title: Calcium Mass Balance during Citrate Hemodialysis: A Randomized Controlled Trial Comparing Normal and Low Ionized Calcium Target Ranges.
abstract: BACKGROUND
  Regional citrate anticoagulation (RCA) during hemodialysis interferes with calcium homeostasis. Optimal ionized calcium (iCa) target range during RCA and consequent calcium balance are unknown.
  
  
  METHODS
  In a randomized controlled trial (ACTRN12613001029785) 30 chronic hemodialysis patients were assigned to normal (1.1-1.2 mmol/) or low (0.95-1.05 mmol/l) iCa target range during a single hemodialysis with RCA. The primary outcome was calcium mass balance during the procedure, using a partial spent dialysate collection method; magnesium mass balance was also measured. Intact parathormone (iPTH), total calcium (tCa) and magnesium were measured before and after procedures.
  
  
  RESULTS
  Mean iCa during procedures was significantly different in the two groups (1.12±0.06 in normal and 1.06±0.07 mmol/l in low iCa group, p <0.001), resulting in different tCa (2.18±0.22 vs. 1.95±0.17, p = 0.003) after the procedure. Mean delivered calcium during the procedure was 58.3±4.8 mmol in the normal and 51.5±8.2 mmol in the low iCa group (p = 0.010), which resulted in a significantly higher mean positive calcium mass balance of 14.6±8.3 mmol (584±333 mg) per procedure in normal as compared to 7.2±8.5 mmol (290±341 mg) in low iCa group (p = 0.024). Linear mixed effects model showed a significant interaction effect of time and iCa target range group on iPTH, i.e. a significant increase in iPTH in the low as compared to normal iCa target group (p = 0.008). Magnesium mass balance was mildly negative and comparable in both groups.
  
  
  CONCLUSIONS
  Low iCa target range resulted in a significantly less positive calcium mass balance, but in a significant increase in iPTH. To achieve a more neutral calcium balance, we recommend allowing a mild hypocalcemia during hemodialysis with RCA, especially when it is used for prolonged periods.
authors.affiliation: Department of Nephrology, University Medical Centre Ljubljana, Ljubljana, Slovenia.|Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Jakob
authors.identifier: http://orcid.org/0000-0002-5394-3729
authors.initials: J
authors.lastname: Gubensek
authors.affiliation: Department of Nephrology, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Alesa
authors.initials: A
authors.lastname: Orsag
authors.affiliation: Department of Nephrology, University Medical Centre Ljubljana, Ljubljana, Slovenia.|Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Rafael
authors.initials: R
authors.lastname: Ponikvar
authors.affiliation: Department of Nephrology, University Medical Centre Ljubljana, Ljubljana, Slovenia.|Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Jadranka
authors.initials: J
authors.lastname: Buturovic-Ponikvar
mesh_terms: D000368:Aged; D002118:Calcium / Q000494:pharmacology*; D002951:Citrates / Q000494:pharmacology*; D004573:Electrolytes / Q000378:metabolism*; D005260:Female; D015312:Hemodialysis Solutions / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis
chemical_list: D002951:Citrates; D004573:Electrolytes; D015312:Hemodialysis Solutions; D002118:Calcium