daisy56 wrote:How important is the minimum air pressure number? Mine is set to 6 right now and seems fine I guess..not sure what it is I want with that number. I know my maximum number is set to 12 and so far I haven't gone pass 11 during my sleep. But my question is why and how do I know if I should set my number to a lower number...the reason I'm asking is because I wondered if I am able to be comfortable at a lower number, like 4 or 5... wouldn't I WANT to set it to that?
In general the min pressure number for an APAP needs to be high enough to be effective at keeping your airway open much of the time---as in at least 50 or 60 percent of the night. If the min pressure is too low, then even with an APAP, the pressure adjustment might not be fast enough to really keep the nastiest of your clusters under control.
For many people on the board, that means that the min pressure setting on an APAP needs to be within 2 or 3 cm of what their long-term 90% pressure reading is. In other words, many people with a 90% pressure reading of 10cm often find that the machine does a better job overall of controlling their apnea (and hence letting them sleep), if the min pressure is around 7 or 8 cm.
But---if you're not getting nasty clusters caused by the machine not ramping up fast enough AND if you're comfortable breathing at 6cm, there's no good reason to increase your min pressure just because others find they need to do so.
As for further reducing the min pressure to 4 or 5 cm. Well, the lower that min pressure, the longer the machine takes to get the pressure up to 10cm in response to your events. That may or may not be a problem, but it is worth considering. And then there's the problem that if your min pressure is set to 4 or 5 cm, sealing the mask is easy at the beginning of the night, but once the pressure gets up near 10cm, there's a real chance that leaks will start. Sealing the mask at the beginning of the night needs to be at pressures that are "close enough" to the maximum pressure that you might need during the night---where "close enough" typically means no more than about 4 or 5 cm below the expected maximum pressure.
As for comfort: There are some of us who are quite comfortable breathing with our machines set to minimum pressure levels---and often we also have rather low therapeutic pressure settings to begin with. But for many people whose therapy pressure is regularly above 8 or 9cm, trying to breathe at 4 or 5cm can cause
comfort problems---they'll describe the feeling as not getting enough air in through the mask or say that it makes them feel as though they are suffocating or breathing through a straw. Such feelings are often a major sign that the person is fully adjusted to breathing against their therapy pressure.
In other words, why would we want more air pumping into us that is really not needed, I feel like I'm making myself more dependent on it or forcing myself to need more air when or if I really don't need it.....I HOPE I have made sense with my question.. Lol
Keep in mind that the main problem with "too much air being pumped in" is aerophagia for those of us unlucky enough to suffer from it. The air being pumped in is just plain old room air so you're not going to become "dependent" on it in the sense of some kind of addiction.
And some other things to keep in mind:
1) Your diaphragm actually has to work a tiny bit harder
with additional air pressure because exhaling against the pressure is a tiny bit harder than just exhaling against ambient air pressure. And the higher your prescribed therapy, the harder your diaphragm has to work.
2) The APAP does NOT force you to breathe like a ventilator does. And hence the pressurized air from the APAP does NOT weaken your lungs or the muscles you use to breath. All the pressurized air does is make it physically much harder for your upper airway to collapse and close during the night.
3) At its maximum pressure setting of 20cm H20, the added pressure is about the difference between the ambient pressure on a bright sunny, "high air pressure" day and a dark and stormy "low air pressure" day. In other words, even if your APAP were set to maximum pressure, you are breathing against pressures that are pretty much "normal" as far as our bodies are concerned. This is also why we get used to breathing with the machines and eventually don't really notice our pressure all that much. (And hence the reason so many of us stick our hand in front of the vent when we wake up just to make sure the mahcine is still on.)
4) Yes, many of us do feel like we become dependent on the machines. But the dependence is not a physical dependence in the sense that we can't breathe without the additional air. The emotional/psychological dependence comes from our brains and bodies realizing just how much better it feels to sleep without the constant battle with the apneas. I'll use myself as an example: Pre-CPAP I never consciously woke up with to a feeling of choking or not being able to breath because of my apneas and hypopneas---indeed, my problem was primarily with "hypopneas with arousal"---my body would arouse itself just enough to restart the breathing before any serious O2 desats occurred and these arousals were not long enough for me to remember the next morning. Now? If I accidentally fall asleep on the couch or in the recliner without my BiPAP, I find that I do startle myself awake with a feeling my breathing is just not right. My brain and body both resent having to arouse to restart the breathing over and over and over now. And it's not that my body is physically dependent on the air being pumped into my lungs that causes this problem----it's that my body and brain resent being expected to wake up every few minutes when trying to sleep. And since it's no longer normal
for my body to have to do this when I'm sleeping, the arousals from the hypopneas are much more likely to cause me to arouse all the way to WAKE than they did pre-PAP.
Thank you in advance so very much. I get these questions in my head and it bothers me so much until I understand.
I'm dealing with Tinnitus (ringing in ears after a sudden moderate hearing loss this past October) so I have been on a chat
forum more for this condition than I have been on this sleep apnea site. I need to take time to read more on here and learn more by reading, but I was diagnosed with sleep apnea and Tinnitus in the same month and it has been a real struggle...Thank you for soooooooo very much for answering my random questions.
It's a bummer about the Tinnitus. I've suffered from it most of my life. Fortunately for me, most of the time mine is not painful and is pretty easy to ignore. One thing that works for me is always trying to have some verry,very soft background noise around. The background noise can be white noise, nature noise, or very, very soft music, but I need to keep the volume really low---the idea is not to drown out the tinnitus, but rather give it some competition for my brain's attention.