just4lizzy: sorry i didnt pay enough attention to the end of your 1st message.
There IS a way to adjust the machine to let you exhale much easier! The System Ones, including the Pro have Cflex. When Cflex is on, when you begin to exhale, the machine will cause the pressure to drop a little, to make exhaling easier. I got a replacement machine once that did not have it set to enabled and I couldn't tolerate it. I don't have my machine right here now, but i'll try and remember: You need to check settings, then turn the button to highlight Cflex and then press the button. Cflex must be "enabled". If not, you may need to take it to your DME or have them send a rep by to enable it. If it is enabled, you can set it at 1, the least drop or 2 or 3, with, I think, 3 giving the most pressure dip to allow you to exhale easier. You can actually hear and feel the drop when you exhale. You can turn the button until Cflex demo
is highlighted and push the button to try it. Let us know how you make out! Scott