Pressure settings -- How dangerous are they?

meister · Post by **meister** » Thu Apr 07, 2005 7:13 am

I was wondering if anyone had any thought on lowering the
pressure on your AutoPap TOO LOW? My understanding is
that you will not get enough Carbon Dioxide flushing going
on when the pressure is TOO LOW and you can asphyxiate.
Anyone have any ideas on lowering the settings below a
pressure of 6? Thanks.

wading thru the muck! · Post by **wading thru the muck!** » Thu Apr 07, 2005 7:22 am

The machine should be safe within the 4cm to 20cm range. I keep my bottom at 7cm to reduce my snores. You may also find that below 6cm it feels as though you are not getting enough air. I did use my PB 420E set with a range of 4cm - 12cm for several months with no problems.

Mikesus · Post by **Mikesus** » Thu Apr 07, 2005 7:29 am

I doubt that you would asphyxiate. As there are MANY people on VERY low settings and so far there are no reported deaths as a result of too low a setting, I would find that statement highly suspect. You might not feel comfortable, but you won't die...

In the infamous words of Peter Farrell of Resmed, "The treatment is as harmless as a bowl of cereal." and "...with 1.5 million machines out we have had a report of an earache in one ear."

Granted he is from a manufacturer, but the research tends to back him up.

The only things that I have read about too low of a pressure have been dealing with comfort issues, not CO2 washout.

meister · Post by **meister** » Thu Apr 07, 2005 7:57 am

If one can get down to a pressure of 4, then maybe there is still
hope to make the jump down to zero? Is a pressure difference of
4 really that significant?

Davidmcc · Post by **Davidmcc** » Thu Apr 07, 2005 8:51 am

I initially set my auto at 4 - 15 and found the 4 uncomfortable as though I had to actively inhale to get sufficient breath. I increased the lower limit to 5 a week ago and find it is more comfortable but I am experiencing a significant number of hyponeas. I intend increasing it to 6 tomorrow night and try that range for a week and will then increase it to 7 and see if the hypopneas significantly decrease. BTW my prescribed level following titration was 7.5 cm H2O. However, I am curious Meister. Why did you nominate 6 as the lower level?

meister · Post by **meister** » Thu Apr 07, 2005 9:11 am

My prescription is for BiPap 17/9 with S/T mode. I am currently
working my way down and am at a pressure of 6 on a PB 402e.
I am not sure who was going to get the most benefit from the
price of $7000 for the ResMed VPAP III that the DME wanted to hook me up to: either the Doctor or the DME??

2listless · Post by **2listless** » Thu Apr 07, 2005 9:26 am

My physician prescribed setting is 5-12. Caused no problems for me but the machine basically would hop right past 5 and up to 7. So, the unphysician prescribed setting is now 8-14. Also, if you are using the ramp setting, it causes a slow rise in pressure. To me it is more of a comfort issue- if the pressure is too low I have to put my hand on the exhaust ports to see if it is on. Do not like the feeling of suffocation from low pressure which I find noticeable with nasal masks.

Davidmcc · Post by **Davidmcc** » Thu Apr 07, 2005 4:13 pm

I was under the impression ramp setting is disabled in auto mode and only available in CPAP (with or withut Cflex) Is this not the case?

rested gal · Post by **rested gal** » Thu Apr 07, 2005 5:02 pm

You're correct, Davidmcc. Ramp is not available in any autos running in auto mode. Ramp is available only in cpap mode.

In fact, if a person is using a Remstar Auto and doing their own set up to run it as an auto (with or without C-Flex), they should set "ramp" at 0 (zero) when the "ramp" window appears in the menu.

If the machine has already been set for "APAP" (auto) or "AFLE" (auto with c-flex enabled) a time can be set, but it would be a big mistake to set it for anything other than zero. The options available - 2 hours, 3 hours, 4 hours - are not really "ramp" times. Those hours are for doing split night studies. The machine will deliver the lowest pressure possible and will not respond to any apneas, hypopneas, etc. that you have during those 2, 3, or 4 hours.

If you're running the Remstar Auto as an auto or as an auto with c-flex, and you fiddle with any settings in the "therapy setup menu" on top of the machine, be sure to keep "ramp" set for zero.

Mikesus · Post by **Mikesus** » Thu Apr 07, 2005 5:23 pm

However, the ramp button does serve a function when in APAP or AFLEX mode. Imagine you wake up and you are at your high end pressure, tap the ramp button and it will drop to the bottom pressure. Great to be able to get back to sleep! It is not a RAMP in the traditional sense, but it does allow you to start back at your lower pressure without having to turn it off, turn it on, turn the humidifier back on.

k8e · Post by **k8e** » Tue Mar 25, 2008 10:11 pm

Mikesus wrote: In the infamous words of Peter Farrell of Resmed, "The treatment is as harmless as a bowl of cereal." and "...with 1.5 million machines out we have had a report of an earache in one ear."
.

I have had an earache in both ears the two nights (really only a a few hours each time) that I have used the Resmed CPAP so far. Oddly, I didn't have any earache during the titration study in between the two Resmed uses.

I cannot see how the machine or the mask would have made any difference as the problem is caused by an inability to equalize the pressure once air is pushed into my middle ears via the Eustachian tubes. The first few times, I was not deeply sleeping, so I was able to pull the mask away from my face to open the Eustachian tubes and equalize the pressure, but the relief only lasts until the next time I swallow. And once I'm asleep, I can't be pulling my mask off myself every 5 minutes to fix the unequal air pressure in my ears. I'm very frustrated and disappointed because I finally got my CPAP after many delays and now it is hurting me.

I have no history of earache or ear infections at all prior to using CPAP.

bigk · Post by **bigk** » Wed Mar 26, 2008 1:18 am

Davidmcc - the Resmed has a settling function in auto mode.

The reason most people recommend 6 as a lowest setting is because they find it difficult to breathe at lower levels.

I changed my minimum setting to 9 after looking at the data I collected for a few weeks as my median pressure was always around 11-13 with a maximum of 15 (which is what the machine was set to). The funny thing is that when I increased my minimum to 9, the maximum now is 11-12. Weird.

cflame1 · Post by **cflame1** » Wed Mar 26, 2008 5:45 am

This thread is from 2005

NightHawkeye · Post by **NightHawkeye** » Wed Mar 26, 2008 6:08 am

Yeah, the thread may be old, but k8e currently has an ear problem he is looking for help with.

k8e wrote:I have had an earache in both ears the two nights (really only a a few hours each time) that I have used the Resmed CPAP so far.
...
I have no history of earache or ear infections at all prior to using CPAP.

A couple of things come to mind which I would try. First, would be going to an APAP. Many of us don't need our titrated pressure all night. With APAP, I spend most of the night at a much lower pressure. At higher pressures my eustachion tubes sometimes clog. I hate it when that happens. Usually, they clear quickly though, so I've never had a problem with ear infections, but I can imagine infections would be a problem if the tubes remained clogged for any length of time.

If you're already using a ResMed APAP, then switching to a Respironics APAP would likely help. Seems like I've seen that the ResMed algorithm is faster responding than the Respironics. Although I've never used a ResMed machine, I do use a PB420E APAP a lot and it exhibits very quick pressure changes. With the PB420E, my ears get clogged frequently because of those rapid pressure changes.

Anyway, bottom line is if I were you I'd want to try an APAP, with a first-preference of Respironics, to see if that helps.

Regards,
Bill

nosbig17 · Post by **nosbig17** » Wed Mar 26, 2008 8:08 am

I have found that pressures much below 7cm will cause the Active (an excellent but outragiously priced interface) to pulse up and down or in and out, however you look at it.

CO2 washout is one of my considerations when looking at a new interface. I look for a mask with the exhaleation vent which is close to the tip of my nose. Along those lines, it's a good idea to have plants in your bedroom to soak up the CO2 and replenish the oxygen.

Lately I've been thinking about having a plastic surgeon install a couple of flapper valves in my chest so that I can exhale directly from my lungs and therefore, have better oxygen flow.

Pressure settings -- How dangerous are they?

Pressure settings -- How dangerous are they?

So low is good -- how about zero?

Working my way down to zero

Low Pressure Setting

Low Pressure

Mask	Humidifier

Additional Comments: S9 Autoset, H5i, Resmed Swift FX, Resscan 3.10