Acid–Base — Compensation Rules

Step 1: pH — acidaemia (7.45)? Step 2: HCO3 vs PCO2 — which is the primary disturbance? Compensation: • Metabolic acidosis: expected PCO2 = 1.5 × HCO3 + 8 (Winter's formula, ±2) • Metabolic alkalosis: PCO2 ↑ by 0.7 mmHg per 1 mmol HCO3 • Acute respiratory acidosis: HCO3 ↑ by 1 per 10 ↑ in PCO2 • Chronic respiratory acidosis: HCO3 ↑ by 4 per 10 ↑ in PCO2 • Acute respiratory alkalosis: HCO3 ↓…