title: Successful rescue of severe hypernatraemia (196 mmol/L) by treatment with hypotonic fluid.
abstract: Hypernatraemia over 160 mmol/L is considered to be severe. This case reports a patient who developed extreme hypernatraemia with a serum sodium concentration of 196 mmol/L. The patient was known to have chronic renal impairment and was admitted with acute deterioration of renal function secondary to dehydration. This was considered to be secondary to poor oral fluid intake (related to depression) and lithium-induced nephrogenic diabetes insipidus with salt-losing nephropathy. The patient had a high urinary sodium excretion but was also in a pure water losing state as evidenced by an inappropriately low urine osmolality for the plasma osmolality and was successfully treated with hypotonic intravenous fluid and desmopressin.
authors.affiliation: Derriford Combined Laboratory, Derriford Hospital, Plymouth PL6 8DH, UK. jinny.jeffery@phnt.swest.nhs.uk
authors.forename: Jinny
authors.initials: J
authors.lastname: Jeffery
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Ayling
authors.forename: Richard J S
authors.initials: RJ
authors.lastname: McGonigle
mesh_terms: D001714:Bipolar Disorder / Q000150:complications / Q000188:drug therapy; D003894:Deamino Arginine Vasopressin / Q000627:therapeutic use*; D003681:Dehydration / Q000150:complications; D003863:Depression / Q000150:complications; D018500:Diabetes Insipidus, Nephrogenic / Q000139:chemically induced; D005260:Female; D006801:Humans; D006955:Hypernatremia / Q000188:drug therapy* / Q000209:etiology; D007038:Hypotonic Solutions / Q000627:therapeutic use*; D007262:Infusions, Intravenous; D016651:Lithium Carbonate / Q000009:adverse effects; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000139:chemically induced / Q000150:complications; D016896:Treatment Outcome
chemical_list: D007038:Hypotonic Solutions; D016651:Lithium Carbonate; D003894:Deamino Arginine Vasopressin