Respironics exhaust port effects

[eudofair]

Hi,

I'm a fairly new user this time, I last used a CPAP machine over 8 years ago, and they are very different now. I'm using a Respironics Remstar Auto with C-Flex and a Mirage Quatro mask. From the way it behaves I've figured out it's behaviour as follows. If anyone knows different please let me know.
When set on CPAP, not Auto and the exhaust port is partly blocked it reduces the fan speed to keep the pressure the same, til the blockage is removed, whereupon it sometimes remains stuck at a low speed and lower pressure than it should be. Quite a bit lower.
When set on CPAP Auto with Cflex and the exhaust port is partly blocked it registers it as if it were a breathing obstruction and ups the air pressure to higher than it should be. Sometimes it stays there when the exhaust blocking is removed and the pressure is Quite high. If this is so, is there a known and recognized way to cope with this? We turn the heat down at night and the head of our bed is right under a window, so head covering with the sheet is to be expected. Last night I tried a stiff piece of plastic bowed up and taped across a portion of the exhaust port and it Did seem better.

Thanks,

Eudofair.

[roster]

.........
When set on CPAP, not Auto and the exhaust port is partly blocked it reduces the fan speed to keep the pressure the same, til the blockage is removed, whereupon it sometimes remains stuck at a low speed and lower pressure than it should be. Quite a bit lower.
..........

On CPAP settings, the machine will change the fan speed to maintain the set pressure. Of course, if the exhaust port becomes partially blocked, the machine will very quickly detect increased pressure and immediately lower the fan speed to achieve the set pressure. When the blockage is removed the machine quickly detects a pressure drop and immediately increases the fan speed to achieve the set pressure.

The detection/adjustment is so quick that the fan speed is decreased as you breathe out and then increased as you breathe in.

Where do you get the idea that the machine "sticks" at a lower speed than needed?

On auto setting, the machine will not know the difference between a human airway blockage and a partial blockage of the exhaust vents. It may increase the fan speed as if you are experiencing a hypopnea. When the machines detect hypopneas and increase the fan speed, they do maintain a higher pressure for some time according to the algorithm instructions.

BTW, the exhaust ports are sized to prevent exhaled air from being rebreathed. If you allow the ports to be partially blocked, you run the risk of rebreathing too much exhaled air and having trouble getting enough oxygen to the lungs.

You have the right idea: Don't allow the exhaust ports to be blocked.

Regards,

[eudofair]

Where do you get the idea that the machine "sticks" at a lower speed than needed?

I've set the fixed CPAP pressure to 10 Cm H2o and after removing the exhaust obstruction it is running at 4-5 Cm for an extended period. From what you say this is probably a defective machine and I should have it looked at, correct?
Also, last night the plastic strip became unfastened on one side, so it was sticking straight up about 5 Cm. This really worked well, no over rev from CPAP Auto!! Great night's sleep!!

Thanks!

Eudofair.

[roster]

.............I've set the fixed CPAP pressure to 10 Cm H2o and after removing the exhaust obstruction it is running at 4-5 Cm for an extended period. ..........

Sounds defective.

Their is another possibility. How do you have the ramp feature set?

(I do not understand the comments about the plastic strip.)

[eudofair]

.............I've set the fixed CPAP pressure to 10 Cm H2o and after removing the exhaust obstruction it is running at 4-5 Cm for an extended period. ..........

Sounds defective.

Their is another possibility. How do you have the ramp feature set?

(I do not understand the comments about the plastic strip.)

Hi, I've not had the ramp feature turned on as I adapt quickly.
I've taped a plastic strip to stick up over the exhaust port of my mask to prevent blockage by bedding. It is working.
Thanks for the help!

Eudofair