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Toluene Poisoning, Emergency Medicine

Basics

Description

- Abused for its euphoric effect - Occupational exposures - Used as organic solvent found in: - Oil paints and stains - Paint thinners - Glues, inks, dyes, correction fluid - Coolants - Petroleum products - Aerosolized household products - Degreasers

- Prevalent in adolescent age group: - Inexpensive "high " ¯ with readily available sources - Many psychosocial problems

- May develop chronic neurologic dysfunction - Mechanism: - Rapidly absorbed by inhalation - Readily crosses blood " “brain barrier, reaching high concentrations in brain - May sensitize myocardium to dysrhythmogenic effect of catecholamines - Inhibits myocardial voltage-gated sodium channels and inward rectifying potassium channels - Alveolar excretion and liver metabolism

- Toxic range: - 100 ppm: Impairment of psychomotor and perceptual performance - 500 " “800 ppm: Headache, drowsiness, nausea, weakness, and confusion, potential lethal ranges - >800 ppm: Convulsions, ataxia, staggering gait - 10,000 " “30,000 ppm: Anesthesia within 1 min

- Acute: - Neurologic: - Depression - Euphoria - Ataxia - Dizziness - Seizures

- GI: - Abdominal pain - Nausea, vomiting - Hematemesis

- Cardiac: - Dysrhythmias - Dilated cardiomyopathy

- Electrolytes, BUN, creatinine, glucose: - Hypokalemia - Normal or high anion gap metabolic acidosis - Hyperchloremia - Impaired renal function - Severe hypocalcemia/hypophosphatemia

- Monitor respiratory status with pulse oximetry, CXR, and ABG if significant inhalation. - Steroids not recommended for pneumonitis. - Correct metabolic abnormalities: - Potassium - Calcium - Phosphate

  • Prototypical volatile hydrocarbon
  • Clear, colorless liquid with sweet odor

Etiology

  • Abused for its euphoric effect
  • Occupational exposures
  • Used as organic solvent found in:Oil paints and stainsPaint thinnersGlues, inks, dyes, correction fluidCoolantsPetroleum productsAerosolized household productsDegreasers
  • Production and use of gasoline is largest source of exposure
  • Prevalent in adolescent age group:Inexpensive "high " ¯ with readily available sourcesMany psychosocial problems
  • May develop chronic neurologic dysfunction
  • Mechanism:Rapidly absorbed by inhalationReadily crosses blood " “brain barrier, reaching high concentrations in brainMay sensitize myocardium to dysrhythmogenic effect of catecholaminesInhibits myocardial voltage-gated sodium channels and inward rectifying potassium channelsAlveolar excretion and liver metabolism
  • Methods of intoxication:Sniffing: Simple inhalation of substance directly from containerHuffing: Vapors inhaled through cloth saturated with substanceBagging: Vapors inhaled from bag containing substance
  • Toxic range:100 ppm: Impairment of psychomotor and perceptual performance500 " “800 ppm: Headache, drowsiness, nausea, weakness, and confusion, potential lethal ranges>800 ppm: Convulsions, ataxia, staggering gait10,000 " “30,000 ppm: Anesthesia within 1 min

Diagnosis

Signs and Symptoms

  • Acute:Neurologic:DepressionEuphoriaAtaxiaDizzinessSeizuresCardiac:Pulmonary:Chemical pneumonitisPulmonary edemaElectrolytes:HypokalemiaHypocalcemiaHyperchloremic metabolic acidosis, likely from hippuric acid metaboliteGI:Abdominal painNausea, vomitingHematemesisRenal:Distal renal tubular acidosisHematuriaProteinuriaMusculoskeletal:
  • Chronic:Neurologic:Peripheral neuropathy (diffuse demyelination)LeukoencephalopathyCerebral/cerebellar atrophyOptic atrophyDementiaCognitive/neurobehavioral abnormalitiesCardiac:DysrhythmiasDilated cardiomyopathyRenal:Distal renal tubular acidosisRenal failureFanconi syndromeMusculoskeletal:Psychiatric:
  • Fetal solvent syndrome reported from mothers who chronically abused toluene while pregnant, resembles fetal alcohol syndrome
  • Infant more likely premature, low birth weight, microcephaly, and developmental delay

History

  • Detailed history of sniffing, huffing, bagging, or other abuse of paints/solvents
  • Occupational exposures

Physical Exam

  • Presence of agent on lips, nose, or clothes (metallic paint has highest concentration)
  • Perioral eczematous dermatitis from chronic huffing or bagging
  • Odor of agents

Essential Workup

  • Detailed physical exam
  • CXR for suspected pneumonitis

Diagnosis Tests & Interpretation

Lab

  • Electrolytes, BUN, creatinine, glucose:HypokalemiaNormal or high anion gap metabolic acidosisHyperchloremiaImpaired renal functionSevere hypocalcemia/hypophosphatemia
  • Urinalysis:Check for myoglobin (rhabdomyolysis)Hematuria and protein often present
  • Creatinine kinase if suspect rhabdomyolysis
  • Alcohol level " ”often coingestant
  • Liver enzymes, prothrombin time (PT), partial thromboplastin time (PTT), INR, as may cause hepatotoxicity
  • Urine for hippuric acid (metabolite of toluene):Confirms exposure but does not correlate with systemic effects
  • Serum levels only detectable for short time after exposure

Imaging

  • EKG:For atrial and ventricular dysrhythmias
  • CXR:Indicated if dyspnea or low oxygen saturationChemical pneumonitis
  • CT head:For altered mental status/chronic exposureCerebral/cerebellar atrophy, white matter hypodensity

Diagnostic Procedures/Surgery

CSF often unremarkable but may be indicated for altered mental status to rule out other etiologies ‚

Differential Diagnosis

  • Alcohol intoxication
  • Other hydrocarbon abuse
  • Other inhalants (nitrous oxide, difluoroethane, butane, etc.)
  • Methanol
  • Ethylene glycol
  • Salicylate
  • Heavy metal exposure
  • Guillain " “Barre syndrome
  • Metabolic abnormalities

Treatment

Pre-Hospital

  • Rapid onset of toxicity
  • Death possible with sudden cardiac dysrhythmias (sudden sniffing death), often from catecholamine surge (e.g., eluding police)
  • Topical decontamination as needed
  • Forced emesis is not indicated:Decreased level of consciousness may lead to aspiration.

Initial Stabilization/Therapy

  • ABCs
  • Supplemental oxygen
  • Cardiac monitor
  • 0.9% NS IV access
  • Naloxone, thiamine, and check glucose if altered mental status

Ed Treatment/Procedures

  • Treat cardiac dysrhythmias in standard fashion:Consider ˇ ²-blocker for tachydysrhythmias.
  • Monitor respiratory status with pulse oximetry, CXR, and ABG if significant inhalation.
  • Steroids not recommended for pneumonitis.
  • Correct metabolic abnormalities:PotassiumCalciumPhosphate
  • Acidosis resolves with IV fluids.
  • If rhabdomyolysis, maintain high urine output.
  • Gastric decontamination for oral ingestion rarely useful and may cause harm:Charcoal does not bind hydrocarbons well and stomach distention may predispose to vomiting and aspiration.

Medication

  • Dextrose: D50W, 1 amp: 50 mL or 25 g (peds: D25W, 2 " “4 mL/kg) IV
  • Naloxone (Narcan): 2 mg (peds: 0.1 mg/kg) IV or IM initial dose
  • Thiamine (vitamin B1): 100 mg (peds: 50 mg) IV or IM

Follow-Up

Disposition

Admission Criteria

  • Altered mental status
  • Dysrhythmias
  • Hepatic dysfunction
  • Renal failure
  • Rhabdomyolysis
  • Severe metabolic derangements
  • Refractory hypokalemia

Discharge Criteria

After 4 " “6 hr of observation: ‚

  • Mental status at baseline
  • No evidence of cardiac, metabolic, or neurologic derangement

Follow-Up Recommendations

  • Psychiatry referral for intentional/repeated ingestions and addiction counseling
  • Cessation of use is most important intervention

Pearls and Pitfalls

  • Myocardial sensitization to catecholamines:Possibility of sudden dysrhythmia/deathCardiac dysrhythmias have poor prognosis
  • Monitor and replete electrolyte abnormalities.

Additional Reading

  • Bowen ‚ SE, Hannigan ‚ JH. Developmental toxicity of prenatal exposure to toluene. AAPS J. 2006;8:E419 " “E424.
  • Filley ‚ CM, Halliday ‚ W, Kleinschmidt-Demasters ‚ BK. The effects of toluene on the central nervous system. J Neuropathol Exp Neurol. 2004;63:1 " “12.
  • Long ‚ H. Inhalants. In: Goldfrank ‚ LR, ed. Goldfranks Toxicologic Emergencies. 9th ed. New York, NY: McGraw-Hill; 2011:1157 " “1165.
  • Tang ‚ HL, Chu ‚ KH, Cheuk ‚ A, et al. Renal tubular acidosis and severe hypophosphataemia due to toluene inhalation. Hong Kong Med J. 2005;11(1):50 " “53.
  • Yucel ‚ M, Takagi ‚ M, Walterfang ‚ M, et al. Toluene misuse and long-term harms: A systematic review of the neuropsychological and neuroimaging literature. Neurosci Biobehav Rev. 2008;32:910 " “926.

The author would like to provide special thanks to the author of the prior edition, Matthew Valento. ‚

Codes

ICD9

  • 305.90 Other, mixed, or unspecified drug abuse, unspecified use
  • 982.0 Toxic effect of benzene and homologues

ICD10

  • F18.10 Inhalant abuse, uncomplicated
  • F18.120 Inhalant abuse with intoxication, uncomplicated
  • T52.2X1A Toxic effect of homologues of benzene, accidental (unintentional), initial encounter
  • T52.2X4A Toxic effect of homologues of benzene, undetermined, initial encounter

SNOMED

  • 212821000 Toxic effect of homologues of benzene (disorder)
  • 70340006 inhalant abuse (disorder)
  • 445931006 Poisoning by fumes (disorder)
  • 216671002 Accidental poisoning by petroleum solvents (disorder)