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New user questions about AHI - logandzwon - 11-23-2013
New BiPAP user here. Just completed night two of what I'm now calling the nighttime torture device. So, I have some questions, but my biggest concern is that, regardless of the several over "side effects" I'm having, according to the data on the screen this machine seems to increasing my AHI numbers, not decreasing them. Is this just me adjusting to the system or this is indication of something not working well?
Sleep study;
AHI 14.9
Hypopneas 74
Central Apnea 15
First night;
AHI 16.93
Hypopnea 0.16
Apnea 14.51
Obstructive 0.48
Clear Airway 1.77
Second night;
AHI 23.00
Hypopnea 0.13
Apnea 11.69
Obstructive 0.51
Clear Airway 10.68
RE: New user questions about AHI - PaulaO2 - 11-23-2013
Several things to point out.
One, it's just been two nights. Give it some time to settle down. Your body and brain are still getting used to all this.
Did you have the diagnosis of Central sleep apnea or Obstructive?
RE: New user questions about AHI - trish6hundred - 11-23-2013
Hi logandzwon,
WELCOME! to the forum.!
What Paula said.
Hang in there for more suggestions and best of luck.
RE: New user questions about AHI - robysue - 11-23-2013
(11-23-2013, 10:55 AM)logandzwon Wrote: First night;The fact that over half of your events are apneas that the S9 could not classify as OA or CA points to a potentially serious leak problem. Are you getting these figures from the S9's LCD or from SleepyHead or ResScan? If you are getting these figures from the LCD, did Mr. Red Frowny Face show up on the Sleep Quality report? Also do you know that the 95% Leak Rate was reported as?
AHI 16.93
Hypopnea 0.16
Apnea 14.51
Obstructive 0.48
Clear Airway 1.77
Second night;
AHI 23.00
Hypopnea 0.13
Apnea 11.69
Obstructive 0.51
Clear Airway 10.68
On the Resmed machines, the reported leak numbers only include the unintentional leaks AND Resmed defines a Large Leak as any leak above 24 L/min. If the leak rate stays above 24 L/min for any length of time, the machine can have trouble maintaining appropriate pressure (so additional apnea events CAN occur) AND the machine can have trouble both detecting the events and classifying the events it does detect. Hence the apneas scored during Large Leaks are often simply labeled as "apneas" rather than OAs or CAs.
It's also important to understand that Mr. Red Frowny Face shows up only if the leak rate is AT or ABOVE 24 L/min for at least 30% of the night. If the time spent in Large Leak territory is less than 30% of the night, Mr. Green Smiley Face shows up. So Mr. Red Frowny clearly indicates you've got a serious leak problem, but seeing Mr. Green Smiley may give you a false sense that leaks are not really a problem when in fact they are. You need the software to tell for sure just how bad you're leaking if you're seeing a lot of events being scored as "apneas" rather than OAs or CAs.
RE: New user questions about AHI - logandzwon - 11-23-2013
In reply to robysue, I don't really understand the smily face. When I wake up and check he is smiling at me. When I go and check it again later in the afternoon he is red and upset. So, I am checking the data using SleepyHead.
I could believe it was a leak issue. I have the full face mask because I have both post nasal drip issues and also I'm a mouth breather.
I also do not understand what 95% means, but here are details from SH;
[attachment=557]
[attachment=558]
Both days do show a lot of time over 24 on the leaks graph. Even when the mask seems to be fitting perfect it seems to hover around 20 though.
RE: New user questions about AHI - logandzwon - 11-23-2013
(11-23-2013, 11:23 AM)PaulaO2 Wrote: Did you have the diagnosis of Central sleep apnea or Obstructive?
I'm not really sure. I think obstructive. I do have copies of my sleep studies. During the first one I had 3 obstructive, 0 mixed, 15 central, and 74 hypopneas. The AHI was 14.9.
RE: New user questions about AHI - zonk - 11-23-2013
(11-23-2013, 02:23 PM)logandzwon Wrote: I also do not understand what 95% means, but here are details from SH;95% percentile means leak was at or below this number for 95% of the time whilst using the machine
Both days do show a lot of time over 24 on the leaks graph. Even when the mask seems to be fitting perfect it seems to hover around 20 though.
Download ResScan, ResScan shows if any of the apneas scored are "unknown". Unknown apnea scored when leak is so high (above 30 L/m) that the machine cannot tell the type of apnea accurately
You do have leak issue but congrats sleeping nearly 8 hours with mask on the second night is not easy feat, I did not sleep more than two hours when started CPAP
RE: New user questions about AHI - PaulaO2 - 11-23-2013
The 95% means that for 95% of the night, you were at that point or lower 95% of the night. So a 95% leak of 93.6 means you have a leak issue. A full face mask is notorious for leaking.
Don't over tighten the mask as that makes leaks worse. Look on YouTube or the manufacturer's website to see if they have any videos on how to properly put on one. (I was having trouble with my current mask and finally looked it up. Here I was messing with the top straps and it was the back ones I actually needed to adjust! Didn't seem like they were the ones I would need to but once I did, it fit!)
As for the central events, you could be having the phenomenon known as "CPAP induced central events". It happens to a lot of people. They should be going away after a few weeks. However, you're having a lot of them. If that number continues to rise *once you have the leak issue tamed*, you will want to contact your sleep doc. You have an autoPAP so having Central events with that is odd. It could be you actually have Mixed Apnea, which means you have both. And it could be why they gave you the VPAP to start off with.
But until you get the leak issue fixed, the other data is rather useless. You can look at the graphs. Any events logged when there is not a leak can be taken seriously but any events otherwise cannot.
RE: New user questions about AHI - robysue - 11-23-2013
logandzwon,
You've got a really bad leak problem. How bad? Well I can tell you this from the little bit of data that you have posted:
Your median leak rates for the two nights are 19.2 L/min and 22.8 L/min. The median leak rate is the the "half-way" mark for your leak rate numbers. In other words, on 11/21 your median leak rate was 22.8 L/min and that means that for 50% of the night your leak rate was AT or BELOW 22.8 L/min and for 50% of the night your leak rate was AT or ABOVE 22.8 L/min. And the Resmed Red Line for Large Leaks is at 24 L/min. So on 11/21 you spent at least half the night in or very close to large leak territory.
And your 95% leak rate number for 11/21 was 93.6 L/min. That means that you spent 95% of the night with a leak rate AT or BELOW 93.6 L/min (remember, 50% of the night your leaks were AT or BELOW 22.8 L/min), but more significantly, a 95% leak rate equal to 93.6 means that for at least 5% of the night your leak rate was AT or ABOVE 93.6 L/min.
It would be useful if you could show us the leak graph for these nights rather than just the statistical numbers. But I think we've identified why your AHI remains high: Your leaks are so large that your S9 is not able to compensate for them, and hence your airway is not getting the proper air pressure it needs to splint it open and the apneas continue to occur. And with the large leaks, the machine is having some real trouble determining the real nature of the apneas that it does detect. In other words, until the leaks are brought under control, I would not worry about the breakdown of As, OAs, and CAs. You really can't trust whether the machine is properly distinguishing OAs from CAs in the presence of the large leaks.
As to Mr. Green Smiley and Mr. Red Frowny's behavior. You write:
Quote:I don't really understand the smily face. When I wake up and check he is smiling at me. When I go and check it again later in the afternoon he is red and upset.I need some clarification. When you say you check for Mr. Smiley when you wake up, are you using the mask fit feature or are you checking the Sleep Quality Report? They are two different things, but they both use the Mr. Smily/Mr. Frowny Faces to report the information to the user. I need to know what you're doing to help you understand what the machine is trying to tell you.
As others have said, something's going seriously wrong with how you're fitting the mask. It could be that you're overtightening the straps. The Quattro uses an air cushion to make the seal, and if the straps are too tight, the air cushion cannot fully inflate and that causes leaks.
It also could be that things are just peachy when you first put the mask on---at low pressure at the beginning of the night (if you're using a ramp or Auto mode). And then everything goes to hell in a handbasket as soon as you get soundly asleep and your facial muscles really relax and the machine increases the pressure.
Some questions:
1) Are you using the ramp? If so, what pressure does the ramp start at and how long is the ramp up period?
2) Are you using your S9 VPAP in fixed bi-level mode---in other words is your EPAP always equal to 9 and your IPAP always equal to 15? Or are you using Auto mode so the EPAP (and hence the IPAP) adjusts throughout the night?
3) You've also got a difference of 6cm between your IPAP and your EPAP. That's pretty significant and that may also be some of the source of the leaks. When you are lying down with your mask on and the machine turned on at your therapeutic settings of 15/9, do you notice any odd noises that correspond to your inhalations? Does the mask seem to lift off your face a bit with every inhalation? Do you hear any "face farts"?
RE: New user questions about AHI - logandzwon - 11-23-2013
(11-23-2013, 03:24 PM)robysue Wrote: Some questions:
1) Are you using the ramp? If so, what pressure does the ramp start at and how long is the ramp up period?
2) Are you using your S9 VPAP in fixed bi-level mode---in other words is your EPAP always equal to 9 and your IPAP always equal to 15? Or are you using Auto mode so the EPAP (and hence the IPAP) adjusts throughout the night?
3) You've also got a difference of 6cm between your IPAP and your EPAP. That's pretty significant and that may also be some of the source of the leaks. When you are lying down with your mask on and the machine turned on at your therapeutic settings of 15/9, do you notice any odd noises that correspond to your inhalations? Does the mask seem to lift off your face a bit with every inhalation? Do you hear any "face farts"?
Thanks everyone for helping understand whats going on! I definitely need to address the leaks before the rest really matters. I now know what I need to start work on next. (the leaks.)
Just for completeness;
1) No ramp.
2) While the machine is capable of auto mode, I am in fixed bi-level mode.
3) The mask does seem to 'float up' a little, but no "face farts." I do have facial hair though which may be masking a leak there. I do not "feel" any air leaking where the skirt meets my face, but now I'm thinking that when I'm asleep and my jaw relaxes it does leak, but the facial hair prevents any sounds from disturbing me.