Oxygen therapy & respiratory calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). The gauge on a size E oxygen cylinder reads 1500 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 patient receives oxygen by nasal cannula at 6 L/min. Using FiO₂ ≈ 21% + 4% per L/min, estimate the inspired oxygen FiO₂ in percent.

Practice exercise (made-up values, not clinical guidance). A patient breathes 15 times a minute with a tidal volume of 330 mL. The anatomical dead space is 180 mL. Find the alveolar ventilation V̇A in L/min.

Practice exercise (made-up values, not clinical guidance). A size E oxygen cylinder (factor 0.28 L/psi) reads 1700 psi and runs at 8 L/min. Keeping a safe residual of 200 psi, how many minutes t will it last? Round down to a whole minute.

Practice exercise (made-up values, not clinical guidance). A patient with acute hypoxaemia and bilateral opacities, not explained by heart failure, has PaO₂ 17.5 kPa on 40% oxygen with a PEEP of 6 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 on high-flow nasal oxygen has SpO₂ 91% on FiO₂ 0.8 and a respiratory rate of 18/min. Find the ROX index ROX = (SpO₂/FiO₂)/RR, with SpO₂ in percent and FiO₂ as a fraction. Round to two decimal places.