Answers:

Question 1:

PH = 7.39, this is with in the normal range

Both PCO2 and HCO3 are within normal ranges.

However, Anion gap is elevated = 144 – (100 + 24) = 20, accordingly we have HAGMA. that is hidden. (The presence of a significantly elevated anion gap indicates the presence of metabolic acidosis regardless of PH and HCO3 levels.

Next we calculate the delta ratio, (AG – 12) / (24 – HCO3) = 8/0 …this is undefined.

A superimposed metabolic alkalosis must be present because the patient must have started with a higher-than-normal bicarbonate level to have experienced a smaller decrease in the bicarbonate level than an increase in the AG.

The rest of the results are not significant.

Accordingly this patient has mixed metabolic acidosis and metabolic alkalosis.

 Question 2:

Looking at the causes of HAGMA using LTKR.. This patient had normal lactate, ketones and urea.. So Toxicological reasons is a potential cause.

Regarding metabolic alkalosis, using CLEVER PD mnemonic

C – contraction (dehydration)

L – liquorice (diuretic), laxative abuse

E – endocrine (Conn’s, Cushing’s)

V – vomiting, GI loss (villous adenoma)

E – excess alkali (antacids)

R – renal (Bartter’s), severe K depletion

P – post hypercapnia

D – diuretics

Looking at the list above, the most probable cause is vomiting.

This case highlights the importance of calculating the AG on every patient, even when metabolic acidosis is not immediately apparent.