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.

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Name: ____________________   Date: ____________

1.Easy

A practice blood gas shows PaO₂ 65 mmHg (8.7 kPa) while the inspired oxygen is 70%. Calculate the ratio P/F = PaO₂/FiO₂ in mmHg.

PaO₂ 65 mmHg (8.7 kPa)FiO₂ 70%
P/F = mmHg
2.Easy
pH7.357.457.53PaCO₂mmHg354530HCO₃⁻mmol/L222624respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.53, PaCO₂ 30 mmHg (4.0 kPa) and HCO₃⁻ 24 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.53PaCO₂ 30 mmHg (4.0 kPa)HCO₃⁻ 24 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
3.Medium

A practice gas shows PaCO₂ 27 mmHg (3.6 kPa). Use the rule that in acute respiratory alkalosis HCO₃⁻ falls by 2 mmol/L for every 10 mmHg that PaCO₂ is below 40, starting from HCO₃⁻ 24 mmol/L, to find the expected HCO₃⁻.

PaCO₂ 27 mmHg (3.6 kPa)baseline: 40 mmHg, 24 mmol/L
HCO₃⁻ = mmol/L
4.Medium
pH7.357.457.54PaCO₂mmHg354550HCO₃⁻mmol/L222641uncompensatedpartially compensatedfully compensated

A practice arterial blood gas shows pH 7.54, PaCO₂ 50 mmHg (6.7 kPa) and HCO₃⁻ 41 mmol/L. The primary disorder is metabolic alkalosis. How far is it compensated? Click your answer.

pH 7.54PaCO₂ 50 mmHg (6.7 kPa)HCO₃⁻ 41 mmol/L
  1. 1uncompensated
  2. 2partially compensated
  3. 3fully compensated
5.Hard

At sea level, a practice gas taken on 30% oxygen shows PaO₂ 54 mmHg (7.2 kPa) and PaCO₂ 40 mmHg (5.3 kPa). Use PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 to find the A–a gradient.

FiO₂ 30%PaO₂ 54 mmHg (7.2 kPa)PaCO₂ 40 mmHg (5.3 kPa)
A–a gradient = mmHg
6.Hard
pH7.357.457.21PaCO₂mmHg354570HCO₃⁻mmol/L222627acutechronicacute on chronic

A practice gas shows a respiratory acidosis: pH 7.21, PaCO₂ 70 mmHg (9.3 kPa), HCO₃⁻ 27 mmol/L. Use the rules ‘HCO₃⁻ rises 1 mmol/L per 10 mmHg (acute) or 3.5 mmol/L per 10 mmHg (chronic)’ to classify it. Click your answer.

pH 7.21PaCO₂ 70 mmHg (9.3 kPa)HCO₃⁻ 27 mmol/L
  1. 1acute
  2. 2chronic
  3. 3acute on chronic

Answer key

  1. 1. P/F = 92.86 mmHg
  2. 2. respiratory alkalosis
  3. 3. HCO₃⁻ = 21.4 mmol/L
  4. 4. partially compensated
  5. 5. A–a gradient = 109.9 mmHg
  6. 6. acute

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