Sun10October0740PM 6

The following blood gas results are obtained from a middle aged patient with diabetes.

pH 7.32 (7.36-7.44)

PaO2 14.5 kPa (11.3-12.6)

PaCO2 2.7 kPa (4.7-6.0)

HCO3- 14 mmol/L (20-28)

Base excess -10 mmol/L (+/-2)

What is the most accurate way of interpreting this data?

(Please select 1 option)

Diabetic ketoacidosis (DKA)

Respiratory acidosis with partial metabolic compensation

Metabolic alkalosis with full respiratory compensation

Metabolic acidosis alone

Metabolic acidosis with partial respiratory compensation Correct

Explanation

This patient has an acidosis, as evidenced by a pH of 7.32.

The bicarbonate level is low suggesting a metabolic origin and the low base excess is in keeping with this.

The PaCO2 is low due to respiratory compensation by the lungs in an effort to maintain pH and there is increased clearance of the acidic carbon dioxide. Some may use the term 'partial compensation' however, this patient is still acidotic therefore it is accurate to describe them as having a metabolic acidosis. Compensation rarely every completely reverses the pH change, so this is a very common picture to see clinically.

It is too much of an assumption to jump to the conclusion of DKA in the absence of appropriate information, as the diagnosis could also be a lactic acidosis (type A or B), or could be due to poisoning.

Answer Statistics

1

4%

2

1%

3

3%

4

2%

5

92%

Times answered: 273