Total concentration of weak acids and bases ([ATOT])
•Weak electrolytes (HA)
–Partially dissociated (H+, A-) in H2O
–
•[ATOT] = [PP] x 0.21 (mEq/L)
–                                                                        (KA = 2.1 x 10-7 Eq/L)
•
•Most important in plasma = plasma proteins