Oxygen therapy & respiratory calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). A patient receives oxygen by nasal cannula at 1 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 E oxygen cylinder reads 2200 psi. Its cylinder factor is 0.28 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 ventilated patient who meets the other Berlin criteria for ARDS has PaO₂ 135 mmHg (18.0 kPa) on 90% oxygen with a PEEP of 5 cmH₂O. Calculate the P/F ratio and click the ARDS severity.

1. 1above 300: no ARDS grade
2. 2mild
3. 3moderate
4. 4severe

Practice exercise (made-up values, not clinical guidance). A patient has Hb 99 g/L, SaO₂ 97% and PaO₂ 87 mmHg (11.6 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 patient with acute hypoxaemia and bilateral opacities, not explained by heart failure, has PaO₂ 7.9 kPa on 45% oxygen with a PEEP of 15 cmH₂O. Grade the ARDS severity with the Berlin definition. Click your answer.

1. 1above 300: no ARDS grade
2. 2mild
3. 3moderate
4. 4severe
5. 5not gradable: PEEP below 5

Practice exercise (made-up values, not clinical guidance). A patient has Hb 166 g/L, SaO₂ 98%, PaO₂ 98 mmHg (13.1 kPa) and a cardiac output of 6.7 L/min. With CaO₂ = 1.34 × Hb (g/dL) × SaO₂ + 0.003 × PaO₂ (mmHg), find the oxygen delivery DO₂ = CaO₂ × CO × 10 in mL/min.