Answer: i am a respiratory therapist and i have frequently tested people, set them up with a cpap/bipap machine in the community and hospital settings. basically the machine will give a constant pressure in (cmh20). the average pressure is 10 usually no greater than 24. some people require bipap which is a higher pressure on inspiration. some people require a back-up respiratory rate on the machine or even oxygen entrained. the majority of people use only cpap. your doc will prescribe the correct pressure to prevent upper airway obstruction. you will probably want to use a nasal mask at first versus a full face mask. some docs won't even prescribe a full face due to the aspiration risk and (very low however) and lack of humidification at night. it will take several nights to get use to it if you require it at home. do not worry there is no danger in using cpap at your sleep lab. at first it will be uncomfortable but you will sleep better when you continue with your therapy. if you do need cpap at home, your machine is worth greater then 2 grand. do not pay more than 300 dollars for your mask and tubing. some provinces in canada will pay for your machine some make you buy it. you may also want to invest in a heated humidifier at home but i would recommend waiting to see if you need it. another note is if you are having a second test your first test must have shown obstructive sleep apnea. usually they only do the second part if your first shows something