High pressure kicking on immediately after exhaling

[drewbiedoo]

Hi all,

I've been using a bi-pap for about 5 months now and things were going fine until about a month ago - one of my kids might have messed with the settings?

My pressure is 4psi exhaling and 7psi inhaling. Most of the time, I'll inhale, the pressure will increase normally, I'll exhale, the pressure decreases normally. However, a few times each night I wake up because the machine is switching to high pressure immediately after I finish exhaling, which does not coincide with my normal breathing pattern (usually a couple seconds between the end of exhaling and the next inhale).

I called my provider who said to change the Bi-Flex setting to 3, which did reduce the frequency of this problem, but has not removed it.

Again, this is inconsistent throughout the night.

Does anybody have any suggestions as to what the problem is and how to fix it?

[trish6hundred]

Hi drewbiedoo,
WELCOME! to the forum.!
Hang in there for answers to your question and much success to you with your CPAP therapy, and getting your pressure problem straightened out.

[Ailu]

Boy, the only other thing I can think of besides a mechanical issue, is maybe the filter on the machine needs cleaning or replacing? A clogged filter could potentially cause pressure anomalies...

[Sleeprider]

Biflex set to 1 gives a faster transition, and Biflex set to 3 is a slower EPAP/IPAP transition. So for what you're concerned about, it sounds like you got good advice. It's unlikely the kids were able to get into the clinical settings, but you should certainly check. Instructions for accessing the clinical menu for your machine are here http://www.apneaboard.com/adjust-cpap-pr...tup-manual

You can also send an email to apneaboard@gmail.com and put "Setup Manual" (without the quotes) in the subject line. Then, in the body of your email specify: Respironics PR System One 60 Series BiPAP Pro with Bi-Flex

[justMongo]

Just an FYI, PAP pressure units are cm-H₂O. 7 PSI would blow your lungs apart.

[Sleeprider]

With a BiPAP you have an alternative to using BiFlex. With Biflex disabled you can adjust the "rise time". Rise time is the time it takes for the device to change from EPAP to IPAP. This screen allows you to adjust the rise time so you can find the desired setting. This is only available if Flex has been disabled and the device is in Bi-level or Auto Bi-level mode.
• 0 (off) reduces the Rise Time feature to the lowest setting (off = 150 msec).
• 1 sets Rise Time to 1 (200 msec).
• 2 sets Rise Time to 2 (300 msec).
• 3 sets Rise Time to 3 (400 msec).

So if you are still feeling the machine rushes you to the next inhale, a higher rise time will slow that transition from EPAP to IPAP.

[drewbiedoo]

Thanks all for your replies. Sorry I haven't continued to participate in the discussion, but life has finally slowed down. Whether elicit replies or for the sake of posterity, my findings are below.

I returned my machine for a new one and the new machine continued with the same problem.

The BiPap machine switches to the high pressure setting when it senses a drop in pressure. The "assumption" that the bipap is making is that any drop in pressure in the user inhaling. Unfortunately, an air leak elsewhere in the system (usually the mask) also causes a drop in pressure, which the bipap treats like an inhalation.

After figuring this out, I went through 4 different masks, attempting to find something with zero leakage. I've come pretty close with a nasal pillow setup (can't remember the name off-hand) that has a plastic stabilizing frame.

Still, my machine continues to switch to high pressure immediately after inhalation, though not quite as often. There have been times when I am certain no leak is coming from my mask, but the pressure issue persists.

It hit me yesterday that the air leak may be occurring within my humidifier. There are 3 rubber connecting points (1. from the bipap to the humidifier, 2. to the tank, 3. from tank to the hose), any of which may leak air at a given time, causing the bipap to "think" I'm inhaling and react accordingly.

When I was having issues last night, I removed the humidifier and connected my hose directly to the bipap and the pressure issue disappeared almost entirely.

I checked the connectors this morning and found no damage, corrosion, bending, flexing or anything of that nature. Maybe it's just not fitting correctly. Maybe I push the tank too hard into the humidifier, which prevents a good seal on the 3rd rubber connector.

Until next time...

[Sleeprider]

Drew, all of those silicone connectors are removable. I would remove and clean each one and ensure it is reassembled properly. It sounds like you're getting closer to finding the issue by process of elimination, and that is commendable work. The seals on the inlet side of the humidifier are called the dry-box seals, and replacements are available. The humidifier lid seal is also available. It's possible one of those is just not seated properly.

[drewbiedoo]

I didn't realize they are removable. Is there any trick to removing and replacing without damaging them?

Best
Andrew

[Sleeprider]

They just pull right off. I have done it many times, especially when reconditioning a used machine. They should seal well if cleaned and applied wet, but you can use a FDA food grade o-ring sealant if you want. It just lubricates and seals and is odorless. If there is ANY damage, they should be replaced. Look for Dry Box seal and Inlet seal under Supplier #1. They are only $4.95 plus shipping. The Humidifier Elbow Seal for the humidifier lid is 5.95.