title: Trace element removal during in vitro and in vivo continuous haemodialysis.
abstract: BACKGROUND
  Continuous renal replacement therapy (CRRT) increasingly is being used to treat critically ill patients with renal disease. CRRT removes waste products but also nutrients. Our understanding of trace element CRRT clearance has been limited by poor assay sensitivity. The development of inductively coupled plasma mass spectrometry (ICP-MS) allows for the measurement of CRRT trace element removal.
  
  
  METHODS
  Continuous venovenous haemodialysis (CVVHD) transmembrane clearances of trace elements and urea were assessed using a bovine blood-based in vitro model using two different haemodialyser types. These findings were validated in 10 critically ill adult patients receiving continuous venovenous haemodiafiltration (CVVHDF). Calculated daily trace element loss was compared with a typical dose of daily trace element supplementation.
  
  
  RESULTS
  The mean +/- SD in vitro CVVHD transmembrane clearances (ml/min) for the polysulfone haemodialyser were chromium 0.97 +/- 0.23, copper 0.47 +/- 0.18, manganese 4.6 +/- 3.6, selenium 1.2 +/- 0.63 and zinc 2.3 +/- 0.32 and for the cellulose diacetate haemodialyser chromium 1.54 +/- 0.91, copper 0.21 +/- 0.07, manganese 7.8 +/- 4.1, selenium 0.76 +/- 0.39 and zinc 2.7 +/- 0.37. The in vivo CVVHDF transmembrane clearances (ml/min) were chromium 5.4 +/- 2.4, copper 0.45 +/- 0.33, manganese 1.9 +/- 4.6, selenium 1.6 +/- 1.2, and zinc 4.0 +/- 1.3.
  
  
  CONCLUSIONS
  ICP-MS assays detected the five trace elements in the effluent of CVVHDF patients. Trace element CVVHD transmembrane clearance estimates for our in vitro model were supported by the in vivo CVVHDF findings. Calculated daily trace element loss attributed to CVVHD and CVVHDF with dialysate flow rates of 33.3 ml/min is less than what is provided in a daily dose of a trace element supplementation product.
authors.affiliation: Department of Pharmacy Practice, University of Toledo College of Pharmacy, 2801 W. Bancroft MS 609, Toledo, OH 43606, USA. mariann.churchwell@utoledo.edu
authors.forename: Mariann D
authors.initials: MD
authors.lastname: Churchwell
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Pasko
authors.forename: Imad F
authors.initials: IF
authors.lastname: Btaiche
authors.forename: Jinesh C
authors.initials: JC
authors.lastname: Jain
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Mueller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004058:Diffusion; D005260:Female; D015312:Hemodialysis Solutions; D006440:Hemofiltration; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008875:Middle Aged; D006435:Renal Dialysis / Q000295:instrumentation* / Q000379:methods*; D051437:Renal Insufficiency; D017582:Renal Replacement Therapy / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D014131:Trace Elements / Q000032:analysis*; D014867:Water / Q000737:chemistry
chemical_list: D015312:Hemodialysis Solutions; D014131:Trace Elements; D014867:Water