Arterial Blood Gas Analysis – Post Test

A 76-year-old gentleman is brought to the ED appearing breathless with a respiratory rate of 35; he has an oxygen saturation of 100% on room air, a temperature of 38.3 °C, and a BP of 98/56. He is complaining of abdominal pain and a working diagnosis of intra-abdominal sepsis is made.

Which one of the following is most likely to explain his tachypnoea?

Which one of the following does not cause metabolic acidosis?

Which one of the following statements is not true of mixed acid-base disorders?

A 63-year-old smoker with COPD presents with acute shortness of breath. He is known to have type 2 respiratory failure. He is acutely unwell and has been commenced on 8 litres O2 via a Venturi controlled flow mask to achieve saturations of 91%. An ABG is taken.

Which one of the following is the most likely result?

A known diabetic is brought to the ED confused and smelling of ketones. Blood sugar is 36, Pulse 135bpm, BP 96/50, O2 saturations 97% on room air, respiratory rate 38.

An ABG shows: pH 7.18, pCO2 3.6, pO2 11.8, bicarbonate 2.1

How can this ABG be described?

A 36-year-old lady, who regularly ingests large amounts of liquorice presents with severe hypertension, swollen ankles and pulmonary oedema. She is found to have sodium of 163 and potassium of 2.4. Observations are:

Pulse 92 bpm
BP 208/110
Respiratory rate 9
An ABG reveals: pH 7.44, pCO2 6.9, pO2 11.1, bicarbonate 42

What does the ABG show?

A 46-year old known alcoholic female arrives by ambulance. She has poor urine output, is confused, peripherally cyanosed with observations as follows:

Pulse 140 bpm
O2 saturations 98% on air
BP 80/48
Respiratory rate 42
Temperature 38.6 °c
ABG shows: pH 7.33, pCO2 1.6, bicarbonate 11, lactate 8.3

Which one of the following is the most appropriate interpretation of the ABG?

A 31-year-old lady attends having fainted at work after experiencing tingling around her lips and in both hands and feet. She is clearly very anxious and has been under a lot of pressure in her stressful job. She has no past medical history. BP 115/70 and pulse is 110 bpm.

If an ABG were taken at this point, it would be most likely to show which one of the following?

A 73-year-old gentleman arrives by ambulance acutely short of breath with O2 saturations on air of 84%. He has been vomiting and is also coughing up copious amounts of green sputum, more than normal according to his carers. Additionally, he is known left ventricular failure on diuretics. He appears incredibly unwell and you inform the carer he is unlikely to survive the next 24 hours. His observations are:

Pulse 140 bpm irregular
O2 saturations 90% on 35% O2
BP 90/40
Respiratory rate 34
An ABG reveals: pH 7.38, pCO2 8.4, bicarbonate 52, pO2 8.9, lactate 4.3, Na+ 124, K+ 2.2, Cl- 86

Which one of the following is the correct interpretation of these results?

A 60-year-old gentleman is brought by ambulance, found in a collapsed state. He has no past medical history. His observations are;

• Pulse106 bpm
• O2 saturations 94% on air
• BP107/65
• Respiratory rate 22
• GCS 11
• An ABG reveals: pH 7.50, pO2 9.6, pCO2 6.9, bicarbonate 45, Na+ 131, K+ 2.5, Cl- 85

This gentleman’s condition is best explained by which of the following?