II. Causes: 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

III. Precautions

  1. Salicylate Poisoning (especially chronic Poisoning) has a high mortality and is easily mis-diagnosed
  2. Consider intentional Overdose (Suicidality) in the elderly

IV. Pathophysiology

  1. Salicylates directly act at the cerebral Medulla, increasing Respiratory Rate (with a Respiratory Alkalosis)
  2. Salicylate Toxicity uncouples oxidative phosphorylation (ATP generation in mitochondria from NADH and FADH2)
    1. Results in shift to anaerobic metabolism, resulting in a Lactic Acidosis (and Metabolic Acidosis with Anion Gap)
    2. Compensatory Hyperventilation (triggered by Metabolic Acidosis) further increases Tachypnea

V. Symptoms

VII. Differential Diagnosis

VIII. Labs: General

  1. Comprehensive metabolic panel findings
    1. Alkalosis or acidosis
      1. Metabolic Acidosis with increased Anion Gap is most typical
    2. Hyponatremia
    3. Hypokalemia
    4. Hyperglycemia or Hypoglycemia
    5. Acute Renal Failure

IX. 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
      1. Done Nomogram (formulated in 1961) is only valid in a single acute Salicylate ingestion
      2. Done Nomogram is not typically used clinically
        1. Not predictive of serious Salicylate Toxicity
        2. Contrast with Rumack-Matthew Nomogram used in Acetaminophen Overdose
    2. Manage Salicylate level based on local lab protocols and poison control
    3. Be aware of Units of Measure (local lab may use a measurement other than mg/dl)
  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

X. Management: Salicylate Overdose

  1. General measures
    1. Start management prior to serum level available if high level of suspicion and symptomatic patient
    2. Consider Gastric Decontamination (e.g. Activated Charcoal, Gastric Lavage) in early presentation or large ingestion
    3. Consult poison control
    4. Supplemental Oxygen
    5. Protect airway
  2. 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 10-20 cc/kg bolus
  3. Alkalinizing urine increases Salicylate excretion
    1. Solution: 3 Sodium Bicarbonate ampules in 850 ml D5W
      1. Add 40 meq KCl (if not hyperkalemic)
      2. Maintain pH 7.4 to 7.5 (by VBG)
      3. Goal Urine Output 1 to 1.5 ml/kg/h
    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
  4. 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
  5. 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 requiring intubation
  6. Intubated patients
    1. Match Ventilatory rate to respiratory prior to intubation
    2. Risk of rapidly progressive, catastrophic Metabolic Acidosis if hypoventilated

XI. References

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Related Studies

Ontology: Poisoning by salicylate (C0161544)

Concepts Injury or Poisoning (T037)
ICD9 965.1
ICD10 T39.0 , T39.091
SnomedCT 123315000, 212593000, 212594006, 7248001
English Salicylates, SALICYLISM, Salicylate poisoning NOS, Poisoning by salicylate, salicylate toxicity, salicylate toxicity (diagnosis), salicylic acid salt toxicity, salicylic acid salt toxicity (diagnosis), toxicity from salicylic acid salts, Poisoning-salicylates, Poisoning by salicylates NOS, salicylism, aspirin poisoning, salicylate poison, aspirin poison, salicylate intoxication, salicylate poisoning, Poisoning by salicylates, Tsalicylate intoxication, Salicylate intoxication, Salicylate poisoning NOS (disorder), Salicylic acid salt poisoning (event), Poisoning by salicylic acid salt (disorder), Salicylate poisoning, Salicylic acid salt poisoning, Salicylism, Poisoning by salicylate (disorder), Poisoning by salicylic acid salt, Poisoning by salicylate, NOS, Poisoning by salicylic acid salt, NOS, Poisoning by salicylic acid salt -RETIRED-, Poisoning by salicylic acid salts
Portuguese SALICISMO, Salicilismo, Intoxicação por salicilatos
French SALICYLISME, Intoxication au tsalicylate, Intoxication aux salicylés, Intoxication par salicylates, Intoxication salicylée
German Vergiftung: Salizylate, Salizylvergiftung, T Salicylatintoxikation, Salicylatintoxikation, Vergiftung durch Salizylate
Korean 살리실산염에 의한 중독
Spanish Intoxicación por salicilatos, Salicilismo, intoxicación por sal ácida salicílica - RETIRADO -, intoxicación por salicilato, SAI, intoxicación por sal ácida salicílica - RETIRADO - (concepto no activo), intoxicación por salicilato, SAI (trastorno), intoxicación por sal ácida salicílica, intoxicación por salicilatos (trastorno), intoxicación por salicilatos, salicilismo
Italian Avvelenamento da salicilati, Salicismo, Intossicazione da salicilato
Dutch salicylisme, vergiftiging door salicylaten, salicylaatintoxicatie, Salicylaten
Czech Intoxikace salicyláty, Salicylismus, Otrava salicyláty
Japanese サリチル酸類中毒, サリチルサンチュウドク, サリチルサンルイチュウドク, サリチル酸中毒
Hungarian Szalicilátok által okozott mérgezés, Salicylismus, Szalicilát intoxicatio