The Oxygen Bleed Adapter is inserted into the CPAP/BPAP circuit to allow oxygen to be mixed into the respiratory circuit. Oxygen is always provided at higher pressure at a set flow-rate, so the dose can be calculated. Several bleed adapters are available, and they are inexpensive. The images below show oxygen bleed adapters for both standard and heated tubing.
[[file:oxygen bleed adapter Standard.png]]
[[file:oxygen bleed adapter Standard.png|thumb|none|Oxygen bleed adapter]]<br />[[file:oxygen bleed adapter heated hose.png|thumb|none|Oxygen bleed adapter connected to PAP]]<br />
=Physical Characteristics of an Oxygen Bleed=
=xPAP Flow Rates vs Pressure=
The following chart shows the expected flow rate for several Resmed mask models and types at different flow rates. These flow rates are for a perfect circuit without unintentional mask leaks or mouth breathing, and so are a conservative estimate of the total flow in an xPAP circuit for different types of masks. It is clear that different mask types have different expected flow rates. Nasal masks have the lowest designed leak rate, followed by nasal pillows, and finally full-face masks. Most new masks include an owner's manual that provides the exact flow/pressure relationship at the back of the manual.
[[file:Resmed Flow vs Pressure.png|thumb|none|1000px|ResMed pressure vs flow for masks]]<br />