Let's say you're in spontaneous/timed mode, and you have a central apnea or for whatever reason don't trigger an inhalation (or your respiratory rate naturally tries to decrease below the set backup rate), it will force a breath at the set Ti (inspiratory time) and backup rate until you start breathing again spontaneously.palerider wrote:
The Ti setting (according to the manual I've got) ranges from 0.5 to 3.0, so, is that meaning how long it'll stay at IPAP?
That's much less flexible than the way Resmed does it.
When you're spontaneously breathing, on a Respironics bi-level, the Ti setting is essentially muted/non-existent. There is no guaranteed minimum inspiration time. This is at best annoying and uncomfortable, and at worst problematic, especially for someone like a neuromuscular disease patient. Because their neural inspiratory time is short (because breathing rapid and shallow is a defense mechanism, it lessens the work of breathing on the muscles), they will keep their shallow, rapid breathing pattern while sleeping, causing premature cycling from IPAP to EPAP - which basically results in insufficient inhalations / inadequate gas exchange.
That is why ResMed is smart to highlight the importance of Ti min - on the internet there are so many stories of people having synchrony problems with their machines, which is often due to the aforementioned issues. I actually had some of these issues but SleepyHead is helpful when you zoom in on the flow chart and see the shape of each breath - I slowly adjusted the Ti min/max and Rise time until I stopped seeing inhalations getting cut off and each breath looked more "smooth" like it was in sync with me.
