No air provided if no inhalation on BiPap?

[sharonious]

A DME told me that the bipap does not work if one does not inhale. If I hold my breath on bipap, it never starts up again. I tried it and it does not begin again until I inhale (well, as long as I could hold my breath). One of my studies showed some minimal CSA and so I found what DME said to be scary. When I asked doctor, he said, absolutely not. Bipap's purpose is to provide (force) air when it does not occur naturally. DME said my machine does not have rate set. Any thoughts from you would be welcome. Thanx!

[rested gal]

A DME told me that the bipap does not work if one does not inhale.

During exhale and after the end of the exhale (during the pause before you start to inhale again) a bipap IS working...it is maintaining the EPAP pressure.

If I hold my breath on bipap, it never starts up again. I tried it and it does not begin again until I inhale (well, as long as I could hold my breath).

It has not stopped providing pressure. It is blowing the EPAP pressure. What you're describing as "it never starts up again" when you hold your breath is that it is not switching to the IPAP pressure until you start to inhale. That's the way "regular" bipap (one that doesn't have timed backup capability or an ST machine that doesn't have a timed rate set) is supposed to work. EPAP pressure will keep blowing until you start to inhale. Then the IPAP pressure will happen.

One of my studies showed some minimal CSA and so I found what DME said to be scary.

some minimal CSA...I wouldn't worry about that. If your main problem is obstructive apneas/hypopneas, OSA is what the machine needs to take care of.

When I asked doctor, he said, absolutely not.

I guess you mean the doctor said the DME was wrong about bipap "not working" until you inhale?

Bipap's purpose is to provide (force) air when it does not occur naturally.

I guess that's still quoting the doctor. Sounds like he's thinking about more than just a "regular" bipap in spontaneous mode. Sounds like he's thinking more along the lines of a bilevel machine with S/T (spontaneous/timed) capability.

DME said my machine does not have rate set.

Still a bit unclear. Do you have a bilevel S/T machine that could use a backup rate (if a rate were set?) Or do you have a regular bilevel (without "S/T" or "ST" or "STA" in its name.)

No matter what, Sharon, if OSA were the real reason I'd been prescribed a machine, I wouldn't worry at all about "some minimal CSA" having shown up in the study. But I'm not a doctor or anything in the health care field.

Links to Central Apnea discussions

[christinequilts]

There are two basic classes of BiPAP- BiPAP S and BiPAP ST. BiPAP S, usually what people mean they say 'BiPAP', is the most commonly used type of BiPAP SPONTANEOUSLY follows your breathing pattern to switch from EPAP, lower exhale pressure, and IPAP, higher inhale pressure. If you don't inhale, it will continue at the EPAP pressure, which is why it is just as important as the IPAP, especially with OSA. They are extremely sensitive to the slightest change and will rapidly change to IPAP from EPAP if you make the tinniest effort.

BiPAP ST does the same thing, SPONTANEOUSLY following your lead unless you do not breath for a certain amount of time, based on a preset backup rate of breaths per minute. When that happens, it switches to the TIMED mode, where it controls switching from IPAP to EPAP until you begin to breath again, to attempt to encourage you to breath. Again, it doesn't take much effort for the machine to let the user take control again. Many people are mistaken that in TIMED mode, it forces you to breath- it cannot force you to breath no matter how hard it tries, as I well know as someone who still had 30+ central apneas per hour on BiPAP ST, down from 60+ without it.


You mention one of your PSG's showed minimal central events, that is different then having been diagnosed with Central Sleep Apnea. Just like someone who has less then 5 obstructive events per hour does not have OSA. It sounds like you have a primary diagnosis of OSA, correct? What did your titration studies show, as far as central events at your prescribed pressure? Did they go away? A BiPAP ST would only be needed if you had significant central events that were not adequately controlled with either CPAP or BiPAP.

BiPAP ST is much more expensive then even a regular BiPAP, as it is more complex, and the Timed backup rate can create more problems then it solves if the person doesn't need it. A good analogy would be walking- do you always take the same size steps and at a constant rate? Probably not unless you are in the Army or a matching band. The Timed back up rate can act like a Drill Sargent, telling you 'Left, Left, Left, Right Left' if you don't stay in step with it. Ever see new recruits learning how to march tripping over their own two feet? You don't want to be doing that in your sleep.