UP FRONT MATTERSUse of the ΔAG/ΔHCO3− Ratio in the Diagnosis of Mixed Acid-Base DisordersRastegar, Asghar Author Information Department of Medicine, Yale University School of Medicine, New Haven, Connecticut Correspondence: Dr. Asghar Rastegar, 1072 LMP, P.O. Box 2080-30, New Haven, CT 06520-8039. Phone: 203-737-2078; Fax: 203-785-6954; E-mail: [email protected] Journal of the American Society of Nephrology 18(9):p 2429-2431, September 2007. | DOI: 10.1681/ASN.2006121408 Buy Metrics Abstract When a strong acid is added to plasma, one expects a quantitative relationship between excess anion gap (ΔAG) and bicarbonate deficit (ΔHCO3−) with the ΔAG/ΔHCO3− ratio close to unity. If true, then this ratio could be used to diagnose mixed acid-base disorders in patients with metabolic acidosis. Although the mean ratio in selected patients is close to unity, this ratio also has a wide range, making its use in individual patients problematic. The ratio should therefore be used cautiously in making a diagnosis of mixed acid-base disorders. Copyright © 2007 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.