title: Efficiency of the Genius batch hemodialysis system with low serum solute concentrations: the case of lithium intoxication therapy.
abstract: BACKGROUND
  The Genius batch system consists of a 90-L closed reservoir, from which fresh dialysate is extracted at the top and to which spent dialysate is returned at the bottom. It was shown in long-term hemodialysis patients that almost the entire amount of unspent dialysate can be used before contamination of fresh with spent dialysate occurs. Separation is caused by differences in density, partly because of the presence of uremic solutes in spent dialysate. The question is raised whether this separation can be maintained during dialysis of patients who experience an intoxication without renal failure.
  
  
  METHODS
  A patient intoxicated with lithium was dialyzed using the Genius system, prepared at 37 degrees C, during 300 minutes. With dialysate flow set at 300 mL/min (5 mL/s) and in the absence of mixing, urea is not expected at the inlet dialysate tubing before minute 300.
  
  
  RESULTS
  In the dialysate inlet tubing, an abrupt increase in lithium and urea concentrations was observed 210 minutes after the start of the session, reflecting contamination of fresh with spent dialysate. At minute 210, only 60.9 L of 90 L of dialysate had crossed the dialyzer. In a control dialysis treatment in a patient with marked renal failure, this mixing occurred only at 300 minutes.
  
  
  CONCLUSIONS
  In the present observation, it is shown that during Genius dialysis in a patient without renal failure, an earlier contamination of fresh with spent dialysate can occur, compared to conditions of renal failure.
authors.affiliation: Renal Division, Department of Internal Medicine, Ghent University, Belgium. annemie.dhondt@Ugent.be
authors.forename: Annemieke
authors.initials: A
authors.lastname: Dhondt
authors.forename: Alain
authors.initials: A
authors.lastname: Verstraete
authors.forename: Koen
authors.initials: K
authors.lastname: Vandewoude
authors.forename: Hannah
authors.initials: H
authors.lastname: Segers
authors.forename: Sunny
authors.initials: S
authors.lastname: Eloot
authors.forename: Johan
authors.initials: J
authors.lastname: Decruyenaere
authors.forename: Raymond
authors.initials: R
authors.lastname: Vanholder
mesh_terms: D000328:Adult; D018692:Antimanic Agents / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics / Q000506:poisoning*; D001714:Bipolar Disorder / Q000150:complications / Q000188:drug therapy; D004058:Diffusion; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D015312:Hemodialysis Solutions / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D016651:Lithium Carbonate / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics / Q000506:poisoning*; D008970:Molecular Weight; D011041:Poisoning / Q000628:therapy; D006435:Renal Dialysis / Q000295:instrumentation*; D013046:Specific Gravity; D014508:Urea / Q000032:analysis; D014635:Valproic Acid / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D018692:Antimanic Agents; D015312:Hemodialysis Solutions; D016651:Lithium Carbonate; D014635:Valproic Acid; D014508:Urea