Oxygen FAQ
Up to date, expert answers to frequently asked questions (FAQ) about oxygen supply systems, respiratory care and pulse oximetry written by OCC & collaborators.
Oxygen Consumption & Cost Calculations
What is the maximum concentration of oxygen delivered for different non-invasive oxygen delivery device types?
Estimated Fraction of Inspired Oxygen (FiO2)
Nasal Cannula
1
0.24
-
2
0.28
-
3
0.32
-
4
0.36
-
5
0.40
Simple Facemask
6-10
0.44-0.50
Non-Rebreather Mask with Reservoir
(reservoir must be fully inflated)
10-20
Approx 0.6-0.8
At RR ~20 & Tidal Volume ~500
20 LPM flow = ~60% FiO2
30 LPM flow = ~70% FiO2
40 LPM flow = ~80% FiO2 (Farias et al).
The values represent estimates of FiO2. Actual FdO2 (delivered O2 concentration) is dependent on multiple factors including oxygen supply quality, patient’s minute ventilation and inspiratory flow rate. One general estimation rule is using oxygen flow rate: FiO2 =0.21 + 0.03 x oxygen flow rate in L/min (Frat et al).