Figure 1From: Bench-to-bedside review: A brief history of clinical acid–baseThe Henderson–Hasselbalch equation. pH, plasma pH; pKa, negative log to base 10 of the apparent, overall dissociation constant of carbonic acid; [HCO3-], plasma bicarbonate concentration; α, solubility of carbon dioxide in blood at 37°C; pCO2, partial pressure of carbon dioxide in blood.Back to article page