Stroke-Induced SIADH

Pathophysiology

• Inappropriate ADH secretion results in concentrated urine and decreased free water excretion despite hyponatremia, as noted by the Annals of Oncology 1

Clinical Presentation and Diagnosis

• Patients with stroke-induced SIADH typically present with euvolemic hyponatremia 2
• Laboratory findings suggestive of SIADH include inappropriately high urine osmolality (>500 mosm/kg) relative to plasma osmolality 2
• Urine sodium >20 mEq/L is also a suggestive finding of SIADH 2
• Serum uric acid <4 mg/dL is another laboratory finding associated with SIADH 2

Management

• The American Heart Association recommends fluid restriction to 1L/day as the cornerstone of treatment for SIADH in stroke patients 3
• Severe symptomatic hyponatremia may require 3% hypertonic saline with careful monitoring, according to the Stroke journal 3
• The rate of sodium correction should not exceed 8 mmol/L in 24 hours to prevent osmotic demyelination syndrome, as advised by the Stroke journal 3

Common Pitfalls

• Using fluid restriction in cerebral salt wasting can worsen outcomes, as warned by Praxis Medical Insights 4
• Failing to recognize and treat the underlying cause of hyponatremia can lead to poor outcomes, according to Praxis Medical Insights 4
• Overly rapid correction of chronic hyponatremia can lead to osmotic demyelination syndrome, as cautioned by Praxis Medical Insights 4