🫁 Winter's Formula (Respiratory Compensation)
Calculate the expected PaCO₂ for a metabolic acidosis with Winter's formula.
Winter's Formula (Respiratory Compensation)
Bicarbonate (HCO₃⁻) (mmol/L)
Measured PaCO₂ (optional) (mmHg)
When to use
Detect a concomitant primary respiratory disorder in metabolic acidosis.
How it works
Expected PaCO₂ = 1.5 × HCO₃ + 8 ± 2 mmHg.
Key points
- Measured > expected → added respiratory acidosis.
- Measured < expected → added respiratory alkalosis.
- Apply only to a primary metabolic acidosis.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.