A 17 year old male presents to the emergency department with nausea, vomiting and abdominal pain. He has no past medical history and takes no regular medication. On examination he has dry mucous membranes, breath smells of acetone and respiration is deep and sighing. An ABG is taken which reveals the following:
pH = 7.32
PaO2 = 12.9 kPa
PaCO2 = 3.1 kPa
HCO3 = 16.9 mmol/L
Glucose = 25 mmol/L
Which type of acid-base abnormality does the ABG show?
Well done, correct.
Answer:
Step 1: Clinical history shown signs of DKA
Step 2: PaO2 is normal and so the patient is not hypoxic.
Step 3: The pH is lower than normal so the patient is acidotic.
Step 4: The PaCO2 is lower than normal.
Step 5: The HCO3 is lower than normal.
Putting the information together and using the ROME mnemonic we come to the conclusion that this is a metabolic acidosis with partial respiratory compensation. The underlying cause in this case is diabetic ketoacidosis.
