| Standard Nasal Canula | 0.5 L/min 1L/min 1.5 L/min 2 L/min 2.5 L/min 3 L/min 3.5 L/min 4 L/min 4.5 L/min 5 L/min 5.5 L/min 6 L/min - |
| High Flow Nasal Canula | 6 L/min 8 L/min 10 L/min 12 L/min 15 L/min - |
This information below applies to ADULTS ONLY
Oxygen supplementation by nasal canula (NC) is common; and estimation of the inspired fraction of oxygen various flow rates generate can be useful when interpreting ABG data or response to oxygen.
Room air is 21% oxygen and the addition of each 1 liter/minute (L/min) flow rate by nasal canula typically raises the FIO 2 by 3%.
Est. FiO 2 = 21% + L/min x 3%
Flow rates at maximum 6 L/min are recommended by NC.
However, in recent times; High Flow Nasal Canulas (HFNC) have become available that allow much higher flow rates, including up to 15 lpm to be used. It is notable, that although the same FiO 2 can be achieved with HFNC as simple masks (SM) or non-rebreather masks (NRM); the variability in actual FiO 2 is much greater with these devices (as it likely is with a standard NC).
| O 2 Flow in liters/min | FiO 2 % mean | Range FiO 2 % |
|---|---|---|
| 6 | 54% | 35-89% |
| 8 | 58% | 33-87% |
| 10 | 66% | 40-88% |
| 12 | 69% | 37-93% |
| 15 | 75% | 39-98% |
Garcia JA, et al. The Oxygen Concentrations Delivered by Different Oxygen Therapy Systems. Chest. 2005;128(4):389S.