Effects of sodium citrate, citric acid and lactic acid on human blood coagulation

Introduction:Citric acid infusion in extracorporeal blood may allow concurrent regional anticoagulation and enhancement of extracorporeal CO2removal. Effects of citric acid on human blood thromboelastography and aggregometry have never been tested before.Methods:In this in vitro study, citric acid, sodium citrate and lactic acid were added to venous blood from seven healthy donors, obtaining concentrations of 9 mEq/L, 12 mEq/L and 15 mEq/L. We measured gas analyses, ionized calcium (iCa++) concentration, activated clotting time (ACT), thromboelastography and multiplate aggregometry. Repeated measure analysis of variance was used to compare the acidifying and anticoagulant properties of the three compounds.Results:Sodium citrate did not affect the blood gas analysis. Increasing doses of citric and lactic acid progressively reduced pH and HCO3−and increased pCO2(p++, from 0.39 (0.36-0.39) and 0.35 (0.33-0.36) mmol/L, respectively, at 9 mEq/L to 0.20 (0.20-0.21) and 0.21 (0.20-0.23) mmol/L at 15 mEq/L (p++(p=0.07). Sodium citrate and citric acid similarly incremented the ACT, from 234 (208-296) and 202 (178-238) sec, respectively, at 9 mEq/L, to >600 sec at 15 mEq/L (pConclusions:Citric acid infusions determine acidification and anticoagulation of blood similar to lactic acid and sodium citrate, respectively.