cpap vs apap setting?

Currently using a cpap with Rx of 16 pressure.
If I switch to apap, will it automatically range up to 16 or just to naturally effective level?
If I'm having problems with 16 and want to lower it to test reaction (re gerd / gut symptoms, for example) do I have to request Rx for lower pressure on apap?
I guess what I'm asking is do need to request a switch to apap AND lower pressure, or just to a switch to apap?
Sorry if this is confusing. Not quite sure of basic differences re cpap and apap.
thanks, tom

If you need lower pressure part of the time, you may find an auto capable of giving you that pressure, and then going up to the 16 that may be necessary for the rest of the time.

At 16 how ever, you are also eligible for a bi-level machine. An APAP will change your pressure up and down, but supply the same pressure for inhalation and exhalation. A bi-level, on the other hand, can be told to supply separate pressures for inhalation and exhalation, which may be very helfpul when you have high pressure, like yours, and gastric symptoms.

Try to ask your doctor about a bi-level since the fixed pressure at 16 is intolerable.
And if a bi-level is recommended, try to get a bi-level auto.

Very helpful! Appreciate the quick response.

ozij wrote:If you need lower pressure part of the time, you may find an auto capable of giving you that pressure, and then going up to the 16 that may be necessary for the rest of the time.

At 16 how ever, you are also eligible for a bi-level machine. An APAP will change your pressure up and down, but supply the same pressure for inhalation and exhalation. A bi-level, on the other hand, can be told to supply separate pressures for inhalation and exhalation, which may be very helfpul when you have high pressure, like yours, and gastric symptoms.

Try to ask your doctor about a bi-level since the fixed pressure at 16 is intolerable.
And if a bi-level is recommended, try to get a bi-level auto.

Hi, the basic difference is that with Cpap you're at one pressure all night. Period. With an Apap (which you can also use just as a Cpap, but not the other way around - so no percentage in getting Cpap if you can get an auto) you'd normally set two pressures, the lower one close to or at your prescribed pressure and the other about 5 numbers higher - e.g. if your script says 10, then you'd set it for 8 and 12 or so, and if you have events that require more than 12 cm, the machine will aim to catch them before they 'arouse' you. However, if your settings are too wide apart (e.g. 6 and 15) and you need 13 to catch an apnea, it may not get there in time, which is why we tend to set narrow ranges rather than e.g. just letting the default machine settings of 4 and 20 try to deal with things - even though a lot of MD's, many of whom really do not understand how it all works, just prescribe Apap, thinking the machine will take care of it all, and the DME's don't bother to do more either. Which is half the reason for this forum, to help people understand what's what and why, and to help get you set up to a reasonable place with your machine to get the most effective therapy. Your aerophagia (gas type of symptoms... not the same as GERD) may be better on an Apap set to e.g. 14 and 18, because if most of the time you actually don't need more than 14, with only the occasional jump higher, your symptoms are likely to fade.