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
pH7.357.457.48PaCO₂mmHg354528HCO₃⁻mmol/L222620respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.48, PaCO₂ 28 mmHg (3.7 kPa) and HCO₃⁻ 20 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.48PaCO₂ 28 mmHg (3.7 kPa)HCO₃⁻ 20 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
2.Easy
pH7.357.457.58PaCO₂mmHg354543HCO₃⁻mmol/L222639respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.58, PaCO₂ 43 mmHg (5.7 kPa) and HCO₃⁻ 39 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.58PaCO₂ 43 mmHg (5.7 kPa)HCO₃⁻ 39 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
3.Medium

A practice gas shows PaCO₂ 21 mmHg (2.8 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 21 mmHg (2.8 kPa)baseline: 40 mmHg, 24 mmol/L
HCO₃⁻ = mmol/L
4.Medium
pH7.357.457.32PaCO₂mmHg354530HCO₃⁻mmol/L222615uncompensatedpartially compensatedfully compensated

A practice arterial blood gas shows pH 7.32, PaCO₂ 30 mmHg (4.0 kPa) and HCO₃⁻ 15 mmol/L. The primary disorder is metabolic acidosis. How far is it compensated? Click your answer.

pH 7.32PaCO₂ 30 mmHg (4.0 kPa)HCO₃⁻ 15 mmol/L
  1. 1uncompensated
  2. 2partially compensated
  3. 3fully compensated
5.Hard

Practice values: Na⁺ 136, Cl⁻ 106 and HCO₃⁻ 9 mmol/L. Calculate the delta ratio (AG − 12)/(24 − HCO₃⁻), using AG = Na⁺ − (Cl⁻ + HCO₃⁻). Give two decimals.

Na⁺ 136 mmol/LCl⁻ 106 mmol/LHCO₃⁻ 9 mmol/L
delta ratio =
6.Hard

At sea level, a practice gas taken on 21% oxygen shows PaO₂ 65 mmHg (8.7 kPa) and PaCO₂ 46 mmHg (6.1 kPa). Use PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 to find the A–a gradient.

FiO₂ 21%PaO₂ 65 mmHg (8.7 kPa)PaCO₂ 46 mmHg (6.1 kPa)
A–a gradient = mmHg

Answer key

  1. 1. respiratory alkalosis
  2. 2. metabolic alkalosis
  3. 3. HCO₃⁻ = 20.2 mmol/L
  4. 4. partially compensated
  5. 5. delta ratio = 0.6
  6. 6. A–a gradient = 27.23 mmHg

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