(10-04-2016 08:33 PM)Patrick Chang Wrote: Hi Rich,
Thank you very much for your reply.
In fact I am iquiring on behalf of my son, 16 yr.
The reason I am stuck on chosing between the ST and ASV machine is that I would like to get the right machine to use for long term, and with extra functions that may be needed in the near future.
My doctor has diagnosed me of mixed apnea, obstructive and central, also with stuffy nose at night, and conditions change often. I have been using a Fisher CPAP machine for over a year, and had already used the sleepy head.
With that CPAP machine, my apnea rate remain very high, over 60.
Recently I have got both ST and ASV machine on loan to try out. And with each machine, pressure set at 16/12, my apnea rate has dropped below 1, and sleep only about 6 hours every day feeling rested well. Before, with the CPAP machine, I could sleep 10 hours and still feel tired.
Is it enough just sleep for 6 hours? Shall I try to sleep longer even I do not feel sleepy or difficult to remain sleeping?
Thanks aagain for your help
Patrick, a pressure of 16/12 can be accomplished by regular bilevel or auto bilevel. What distinguishes the ST is the ability to work with both spontaneous breathing (like other bilevels), AND to switch to IPAP when not enough breaths per minute are taken. It is mainly used for restrictive or obstructive pulmonary disease or obesity hypoventilation.
ASV on the other hand, can use auto bilevel with variable EPAP and IPAP as well as variable pressure support (PS). So it uses a minimum PS used for ventilation and comfort, and maximum PS used to overcome central apnea. It generally takes PS greater than 8.0 cm to induce breathing in a central event, so on a breath by breath basis, you might see 20/12 or greater when a central is in progress, and the machine resumes 16/12 when spontaneous breathing is present. The very sophisticated ASV machines today, can run with much lower EPAP pressures, and still resolve OA with variable EPAP pressure, and CA with variable PS. Examples are the Resmed Aircurve 10 ASV and Philips Respironics System One 60 Series SV Advanced.
I doubt that your son requires ST, and the ASV machines are more versatile in dealing with complex apnea and centrals. Any of these advanced machines should be used and setup with professional guidance. While you have been diagnosed with "mixed apnea, obstructive and central, also with stuffy nose", this does not mean your son needs bilevel, ASV or ST. An auto bilevel like the one I use is appropriate and comfortable for obstructive apnea, but unless your son has a complex apnea or other pulmonary issue that has been diagnosed, moving to ASV or ST may be completely inappropriate.