Cause of acidosis?
- pCO2 = 73.6 ∴ Primary respiratory acidosis
Is there appropriate metabolic compensation or a concomitant process?
- HCO3 = 24 + 0.1(CO2 - 40) = 24 + 0.1(73.6 - 40) = 27.36
- Actual HCO3 = 24.0 ∴ 𝛥HCO3 = - 3.36 ∴ Concomitant metabolic acidosis
What type of metabolic acidosis is it?
- Anion Gap = 142 - 24 - 104 = 14 ∴ NAGMA
Overall: Primary respiratory acidosis with partial metabolic compensation (ie metabolic acidosis)
- Actual Na - mNa + (Glc - 5)/3 = 142 + (13.1 - 5)/3 = 144.7 ∴ Normonatraemic
K (for pH)
- Expected K = 5(7.4 - pH) + 5 = 5(7.4 - 7.140) + 5 = 6.3
- Actual K = 3.8 ∴ 𝛥K = -2.5 ∴ Severe Hypokalaemia
Ca (for alb)
- CorrCa = 1.17 ∴ Normocalcaemic
Cl (no correction req)
- Cl = 104 ∴ Normochloraemic
Glc high
Hb normal
COHb normal
MetHb normal
Respiratory acidosis: given age, likely due to drug-induced respiratory depression ∴ look for other features of tox as well as other causes of altered level of consciousness (esp trauma)
Metabolic acidosis: You would assume that this was due to lactic acidosis - however LA should give you a RAGMA and not a NAGMA. In the context of severe hypokalaemia, it is worth considering RTA type 1 & 2, severe diarrhoea or recovering DKA given the high-ish BSL - further hx & ex is worth considering if the metabolic acidosis does not improve with correcting the primary respiratory acidosis.
Cause of hypokalaemia unclear - consider vomiting as main cause in this presentation