Salicylate Overdose

1. Preparations: Salicylate sources
   1. Aspirin
   2. Pepto Bismol
   3. Topical Salicylates
      1. Ben Gay
      2. Salicylic Acid
      3. Methyl Salicylate (oil of wintergreen)
         1. One teaspoon contains 7000 mg of Salicylate
2. Symptoms or Signs
   1. Alkalosis or acidosis
   2. Coma
   3. Diaphoresis
   4. Disorientation
   5. Hyponatremia
   6. Hyperglycemia or Hypoglycemia
   7. Hyperventilation
   8. Nausea and Vomiting
   9. Renal Failure
   10. Seizures
   11. Tinnitus
   12. Deafness
3. Lab: Plasma Salicylate level (Dose related Aspirin effect)
   1. Precautions
      1. Interpret Salicylate level based on Salicylate nomogram in the context of time since ingestion
      2. Manage Salicylate level based on local lab protocols and poison control
   2. Serious toxicity occurs with ingestion >150 mg/kg
   3. Therapeutic Levels
      1. Plasma Salicylate level <10 mg/dl: Analgesic effect
      2. Plasma Salicylate level 10-20 mg/dl: Anti-inflammatory
   4. Overdosage levels (based on 6 hour Salicylate levels in acute toxicity)
      1. Plasma Salicylate level 20-45 mg/dl: Asymptomatic mild toxicity
      2. Plasma Salicylate level 45-65 mg/dl: Mild symptomatic toxicity
         1. Tinnitus (especially children) or decreased hearing (especially adults)
         2. Hyperventilation
      3. Plasma Salicylate level 65-90 mg/dl: Moderate toxicity
         1. Fever
         2. Metabolic Acidosis
      4. Plasma Salicylate level 90-110 mg/dl: Severe toxicity
         1. Coma
         2. Cardiovascular instability
      5. Plasma Salicylate level >110 mg/dl: Lethal toxicity
         1. Renal Failure
         2. Respiratory failure
4. Management: Salicylate Overdose
   1. Start management prior to serum level available if high level of suspicion and symptomatic patient
   2. Consider Gastric Decontamination (e.g. Gastric Lavage) in early presentation or large ingestion
   3. Load crystalloid to maintain urine output (critical to maximize urine Salicylate excretion)
      1. Adult: Start with NS 1-2 Liter bolus
      2. Child: Start with NS 20 cc/kg bolus
   4. Alkalinizing urine increases Salicylate excretion
      1. Solution: 3 Sodium Bicarbonate ampules in 850 ml D5W
         1. Add 40 meq KCl (if not hyperkalemic)
      2. Adult: Infuse above solution at 150-200 ml/hour or 2-3 ml/kg/hour
         1. Consider preceding infusion with 1-2 amps of Sodium Bicarbonate
      3. Child: Infuse above solution at 1.5 to 2 times maintenance
         1. Consider preceding infusion with 1-2 meq/kg of Sodium Bicarbonate
   5. Monitoring
      1. Urine pH
         1. Confirm Urine pH 7.5 to 8.0 at 1-2 hours after starting Sodium Bicarbonate infusion
         2. Adjust alkalinization protocol if urine not adequately alkalinized
      2. Serum Potassium
         1. Correct Hypokalemia
      3. Mental Status
         1. Salicylates cross the blood brain barrier in Metabolic Acidosis
         2. Mental status may paradoxically worsen despite a decreasing serum Salicylate level
   6. Hemodialysis indications
      1. Acute toxicity: Salicylate level >100 mg/dl in adults (>80 mg/dl in children)
      2. Chronic toxicity: Salicylate level >60 mg/dl in adults
      3. Worsening mental status
      4. Patient requires intubation
5. References
   1. Claudius and Levine in Majoewsky (2012) EM:Rap 12(5): 7
   2. Done (1960) Pediatrics 26:800