Interpretation

Question 1

What causes metabolic acidosis with a raised anion gap?

Answer 1

Increased Acid in the gut

MUDPILES
Methanol
Uraemia
Diabetic ketoacidosis
Propylene glycol
Isoniazid/ Iron
Lactate
Ethanol
Salicates

Question 2

What causes metabolic acidosis with a normal anion gap?

Answer 2

Increased loss of HCO3-
- Vomiting/ Diarrhoea

Retained H+
- Renal tubular acidosis
- Renal failure
- Addison’s disease

Question 3

What causes metabolic alkalosis

Answer 3

Loss of acid
Does it respond to saline?
Yes:
- Gastric loss
- Diuretics

Does it not?
- Hyperaldosteronism
- Hypokalaemia

Question 4

What causes respiratory acidosis

Answer 4

More CO2 retention
- Obstructive lung disease e.g. COPD/ asthma
- CNS depression - decreased resp drive
- Neuromuscular e.g. obesity/ Guillain Barre/ myasthenia gravis

Question 5

What causes Respiratory alkalosis?

Answer 5

Hyperventilation
- Panic
- hypoxia
- Acute pulmonary insult

Question 6

What would you expect to seen on the ABG of an acute episode in asthmatic?

Answer 6

Respiratory alkalosis
CO2 is decreased due to hyperventilation
02 is increased