Arterial blood gas interpretation worksheet with answers

Free printable Arterial blood gas interpretation worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy

A practice blood gas shows PaO₂ 84 mmHg (11.2 kPa) while the inspired oxygen is 80%. Calculate the ratio P/F = PaO₂/FiO₂ in mmHg.

PaO₂ 84 mmHg (11.2 kPa)FiO₂ 80%
P/F = mmHg
2.Easy
pH7.357.457.32PaCO₂mmHg354580HCO₃⁻mmol/L222640respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.32, PaCO₂ 80 mmHg (10.7 kPa) and HCO₃⁻ 40 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.32PaCO₂ 80 mmHg (10.7 kPa)HCO₃⁻ 40 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
3.Medium

A practice gas shows PaCO₂ 72 mmHg (9.6 kPa). Use the rule that in acute respiratory acidosis HCO₃⁻ rises by 1 mmol/L for every 10 mmHg that PaCO₂ is above 40, starting from HCO₃⁻ 24 mmol/L, to find the expected HCO₃⁻.

PaCO₂ 72 mmHg (9.6 kPa)baseline: 40 mmHg, 24 mmol/L
HCO₃⁻ = mmol/L
4.Medium

A practice gas shows PaCO₂ 21 mmHg (2.8 kPa). Use the rule that in chronic respiratory alkalosis HCO₃⁻ falls by 5 mmol/L for every 10 mmHg that PaCO₂ is below 40, starting from HCO₃⁻ 24 mmol/L, to find the expected HCO₃⁻.

PaCO₂ 21 mmHg (2.8 kPa)baseline: 40 mmHg, 24 mmol/L
HCO₃⁻ = mmol/L
5.Hard

At sea level, a practice gas taken on 24% oxygen shows PaO₂ 68 mmHg (9.1 kPa) and PaCO₂ 55 mmHg (7.3 kPa). Use PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 to find the A–a gradient.

FiO₂ 24%PaO₂ 68 mmHg (9.1 kPa)PaCO₂ 55 mmHg (7.3 kPa)
A–a gradient = mmHg
6.Hard

Practice values: Na⁺ 139, Cl⁻ 94 and HCO₃⁻ 13 mmol/L. Calculate the delta ratio (AG − 12)/(24 − HCO₃⁻), using AG = Na⁺ − (Cl⁻ + HCO₃⁻). Give two decimals.

Na⁺ 139 mmol/LCl⁻ 94 mmol/LHCO₃⁻ 13 mmol/L
delta ratio =

Answer key

  1. 1. P/F = 105 mmHg
  2. 2. respiratory acidosis
  3. 3. HCO₃⁻ = 27.2 mmol/L
  4. 4. HCO₃⁻ = 14.5 mmol/L
  5. 5. A–a gradient = 34.37 mmHg
  6. 6. delta ratio = 1.818

Full step-by-step solutions: practise this topic on examproblems.com.