Why is CPAP capped at 20cm?

[robertbuckley]

Walla Walla - In Bi-Pap mode there is a spread between the ex and inhale pressures - the 25 is an inhale. In CPap the 20 is for both, and thus limited.

[Walla Walla]

Robert, Thank you. I have a BIPAP and know you can setup the IPAP and EPAP both to 25 cm which would be the same as a CPAP that went to   25 cm. Since you can do that why do they cap CPAP mode to 20cm on the BIPAP?

[robertbuckley]

Very good question. I do not know. But from a practical matter, have you ever tried to exhale against 20 or 25 cmH2O pressure?

[Walla Walla]

Robert, Yes last night my EPAP maxed out at 22.5 cm. Once you get pass the first breath or two it's no big deal. Some people think 10 cm is a lot of pressure. But once they get use to it they don't even notice. The two things I do notice though is the air stream exiting the mask is stronger and the humidifier clicks a little due to the pressure. I can't prove it but I'm beginning to believe it's all about marketing. If you want a higher pressure you have to buy the more costly BIPAP Machine. They could make a CPAP at 25cm but it wouldn't make them any more money.