Difluoroethane toxicity

Background

A common source of Difluoroethane

• Difluoroethane (DFE) is a hydrofluorocarbon (HFC) commonly used as a propellant in aerosol products, including computer keyboard cleaners and refrigerants.
• Though considered non-toxic for industrial use, DFE is increasingly recognized as a substance of abuse, especially among adolescents and young adults, due to its rapid-onset euphoric effects when inhaled—a practice known as "huffing."

Key Pearls

• Sudden cardiac death from DFE abuse can occur in previously healthy individuals.
• Always obtain an EKG and initiate cardiac monitoring.
• Do not rely on routine tox screens—DFE often won’t show up.
• Avoid exogenous catecholamines if arrhythmia risk is present.
• Suspect DFE in cases of unexplained syncope, seizures, or cardiac arrest—especially in youth or with aerosol products nearby

Pathophysiology

DFE is rapidly absorbed through the lungs and acts primarily as a CNS depressant. Its volatile properties and lipid solubility allow it to penetrate the brain quickly, producing an intoxicating effect within seconds of inhalation.

Key pathophysiologic effects:

• Sensitization of myocardium to catecholamines → increased risk of fatal arrhythmias ("sudden sniffing death")
• Hypoxia and asphyxia due to displacement of alveolar oxygen
• Central nervous system depression, including coma and seizures
• Pulmonary injury: inflammation, hemorrhage, and edema
• Hepatic and renal injury with chronic or massive exposure

Clinical Features

Acute Presentation:

• Euphoria, dizziness, slurred speech
• Confusion, ataxia, lethargy
• Nausea, vomiting
• Seizures, particularly in high-dose exposure
• Syncope or cardiac arrest (especially with exertion or catecholamine surge)

Cardiac Effects

• Palpitations
• Premature ventricular contractions (PVCs)
• Ventricular tachycardia/fibrillation
• QT prolongation, possibly torsades de pointes

Pulmonary Effects

• Cough, dyspnea
• Chemical pneumonitis
• Pulmonary hemorrhage (in rare cases)

Chronic Use

• Cognitive decline
• Peripheral neuropathy
• Hepatotoxicity or nephrotoxicity
• Dermal frostbite or oronasal irritation from direct contact with aerosol can

Evaluation

Workup

• EKG: assess for QT prolongation, PVCs, ventricular arrhythmias
• Cardiac monitoring
• Chest X-ray if respiratory symptoms are present
• Basic labs:
  • CBC, BMP, troponin
  • Creatinine kinase (CK)
  • ABG if hypoxia suspected
  • Urine toxicology screen: may not detect difluoroethane but can help rule out co-ingestions

Diagnosis

• Consider DFE toxicity in any young patient with sudden unexplained arrhythmia, altered mental status, or seizure
• Ask about recent use of aerosol sprays, cleaning products, or refrigerants
• Look for signs of inhalant abuse:
  • Chemical odor on breath
  • Perioral or hand burns
  • Empty aerosol cans
  • Skin frostbite

Management

Supportive Care is the Mainstay:

• Airway, breathing, circulation (ABCs)
• Supplemental oxygen as needed
• Continuous cardiac monitoring due to risk of arrhythmia
• Avoid catecholamines (e.g., epinephrine, norepinephrine) unless absolutely necessary—may precipitate fatal arrhythmias

Treat Complications as They Arise:

• Ventricular arrhythmias → defibrillation, amiodarone (avoid lidocaine in some cases)
• Seizures → benzodiazepines
• Respiratory failure or chemical pneumonitis → consider intubation and supportive ventilation
• Skin or mucosal injury → treat as chemical burns or frostbite

Disposition

Admission

• Persistent arrhythmias or EKG abnormalities
• Seizure activity
• Altered mental status or respiratory compromise
• Suspicion of recurrent or chronic use (requires observation)

Discharge

• Normal mental status
• Normal EKG and cardiac monitoring for at least 4–6 hours post-exposure
• No signs of pulmonary or neurologic complications

Referral Considerations=

• Substance abuse counseling or addiction medicine
• Consider social work consult for adolescents or vulnerable individuals
• Outpatient follow-up with primary care or mental health services