Last reviewed: November 2017
Last updated: November  2017

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • absence of hypovolaemia
  • absence of hypervolaemia
  • absence of signs of adrenal insufficiency or hypothyroidism
  • nausea
  • vomiting
  • altered mental status
  • headache
  • seizure
  • coma

Other diagnostic factors

  • no hx of recent diuretic use

Risk factors

  • age >50 years
  • pulmonary conditions (e.g., pneumonia)
  • nursing home residence
  • postoperative state
  • malignancy
  • medicine associated with SIADH induction
  • CNS disorder
  • endurance exercise

Diagnostic investigations

1st investigations to order

  • serum sodium
  • serum osmolality
  • serum urea
  • urine osmolality
  • urine sodium
Full details

Investigations to consider

  • diagnostic trial with normal saline infusion
  • serum uric acid
  • fractional excretion of sodium
  • fractional excretion of urea
  • serum TSH
  • serum cortisol level
  • serum arginine vasopressin (AVP)
Full details

Treatment algorithm

Contributors

Authors VIEW ALL

Nephrologist

Arizona Kidney Disease and Hyptertension Center

Phoenix

AZ

Disclosures

MD declares that she has no competing interests.

Professor Emeritus of Medicine

Division of Nephrology

University of Arizona

Tucson

AZ

Disclosures

HL is an author of a reference cited in this monograph.

Peer reviewers VIEW ALL

Associate Director

Nephrology

Washington Hospital Center

Washington

DC

Disclosures

JHV declares that she has no competing interests.

Consultant Nephrologist

Renal Unit

Lancashire Teaching Hospitals

Fulwood

Preston

UK

Disclosures

LS declares that he has no competing interests.

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