Ionized Magnesium and Regional Citrate Anticoagulation for Continuous Renal Replacement Therapy

Background: The regional citrate anticoagulation (RCA) induces changes in total (Ca tot ) and ionized (Ca 2+ ) calcium. As of now, we do not have much information about parallel changes of total (Mg tot ) and ionized (Mg 2+ ) magnesium. Methods: The authors compared changes of Mg 2+ and Mg tot with changes of Ca 2+ and Ca tot in 32 critically ill patients on 4% trisodium citrate (4% TSC) with calcium-free fluids. Results: The median continuous venovenous hemodiafiltration balance of Mg tot was –0.91 (–1.18 to –0.53) mmol/h compared to the median balance of Ca tot 0.86 (0.08–1.55) mmol/h. Postfilter Mg 2+ decreased by 68.3% (70.8–65.6) in parallel (r = 0.41, p = 0.03) to decrease of postfilter Ca 2+ (by 70.2% (73.0– 66.1)) and was significantly related to the postfilter Ca 2+ (r = 0.50, p < 0.001). The decrease of prefilter to postfilter Ca 2+ correlated to a dosage of 4% TSC per blood flow (r = 0.37, p = 0.04). Conclusions: The loss of Mg tot during RCA is not covered by magnesium concentration in ordinary dialysis/subReceived: April 21, 2015 Accepted: September 8, 2015 Published online: October 20, 2015 Martin Balik Department of Anesthesiology and Intensive Care, First Faculty of Medicine Charles University and General University Hospital U nemocnice 2 , Prague 2, 12000 (Czech Republic) E-Mail martin.balik @ vfn.cz © 2015 S. Karger AG, Basel 0253–5068/15/0413–0041$39.50/0