ABG Q1 - answer

Your patient is a 60 year old lady, who came into A & E complaining of a UTI and dizziness. She was hypotensive and was given antibiotics and fluid boluses in the ED. She has been brought to your unit for haemodynamic management. She is self-ventilating, on 35% oxygen via a facemask.

Her ABG shows: pH 7.32, PO2 15.5 kPa, PCO2 3.5 kPa, HCO3- 16 mmol/L, BE -8

This shows:

Your answer: Respiratory acidosis with metabolic compensation.

No that's not correct. The patient's BE is negative, with a low HCO3-, this shows she has a metabolic acidosis. Her PCO2 is below the normal range (4.5 - 6), and so she has a respiratory alkalosis.

As she has an overall acidaemia, her original problem was the (metabolic) acidosis, and she is compensating for this by hyperventilating, and developing a metabolic alkalosis.

So the answer is metabolic acidosis with respiratory compensation

page last modified 26.04.2018