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
pH7.357.457.29PaCO₂mmHg354541HCO₃⁻mmol/L222619respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.29, PaCO₂ 41 mmHg (5.5 kPa) and HCO₃⁻ 19 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.29PaCO₂ 41 mmHg (5.5 kPa)HCO₃⁻ 19 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
2.Easy
pH7.357.457.50PaCO₂mmHg354521HCO₃⁻mmol/L222616respiratorymetabolicacidosisalkalosis

A practice arterial blood gas shows pH 7.50, PaCO₂ 21 mmHg (2.8 kPa) and HCO₃⁻ 16 mmol/L. Which primary disorder is it? Click the cell in the grid.

pH 7.50PaCO₂ 21 mmHg (2.8 kPa)HCO₃⁻ 16 mmol/L
  1. 1respiratory acidosis
  2. 2metabolic acidosis
  3. 3respiratory alkalosis
  4. 4metabolic alkalosis
3.Medium

Practice values: Na⁺ 150 mmol/L, glucose 7.4 mmol/L and urea 23.7 mmol/L. Calculate the serum osmolality Osm = 2·Na⁺ + glucose + urea to the nearest whole number.

Na⁺ 150 mmol/Lglucose 7.4 mmol/Lurea 23.7 mmol/L
Osm = mOsm/kg
4.Medium

A practice gas shows PaCO₂ 79 mmHg (10.5 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 79 mmHg (10.5 kPa)baseline: 40 mmHg, 24 mmol/L
HCO₃⁻ = mmol/L
5.Hard

Practice values: Na⁺ 146, Cl⁻ 117 and HCO₃⁻ 13 mmol/L. Calculate the delta ratio (AG − 12)/(24 − HCO₃⁻), using AG = Na⁺ − (Cl⁻ + HCO₃⁻). Give two decimals.

Na⁺ 146 mmol/LCl⁻ 117 mmol/LHCO₃⁻ 13 mmol/L
delta ratio =
6.Hard
pH7.357.457.32PaCO₂mmHg354530HCO₃⁻mmol/L222615added normal-gap acidosispure high-gap acidosisadded metabolic alkalosis

A practice gas shows pH 7.32, PaCO₂ 30 mmHg (4.0 kPa) and HCO₃⁻ 15 mmol/L, with Na⁺ 142 and Cl⁻ 101 mmol/L. Use the anion gap and the delta ratio to click the best interpretation.

pH 7.32PaCO₂ 30 mmHg (4.0 kPa)HCO₃⁻ 15 mmol/LNa⁺ 142 mmol/LCl⁻ 101 mmol/L
  1. 1added normal-gap acidosis
  2. 2pure high-gap acidosis
  3. 3added metabolic alkalosis

Answer key

  1. 1. metabolic acidosis
  2. 2. respiratory alkalosis
  3. 3. Osm = 331 mOsm/kg
  4. 4. HCO₃⁻ = 27.9 mmol/L
  5. 5. delta ratio = 0.3636
  6. 6. pure high-gap acidosis

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