title: Serum sodium shift in hyponatremic patients undergoing liver transplantation: a retrospective cohort study.
abstract: BACKGROUND
  We aimed to describe the pre-operative incidence of hyponatremia in patients undergoing liver transplantation (LTx), as well as the rate and consequences of rapid peri-operative sodium rises in these patients.
  
  
  METHODS
  This was a retrospective before and after observational study performed at a University-affiliated LTx center between January 2007 and June 2013. The primary exposure was pre-operative hyponatremia, defined as a serum sodium (SNa) <133 mmol/L. The primary outcome was occurrence of a rapid SNa shift, defined as ≥10 mmol/L in the first 24 h following LTx. The rates of rapid peri-operative SNa shift were compared before and after a focused quality assurance (QA) initiative performed in July 2009.
  
  
  RESULTS
  Of 366 LTx, 69 (18.9%) had pre-operative hyponatremia, 6 (8.7%) of whom had a rapid rise in serum sodium (SNa). Rapid rise was associated with a greater intra-operative positive fluid balance (p < 0.001) and use of intra-operative continuous renal replacement therapy (CRRT) (p = 0.017). A rapid rise in SNa was associated with more neurological investigations in the post-transplant period (brain computed tomography, electroencephalogram, swallow studies), increased neurological deficits (p = 0.006), more abnormal swallowing assessments (p = 0.003), a tendency for more neurology consultations (p = 0.058), increased discharge to a rehabilitation or long-term care facility (p < 0.001), and increased 6-month mortality (p < 0.001). Following a QA initiative, rapid peri-operative rises in SNa among hyponatremic patients was significantly reduced (20% vs. 0%, p < 0.003).
  
  
  CONCLUSIONS
  Pre-operative hyponatremia and rapid peri-operative SNa shifts are associated with a more complicated post-operative course and worse outcomes following LTx. Increased education and awareness, along with process changes, such as standardizing CRRT prescription, can reduce iatrogenic rapid peri-operative shifts in SNa.
authors.affiliation: Division of Critical Care Medicine, University of Alberta , Edmonton , Canada .
authors.forename: Adam
authors.initials: A
authors.lastname: Romanovsky
authors.forename: Luciano C P
authors.initials: LC
authors.lastname: Azevedo
authors.forename: Glenda
authors.initials: G
authors.lastname: Meeberg
authors.forename: Rayna
authors.initials: R
authors.lastname: Zibdawi
authors.forename: David
authors.initials: D
authors.lastname: Bigam
authors.forename: Sean M
authors.initials: SM
authors.lastname: Bagshaw
mesh_terms: D000328:Adult; D002170:Canada; D003943:Diagnostic Techniques, Neurological; D019468:Disease Management; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D016031:Liver Transplantation / Q000009:adverse effects / Q000379:methods; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D009422:Nervous System Diseases / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D019990:Perioperative Care / Q000009:adverse effects / Q000379:methods; D057234:Preoperative Period; D012964:Sodium / Q000097:blood / Q000494:pharmacology; D014882:Water-Electrolyte Balance / Q000187:drug effects
chemical_list: D012964:Sodium
keywords: Central pontine myelinolysis; continuous renal replacement therapy; hyponatremia; liver transplant; osmotic demyelination