Bipap versus auto CPAP

So I admit as a newbie, I'm kind of confused as to why/when BiPAP is used as opposed to auto CPAP. What are the pros and cons of each type? What circumstances would make one preferred over the other?

Generally speaking, bipap is used with higher pressure. The bipap machines allow a larger difference between the inhale pressure (IPAP) and exhale pressure (EPAP). The difference between the two is called pressure support. CPAP machines only go to 20 cm H2O while bipap machines go to 25 cm H2O. Auto cpap will give a range of pressures up to 20 cm H2O but have an maximum EPR of 3 cm H2O. At 20 cm you would be trying to exhale against 17 cm pressure. My machine runs 20 - 25 cm H2O with a pressure support of 5 cm H2O which give me an EPAP of 15 - 20. It very seldom goes much over 20 cm, but it can if necessary.

So if I'm understanding this correctly, if you have to use high pressures to control apnea, the advantage of bipap over auto CPAP is the exhale pressure can be 5 cm H2O lower than the inhale pressure with bipap but only 3 cm H2O lower with the autoCPAP. So that would be a lot more comfortable for the user? Would this also reduce aerophagia?
Thanks for the explanation (and as a bonus, I now I also understand what IPAP and EPAP are!)

Helpful thread. Learned new stuff today as well.

Sent from hell

Bilevel machines help people with bad aerophagia caused by cpap pressure...commonly associated with higher pressures but people can have significant aerophagia issues with as little as 7 or 8 cm pressure and get a bilevel machine.
Even if aerophagia hasn't reared it's ugly head for people needing pressures in the teens...sometimes it's just difficult to exhale against those pressures and bilevel's way of doing inhale and exhale offers a lot more comfort.
I will explain further when we get a chance to chat.

Keep in mind with all that pressure difference, my mask would bounce up and down on my face all night (like a yo-yo). Large pressure changes can cause a lot of action. Still... folks would need the bipap have achieved successful therapy.

Sheriff