Lengthy Obstuctives and ResMed S9

[empezza]

Hi,
My ResScan detailed report for last night included one Obstructive for 36 seconds. The pressure only rose to 8.82. My machine is set at Minimum Pressure 6.0 and Maximum Pressure 16.0.
I had 9 obstructives in total during the night - one for 36, one for 26 and another for 21 seconds.
I have a ResMed S9 machine with humidifier that is 3 1/2 years old - Never had any problems with it. I don't go back to my Specialist until June 2014.

Could there be a problem with the S9? Why didn't the pressure increase above 8.82 to stop the Obstructive?

Hope that someone can assist me!

[robysue]

APAPs do not raise pressure during an apnea in an effort to make you breath----that would make an APAP into a noninvasive ventilator and it would be a much more expensive machine like an ASV.

APAPs wait until the apnea is over. And if even then, the machine won't typically raise the pressure unless the apnea is the second event to occur in a relatively small amount of time like 5 minutes or so. APAPs will raise the pressure in response to snoring and flow limitations since these are thought to indicate the airway might be in danger of collapsing. The idea is to raise the pressure before the airway actually collapses.

The idea behind how the APAP algorithm(s) work is this: If two or more events happen close to each other, the current pressure is clearly not sufficient to prevent the airway from collapsing in the (near) future. And pressure is used to prevent future events from happening; pressure is not used to try to "end" an on-going event.

If you are concerned about the length of the OAs that get through the APAP defenses, you might try raising the minimum pressure setting on your APAP or reducing the EPR setting if you have EPR turned on.