30 yr Male Just Diagnosed w/ Severe OSA

[Sleeprider]

I have enjoyed reading your story on being well informed, getting started and the good working relationship you have with your doctor. I have a similar relationship with mine, and it makes a difference when your thoughts and ideas are listened to and respected. You ended up with what I consider the best auto CPAP machine on the market today, and you're off to a great start. The tweak I'd suggest is a minimum pressure of 7.0 and increase EPR to 3. All of your pressure movements are on flow limitations. The increase in minimum pressure will give you more room for the higher EPR and should help stabilized pressure. Well done!

[jbsix]

I have noticed something rather peculiar about the attitudes of people in the medical industry when it comes to CPAP. It's almost like there's this entrenched attitude that all the patients are stupid and can't be trusted to do the simplest things. For example, it becomes very apparent when you try to engage them in anything more than just the basics about CPAP therapy. They constantly interrupt you and won't let you finish your points and then go back to, "You need a prescription to change the pressure. Don't do that." Or they just keep saying the same things. It's like they aren't really listening to you, and they even get emotional as if their way of life was being attacked or something. Luckily, my doctor wasn't like this and it was possible to have an actual discussion about the topic without feeling like the other party was talking down to you.

Over the years i've seen a total of 5 pulmunologists about sleep therapy and i wonder if i should trust any of them to treat anything more than a cold. i've come to the conclusion (based on my own intuitions and observations mind you) that sleep therapy is but a tiny chapter in the vast world of pulmunology and that most pulmunologists aren't equipped to deal with it in any meaningful way. the rude reactions you've observed strike me as one of these doctors who might try to camoflauge their subconscious inadequacy with a god complex front.


I think good sleep doctors are few and far between and sadly i've yet to find one. About 95% of my cpap therapy is based on the advice and information provided by the good folks here and i think i've been the better for it.

[ReturnofXile]

I have enjoyed reading your story on being well informed, getting started and the good working relationship you have with your doctor.  I have a similar relationship with mine, and it makes a difference when your thoughts and ideas are listened to and respected.  You ended up with what I consider the best auto CPAP machine on the market today, and you're off to a great start.  The tweak I'd suggest is a minimum pressure of 7.0 and increase EPR to 3.  All of your pressure movements are on flow limitations.  The increase in minimum pressure will give you more room for the higher EPR and should help stabilized pressure.  Well done!

Okay, so I looked at my data to try and figure out what you were talking about when it comes to flow limitations. I'll be honest, I'm not sure if I'm reading this chart correctly. For example, if you look at the Flow limit chart and it says .16, does that mean that there's been a 16% reduction in the baseline exhalations and inhalations in terms of liters/min? 

I did notice that according to the flow rate chart, it seemed that ~18 liters/min was a common peak value during the inhalation phase, but there were times later in the night where it seemed to be about ~13-15 liters/min. Are these the flow limitations that you are talking about? I just always thought that the reduction would caused by being more relaxed and in a deeper sleep. Interested to know what you think.

[Sleeprider]

Flow limitations are discussed in this wiki article http://www.apneaboard.com/wiki/index.php...imitations It is an upper airway restriction that causes the flow rate of inspired air to slow before inhale ends. The appearance on the flow chart is a flattened or downward sloping top on the inspiratory wave, rather than a nice rounded shape. The restriction of flow means that you may not get a full normal breath, and this can cause a RERA (respiratory event related arousal), which is the type of event you have. So this is a form of sleep disordered breathing that can result in sleep disruption. http://www.apneaboard.com/wiki/index.php...erapy#RERA

[Shipmate]

"In fact the mask I had ordered ended up fitting better than the one they gave me at the sleep study."

Really? I'm confused now, my sleep study had me wired up to more sensors than you can shake a stick at, but there was no mask involved.

[Gideon]

There is a diagnostic study that is without a mask usually followed by, on another night, a titration study that includes both mask and machine.

[ardenum]

I hate to say it, but it sounds too good to be true!  A doctor who didn't discourage you from getting actively involved in your own recovery?  Who seemed interested in your decision-making borne from learning, including fiddling with your therapy parameters?  And the professional therapist/sleep lab tech didn't slip some information to you and deferred to the physician instead?  Wow.  And you didn't get the sales pitch to purchase a 'brick' from the doctor's handy-dandy CPAP, Drug, 'n Tire Centre just around the corner?

Geeeez….

My doctor asked me if i read my data with resscan or sleepyhead, these things happen sometimes.

[Shipmate]

There is a diagnostic study that is without a mask usually followed by, on another night, a titration study that includes both mask and machine.

Thank you, I was not aware.

[ReturnofXile]

Flow limitations are discussed in this wiki article http://www.apneaboard.com/wiki/index.php...imitations   It is an upper airway restriction that causes the flow rate of inspired air to slow before inhale ends.  The appearance on the flow chart is a flattened or downward sloping top on the inspiratory wave, rather than a nice rounded shape.  The restriction of flow means that you may not get a full normal breath, and this can cause a RERA (respiratory event related arousal), which is the type of event you have.  So this is a form of sleep disordered breathing that can result in sleep disruption. http://www.apneaboard.com/wiki/index.php...erapy#RERA

I tried your suggestions and it did get rid of the RERAs. Here's some of the things that I noticed. Having the EPR set at 3 slightly increased my respiration rate (probably because it was easier to breathe out) and it lowered the flow limit. Thank you for your suggestions. I wouldn't have thought to do that. It was quite interesting learning about EPR and how it effects EPAP rate. It's like you can set up the ResMed Airsense 10 Autoset to kind of perform as a Bipap machine, lol. 

You can correct me if I'm wrong, but wouldn't it be better to look at the average tidal volume (and oxygen de-saturation) when trying to diagnose flow limitations? I say this because depending on how much you zoom in or stretch or minimize the size of the actual flow chart, you can manipulate the shapes of the flow pattern (for example making the tops flat looking so it looks like a RERA, or by stretching it to make them look steeper). Wouldn't there need to be some type of standard?

Also, I thought that my average tidal volume would increase because of the pressure changes, but it stayed the same at 400 mL. I read from google that the average is about 500 mL and that you can also take your weight in kg and multiple by 7 mL to get a reasonable figure. I weight just over 100kg, so that puts my estimated tidal volume around 700 mL. My current TDV seems extremely low. 

The reason why I'm concerned with this is because it would seem to me that the larger the tidal volume, the more air (and hence oxygen) would be able to reach your lungs in each breath. So there'd be a greater increase in oxygen exchange in the lungs. But maybe I'm over thinking this. I guess you would also need to take into consideration the respiratory rate as well if you wanted to see how much oxygen you were getting per minute. I guess if I was worried about my low tidal volume cause oxygen desaturations, I could just wear a pulse oximeter. Idk, do you think this is anything to be concerned about? 


PS.
Btw, I feel freakin amazing! This is the second day that I got up early (around 7am) and I didn't even need an alarm clock. I felt completely alert with no fatigue or anything. Today, I actually had to force myself to go back to sleep because I could've gotten up around 5am. All my life, I have always slept on average 9-10 hours and if left to my own devices, I would sleep about 12 hours. I can't believe how much of a difference it is making. And quite honestly, I'm shocked at the low AHI readings that I've been getting. I really thought it was going to take at least a couple of months of trial and error to get below 1. That was my main goal. I'm starting to wonder if my machine is broken, lol. Idk, maybe I'm just a good responder to CPAP therapy. If this keeps up, I'm going to have to write a cpap success story on the sticky.

[Sleeprider]

Excellent results, and good questions.

You can correct me if I'm wrong, but wouldn't it be better to look at the average tidal volume (and oxygen de-saturation) when trying to diagnose flow limitations? I say this because depending on how much you zoom in or stretch or minimize the size of the actual flow chart, you can manipulate the shapes of the flow pattern (for example making the tops flat looking so it looks like a RERA, or by stretching it to make them look steeper). Wouldn't there need to be some type of standard?

Inspiratory flow limitation is a slowing rate of flow (mL/second) during inhale. Tidal volume is the total exhaled volume in mL in any breath. We can reduce inspiratory restriction without affecting expired volume, so these two variables are independent. Notice your inspiratory time is slightly shorter (1.52) at EPR 3 than at EPR 2 (1.60). Your inhaled the same volume of air but at a faster rate, so tidal volume did not change. The lower effort is why you feel better, even if it didn't really change your volumes. As far as a standard appearance, I try to get members to post flow rate zoomed shots that cover approximately a 2-minute interval. That gives me a consistent look at what is going on, but I also look at the respiratory statistics in the left column to understand what is going on.

The reason why I'm concerned with this is because it would seem to me that the larger the tidal volume, the more air (and hence oxygen) would be able to reach your lungs in each breath. So there'd be a greater increase in oxygen exchange in the lungs. But maybe I'm over thinking this. I guess you would also need to take into consideration the respiratory rate as well if you wanted to see how much oxygen you were getting per minute. I guess if I was worried about my low tidal volume cause oxygen desaturations, I could just wear a pulse oximeter. Idk, do you think this is anything to be concerned about?

The more appropriate metric to watch is minute vent (L/min), which is the product of tidal volume (mL) and respiratory rate (BPM). So you are correct that the respiratory rate needs to be taken into account. In your case, we only increased EPR by 1-cmH2O, so the changes were not very dramatic but you "felt" the difference, and it was sufficient to overcome most of the residual upper airway resistance and flow limitation. To get to the next level, you need a true bilevel which is not limited to pressure support of 3-cm. Your results are outstanding and we were only tweaking the settings to optimize them. I would not waste my time or money on an oximeter in your case.