(10-10-2015, 07:27 AM)Cookie Wrote: I also increased my PS to 2-6. I believe this is correct if the difference between my EPAP and IPAP is 6.5. I am not sure I completely understand the function of PS so if I am not thinking about this correctly let me know.
I think your new settings (Min EPAP 7.5, Min Pressure Support 2, Max Pressure Support 6, Max IPAP 14) are reasonable.
Increasing the Max IPAP and Max Pressure Support as you have done will likely allow your machine to (very slowly, within several minutes or even more slowly) raise PS as high as needed to avoid or reduce Flow Limitation, while also likely allowing the EPAP to be raised as much as needed to prevent other obstructive events. For example, if PS has already been automatically raised to 4, EPAP could be automatically raised as high as 10, if needed.
Pressure Support is the increase in pressure during inhalation. Pressure Support makes it easier for us to breathe. It does for us some of the work of breathing.
In my case I am susceptible to central apneas, and when a central apnea begins my ASV machine will immediately (within a few seconds) switch to a backup breathing rate and will immediately (within a few seconds) raise PS from my minimum up to perhaps 10, in order to do for me 100% of the work of inhaling.
When breathing on my own, my EPAP needs to be around 15 to avoid obstructive apneas and my Min PS may be around 5, resulting in my IPAP normally being around 20. This means PS is normally doing for me about half the work of breathing, which I like. This high Min PS setting makes it more likely that I may experience "CO2 wash out" which means my blood CO2 may become too low and therefore I may lose the drive to breathe, leading to more central apneas. But, since my ASV machine treats central apneas by automatically switching to a backup respiration rate of around 15 breaths per minute and (very quickly, within seconds) automatically raising PS enough to maintain nearly my normal amount of breathing airflow, central apneas are prevented and are not a problem for me.
In your case, you tend to have lots of Flow Limitation, which means the suction needed during inhalation to pull air into your lungs is causing your airway to narrow during inhalation, partially impeding inhalation. So, during inhalation you need the pressure to be increased, which Pressure Support does for you, reducing the effort needed during inhalation, treating Upper Airway Resistance Syndrome (UARS) and avoiding Respiration Effort Related Arousal (RERA).