S9 Autopap Questions

In the clinicians menu I see the AHI and I understand what that means, but below that it shows the Central AI. Does this stand for central apneas, because centrals mean that I either have a heart or neurological problem. Also, what does EPR stand for? One last thing. Last night I slept 7 hours but I got up once to use the restroom. The machine showed that I only slept 3.9 hours, does it start recalculating every time there is a break? Thank You.

nommie5 wrote:In the clinicians menu I see the AHI and I understand what that means, but below that it shows the Central AI. Does this stand for central apneas, because centrals mean that I either have a heart or neurological problem. Also, what does EPR stand for? One last thing. Last night I slept 7 hours but I got up once to use the restroom. The machine showed that I only slept 3.9 hours, does it start recalculating every time there is a break? Thank You.

The Central AI does stand for central or "clear airway" apnea, but it does not necessarily mean you have a heart or neurological problem. It depends on how many you're having, how they're clustered if they are, and what portion of your AHI is due to centrals. You are welcome to post some numbers for us to look at.

EPR is exhalation pressure relief -- can be set to drop 1, 2, or 3 cms when you exhale. Some people use it and like it, others prefer to leave EPR off.

If the machine shows 3.9 hours and you know you slept more -- did you sleep past noon? ResMed machines start a new day at noon. It doesn't recalculate for an interruption during the night, but if you slept past noon it will show as two different days, each with their own AHI numbers.

How long have you been using your Autoset? What is your typical AHI and Central AI ? It's pretty common to have a few centrals flagged by the machine because we sometimes pause in our breathing when we change position, sigh, during dreams and during transitions from one stage of sleep to another. I've seen centrals flagged sometimes when I know I was actually awake. Remember our machines don't know when we're awake or asleep.

For an easy guided tour through the clinicians menu on the S9 Autoset, follow the link below in my signature box.

Welcome to the forum.

Thank you for the info. The EPR dropping by 1, 2 or 3 cm's sounds like I have a bi-level option! Good. The central AI's are only around .3 or .7. I have only used this machine a few nights. Yes, I do sleep during the day past noon (I work nights at a hospital) so that explains the interruption. Have A good one.

nommie5 wrote:In the clinicians menu I see the AHI and I understand what that means, but below that it shows the Central AI. Does this stand for central apneas, because centrals mean that I either have a heart or neurological problem. Also, what does EPR stand for? One last thing. Last night I slept 7 hours but I got up once to use the restroom. The machine showed that I only slept 3.9 hours, does it start recalculating every time there is a break? Thank You.

Welcome to the board. Please fill in your equipment on your profile. There's a link in my signature line on how to do this.

Some people develop central apnea when under CPAP pressure, especially when they first start. It doesn't necessarily mean you have heart or neurological problems.

The CPAP pressure can change the balance of CO2 and O2 in your blood. It can also cause you to inflate your lungs more fully. Both of these can reduce your respiratory drive and cause you to stop breathing for a short period of time while you're connected to the machine. It's not a problem unless it happens too often or if individual central apneas last too long. Central apneas count just as much as obstructive, but they aren't necessarily any more harmful than obstructive apnea. They may be harder to eliminate.

Get the free SleepyHead or other CPAP software and look at the airflow waveforms and statistics to see if the central apneas are lasting a long time.

Everyone can have a few centrals...it's normal in fact. Some are when we transition into sleep stage (sleep onset) and others can happen randomly during the night.
Other central flags may not be real centrals though...especially for newbies having trouble sleeping with the machine and mask. The machine doesn't know if you are awake or not so it sometimes gets fooled by irregular awake/semi awake breathing and flags apnea events by mistake.
Get the software and find out when you are actually seeing the centrals being flagged....some of them might be when you know you were awake and they can't be counted for real but we can't do much except mentally remove them from the calculations.

If your AI is less than 1.0 though...even if they were all centrals that were the real deal it doesn't mean anything bad as that is still well within acceptable numbers for either apnea event.

Yes..EPR makes it work like a bilevel...how cool is that.

It isn't uncommon to have central apneas at sleep onset. If your sleep is being interrupted somehow (say your dog is barking or your partner is snoring!) this may cause you to wake up. In turn, you may have some more sleep onset centrals since you have woken up and are establishing sleep again.

Having centrals does not necessarily mean there is a heart or neurological problem; however, if this concerns you, you need to speak to your physician