
ACID–BASE 4 BALANCE AND REGULATION OF pH
pH=6.1+log [HCO3-] 0.03 × pCO2 Fig. 4.1 Effect of changes in HCO 3-and pCO 2 on net pH of the plasma. This is an applied version of the Henderson–Hasselbalch equation. Normal plasma [HCO 3-] = 24mmol/L, normal pCO 2 = 40mmHg, giving a normal plasma pH of 7.40. The pH will return to 7.40 as long as the ratio of [HCO 3]:[0.03 ¥ pCO 2] is 20:1 ...