Initial feedback on these summary numbers?

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john_dozer
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Joined: Sun Sep 07, 2008 5:04 pm

Initial feedback on these summary numbers?

Post by john_dozer » Sun Dec 12, 2010 8:02 pm

Hi,
found a link from an Uncle_BoB post today that should help me get more detailed information, but I would like some feedback on these summary numbers from my S9 Autoset?

Code: Select all

Day         	1           	2           	3           	4           	5           	6           	7           	8           
Range       	6-20        	8-12.5      	8-12.5      	8.5-12.5    	8.5-12.5    	9-13        	9-13        	9-13        
Pressure    	14.8        	12.4        	12.4        	12.2        	12.4        	12.8        	12.4        	12.6        
Leak        	13.2        	9.5         	13          	16.8        	13.2        	21.6        	10.8        	14.4        
AHI         	6.5         	6.9         	4.8         	6           	5.7         	6.2         	5.6         	5.7         
AI          	1.5         	1.5         	2.2         	1.6         	3.3         	1.6         	2           	2.4         
Central     	2.5         	0.2         	0.2         	0.4         	0.5         	0.6         	0.3         	0.3         
Notes       	(from memory on day 1) 	            	            	            	            	            	            	            
First off, I feel different from this new machine. I don't feel as mentally dull as before as on the bottom end S8 model my DME had given me set to about 10 (maybe 10.5, I don't quite recall). But my body feels sore for some reason.

I'm concerned about the leakage numbers. I go to sleep and wake up with no detectable leaks, not even a trace. I'm concerned that I dislodge the mask in my sleep. In which case, some of the numbers I see may be due to that itself.

The other concern i had, and it was reinforced by my first night. With a wide open pressure, the system wanted to drive my pressure up and it started giving me centrals. And if I read this correctly I'm having some obstructive events, but also having more Hyponeas. Can the Hyponeas be central related?

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robysue
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Re: Initial feedback on these summary numbers?

Post by robysue » Sun Dec 12, 2010 9:11 pm

First off, since these are numbers that came from the S9's LCD, the pressure and leak rate numbers are what are called 95% numbers. That means that your pressure or leak rate was AT or BELOW the given number for 95% of the time the S9 was running overnight. It also means that your pressure or leak rate was AT or ABOVE the given number for 5% of the time the machine was running overnight. To help understand how long 5% of the night is, you can remember this: Five percent (5%) of one hour is three minutes. So if you multiply the leak rate number by the usage number on each night you get an upper bound on how long you were leaking at a rate EQUAL TO or ABOVE the leak rate number on the S9's LCD. LIkewise, you can find out what the maximum time your pressure was EQUAL TO or ABOVE the pressure number by doing the same muliplication.

(For a more detailed explanation of 95% leak and pressure rate numbers, see this post: viewtopic.php?f=1&t=58082&p=546898#p546898 )

Your leak rate numbers are low enough where you should still be seeing the Green Smiley Face on the short version of the Sleep Quality menu. The Red Frowny Face shows up if your 75% leak rate is AT or ABOVE 24 L/min. In other words, if you have a Red Frowny face in the morning, your leak rate was AT or ABOVE 24 L/min for 25% of the night (or an average of 15 minutes per hour of time the machine was run). ResMed's information indicates that their engineers believe that leaks that are AT or ABOVE 24 L/min for extended periods of time (i.e. at least 25% of the night) are enough to compromise the data the machine is recording, the algorithm the machine uses to increase pressure in response to events when running in Auto mode, and your therapy. Clearly, your numbers are below this threshold.

But just because the machine is happy enough with your leak rate may or may not mean anything to you: If the leaks are waking you up or keeping you from getting to sleep or otherwise bothering you, then they are a problem regardless of how big or small they are. If the leaks aren't really bothering you, then you need to look at the median leak rate number in ResScan. If it is really low or 0.0, that means that for (at least) half the night, you really weren't leaking very much. But if your median leak rate is middle sized or large, that indicates you had middle sized leaks for at least half the night.

You also say:
First off, I feel different from this new machine. I don't feel as mentally dull as before as on the bottom end S8 model my DME had given me set to about 10 (maybe 10.5, I don't quite recall). But my body feels sore for some reason.
and
The other concern i had, and it was reinforced by my first night. With a wide open pressure, the system wanted to drive my pressure up and it started giving me centrals.
The data you show do indicate that your 95% pressure levels are between 12.4 and 14.8 (that first night). That is more pressure than your old machine was set at. It could very well be that even though your pressure on the S9 is ABOVE these numbers for no more than 5% of the time, that your pressure is close to (or even equal to) these numbers for an extended time. And since you are not (yet) used to breathing out against this much pressure, that could be part of why you feel a bit sore.

And yes, that data from the first night does seem to indicate that if the S9 increases the pressure too much, it may begin to trigger some centrals. The S9 is supposed to NOT increase pressure in response to what it regards as centrals. In my opinion you might want to reduce the max pressure from the default setting of 20cm to something more in the range of 13cm--14cm to make sure the pressure doesn't get high enough to start causing problems with centrals.
And if I read this correctly I'm having some obstructive events, but also having more Hyponeas. Can the Hyponeas be central related?
Hypopneas can either be obstructive or central if I recall correctly. And there's really no way for the S9 to tell them apart. In a sleep lab, the obstructive hypopneas can be distinguished from the central ones because the belts measure breathing effort while the flow monitors measure how much air is actually getting inside of you. If there's a lot of effort, but decreased airflow, that's an indication the airway is at partially obstructed. But the S9 can't measure breathing effort because it doesn't have any belts around your chest or abdomen. If I recall correctly, the S9 does not automatically respond with pressure increases to hypopneas; but it does attempt to measure something called a "flow limitation" by analyzing the shape and size of the waveflow data---which is tied to how the airflow changes when you inhale and exhale.

Now as far as overall impression of your data: The differences between the AHI and AI numbers do indicate that the S9 is detecting a pretty significant number of hypopneas: The hypopnea index (HI) is equal to AHI - AI. And it looks like on most nights, the hypopneas make up most of your events since the HI is higher than the AI. In this week, your AHI numbers are clustering 5.5 and 7 (with the exception of night 3). That means that the S9 detected an average of 5.5 to 7 apneas and hypopneas for each hour the machine was run each night. [And so the number of actual apneas and hypopneas for the night is computed by multiplying the AHI by the usage hours and rounding up to the nearest whole number.] Those AHI numbers are not quite as low as what sleep doctors want to see---they'd really prefer that the AHI to be consistently less than 5. But since you report that you "don't feel as mentally dull as before as on the bottom end S8 model" you started out with, it may well be that at your original pressure of 10 (or 10.5), you were having even more events.

I'd say work on the leaks and maybe think about increasing the minimum pressure setting on the S9 auto to something like 8 or 9 cm so that it doesn't take the S9 as long to appropriately increase the pressure level to what you need when it detects events.

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john_dozer
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Joined: Sun Sep 07, 2008 5:04 pm

Re: Initial feedback on these summary numbers?

Post by john_dozer » Sun Dec 12, 2010 10:57 pm

Thanks. The pressure settings are listed in the second row of the data. I have tweaked to a 9-13 pressure range up from a 8-12.5 pressure. My pressure numbers are usually close to the limit at 12.5, although not quite all the way to 13 but I suspect if I allowed it to go higher, it might drift higher.

The concern I have is if the hyponeas are central related, then I have two questions. Can central hyponeas lead to OSA events? Am I at a point where increasing pressure increases the severity of my hyponeas turning them into full fledged centrals and/or increasing my chances of a OSA event?

Long story short, I had two sleep studies earlier this year with my sleep doctor. The first study didn't go well, I didn't get much sleep. Also, the doctor said I increased the number of events with increasing pressure and that had him scratching his head a bit. The second study he gave me an ambien to use. I had a great sleep and my sleep study ran well with the pressure at 10 being just above stopping my apneas. Of course I had googled apnea and abien and found that ambien seems to suppress central apneas. So to me, first the doctor was pretty useless, second I got the impression centrals or central-related effects seemed to be in play.

I can't express how well that night with an ambien was. Its been years, even with CPAP which at first seemed decent, that I've had restorative sleep that good. The effect seemed to carry over a few more days to a lesser degree.

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