Oxygen therapy & respiratory calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). The team wants an inspired oxygen of about 45% 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). A patient breathes 29 times a minute with a tidal volume of 420 mL. Find the minute ventilation V̇E in L/min.

Practice exercise (made-up values, not clinical guidance). A patient breathes 13 times a minute with a tidal volume of 350 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 ventilated patient who meets the other Berlin criteria for ARDS has PaO₂ 67 mmHg (8.9 kPa) on 60% oxygen with a PEEP of 10 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 151 g/L, SaO₂ 94%, PaO₂ 73 mmHg (9.7 kPa) and a cardiac output of 3.2 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.

Practice exercise (made-up values, not clinical guidance). A ventilated woman is 166 cm tall and weighs 87 kg. Lung-protective ventilation is set at 6 mL per kg of predicted body weight. Using PBW = 45.5 + 0.91 × (height cm − 152.4) kg, find the tidal volume V_T to the nearest mL.