In reference to Positive Airway Pressure Titration Task Force of the American Academy of Sleep Medicine. Clinical guidelines for the manual titration of positive airway pressure in patients with obstructive sleep apnea. Journal of Clinical Sleep Medicine 2008;4:157-171.

The Positive Airway Pressure Titration Task Force recommended in their guidelines for manual titration of positive airway pressure in patients with obstructive sleep apnea that “if the patient is uncomfortable or intolerant of high pressures on CPAP, the patient may be tried on BPAP.”1 Pressure relief CPAP or “C-Flex” is an alternative to BPAP when tolerance of high pressures is the reason for using BPAP. We found that BPAP frequently induced or worsened central apneas and periodic respiration among patients with OSA intolerant of CPAP, and that pressure relief is able to improve tolerance in these patients with less risk of exacerbating central apneas or complex sleep.2 If there are central apneas on C-Flex with comfort setting of 3, then lower comfort settings should be tried. The cost of pressure relief CPAP machines is lower that that for BPAP. We recommend that for OSA patients intolerant of high CPAP pressures, pressure relief CPAP should be tried prior to BPAP.