Differnce between BPAP and A-FLex??

[MrEGuy]

Just a stray thought, one of the features of the trial machine my wife is using is that it has A-Flex to reduce the pressure while exhaling. This also seams to be similar to what I believe BPAP is in that a BPAP changes pressure to help the user exhale. Is it that BPAP has a measured change in pressure while the change in pressure from A-flex isn't necessarily a controlled one??

[DeepBreathing]

I'm not an expert in Philips machines, but I believe the flex settings are limited to 3 cm pressure relief. With a bpap the pressure support can go up to 15 cm, so there is potentially a very substantial difference.

[Sleeprider]

Flex provides a flow based pressure relief of up to 2-cmH2O pressure. The Resmed machines with EPR (exhale pressure relief) provide up to 3-cm. It does result in lower EPAP, but unlike a bilevel it is limited to 2-3 cm, while bilevels can use pressure support of a much wider range. Even with pressure relief, the machines are classified as CPAP and have significantly lower prices than BPAP, but it does blur the lines a bit.

[PaulaO2]

Some things to help you as you go along:

http://www.apneaboard.com/wiki/index.php...ical_terms

http://www.apneaboard.com/wiki/index.php?title=Acronyms

[robysue]

Flex provides a variable amount of pressure relief at the beginning of each exhalation. The actual amount of pressure relief depends on both the Flex setting and the force of the exhalation. The maximum amount of pressure is roughly 2 to 2.5 cm when Flex is set to 3 and the exhalation is extremely strong. With A-Flex and C-Flex+, the pressure is increased partway back to the therapeutic setting during the second half of the exhalation and then is increased all the way back up as soon as the inhalation is detected. With SH 1.0 you can see Flex in action in the Pressure graphs for the PR machines.

BiPAP has both an inhalation pressure (IPAP) and an exhalation pressure (EPAP). The difference between IPAP and EPAP is typically in the 3-6cm range, but it can be allowed to be much greater than 6cm. The actual difference between IPAP and EPAP is fixed if you are using "fixed BiPAP" mode, but the difference between IPAP and EPAP is allowed to vary if you are using "Auto BiPAP" mode. At the beginning of each exhalation, the pressure is dropped from IPAP to EPAP. When the beginning of the inhalation is detected, the pressure is increased from EPAP to IPAP.

BiFlex allows the Flex exhalation relief system to work with the BiPAP algorithm. If BiFlex is turned ON, you get an additional variable amount of exhalation relief at the very beginning exhalation that is beyond just the drop from IPAP to EPAP. The amount of additional exhalation relief depends on the BiFlex setting and the strength of the exhalation. The pressure is increased back up to the EPAP setting during the second half of the exhalation. The pressure is increased all the way to IPAP when the beginning of the next inhalation is detected.

[MrEGuy]

Thanks for that. All clear now :-)