For a basic approach to blood gas interpretation see here
1. What is the Acid-Base disturbance?
pH = 6.98 ∴ severe acidosis
Work out the cause of the acidosis:
Is there appropriate respiratory compensation or concomitant process?
Work out the cause of the metabolic acidosis:
Is there another concomitant metabolic process?
Overall Acid-Base disturbance
Mixed HAGMA & NAGMA with associated Respiratory Acidosis
Work out the cause of the acidosis:
- CO2 = 19 ∴ metabolic acidosis
Is there appropriate respiratory compensation or concomitant process?
- Expected CO2 = 1.5 x HCO3 + 8 = 14
- Actual CO2 = 19 ∴ concomitant respiratory acidosis
Work out the cause of the metabolic acidosis:
- Anion Gap = 140 - 111 - 4 = 25 = HAGMA
Is there another concomitant metabolic process?
- Delta Ratio = (AG - 12) / (24 - HCO3) = (25 - 12) / (24 - 4) = 0.65
- 0.65 = mixed HAGMA + NAGMA
Overall Acid-Base disturbance
Mixed HAGMA & NAGMA with associated Respiratory Acidosis
2. Are there any electrolyte issues?
Na (for Glc)
K (for pH)
Ca (for alb)
- Actual Na = mNa + (Glc - 5)/3 = 140 + (48 - 5)/3 = 154.3
- ∴ Relative hypernatraemia
K (for pH)
- Expected K = 5(7.4 - pH) + 5 = 5(7.4 - 6.98) + 5 = 7.1
- Actual K = 5.6 ∴ severe hypokalaemia
Ca (for alb)
- Neither Ca or Albumin reported
3. Are there any oxygenation issues?
This is a venous sample ∴ unable to calculate
4. What is your overall impression?
This patient has a life threatening acidosis due HAGMA with concomitant NAGMA and respiratory acidosis with a relative hypernatraemia and severe hypokalaemia.
Given her age and her BSL, the most likely cause is:
1. HAGMA = DKA
2. NAGMA = Aggressive NaCl resuscitation or recovering DKA
3. Respiratory Acidosis = Getting tired from having to resp compensate
Given her age and her BSL, the most likely cause is:
1. HAGMA = DKA
2. NAGMA = Aggressive NaCl resuscitation or recovering DKA
3. Respiratory Acidosis = Getting tired from having to resp compensate