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

Practice values: Na⁺ 138, K⁺ 4.8, Cl⁻ 101 and HCO₃⁻ 26 mmol/L. Calculate the anion gap AG = Na⁺ − (Cl⁻ + HCO₃⁻), without potassium.

Na⁺ 138 mmol/LK⁺ 4.8 mmol/LCl⁻ 101 mmol/LHCO₃⁻ 26 mmol/L
AG = mmol/L
2.Easy
pH7.357.457.23PaCO₂mmHg354542HCO₃⁻mmol/L222617respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.23, PaCO₂ 42 mmHg (5.6 kPa) and HCO₃⁻ 17 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.23PaCO₂ 42 mmHg (5.6 kPa)HCO₃⁻ 17 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
3.Medium

A practice gas shows a metabolic acidosis with HCO₃⁻ 6 mmol/L. Use Winter’s formula to find the expected PaCO₂ (the centre of the range) in mmHg.

HCO₃⁻ 6 mmol/L
PaCO₂ = mmHg
4.Medium
pH7.357.457.43PaCO₂mmHg354558HCO₃⁻mmol/L222637uncompensatedpartially compensatedfully compensated

A practice arterial blood gas shows pH 7.43, PaCO₂ 58 mmHg (7.7 kPa) and HCO₃⁻ 37 mmol/L. The primary disorder is metabolic alkalosis. How far is it compensated? Click your answer.

pH 7.43PaCO₂ 58 mmHg (7.7 kPa)HCO₃⁻ 37 mmol/L
  1. 1uncompensated
  2. 2partially compensated
  3. 3fully compensated
5.Hard
pH7.357.457.27PaCO₂mmHg354525HCO₃⁻mmol/L222611added normal-gap acidosispure high-gap acidosisadded metabolic alkalosis

A practice gas shows pH 7.27, PaCO₂ 25 mmHg (3.3 kPa) and HCO₃⁻ 11 mmol/L, with Na⁺ 146 and Cl⁻ 114 mmol/L. Use the anion gap and the delta ratio to click the best interpretation.

pH 7.27PaCO₂ 25 mmHg (3.3 kPa)HCO₃⁻ 11 mmol/LNa⁺ 146 mmol/LCl⁻ 114 mmol/L
  1. 1added normal-gap acidosis
  2. 2pure high-gap acidosis
  3. 3added metabolic alkalosis
6.Hard

At sea level, a practice gas taken on 30% oxygen shows PaO₂ 56 mmHg (7.5 kPa) and PaCO₂ 56 mmHg (7.5 kPa). Use PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 to find the A–a gradient.

FiO₂ 30%PaO₂ 56 mmHg (7.5 kPa)PaCO₂ 56 mmHg (7.5 kPa)
A–a gradient = mmHg

Answer key

  1. 1. AG = 11 mmol/L
  2. 2. metabolic acidosis
  3. 3. PaCO₂ = 17 mmHg
  4. 4. fully compensated
  5. 5. added normal-gap acidosis
  6. 6. A–a gradient = 87.9 mmHg

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