title: Investigation and management of severe hyponatraemia in a hospital setting.
abstract: OBJECTIVE
  To evaluate the assessment and management of severe hyponatraemia in a large teaching hospital.
  
  
  METHODS
  Inpatients with serum sodium <125 mmol/l were identified prospectively from a laboratory database over a six month period. Notes were examined and data extracted. Case notes were carefully reviewed retrospectively by a consultant endocrinologist with regard to accuracy of the diagnosis and the appropriateness of investigations and management.
  
  
  RESULTS
  104 patients with a serum sodium <125 mmol/l were identified. Mean (SD) age was 69 (14), 52% were female, mean hospital stay was 16 (12) days, and overall mortality 27%. Adequate investigations were rarely performed. Only 28 (26%) had plasma osmolality measured, 29 (27%) urine osmolality, 11 (10%) urinary sodium, 8 (8%) plasma cortisol, and 2 (2%) a short Synacthen test. Comparing the "ward" and "specialist review" diagnoses, there were significant discrepancies for "no cause found" (49% v 27%, p<0.001), alcohol (6% v 11% p<0.01), and syndrome of inappropriate antidiuresis (20% v 32%, p = 0.001). Treatment was often illogical with significant management errors in 33%. These included fluid restriction and intravenous saline given together (4%) and fluid restriction in diuretic induced hyponatraemia (6%). Mortality was higher in the group with management errors (41% v 20% p = 0.002).
  
  
  CONCLUSIONS
  Severe hyponatraemia is a serious condition, but its investigation and evaluation is often inadequate. Some treatment patterns seem to be arbitrary and illogical, and are associated with higher mortality.
authors.affiliation: Department of Diabetes and Endocrinology, University Hospital Aintree, Liverpool, UK. bobhuda@liv.ac.uk
authors.forename: M S B
authors.initials: MS
authors.lastname: Huda
authors.forename: A
authors.initials: A
authors.lastname: Boyd
authors.forename: K
authors.initials: K
authors.lastname: Skagen
authors.forename: D
authors.initials: D
authors.lastname: Wile
authors.forename: C
authors.initials: C
authors.lastname: van Heyningen
authors.forename: I
authors.initials: I
authors.lastname: Watson
authors.forename: S
authors.initials: S
authors.lastname: Wong
authors.forename: G
authors.initials: G
authors.lastname: Gill
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection