Hydrocarbon Toxicity Clinical Presentation

In cases of suspected hydrocarbon intoxication, it is important to determine the agent ingested, the route of ingestion (eg, oral, dermal, inhalational) the amount of substance ingested, and the time of the ingestion. In addition, the history should include questions about co-ingestants, any vomiting or coughing prior to arrival, and any attempt to treat the patient prior to arrival.

Respiratory distress

The lung is the primary site of most common toxicity following hydrocarbon exposures. Pulmonary toxicity most often occurs following ingestion and subsequent aspiration of hydrocarbon. Respiratory symptoms (eg, coughing, gagging, choking) usually occur within 30 minutes of exposure but often can be delayed several hours.

Many patients develop a transient cough. A prolonged cough and hypoxia, however, is more concerning for aspiration. Lack of coughing does not exclude the possibility of aspiration.

Nervous system

The most common CNS symptoms include headache, lethargy, and decreased mental status. Nonspecific symptoms such as weakness and fatigue may also be reported.

Because many of the solvents are highly lipophilic, solvent abuse causes a transient euphoria.

With prolonged exposure to n -hexane, MnBK, and possibly toluene, an axonopathy can occur. This peripheral neuropathy usually begins in the extremities and then progresses more proximally.

Cardiovascular

The patient may complain of dyspnea or syncope.

In addition, because of sensitization of the myocardium to catecholamines, a relatively young and previously healthy patient can present in full cardiac arrest after being suddenly startled or following strenuous athletic events. A common scenario for the cardiac arrest patient is the teenager who is huffing, or bagging alone in a dark room, who then gets startled when a parent opens the door. This "sudden sniffing death syndrome" results in ventricular fibrillation or ventricular tachycardia, following a large catecholamine exposure to a myocardium that is already sensitized to the effects of the catecholamines. This syndrome is more common following exposure to the halogenated hydrocarbons, but it can occur following exposure to aromatic hydrocarbons as well.

Gastrointestinal

Nausea, vomiting, and sore throat are frequent but are relatively mild.

Local reactions such as a burning sensation in the mouth, pruritus, or a perioral rash are not uncommon and are usually mild.

Diarrhea, melena, and hematemesis are rare.

Prior to instituting the physical examination, the patient should be appropriately decontaminated, if indicated.

The physical examination should focus on the patient's airway, breathing, and circulation (ABCs).

Patients who are experiencing any respiratory compromise should be placed on supplemental oxygen. For those patients who are in severe respiratory distress, or who are too lethargic to be able to adequately protect their airway, advanced airway management may be required.

Respiratory

• Coughing
• Gagging
• Choking
• Tachypnea
• Hemoptysis
• Rales
• Rhonchi
• Wheezes
• Hypoxia
• Cyanosis

Cardiovascular

• Tachycardia
• Dysrhythmias
• Hypotension

CNS

• Headache
• Ataxia
• Weakness
• Lethargy to coma
• Seizures

GI - Nausea/vomiting

Dermal

• Erythema
• Blistering
• Pain
• Nasal dermatitis or perioral dermatitis (with chronic abuse)
• Skin irritation (with single use) at an intravenous, intramuscular, or subcutaneous injection site

Hydrocarbon exposure can be divided into the following 4 broad categories:

• Nonintentional nonoccupational exposure: Accidental ingestions are the most frequent type and commonly involve young children tasting a hydrocarbon. Typically, children do not drink large quantities, as hydrocarbons generally taste bad. Adults and older children occasionally consume a hydrocarbon if liquid is placed in an unlabeled can or bottle resulting in accidental ingestion.
• Recreational exposure: Inhaling of hydrocarbons or other volatile solvents for the purpose of producing a transient state of euphoria is becoming more common. This pattern of use is most common in junior high and high-school aged children.
• Occupational exposure: This type of exposure is most often industrial, where a worker has either a dermal exposure to the liquid or an inhalational exposure to the vapors.
• Intentional: This type of exposure usually involves consuming a large amount of the hydrocarbon as an oral ingestion during a suicide attempt.