relaxing before we are fully asleep, and these events may legitimately be ignored (subtracted from the calculation of CAI or HI), but subtracting these events would need to be done manually (by you) because your machine does not attempt to decide at what time you actually fell alsleep or woke up.
(You will likely be able to decide when you actually fell asleep by looking at the plot of your tidal Volume (Vt), which is the volume of air being inhaled or exhaled each breath, I think averaged over the most recent 5 or 6 breaths. Likely, when you start to fall asleep the Vt will suddenly get very steady and start drifting lower until it stabilizes at a lower level than when you were awake, and then, throughout the night, it will rise or fall as your stage of sleep changes, or whenever you swallow in your sleep, etc.)
When you do look at your data you will be tempted to change the settings.
I suggest you consider looking at your data right away (and posting for comments your statistics or better yet waveforms) but not changing settings for at least a week or a month, and if feasible keeping your doctor informed before making changes.
However, I suggest you may want to raise the minimum pressure (raise the low end of the pressure range) a little closer to your max pressure right away whenever you wake up during the night feeling like you are needing to work too hard to breath in. Sometimes, raising the minimum pressure can make breathing in more comfortable. Personally, having gotten used to high pressure, I would prefer a minimum pressure of 10.
Also, to make it easier to breath out against pressure, what ResMed calls Expiration Pressure Relief (EPR) can be used. EPR lowers the pressure 1, 2 or 3 cmH2O only while you are exhaling. However, if
your CAI makes up the majority of your AHI then, although you may need to use EPR at first to make breathing out against pressure less uncomfortable, after you get used to breathing out against pressure then you may want to consider lowering or turning off EPR, since for a few people (like me) EPR makes their CAI worse.