Lab case 331 interpretation

 Question 1

PH = 6.71, that is severe acidosis.

HCO3 = 7 (<24), so we have metabolic acidosis.

Next we need to calculate anion gap and compensation.

Anion gap = Na – (Cl + HCO3) = 131 – (98 + 7) = 26, so we have HAGMA.

For compensation we use Winter’s formula. That is expected PCO2 = 1.5 x HCO3 + 8 (+/-2).

Accordingly, expected PCO2 is 1.5 x 7 + 8 = 18 (16-20), So we have additional respiratory acidosis as PCO3 is slightly higher than that (23).

Next we will calculate the delta ratio to make sure that this patient doesn’t have additional metabolic process.

Delta ratio = AG – 12/ 24 – HCO3 = (26-12)/(24-7) = 0.82, so we have pure HAGMA here.

Accordingly, this patient has combined severe HAGMA with mild respiratory acidosis.

Other abnormal findings.

The most striking abnormal finding is blood glucose level of 32 mmol/L. and the lactate level of 6.9 mmol/L (reflects poor tissue perfusion).

Na = 131 mmol/L, However, in the presence of hyperglycemia, Na level is falsely low.

Corrected Na = Measured Na + (Glucose level – 5)/3 = 13 + (32 – 5)/3 = 140. That is with in normal range.

K = 5.2, that is mildly elevated. However, in the presence of acidosis, the measured level is falsely elevated. Usually K level drops by 0.5 mmol for every 0.1 PH below 7.4.

Accordingly corrected K = 5.2 – (7×0.5) = 1.7

This patient has DKA (unfortunately, we don’t have the ketones level in this case). The trigger for it was right lower lobe pneumonia.

 Question 2

Each hospital follows a certain DKA protocol

This patient is very unwell. He will need to be treated in a resuscitation bay. Get 2 IV access and monitor fluid input and output strictly.

IV hydration, start with normal saline until glucose level is 13 mmol or less then switch to dextrose solution ( 5% or 10%).

IV insulin at a rate of 0.1 Unit/Kg per hour and adjust the rate according to glucose and ketones levels.

Start replacing K when the measured level is less than 5 mmol/L.

Treat the predisposing condition, in this case give broad spectrum antibiotics for pneumonia.

This patient will need1 hourly BSL and ketones check with continuous monitoring of the vital signs and urine output.