ABG

pH

7.10

PaCO₂

20 mmHg

HCO₃

6 mmol/L

Na

138

Cl

100

Glucose

32 mmol/L

Ketones

5.2 mmol/L

Interpretation

• • Acidaemia (pH 7.10) with low HCO₃ → metabolic acidosis
• • AG = 138 − (100 + 6) = 32 → HAGMA
• • Winters: expected CO₂ = 1.5 × 6 + 8 = 17 ± 2 → actual 20 (appropriate)
• • Ketosis + hyperglycaemia → DKA
• • Δgap ratio = 20/18 ≈ 1.1 → pure HAGMA

Next steps

• • Fluids 0.9% NaCl 1 L over 1 h
• • Fixed-rate insulin 0.1 U/kg/h
• • Replace K when ≤5.5
• • Hourly glucose, 2-hourly K, VBG