Oxygen therapy & respiratory calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). A patient receives oxygen by nasal cannula at 2 L/min. Using FiO₂ ≈ 21% + 4% per L/min, estimate the inspired oxygen FiO₂ in percent.

Practice exercise (made-up values, not clinical guidance). The gauge on a size H oxygen cylinder reads 1100 psi. Its cylinder factor is 3.14 L/psi. How many litres V can be used before the safe residual of 200 psi is reached?

Practice exercise (made-up values, not clinical guidance). A patient has Hb 173 g/L, SaO₂ 95% and PaO₂ 74 mmHg (9.9 kPa). Find the arterial oxygen content CaO₂ = 1.34 × Hb (g/dL) × SaO₂ + 0.003 × PaO₂ (mmHg) in mL O₂/dL.

Practice exercise (made-up values, not clinical guidance). A ventilated patient who meets the other Berlin criteria for ARDS has PaO₂ 52 mmHg (6.9 kPa) on 100% oxygen with a PEEP of 5 cmH₂O. Calculate the P/F ratio and click the ARDS severity.

1. 1above 300
2. 2mild
3. 3moderate
4. 4severe

Practice exercise (made-up values, not clinical guidance). A transfer will take 120 minutes. The size D cylinder (factor 0.16 L/psi) reads 2100 psi. Keeping a safe residual of 200 psi, what is the highest whole-number flow Q in L/min that lasts the whole transfer?

Practice exercise (made-up values, not clinical guidance). A patient with acute hypoxaemia and bilateral opacities, not explained by heart failure, has PaO₂ 14.5 kPa on 35% oxygen with a PEEP of 5 cmH₂O. Grade the ARDS severity with the Berlin definition. Click your answer.

1. 1above 300
2. 2mild
3. 3moderate
4. 4severe
5. 5not gradable: PEEP below 5