Lab case 446 interpretation

PH = 7.238, that is moderate acidaemia.

pCO2 = 49.1 mmHg. that is suggestive of respiratory acidosis

HCO3 = 20.2 mmol/L, that is suggestive of metabolic acidosis.

According to these results patient should have combined metabolic and respiratory acidosis.

Next we need to calculate the anion gap for this patient (Since we have metabolic acidosis). Anion gap is calculated as: AG = Na – (Cl + HCO2) = 44, that is extremely high. (Very unusual value).

Next we will look for any other abnormal findings:

The most striking abnormality is Ca+2 level < 0.20 mmol/l. That is incompatible with  life (2nd unusual value).

Na = 155 mmol/L, that is moderate hypernatraemia.

K = 3.1 mmol/L, that is mild hypokalaemia. However, this patient acidotic process. Potassium level is usually falsely elevated in the presence of acidosis due to extracellular shift….(This is a third unusual value.)

Cl = 91 mmol/L, this is hypochloraemia. However, usually Na and Cl levels go in the same direction ,,,. (This is unusual as well).

This blood was contaminated by Sodium Citrate (From a blue-top tube). Sodium citrate chelates Ca, has Na and is acidic.

Repeat blood gas for that patient was normal.