If the patient is receiving Oxygen therapy their PaO2 should be approximately 10kPa less than the % inspired concentration FiO2 (so a patient on 40% Oxygen would be expected to have a PaO2 of approximately 30kPa /225mmHg).
- Remember room air has an Oxygen concentration of 21% already.
- FiO2 stands for fraction of inspired Oxygen (O2).
- Every litre approximately increases the FiO2 by about 4 percent.
Nasal canula rates:
- 1L / min – 24%
- 2L/ min – 28%
- 3L/ min – 32%
- 4L / min – 36%
Reservoir (non-rebreath) mask
Reservoir masks deliver Oxygen at concentrations between 60% and 90% when used at a flow rate of 10–15 l/min.³
Simple face mask:
Simple face masks can deliver a maximum FiO2 of approximately 40%-60% at a flow rate of 15L/min.
Venturi Masks
