Chapter 111. Hydrocarbons and Volatile Substances

Products containing hydrocarbons are found in many household and workplace settings and include fuels, lighter fluids, paint removers, pesticides, polishers, degreasers, and lubricants. Some volatile substances may be recreationally abused. Exposure may cause mild to severe toxicity and, rarely, sudden death.

Toxicity depends on route of exposure, physical characteristics, chemical characteristics, and the presence of toxic additives (eg, lead or pesticides). See Table 111-1 for clinical features.

Chemical pneumonitis is the most common pulmonary complication, and is most likely to occur following aspiration of a hydrocarbon with low viscosity, high volatility, and low surface tension. Symptoms occur quickly and include cough and dyspnea. Physical examination may reveal tachypnea, wheezing, grunting, and an elevated temperature. Radiographic findings may lag behind the clinical picture by 4 to 24 hours; however, most radiographic abnormalities are apparent within 6 hours. Less common pulmonary complications include pneumothorax, pneumomediastinum, and pneumatocele.

Cardiac toxicity manifests as potentially lethal dysrhythmias resulting from myocardial sensitization to circulating catecholamines (“sudden sniffing death syndrome”). Halogenated hydrocarbon solvents are most frequently implicated.

Central nervous system toxicity may present as intoxication, ranging from initial giddiness, agitation, and hallucinations to seizures, slurred speech, ataxia, and coma. Chronic exposure may cause recurrent headaches, cerebellar ataxia, and mood lability.

Gastrointestinal toxicity can include vomiting (which can lead to aspiration), abdominal pain, anorexia, and hepatic damage (particularly from halogenated hydrocarbons).

Dermal toxicity includes contact dermatitis and blistering with progression to full-thickness burns. Injection of hydrocarbons can cause tissue necrosis.

Less common acute toxicities include hematologic disorders such as hemolysis, methemoglobinemia, carboxyhemoglobinemia (from methylene chloride), and renal disorders.

Diagnosis is made by history and physical examination findings, bedside monitoring, laboratory tests, and chest radiograph. An abdominal radiograph may reveal ingestion of radiopaque substances (eg, chlorinated hydrocarbons).

1. Secure the airway and maintain ventilation support. Administer oxygen to symptomatic patients and place them on a cardiac monitor (see Table 111-2).

2. Treat hypotension with intravenous crystalloid infusion. Avoid catecholamines except in cases of cardiac arrest. Treat tachydysrhythmias with propranolol, esmolol, or lidocaine. Avoid class IA and III agents.

3. Follow standard hazardous material measures for decontamination of the patient. Most hydrocarbon ingestions do not require GI decontamination. GI decontamination within 1 hour of ingestion is suggested only for a few hydrocarbons. Check with the local Poison Control Center before attempting GI decontamination as this can lead to further aspiration of volatile substances.

4. Meticulous wound care with potential surgical debridement is indicated for dermal exposures. Treat tar and asphalt injuries with debridement of blistered skin and application of petrolatum ointment or polyoxyethylene sorbitan monolaurate (Polysorbate).

5. Hyperbaric oxygen therapy may be indicated for patients who develop significant carbon monoxide toxicity after exposure to methylene chloride.

6. Admit symptomatic patients, those exposed to hydrocarbons capable of producing delayed toxicity (eg, halogenated hydrocarbons), and those exposed to hydrocarbons with toxic additives (eg, pesticides or organic metal compounds). Patients with a normal chest radiograph who remain asymptomatic after 6 to 8 hours of observation may be discharged with strict return precautions.