New user S9 (need advice)

So I am on week 2 with the S9..the original pressure setting my machine was set to was 9.0. After 4 nights of use, my Girlfriend informed me that I am still gasping for air (even with a full face mask on this thing) I was told that I stopped breathing 24 times per hour (according to my sleep study) I called to tell my doc that I am still not breathing and literally gasping for air and the next appointment I could get was one month out. So..I went and did some research, downloaded the software for this, and took it upon myself to change the setting of the pressure to 10. Now..I need some help on reading the info on the hourly "incidents" etc..I just looked on the machine by holding down the Info and check button and here are the readouts I see; leak is 7.2 L/min ...AHI 42.3...Total AI 38.5...Central AI 13.0 I am trying to figure out if this machine is helping me. can someone tell me what these numbers mean (like I said it will take another month before I even get in to see my doc) I am assuminmg that increasing the pressure was a good idea since my girlfriend says I don't appear to be gasping for air anymore since I changed it to 10. Also, should I increase this even more according to the readouts? Any advice is greatly welcome!

Erick

There are several good posts on this forum describing AHI, HI, and AI numbers. So a search for AHI and you should find them. I'm too new a user to give you any cpap or mask advice, but I can tell you that changing the pressure from 9 to 10 should not make any difference as it's too small a change.

I recommend you ask for an S-9 autoset, then run it 9-20 and see how high a pressure you need to prevent "any" apneas. Seems your pressure is too low if your girlfriend heard you gasping still. You may need to get your Dr. to write a prescription for an auto machine, but will be glad you have one after you learn more about your therapy, an auto can be run in auto or straight cpap. Your leaks are not bad, but I would like to see less apnea events of any kind, just IMHO. Track down Uncle Bob and download the free software under his signature and you can look at your data on your puter and follow patterns better. john

D00kie wrote:Now..I need some help on reading the info on the hourly "incidents" etc..I just looked on the machine by holding down the Info and check button and here are the readouts I see; leak is 7.2 L/min ...AHI 42.3...Total AI 38.5...Central AI 13.0 I am trying to figure out if this machine is helping me. can someone tell me what these numbers mean (like I said it will take another month before I even get in to see my doc) I am assuminmg that increasing the pressure was a good idea since my girlfriend says I don't appear to be gasping for air anymore since I changed it to 10. Also, should I increase this even more according to the readouts? Any advice is greatly welcome!

Erick

First and Foremost: Those AHI, AI, and CI are WAY, WAY too high! For your apnea to be considered "effectively" treated, those numbers should all be at or below 5.0. These numbers indicate that you are still suffering from severe apnea in spite of the CPAP. Why? I don't know---that's a question for the doctor. If I were you, I would call the doctor's office TODAY and tell the receptionist that your S9 is reporting an AHI of 42.3 and that you NEED to talk to somebody as soon as possible. Ask to be put on their CANCELLATION list. Ask if there is anyway at all for them to squeeze you in before your next scheduled appointment. Tell the receptionist that at a minimum you need to speak to a nurse or the doctor by phone and that you'd appreciate a call back and give a number that you KNOW he/she will be able to reach you at.

Let's look at what those AHI, AI, and CAI numbers on your LCD actually mean. In your post you say the numbers are:

AHI = 42.3 (Shown on the S9's LCD)
AI = 38.5 (Shown on the S9's LCD)
CAI = 13.0 (Shown on the S9's LCD)

And even though the OAI and HI are not shown on the S9's LCD, they're easy to get: the OAI = 38.5 - 13.0 = 25.5 and the HI = 42.3 - 38.5 = 3.8.

First the AHI, AI, CAI, OAI, and HI are all indices. They indicate how many events of the given type you had per hour on average during the time the machine was on:

• AHI = average number of apneas (all types) + hypopneas per hour the machine was running
  AI = average number of apneas (all types) per hour the machine was running
  CAI = average number of central apneas per hour the machine was running
  OAI = average number of obstructive apneas per hour the machine was running
  HI = average number of hypopneas per hour the machine was running

And it helps to know what each kind of event is:

• * The S9 will score a hypopnea when your airflow is reduced by at least 50% from baseline lasting at least 10 seconds. (and it believes there is some flow limitation, I think)
  
  * The S9 will score an obstructive apnea when your airflow is reduced by at least 80% from baseline (i.e. you're not breathing) lasting at least 10 seconds AND the S9 has determined that there is an obstruction in the airway
  
  * The S9 will score an central apnea when your airflow is reduced by at least 80% from baseline (i.e. you're not breathing) lasting at least 10 secondsAND the S9 has determined that there is appears to be no obstruction in the airway

The S9 computes each of these numbers (AHI, AI, CAI, OAI, HI) by dividing the number of events (of the particular type) by the time the machine was running. We can compute the number of events of each type you had during the given night without going into Rescan if we know how long you used the machine. Since you didn't post the usage number, I'll assume that you slept with the machine running for 7.5 hours overnight. In that case, the number of each type of event you can be computed from the LCD data as follows:

• (42.3 events per hour)x(7.5 hours) = 317.25, which equals about 318 events that night
  (38.5 apneas per hour)x(7.5 hours) = 288.75, which equals about 289 apneas that night
  (13.0 central apneas per hour)x(7.5 hours) = 97.5, which equals about 98 central apnea that night

A bit more arithmetic shows that there were likely 29 hypopneas (318 events - 289 apneas = 29 hypopneas) and 191 obstructive apneas (289 apneas - 98 central apnea = 191 obstructive apneas)

Now remember what I said at the start: These numbers are WAY, WAY TOO HIGH for apnea being treated with CPAP and you NEED to contact the doctor's office and tell them what your S9's AHI, AI, and CAI numbers are. And insist on at least speaking to a nurse or doctor or physician's assistant by phone

Now let's look at what the rest of those numbers actually mean. I'll start with some really important key definitions so you know what these numbers actually mean. It's easiest to start with some examples. Since you don't say whether you're using an S9 Elite (CPAP only) or an S9 AutoSet running in CPAP mode, I'll assume you've got the S9 AutoSet running in CPAP. I'll use the numbers that you posted, as well as the fact that you currently have your S9 set to 10cm. And I'll continue to suppose that you slept with the S9 running for 7.5 hours and we're looking at the overnight data in ResScan or off the LCD for the numbers it shows. Now let's look at your leak data. And we'll suppose:

• 
  Median = 1.0 L/min [Made up number; you can only get this number from the ResScan software.]
  95% = 7.2 L/min [This is the Leak number shown on your S9's LCD]
  Max = 15 L/min [Made up number; you can only get this number from the ResScan software.]

The median leak rate = 1.0 L/min means that for 50% of the time the S9 was on, your leak rate was LESS THAN or EQUAL TO 1.0 L/min. And so for 50% of the night, your leak rate was also GREATER THAN or EQUAL TO 1.0 L/min. So in the 7.5 hours you slept with the machine, for 3.25 hours (3 hours and 15 minutes) you had a leak rate of LESS THAN or EQUAL TO 1.0 L/min.

The 95% leak rate = 7.2 L/min means that for 95% of the time the S9 was on, your leak rate was LESS THAN or EQUAL TO 7.2 L/min. And so for 5% of the night, your leak rate was GREATER THAN or EQUAL TO 7.2 L/min. Now it's important to realize that 5% of one hour is equal to three minutes. Since you slept for 7.5 hours, that means your leak rate was GREATER THAN or EQUAL TO 7.2 L/min for a grand total of (3 minutes)*(7.5 hours)=22.5 minutes. That 22.5 minutes of "high leak rates" might be in one giant half hour leak or it could be in several smaller leaks---the only way to know is that to look at the detailed graphs in ResScan. [You find the detailed graphs under the "Detailed Graphs" tab. If you only download "summary data" the detailed graphs won't be there.]

The max leak rate=15L/min indicates that at some point when the S9 was sampling leak data, it detected a leak that was as large as 15L/min. It may have been a very short lived thing---when you broke the seal to scratch your nose for example. Or it could be that on one or two of the big leaks that you had, the leak pretty quickly went from in the neighborhood of 2.5 L/min to 15 L/min and stayed there. But you know for sure that you could not have leaked at a rate of 15L/min for more than about 22 minutes because of the 95% leak rate number and the time the machine was on.

Interpreting the leak rate data is also important:

First, on the Short Sleep Quality menu, if you see a Red Frowny face, that indicates your 75% leak rate is AT or ABOVE 24 L/min and Resmed's litertature indicates that you are leaking AT or ABOVE a rate of 24 L/min for 25% of the night. And at that point, the ResMed engineers believe that your therapy can and probably is being compromised. Your posted leak number is significantly below this rate, hence the S9 does not believe your leaks are sufficiently large to compromise your therapy.

Many people take the 95% Leak Rate to be the key stat Leak data. But it is worth looking at the median leak rate as well, in my opinion. The reason I look at both is that the median leak rate tells me whether I was leaking off and one all night long or not, where the 95% leak rate tells me if my worst leaks were bad ones or not. To illustrate what I mean, let's look at two examples:

Person A sleeps for 7.5 hours and is leaking off and on all night at a rate of 5.5 L/M and for about 25 minutes during the night, the leak rate actually is between 7 and 10 L/min. So A's leak numbers look like this:

median=5.5, 95%=7.0, and max=10.0

Now suppose Person B sleeps for 7.5 hours and has NO leaks at all for most of the night, but has ONE 25 minute leak where the leak rates are from 8 to 10 L/min during this leak. B's leak numbers look like this:

median=0.0, 95%=8.0, and max=10.0

Neither person's leak rates are grate enough to trigger the Red Frowny face in the short Sleep Quality menu on the LCD. But Person A is likely to be having more significant problems with comfort due to leaking all night long.

Obviously, the closer to 0 your leak rate data is, the better obviously. But the information from Resmed seems to indicate that leaks above 24 L/min (the RED LINE in ResScan's detailed graphs) are enough to cause problems with the algorithms the S9 uses in order to detect and respond to apneas, hypopneas, flow limitations, and snores. So in any case you really want your 95% leak rate under 24 L/min to insure that you're getting some kind of meaningful therapy. But comfort is as a much of an issue as therapy is in my opinion: Nasty leaks cause most people real discomfort and they frequently cause people to wake up multiple times during the night to fiddle with the mask even when the leak is well below 24 L/min. For me, I don't worry at all if my 95% leak rate is below 10 L/min unless I had to fiddle with my mask more than once in the night. And if I wake up multiple times needing to fiddle with my mask because of leaks, then the leak rate IS a problem regardless of how low the 95% leak rate is.

Now, your signature seems to indicate that you are either using an S9 Elite (CPAP only---fixed pressure) or an S9 AutoSet (but running in CPAP mode). It would help to select Text in the equipment description so that it's clear when you're asking for help.

But since you are using a fixed pressure, the pressure data in ResScan will be boring: The median, 95% pressure, and max pressure (in ResScan) will all read 10cm since the pressure was constant. If you ever run in Auto mode, however, the meanings of median, 95%, and max pressure are similar to those of median, 95%, and max leak.

Now as to whether you need to increase your pressure or do something else to obtain better therapy, that's really for your doctor to determine. Me, personally, I wouldn't go increasing pressure without the doctor's ok. But then I also seem highly sensitive to pressure-related side affects and I get very, very uncomfortable if my pressure is at 9cm (my original prescription). In light of your very high AHI number WITH TREATMENT, I think you need to be working pretty closely with a medical team to figure out why the CPAP is not effectively treating your apnea.