IF oxygen concentrator - what kind of "mask"?

[Stephen Tashiro]

What kind of "cannula" or mask does a patient using an intermittent flow oxygen concentrator use? Is it the same cannula that is used for continouous flow oxygen ? I don't understand how the persons breathing is synchronized with the pulses of oxygen from an IF machine. Perhaps it isn't?

[Dave Richards]

For intermittent flow devices are triggered by a slight low pressure on the distal (patient) end. When the patient inhales they create a slight negative pressure--maybe on the order of 0.5 cmH2O or even less. This is enough to trigger the flow device to open and allow oxygen to flow. It's similar to a SCUBA regulator assembly although the device is placed on the concentrator or on a portable liquid O2 unit. sometimes they are put on an E-cylinder but there's less O2 capacity in the cylinder than in a small portable liquid unit. The patient might wear a mask but I expect most folks use a nasal cannula because it is less obtrusive.

[Stephen Tashiro]

Thank you for that very precise answer, Dave.

[Dave Richards]

You're quite welcome.