Hydrocarbon Inhalation Injury Clinical Presentation

A high index of suspicion is required because exposure to most volatile substances is not detectible by physical examination and because people who intentionally abuse inhalants initially deny hydrocarbon inhalation. Presentation of a patient with a characteristic odor of gasoline or kerosene likely suggests exposure; however, patients who present with altered mental status or intoxication should be scrutinized for the possibility of inhalation abuse in addition to abuse of other common drugs.

Populations at higher risk should be questioned more carefully; high-risk populations include children and adolescents from families of low socioeconomic status, in whom unemployment and poverty rates are high, as well as those lacking adult supervision.

Common symptoms between episodes of abuse include poor social functioning, underachievement at work or school, apathy, chest pain, and thirst.

Carefully investigate the possibility of illicit solvent inhalation in all patients presenting with the following unexplained symptoms or factors:

• Altered mental status, cerebellar dysfunction, peripheral neuropathy
• Behavioral changes, deteriorating school performance
• Pulmonary hypertension with or without cor pulmonale
• Acute rhabdomyolysis
• Renal tubular acidosis with severe hypokalemia and hypophosphatemia
• GI symptoms, such as abdominal pain, hematemesis, nausea, and vomiting
• Mothers of infants with toluene embryopathy
• Evaluate all patients who present after autoerotic asphyxiation for solvent abuse because such chemicals may be used to relax inhibitions.

When inhalant abuse is identified, make efforts to specifically identify the toxins involved because abusers often ingest various solvent-inhalants and frequently misidentify the substances involved. Hydrocarbons are not often part of a routine toxicology screen; therefore, if such an exposure is clinically suspected, the laboratory must be alerted and specific identifying tests must be obtained.

Patients who have acute decompensation from solvent-inhalant abuse are frequently found near the offending agent; however, many patients who present to medical care have no obvious physical findings to suggest hydrocarbon exposure or inhalant abuse. Some patients may present with subtle signs of abuse, such as paint staining around the mouth or nose. A characteristic odor may be detectable on presentation because a significant proportion of the absorbed chemical exits the body via the lungs. Also, the product may have been spilled onto clothing during use.

Evidence of chronic inhalant abuse may be more subtle. Patients presenting with unexplained peripheral neuropathy and weakness, diffuse GI symptoms, or neuropsychiatric symptoms should raise suspicion of chronic solvent-inhalant abuse. Electrolyte abnormalities, including hypokalemia, hypophosphatemia, and acidosis, should further raise suspicion. However, the nature of these symptoms is not diagnostic of solvent-inhalant abuse; therefore, a very broad differential diagnosis is required.

Signs and symptoms

A single, loud S₂ may be evident as a result of pulmonary hypertension. Ventricular arrhythmias or bradycardia may be observed. Discolored urine may be evident from rhabdomyolysis.

Adolescents who present with unexplained obtundation or seizures should be examined carefully for evidence of recent solvent-inhalant exposure. Physical findings of recent solvent-inhalant abuse include flecks of paint around the nose and mouth and staining of the fingers, nails, and clothing.

A solvent aroma may be present on the breath. Rhinitis, nasal mucosal erosions, epistaxis, hoarse voice, and conjunctivitis may result from local exposure.

The acute neurologic effects of inhaled solvents generally wear off within minutes to a few hours, but the effects of more chronic use may persist.

Muscle weakness, diffuse GI symptoms, and neuropsychiatric symptoms are 3 major symptom patterns of chronic abuse.

The common idea that solvent inhalation is innocuous undoubtedly contributes to solvent-inhalant abuse. The wide availability of organic solvents in commonly used household products makes them readily accessible.

Commonly abused products include the following:

• Liquids - Model glue, gasoline, contact cement (rubber cement), lacquers, nail-polish remover, dry-cleaning fluids
• Aerosols - Spray paints, butane fuel, lighter fluid, cooking sprays, cosmetics, hairspray, toiletries, deodorants

Chemicals found in abused inhalants include the following:

• Propane
• Butane
• n-Hexane
• Trichloroethylene
• Freon
• Benzene
• Toluene
• Xylene
• Acetone
• Methyl isobutyl ketone