williamwu1107 wrote: ↑Wed May 07, 2025 10:43 am
How are positive pressure ventilators currently used to handle
RERA and Flower Limitation events?
1) CPAPs and APAPs are not ventilators. Whether one considers a bilevel PAP machines like a Resmed VAuto or a PR BiPAP a ventilator or not is a slightly different question, but these bilevels do NOT have the ability to
trigger an inhalation in a person using the machine. Machines like bilevel ST and ASV machines can be set to attempt to trigger inhalations, and may be considered forms of non-invasive ventilation, but they are also not used to treat plain old ordinary sleep apnea and RERAs or flow limitations.
2) Auto adjusting PAP machines will typically raise the pressure when their algorithms detect changes in the flow rate that indicate a
RERA may have occurred or that the inhalations have characteristics of flow limitations. (Flower limitation must be a typo.) How big of a pressure increase will be triggered depends on a whole bunch of things: The machine's proprietary algorithm; how many RERAs are scored in a short period of time; how distorted the inhalations actually are and whether the distortion gets any better with a slight pressure increase; and whether the RERAs/flow limitations are being recorded in the presence of snoring and/or OAs and Hs. A fixed pressure machine (ordinary CPAP or a fixed pressure bilevel) probably won't even bother flagging breathing passages that might indicate a
RERA or flow limitation has occurred.
3) In general: You want the
minimun pressure setting on an APAP (or auto adjusting bilevel) to be set high enough to prevent most obstructive things from happening during most of the night. In other words, if you are using an APAP and you see a lot of RERAs or flow limitations in the data
and you have reason to believe that the flow limitations are actually disturbing your sleep, then it's worth bumping up the minimum pressure to around the median pressure level recorded over several nights data. (Some people would argue to just bump it up to the 90% or 95% pressure setting, but that can lead to aerophagia problems and/or potential problems with CAs in some people.)
williamwu1107 wrote: ↑Tue May 13, 2025 10:44 am
Can the use of BiPAP solve
RERA and Flower Limitation?
Whether the additional pressure support available on a bilevel (PR BiPAP Auto or Resmed VAuto) will do a better job of addressing problems with RERAs and flow limitations than an APAP is a murky question. On a Resmed VAuto, when flow limitations and/or RERAs are detected, both the EPAP and IPAP will be increased by the same amount. On a PR BiPAP Auto? only the IPAP will increase when flow limitations or RERAs are detected. So it's not at all clear to me if the fact that PS (i.e. IPAP-EPAP) can be set to more than 3 on a bilevel machine might help with attempting to reduce the number of RERAs and the amount of flow limitation being recorded by the machine.