inhalation exhalation ratio worries

Have used breathing exercises that increase exhalation time for stress management -- increasing exhalation time promotes relaxation (the opposite of gasping and panting -- stress states).

So was worried last night when I realized that on CPAP my inhalation times are significantly greater than exhalation times.

I tried to slow exhalation down but it was very difficult on CPAP and I couldn't seem to get is longer than inhalation time.

(Am using a pressure setting of just 7 and C-flex set at level 3 -- which actually seems to make no noticeable difference in exhalation pressure.)

Normal inhalation/exhalation (I:E) ratio is about 1:2. On CPAP, mine is more like 2:1, quite a change.

Could reversing the I:E ratio like this bring about health problems or increased anxiety over the long run? Could impact quality of sleep?

Is there some type of CPAP that could yield a more normal I:E ratio?

(Was awake much of the night worrying about this!)

My sleep Dr. told me (when I became alarmed that my breath rate was a whopping 22 to 24 bpm!) that when you have weakened breathing muscles, your body usually finds it easier to breathe in more frequent, shallow breaths - almost like panting - than to use slow deep breaths. Let your body breathe the way it feels best. Trying overmuch to control this can put a strain on your muscles (hehe.... and your brain!)

That said, I do also practice pranayam (yogic breathing exercises), but at my own pace.

- JB

[quote="ahujudybear"]My sleep Dr. told me (when I became alarmed that my breath rate was a whopping 22 to 24 bpm!) that when you have weakened breathing muscles, your body usually finds it easier to breathe in more frequent, shallow breaths - almost like panting - than to use slow deep breaths. Let your body breathe the way it feels best. Trying overmuch to control this can put a strain on your muscles (hehe.... and your brain!)"

Did your breath rate ever improve much?

But rate of breath and I:E ratio affects bodily functioning. Panting rapidly will increase adrenaline levels, whether you're running from a tiger or doing it because of weak muscles. So I'm concerned about your doctor's pat answer. (Sounds like a brush-off to me.)

I find 1:7 breathing very pleasant and use it for relaxation. It isn't a strain but neither is it natural. I just something approaching a natural 1:2 I:E rate. That's the rate that life support breathing machines are usually set at -- for good reasons!

Did your breath rate ever improve much?

"improve"? No. That's the way it is. And I just learned this info about three weeks ago. My muscles are very weak and there is no prospect to improve on that. In deep sleep my breathing slows to about 8 or 10 bpm, but for no longer than about 5 minutes or so? And not every night at that. I only noticed it twice in three weeks' data from the BiPAP.

I can control my breath to make it slower, but only for a short time or the effort will cause chest/back spasms and eventually dislocated ribs. With those options, I can live with a rate of 22.

- JB

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So was worried last night when I realized that on CPAP my inhalation times are significantly greater than exhalation times.

I tried to slow exhalation down but it was very difficult on CPAP and I couldn't seem to get is longer than inhalation time.

(Am using a pressure setting of just 7 and C-flex set at level 3 -- which actually seems to make no noticeable difference in exhalation pressure.)

Sounds exactly like what happened to me when I started using C-Flex. I talked at length with a couple of the RT's at work and they told me that I was having "breath stacking." This was a new thing for me that had never happened before I used C-Flex. In essence, you are starting to inhale BEFORE you are finished exhaling --carbon dioxide builds up, heart races to deal with it, blah, blah, blah... not good.

I tried turning down the C-Flex to two, then one. I was still waking up panting several times during the night so, I turned the C-Flex off entirely and all was fine.

C-Flex is great for lots of patients, but for some, it is terrible. Try turning it off entirely and see how you do. I know that breathing out against the pressure can be difficult, but most manage to get used to it. At risk of sounding trivial, 7 is not an overly high pressure. I recognize that pressure tolerance is entirely idiosyncratic so please don't be offended by my comment that 7 is not overly high.

If you find that turning off the C-Flex resolves the problem but you still cannot get used to the pressure, you might try switching to a bi-level machine or, an autopap.

Good luck!

Hi gracie97. You have a very unusual problem or at least it is thought that you do. Assuming this is real, the only solution I know of is to move to a bilevel machine, preferably one with a timed mode. It may be that a higher IPAP (inhalation pressure) in relation to EPAP (exhalation pressure) will much shorten your IPAP percent. If it does not, the machine can be put in a timed mode that will allow the specific IPAP time to be set. Good luck. We care!

Gracie, I second WillSucceed's suggestion that you give your machine a try with C-Flex turned off.

I noticed that C-flex starts raising the pressure before a person is quite through exhaling. It starts that raise just a tiny bit prematurely for a reason. As best I understood it when SWS explained it (gawd, how we miss him here!), the prescribed pressure is supposed to come back in (with C-Flex) at the tailend before the exhalation is absolutely completed.

It deliberately does that slightly premature raise of pressure in order to make sure we get our full pressure again with no break between exhale/inhale. Prevents throat collapse at the end of an exhalation during the split second it takes for the machine to switch gears, so to speak.

That premature kicking back in of pressure with C-flex bothered me at first. When I felt (and heard) the pressure switch to going back up, I thought that meant I was supposed to start inhaling, even though I was not quite finished breathing out. Almost, but not quite.

I started taking slightly faster breaths, trying to match my breathing with the machine. A futile attempt, of course, since C-Flex is always going to start raising the pressure near the end of each exhalation...not after it. I wondered if something was wrong with the machine!

Once SWS reassured me that that was the way C-Flex was supposed to work, I was able to ignore the change in sound and the feel of that "kick-in". I relaxed and stopped trying to inhale until I was good and ready. I started breathing the way I wanted to instead of trying to match what the machine was doing at the end of an exhalation.

It might be that you're thinking too hard about your breathing pattern. The newness of all this, plus the way C-Flex changes the pressure up again when it senses the soft, dwindling last part of an exhalation could be making you feel like you need to rush into inhaling before you want to.

When asleep, most people probably wouldn't notice it, much less try to match it. (However, WillSucceed's respiratory system apparently was still subconsciously trying to do that in his sleep.) But while you're lying there awake, it definitely is noticeable....especially if you are deliberately trying to do very long, slow exhalations.

There's no way to get C-flex in perfect sync...no way to make it wait until YOU start your inhale. It is going to do its own thing, raising the pressure near the end of an exhalation....not at or after the end. The softer and slower the tailend of an exhalation becomes, the more apt C-flex is to start the pressure back up again.

You just have to ignore the pressure starting back up - or, turn C-flex off. I was able to get used to it once I understood that I really didn't have to try to play a game I couldn't win. I really wasn't expected to suddenly breathe in just because C-flex felt and sounded like it was saying, "Now!"

C-Flex can be disconcerting at first until you realize you are not supposed to try to keep up with it. From that point on, it's very easy for most people to get used to. I like the comfort of C-Flex, but some, like WillSucceed (and perhaps you) don't gee and haw with it well.

A bi-level machine, on the other hand, will let you dwindle an exhalation down to nothing, and even let you hold your breath at the end of the exhalation. The bi-level won't even start the higher inhale pressure (unless you have a bi-level with ST and have a backup time set) until you actually start to draw the breath.

C-flex jumps the gun a tad at the tailend of every exhalation. Bi-level, on the other hand, can cut off the top of a very long inhalation before it's finished. Each has its own way of handling things. Both have the goal of an easier, lower pressure to breathe out against.

At your pressure of 7, operating your machine at straight cpap with no C-Flex should be easy enough to breathe with and might suit you better.

Hmmm...

My PB 425 (BiPAP) sometimes gives me a breath while I'm still exhaling. It may be that my exhalation pressure has dropped enough to satisfy the machine, so it kicks in and ups the pressure for an inhalation experience - even though I may not be quite ready for it.

So maybe the 425 does act like an AutoPAP at times? I too have tried "chasing the timer" to no avail and eventually fall asleep. When I wake up the machine is in perfect sync with my breathing so that I often cannot even tell that it's on.
- JB

My PB 425 (BiPAP) sometimes gives me a breath while I'm still exhaling. It may be that my exhalation pressure has dropped enough to satisfy the machine, so it kicks in and ups the pressure for an inhalation experience - even though I may not be quite ready for it.

Does your PB 425 bi-level machine have an ST feature? If so, perhaps it's set for a timed backup rate?

The VPAP III (ResMed's bi-level machine) that I'm playing around with now is a VPAP III ST. When I had it set for Spontaneous/Timed, it was kicking into "Inhale" while I was still exhaling. Rather than fiddle with getting the "Timed" part adjusted to suit me while I was still getting familiar with the machine, I set it for just "Spontaneous." That completely stopped the premature kick-in of inhalation pressure. With "timed" no longer enabled, it waits for me to draw a breath, just like the Respironics BiPAP did.

I haven't gotten around to using the VPAP III ST in S/T mode again. Want to use it awhile as a bi-level that goes along with my breathing, before doing the more complicated adjustments needed for a Timed backup rate.

Not according to the literature - or the skuttlebutt. The company rep I contacted on line said that the machine with the S/T feature should be on the market sometime "later this year" (I think that was a message he sent in May?)

[quote="rested gal"]Gracie, I second WillSucceed's suggestion that you give your machine a try with C-Flex turned off."

Much thanks to you, WillSucceed and others who all provided useful ideas on this topic!

I had not been able to perceive the changes in pressure in the C-flex cycle (perhaps because 7 is such a low pressure) until I played around with it last night and paid close attention to what C-flex does at the end of the cycle.

Seemed like the more I tried to draw out the exhalations, the more C-flex fought back, forcing me to inhale.

The scanty user guide provided with the machine gives no clue about how to turn off C-flex altogether. Can you direct me to some source of that material? (Somewhere on this site?)

Perhaps it will become possible to use C-flex comfortably when I get more used to CPAP -- last night was my 4th night.

Although my pressure setting is only a wimpy 7, I'm thinking of pushing to try a biPAP or VPAP that would respond to how I want to breathe or could at least be set for long, relaxing exhalations.

Shouldn't my comfort and rest be a deciding factor, even if the data shows I can manage to breathe against level 7 pressure?

Why settle for breathing out against any appreciable degree of pressure at all if that can be avoided? We're supposed to be resting while we're asleep, and the more we can relax rather than forcing exhales the better.

Gracie 97 wrote

The scanty user guide provided with the machine gives no clue about how to turn off C-flex altogether. Can you direct me to some source of that material? (Somewhere on this site?)

Gracie: I'm very sympathetic to how uncomfortable C-Flex can be and, if your supplier is not available to quickly help you, send me a private message and I will assist you with turning it off.