The pH and Titratable Acidity of Intravenous Infusion Solutions

Abstract

The acidic nature of infusion solutions may contribute to local thrombophlebitis or systemic acidosis. The pH of four commercially available solutions ranged from 4·55 to 6·40 and titratable acidities (to pH 7·4) ranged from 0·18 to 1·08 meq acid/litre. When equilibrated in vitro at PCO2 of 40 mm Hg the pH ranged from 4·5 to 6·0 and titratable acidity ranged from 20 to 26 meq acid/litre. Two solutions prepared from commercial solutions and containing 28 meq/litre sodium bicarbonate had a pH of 7·5 and a titratable acidity of 4–5 meq base/litre when equilibrated at a PCO2 of 40 mm Hg. Systemic acidosis due to some infusions may be prevented by the addition of sodium bicarbonate to the infusion solutions to produce a pH of 7·4 at PCO2 of 40 mm Hg.