bipap problem

My Respironics System 1 is driving me crazy. It is set at AUTO, starts at 8.0 psi and doesn't seem to have an upper limit. When I toss and turn, my mask dislodges and the bipap psi increases, last nite to the point where I had to turn off the machine and start over. This morning when I awoke the psi was at 23.2 and my mask would leak with every breath. Any ideas?

Thanks for your help.

easylivin,

First, let's get the units correct: The pressure on your System One is measured in centimeters of H2O (cm H2O or cm for short) instead of "pounds per square inch". One cm H2O equals 0.0142 psi.

Next, you say the machine is a System 1 BiPAP set to Auto. It's important for dealing with your problems to know what the exact therapeutic settings are. If you are using a BiPAP in Auto BiPAP mode, there are four important settings that you need to find in the clinical menu:

Min EPAP =
Max IPAP =
Min PS =
Max PS =


These four settings induce two other "settings" for your machine:
Min IPAP = Min EPAP + Min PS
Max EPAP = Max IPAP - Min PS

You write:

easylivin wrote:My Respironics System 1 is driving me crazy. It is set at AUTO, starts at 8.0 psi and doesn't seem to have an upper limit.

I suspect that either min EPAP = 8.0 or Min IPAP = Min EPAP + Min PS = 8.0. But from what you've written I can't tell which. When you put the mask on and turn the machine on WITHOUT hitting the ramp button, the numbers on the machine's LCD should switch back and forth between an E (EPAP) number when you are exhaling and an I (IPAP) number when you are inhaling. What are BOTH numbers?

When I toss
and turn, my mask dislodges and the bipap psi increases,

The airflow into the mask increases in an effort to maintain the desired pressure within the pressurized system made up of your airway, the mask, the hose and the blower unit. It does NOT increase the pressure in response to leaks however. And if the leak is large enough, the machine will actually lower the pressure setting in an effort to get the mask to reseal.

last nite to the point where I had to turn off the machine and start over. This morning when I awoke the psi was at 23.2 and my mask would leak with every breath. Any ideas?

It sounds like your max IPAP is set to 25 cm H2O and that the machine is finding an excuse to raise the pressure up to (or close to) the maximum settings.

Looking at the data in SleepyHead would help us figure out why your machine is increasing the pressure to such a great extent. In general, the System One BiPAP increases the pressure for the following reasons:

• Clusters of two or more OAs and Hs. A cluster is when two or more events are scored within about 2 minutes of each other.
• Snoring
• Flow limitations
• RERAs
• The "Search" algorithm detecting improvements in the shape of the inhalations during a periodic "test" pressure increase.

It's also important to understand that wake breathing is much less regular than normal sleep breathing. And this can cause normal wake breathing to be mis-scored as sleep disordered breathing by the machine: The System One has no way to tell whether you are wake or asleep when you are using the machine. So if you were tossing and turning for a significant time while drifting back and forth between sleep and wake, it could be that the machine mis-scored some wake breathing as sleep disordered breathing and increased the pressure as a result.