title: Falsely elevated lithium levels in plasma samples obtained in lithium containing tubes.
abstract: METHODS
  We present a case of lithium poisoning in a 15-month-old child. Delayed elevation of the plasma lithium concentration at 13 hours after admission to a hospital was noted. This appeared to be factitiously related to the collection of samples in a speckled green top tube which contains lithium heparin as an anticoagulant.
  
  
  CONCLUSIONS
  This type of false elevation has not been reported in the medical literature. A follow-up study in five healthy volunteers showed that the lithium concentrations of plasma samples obtained in speckled green top tubes are increased by approximately 1.5 mEq/L (1.5 mmol/L).
authors.affiliation: Medical College of Pennsylvania, Philadelphia.
authors.forename: D C
authors.initials: DC
authors.lastname: Lee
authors.forename: M N
authors.initials: MN
authors.lastname: Klachko
mesh_terms: D000328:Adult; D062787:Drug Overdose; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007223:Infant; D008094:Lithium / Q000097:blood*; D016651:Lithium Carbonate / Q000506:poisoning*; D008297:Male; D009661:Nortriptyline / Q000506:poisoning*; D013048:Specimen Handling / Q000379:methods*
chemical_list: D016651:Lithium Carbonate; D008094:Lithium; D009661:Nortriptyline