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
pH7.357.457.50PaCO₂mmHg354525HCO₃⁻mmol/L222619respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.50, PaCO₂ 25 mmHg (3.3 kPa) and HCO₃⁻ 19 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.50PaCO₂ 25 mmHg (3.3 kPa)HCO₃⁻ 19 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
2.Easy
pH7.357.457.55PaCO₂mmHg354520HCO₃⁻mmol/L222617respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.55, PaCO₂ 20 mmHg (2.7 kPa) and HCO₃⁻ 17 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.55PaCO₂ 20 mmHg (2.7 kPa)HCO₃⁻ 17 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
3.Medium

A practice gas shows PaCO₂ 31 mmHg (4.1 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 31 mmHg (4.1 kPa)baseline: 40 mmHg, 24 mmol/L
HCO₃⁻ = mmol/L
4.Medium

A practice gas shows a metabolic acidosis with HCO₃⁻ 14 mmol/L. Use Winter’s formula to find the expected PaCO₂ (the centre of the range) in mmHg.

HCO₃⁻ 14 mmol/L
PaCO₂ = mmHg
5.Hard
pH7.357.457.24PaCO₂mmHg354524HCO₃⁻mmol/L222610added normal-gap acidosispure high-gap acidosisadded metabolic alkalosis

A practice gas shows pH 7.24, PaCO₂ 24 mmHg (3.2 kPa) and HCO₃⁻ 10 mmol/L, with Na⁺ 136 and Cl⁻ 96 mmol/L. Use the anion gap and the delta ratio to click the best interpretation.

pH 7.24PaCO₂ 24 mmHg (3.2 kPa)HCO₃⁻ 10 mmol/LNa⁺ 136 mmol/LCl⁻ 96 mmol/L
  1. 1added normal-gap acidosis
  2. 2pure high-gap acidosis
  3. 3added metabolic alkalosis
6.Hard
pH7.357.457.32PaCO₂mmHg354567HCO₃⁻mmol/L222633acutechronicacute on chronic

A practice gas shows a respiratory acidosis: pH 7.32, PaCO₂ 67 mmHg (8.9 kPa), HCO₃⁻ 33 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 7.32PaCO₂ 67 mmHg (8.9 kPa)HCO₃⁻ 33 mmol/L
  1. 1acute
  2. 2chronic
  3. 3acute on chronic

Answer key

  1. 1. respiratory alkalosis
  2. 2. respiratory alkalosis
  3. 3. HCO₃⁻ = 19.5 mmol/L
  4. 4. PaCO₂ = 29 mmHg
  5. 5. pure high-gap acidosis
  6. 6. chronic

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