Nomogram showing bands for uncomplicated respiratory or metabolic acid-base disturbances in intact subjects. Each confidence band represents the mean ±2 SD for the compensatory response of normal subjects or pts to a given primary disorder. Ac, acute; acid, acidosis; alk, alkalosis; chr, chronic; met, metabolic; resp, respiratory. (Reprinted with permission from Arbus GS. An in vivo acid-base nomogram for clinical use. Can Med Assoc J 109:291, 1973.)