Oxygen Therapy

Question 1

What is the difference between SpO2, SaO2 and PaO2?

Answer 1

• SpO2 - indirect measurement of haemoglobin saturation. Does not identify saturator (e.g. CO, O2, CO2). Obtained from pulse oximeter
• SaO2 - direct measurement of haemoglobin saturation by oxygen. Obtained from ABGs
• PaO2 - partial pressure of O2 in arterial blood. Obtained via ABGs

Question 2

What flow rates and FiO2 can be delivered with nasal cannulae?

Answer 2

• Flow rates 1-5 L/min
• FiO2 0.24-0.40

Question 3

What flow rates and FiO2 can be delivered with Hudson masks?

Answer 3

• Flow rates 6-10 L/min
• FiO2 0.40-0.60
• Not to be used with flow less than 6 L/min or risk of rebreathing

Question 4

What flow rates and FiO2 can be delivered with a non-rebreather mask?

Answer 4

• Flow rates >10 L/min
• FiO2 0.80-1.00
• Do not let bag collapse