title: The Effects of High Level Magnesium Dialysis/Substitution Fluid on Magnesium Homeostasis under Regional Citrate Anticoagulation in Critically Ill.
abstract: BACKGROUND
  The requirements for magnesium (Mg) supplementation increase under regional citrate anticoagulation (RCA) because citrate acts by chelation of bivalent cations within the blood circuit. The level of magnesium in commercially available fluids for continuous renal replacement therapy (CRRT) may not be sufficient to prevent hypomagnesemia.
  
  
  METHODS
  Patients (n = 45) on CRRT (2,000 ml/h, blood flow (Qb) 100 ml/min) with RCA modality (4% trisodium citrate) using calcium free fluid with 0.75 mmol/l of Mg with additional magnesium substitution were observed after switch to the calcium-free fluid with magnesium concentration of 1.50 mmol/l (n = 42) and no extra magnesium replenishment. All patients had renal indications for CRRT, were treated with the same devices, filters and the same postfilter ionized calcium endpoint (<0.4 mmol/l) of prefilter citrate dosage. Under the high level Mg fluid the Qb, dosages of citrate and CRRT were consequently escalated in 9h steps to test various settings.
  
  
  RESULTS
  Median balance of Mg was -0.91 (-1.18 to -0.53) mmol/h with Mg 0.75 mmol/l and 0.2 (0.06-0.35) mmol/h when fluid with Mg 1.50 mmol/l was used. It was close to zero (0.02 (-0.12-0.18) mmol/h) with higher blood flow and dosage of citrate, increased again to 0.15 (-0.11-0.25) mmol/h with 3,000 ml/h of high magnesium containing fluid (p<0.001). The arterial levels of Mg were mildly increased after the change for high level magnesium containing fluid (p<0.01).
  
  
  CONCLUSIONS
  Compared to ordinary dialysis fluid the mildly hypermagnesemic fluid provided even balances and adequate levels within ordinary configurations of CRRT with RCA and without a need for extra magnesium replenishment.
  
  
  BACKGROUND
  ClinicalTrials.gov Identifier: NCT01361581.
authors.affiliation: Dept. of Anesthesiology and Intensive Care, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
authors.forename: Mychajlo
authors.initials: M
authors.lastname: Zakharchenko
authors.affiliation: Dept. of Clinical Biochemistry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Los
authors.affiliation: Dept. of Clinical Biochemistry, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
authors.forename: Helena
authors.initials: H
authors.lastname: Brodska
authors.affiliation: Dept. of Anesthesiology and Intensive Care, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Balik
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000737:chemistry*; D002951:Citrates / Q000737:chemistry*; D019343:Citric Acid; D016638:Critical Illness; D015314:Dialysis Solutions / Q000737:chemistry*; D005260:Female; D006440:Hemofiltration / Q000009:adverse effects; D006706:Homeostasis; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008274:Magnesium / Q000737:chemistry* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D006435:Renal Dialysis; D051437:Renal Insufficiency / Q000628:therapy
chemical_list: D000925:Anticoagulants; D002951:Citrates; D015314:Dialysis Solutions; D019343:Citric Acid; D008274:Magnesium