title: Differential diagnosis of hyponatraemia.
abstract: The appropriate management of hyponatraemia is reliant on the accurate identification of the underlying cause of the hyponatraemia. In the light of evidence which has shown that the use of a clinical algorithm appears to improve accuracy in the differential diagnosis of hyponatraemia, the European Hyponatraemia Network considered the use of two algorithms. One was developed from a nephrologist's view of hyponatraemia, while the other reflected the approach of an endocrinologist. Both of these algorithms concurred on the importance of assessing effective blood volume status and the measurement of urine sodium concentration in the diagnostic process. To demonstrate the importance of accurate diagnosis to the correct treatment of hyponatraemia, special consideration was given to hyponatraemia in neurosurgical patients. The differentiation between the syndrome of inappropriate antidiuretic hormone secretion (SIADH), acute adrenocorticotropic hormone (ACTH) deficiency, fluid overload and cerebral salt-wasting syndrome was discussed. In patients with SIADH, fluid restriction has been the mainstay of treatment despite the absence of an evidence base for its use. An approach to using fluid restriction to raise serum tonicity in patients with SIADH and to identify patients who are likely to be recalcitrant to fluid restriction was also suggested.
authors.affiliation: Academic Department of Endocrinology, Beaumont Hospital and RCSI Medical School, Beaumont Road, Dublin 9, Ireland. christhompson@beaumont.ie
authors.forename: Chris
authors.initials: C
authors.lastname: Thompson
authors.forename: Tomas
authors.initials: T
authors.lastname: Berl
authors.forename: Alberto
authors.initials: A
authors.lastname: Tejedor
authors.forename: Gudmundur
authors.initials: G
authors.lastname: Johannsson
mesh_terms: D000465:Algorithms; D001810:Blood Volume; D003937:Diagnosis, Differential; D004700:Endocrine System Diseases / Q000150:complications; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis* / Q000209:etiology; D007177:Inappropriate ADH Syndrome / Q000150:complications; D009422:Nervous System Diseases / Q000150:complications; D009994:Osmolar Concentration; D012964:Sodium / Q000097:blood / Q000652:urine; D014556:Urine
chemical_list: D012964:Sodium