[Combined disorders of the acid-base equilibrium. Clinical comments]

The submitted paper contains comments on the evaluation of combined disorders of the acid-base balance. Some different definitions of the acid-base balance are given as well as their importance for the evaluation of combined conditions. The author discusses parallel and opposite deviations which develop inside and outside the cell, disorders associated with the mere accumulation of some ions and disorders associated with an impaired energy balance. On several examples clinical manifestations of impaired acid-base balance are illustrated where the laboratory finding may be atypical.