Emergent Care / Stabilization:
Halogenated hydrocarbons require specific attention. These substances are postulated to sensitize the myocardium to stress or catecholamines. Patients who engage in abusing these substances, if startled, may subsequently go into cardiac arrest with recalcitrant ventricular dysrhythmias. Standard advanced cardiac life support should be initiated by a trained provider.

Diagnosis Overview:
Broadly, inhalational agents of abuse can be classified into nitrates, hydrocarbons, and halogenated hydrocarbons, with each group harboring its own specific nuances regarding pathophysiology, presentation, and treatment. All these agents can be used via huffing (using a soaked cloth under the nose / face), sniffing (spraying directly into the nose or heating a substance to enhance vaporization), and bagging (using a bag placed over the mouth or head with substance contained in the bag).

Inhalant abuse is more common among younger people, males, and those from disadvantaged backgrounds. Inhalants are used to produce an experience of euphoria and lightheadedness similar to ethanol intoxication. However, users can also experience depressed mood and suicidality. The high lipophilicity of these compounds leads to high blood-brain permeability. Agonism of gamma-aminobutyric acid (GABA) receptors and antagonism of N-methyl-D-aspartate (NMDA) receptors lead to the clinical effects seen.

Presentation of inhalant toxicity varies based on the route of exposure. Oral ingestions, dependent on substance viscosity and volatility, can cause profound aspiration pneumonitis, pneumonia, pulmonary edema, and acute respiratory distress syndrome (ARDS) through dissolution of pulmonary surfactant and direct inflammation. Hemorrhagic gastritis has also been reported in animal models and those with isopropanol ingestions. Inhalational exposures typically show a spectrum of altered mental status, primarily central nervous system (CNS) depression.

Many toluene-containing inhalants cause profound and life-threatening hypokalemia. This is a total body loss of potassium, not a simple intracellular shift.

Some inhalants may contain methanol and cause profound acidosis and potentially ocular toxicity if orally ingested.

Examples of substances in each class: 

Nitrates / nitrous oxide:

• Compressed nitrous oxide canisters / whippets
• Whipped cream cans
• Amyl / butyl nitrite "poppers"

Hydrocarbons:

• Gasoline and other fuel oils
• Glues
• Paint
• Toluene and other solvents

Halogenated hydrocarbons:

• Keyboard duster
• Refrigerants

Standard emergent assessment of a patient's airway, breathing, and circulatory status is paramount, in addition to obtaining large-bore intravenous (IV) access. Assessment of blood glucose and need for naloxone or thiamine supplementation should be considered.