Oxygen therapy & respiratory calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). The team wants an inspired oxygen of about 41% by nasal cannula. Using the rule of thumb FiO₂ ≈ 21% + 4% per L/min, what flow Q does it suggest? (Real FiO₂ varies with the patient's breathing.)

Practice exercise (made-up values, not clinical guidance). The gauge on a size H oxygen cylinder reads 800 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 ventilated patient who meets the other Berlin criteria for ARDS has PaO₂ 102 mmHg (13.6 kPa) on 70% oxygen with a PEEP of 12 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 patient breathes 18 times a minute with a tidal volume of 660 mL. The anatomical dead space is 150 mL. Find the alveolar ventilation V̇A in L/min.

Practice exercise (made-up values, not clinical guidance). A patient with acute hypoxaemia and bilateral opacities, not explained by heart failure, has PaO₂ 11.7 kPa on 35% oxygen with a PEEP of 4 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

Practice exercise (made-up values, not clinical guidance). A patient with acute hypoxaemia and bilateral opacities, not explained by heart failure, has PaO₂ 16 kPa on 35% oxygen with a PEEP of 12 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