Salicylate Poisoning

Description

• Respiratory alkalosis and metabolic acidosis:
  • Secondary to inhibition of Krebs cycle and uncoupling of oxidative phosphorylation
• Dehydration, hyponatremia or hypernatremia, hypokalemia, hypocalcemia:
  • Owing to increased sweating, vomiting, tachypnea
• Noncardiogenic pulmonary edema:
  • Because of toxic effect of salicylate on pulmonary endothelium resulting in extravasation of fluids
• Salicylate pharmacokinetics change from first order to zero order in overdose setting; i.e., a small dosage increment results in a large increase in salicylate concentration

• Greater morbidity
• Respiratory distress/altered mental status indicative of severe toxicity
• Diagnosis of salicylate intoxication delayed because underlying disease states mask signs and symptoms; e.g., CHF

• Children exhibit faster onset and more severe signs and symptoms than adults:
  • Results from salicylate being distributed more quickly into target organs such as brain, kidney, and liver
• Respiratory alkalosis (hallmark of salicylate poisoning in adults) may not occur in children
• Metabolic acidosis occurs more quickly in children than in adults
• Hypoglycemia more common than hyperglycemia
• Ingestion of more than “a taste” of oil of wintergreen (98% methyl salicylate) by children <6 yr or >4 mL of oil of wintergreen by patients >6 yr warrants ED assessment

Etiology

• Aspirin:
  • Ingestion of >150 mg/kg can cause serious toxicity
• Oil of wintergreen:
  • Any exposure should be considered dangerous
• Bismuth subsalicylate
• Salicylsalicylic acid (salsalate)