The lowest setting on most Cpap machines is 4.0cmh20. The lowest settings you barely even notice the pressure so I don’t think you would be mortal danger compa

The lowest setting on most Cpap machines is 4.0cmh20. The lowest settings you barely even notice the pressure so I don’t think you would be mortal danger compared to not using it all at that level. The problem is finding the correct pressure level because going too high can cause central sleep apnea events due to co2 washout. That’s why titration is done under the guidance of a medical professional for liability reasons. I wouldn’t buy a used machine online because you don’t know what kind of gunk, smoker residue or bacteria build up the prior owner had. If they kept up with the cleaning and filter schedule etc. Most advanced Cpap users who have a prescription use the SD card and look at all the logs and data in a program called Oscar it’s open source I think. I used that data to fine tune to reduce my central sleep apnea events reduce my apnea, hyponea and rera events.