what is glue sniffing and why is it clinically important? Causes The commonly held notion 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 * o Liquids + Model Glue + Gasoline + Contact cement (rubber cement) + Lacquers + Nail-polish remover + Dry-cleaning fluids o Aerosols + Spray paints + Butane fuel, lighter fluid + Cooking sprays + Cosmetics, hairspray + Toiletries, deodorants * Chemicals found in abused inhalants o Propane o Butane o n-Hexane o Trichloroethylene o Freon o Benzene o Toluene o Xylene o Acetone o Methyl isobutyl ketone Background Inhalation injury due to hydrocarbons can occur as a result of either accidental or intentional exposure. Inhalant use, the deliberate inhalation of hydrocarbons as a form of recreational drug use, has become a significant health issue affecting children today. Recent epidemiologic data demonstrate that among adolescents, inhalants are the second most widely used class of illicit drugs, and more than 2 million children aged 12 to 17 years report using inhalants at least once in their lifetime. Death from intentional inhalation of hydrocarbon fumes is not uncommon and is usually due to sudden cardiac events or central nervous system depression. The recognition and treatment of inhalant abuse remain challenges for pediatricians and emergency physicians. Deliberate inhalation of volatile hydrocarbons for their mood-altering effects is popular among adolescents. Their low cost, ready availability, and ease of use contribute to this problem. Volatile hydrocarbons are contained in glues, solvents, lighter fluid, gasoline, and paints. Most inhalants are composed of several compounds, and almost all pressurized aerosol products can be abused because the propellants are volatile hydrocarbons. Pathophysiology Most recreational abuse of hydrocarbons by inhalation is accomplished in 3 ways: sniffing, huffing, and bagging. * Sniffing, the least potent delivery method, is the inhalation of the volatile substance through the nostrils (ie, sniffing glue). * Huffing is the placing of a rag soaked with an inhalant such as gasoline or lighter fluid over the nose and mouth. * Bagging involves repeated deep inhalations from a plastic or paper bag filled with a particular hydrocarbon such as spray paint or another propellant. Chronic abusers generally inhale 3-4 times daily for 10-15 minutes each time, although prolonged sessions of inhaling 6-7 hours a day as a group activity have been described. Tolerance and physical dependence can occur, although withdrawal symptoms are only infrequently reported. Two primary organ systems are affected by inhalation hydrocarbon toxicity: the CNS and the cardiopulmonary system. Volatile hydrocarbons are highly lipid soluble and readily cross the blood-brain barrier. Rapid absorption occurs across the large surface area of the pulmonary vascular bed, and peak blood levels are noted approximately 15-30 minutes after inhalation. Confusion, disorientation, disinhibition, and euphoria are exhibited early. Speech becomes slurred, and motor function becomes impaired, with gait becoming staggered. Hallucinations are frequently described, followed by CNS depression, drowsiness, and sleep. Coma can occur with prolonged or repeated exposures; however, this is unusual because the intentional exposure ceases as the user becomes drowsy. Sudden sniffing death syndrome was first described by Bass in 1970. Death occurs after the user is startled during or soon after inhalation. Hydrocarbons can sensitize the myocardium to endogenous and exogenous catecholamines, which can precipitate ventricular dysrhythmias and sudden death. In addition, some limited data have shown toxic effects of hydrocarbons directly on the myocardium, and excess catecholamine concentrations may cause an increase in oxygen demand, coronary artery spasm, platelet aggregation, and thrombus formation. A number of case reports also detail acute myocardial infarction as a complication following hydrocarbon inhalation. With acute intoxication, deaths due to asphyxiation from a plastic bag over the head or aspiration of stomach contents are not unusual. Also, trauma-related injury and motor vehicle accidents have been reported, resulting from disinhibition and disorientation following inhalation. Other reported complications include renal tubular acidosis with subsequent hypokalemia and hyperchloremia; frostbite with facial injury and burns to the trachea, mainstem bronchi, esophagus, and oral cavity from intentional inhalation of fluorinated hydrocarbon; bone marrow damage, aplastic anemia, and leukemia due to benzene exposure; and toxic hepatitis from toluene. In contrast to pulmonary injury from aspiration of liquid hydrocarbons, direct pulmonary injury from acute inhalation exposure has not been described. Many solvents, particularly toluene, are lipophilic and readily cross the placenta, resulting in characteristic fetal anomalies that include microcephaly, narrow bifrontal diameter, short palpebral fissures, hypoplastic mid face, wide nasal bridge, abnormal palmar creases, and blunt fingertips. The syndrome of toluene embryopathy closely resembles the phenotypic features found in fetal alcohol syndrome. With long-term hydrocarbon inhalation, CNS damage occurs, including loss of cognitive functions, gait disturbances, and loss of coordination. Radiographic tests have demonstrated loss of brain mass and white-matter degeneration. Additionally, certain chemicals have been shown to have associations with specific CNS injuries, including peripheral neuropathy, deafness, and optic neuropathy. Other, less common complications of long-term hydrocarbon inhalation include restrictive pulmonary disease, pulmonary hypertension, and reduced diffusion capacity. Of note, pulmonary toxicity can occur as a result of hydrocarbon aspiration. This injury differs from hydrocarbon inhalation injury. The most common clinical scenario of hydrocarbon aspiration is that of a young child unintentionally ingesting a hydrocarbon-containing compound such as lamp oil or a cleaning solvent. Hydrocarbons cause direct injury to the respiratory epithelium, producing inflammation and bronchospasm. Direct contact with alveolar membranes can lead to hemorrhage, hyperemia, edema, surfactant inactivation, leukocyte infiltration, and vascular thrombosis. The result is poor oxygen exchange, atelectasis, and pneumonitis. For more information, see Toxicity, Hydrocarbons. Frequency United States National surveys of adolescents in the United States have revealed that, after marijuana, inhalants are the most commonly used class of illicit drugs for 8th and 10th graders; inhalants are the third most widely used illicit drugs for 12th graders. The low cost, ease of use, and ready availability of organic solvents perpetuate their abuse. Recent epidemiologic data suggest a decrease in the prevalence of inhalant abuse, but the overall abuse rates remain high. Inhalant abuse by adolescents in the United States is common: in 2000, more than 2 million adolescents aged 12-17 years reported using inhalants at least once in their lifetime. Since 1975, the National Institute on Drug Abuse annual survey of high-school seniors has documented a lifetime incidence of inhalant abuse of 15-20%, with the highest prevalence of use being in 8th graders. Although the trend of lifetime use decreases between the 8th and 12th grades, these data may underestimate the true lifetime use of older adolescents, because many students have dropped out of school by the 12th grade and thus are no longer included in the survey. The typical inhalant abuser is a young male of lower socioeconomic class. Overall, males are twice as likely to abuse inhalants as females are; however, between the 8th and 12th grades, the difference is less pronounced. Immigrants from Latin America and American Indians have a higher prevalence of use, and African Americans have a low prevalence of inhalant abuse. Although inhalant abuse is typically thought of as being most common among adolescents, use among adults is also well described, and use in children as young as age 4-6 years has been reported. International The United Kingdom is the only major country in the Western world that tracks inhalant-abuse fatalities, where an incidence of 2 deaths per week has been documented. In Canada , the patterns of inhalant use are similar to those associated with other illicit substances for experimenters, intermittent users, and long-term abusers. Long-term use tends to be endemic in both the inner-city areas and remote communities, and data show an association between chronic use, lower socioeconomic class, and family dysfunction. Mortality/Morbidity Although hydrocarbon inhalation was previously thought to be a benign fad, permanent and significant pulmonary and neurologic sequelae clearly may persist even after abuse has discontinued. Recreational solvent inhalation may account for as much as 2% of all deaths among adolescent males. In the United Kingdom, 15% of deaths caused by inhalants occur as a result of suffocation, 15% by accidental trauma, and 15% by aspiration, whereas the remaining 55% are a result of sudden sniffing death syndrome. Of significant concern is that 22% of victims of sudden sniffing death syndrome had no history of inhalant abuse, demonstrating that death can result from any episode of inhalant abuse. In the United States, inhalant abuse was responsible for 12.2% of the deaths reported to poison control centers in the group aged 13-19 years. Given that many inhalant-related deaths are never reported to poison control centers, this statistic grossly underestimates the true mortality due to inhalant abuse. Ongoing inhalant use has been associated with significant psychosocial Pathology , including failure in school (a high correlation exists between poor academic performance and inhalant abuse) and delinquency. In patients with neurologic symptoms who abused toluene as an inhalant, nearly one third showed deficits in orientation, attention, learning, arithmetic calculation, abstraction, construction, and recall. As solvent abuse becomes chronic, damage to the CNS becomes irreversible, with changes occurring in the cerebellar and cerebral white matter, including demyelination and gliosis. Psychiatric disorders, spasticity, cognitive changes, and secondary Parkinson disease have been reported. Attention deficit as well as decreased memory retrieval may also occur. Race Previous data suggested the highest inhalant abuse to be among Latin American immigrants, but in adolescents aged 12-17 years, inhalant users were more likely to be American Indian or Alaskan Native (13.2%), followed by multiracial (11.2%) and white (9.5%). Lowest reported rates were among blacks (5.3%) and Asians (6.5%). Sex According to data from Wu et al in 2004, the lifetime prevalence rates of inhalant abuse were not significantly different for males and females aged 12-17 years. Age Peak age of inhalant abuse is 14-15 years, with onset of abuse occurring from ages 6-8 years. Use typically declines by the late teenage years; however, some users will continue to abuse inhalants into adulthood. CLINICAL Section 3 of 10 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic � * Authors and Editors * Introduction * Clinical * Differentials * Workup * Treatment * Medication * Follow-up * Miscellaneous * References History A high index of suspicion is required because exposure to most volatile substances is not detectible on 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; higher-risk populations include children and adolescents from families of low socioeconomic status, where 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: o Altered mental status, cerebellar dysfunction, peripheral neuropathy o Behavioral changes, deteriorating school performance o Pulmonary hypertension with or without cor pulmonale o Acute rhabdomyolysis o Renal tubular acidosis with severe hypokalemia and hypophosphatemia o Gastrointestinal symptoms, such as abdominal pain, hematemesis, nausea, and vomiting o Mothers of infants with toluene embryopathy * Evaluate for solvent abuse all patients who present after autoerotic asphyxiation, because such chemicals may be used to relax inhibitions. * When inhalant abuse is identified, make efforts to specifically identify the toxins involved, recognizing that abusers often ingest a variety of solvent-inhalants and frequently misidentify the substances involved. Hydrocarbons are not often part of a routine toxicology screen; therefore, if clinical suspicion of such an exposure exists, the laboratory must be alerted and specific identifying tests must be ordered. Physical 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 gastrointestinal symptoms, or neuropsychiatric symptoms should raise suspicion of chronic solvent-inhalant abuse. Electrolyte abnormalities, including hypokalemia, hypophosphatemia, and acidosis, should further raise suspicion. The nature of these symptoms, however, is not diagnostic of solvent-inhalant abuse; therefore, a very broad differential diagnosis is required. Signs and symptoms are as follows: * A single, loud S2 may be evident as a result of pulmonary hypertension. * Ventricular arrhythmias or bradycardia * Discolored urine may be evident from rhabdomyolysis. * Adolescents presenting 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 gastrointestinal symptoms, and neuropsychiatric symptoms make up 3 major symptom patterns of chronic abuse. Causes The commonly held notion 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 * o Liquids + Model Glue + Gasoline + Contact cement (rubber cement) + Lacquers + Nail-polish remover + Dry-cleaning fluids o Aerosols + Spray paints + Butane fuel, lighter fluid + Cooking sprays + Cosmetics, hairspray + Toiletries, deodorants * Chemicals found in abused inhalants o Propane o Butane o n-Hexane o Trichloroethylene o Freon o Benzene o Toluene o Xylene o Acetone o Methyl isobutyl ketone DIFFERENTIALS Section 4 of 10 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic � * Authors and Editors * Introduction * Clinical * Differentials * Workup * Treatment * Medication * Follow-up * Miscellaneous * References Acidosis, Metabolic Inhalation Injury Status Epilepticus Toxicity, Carbon Monoxide Toxicity, Ethanol Toxicity, Tricyclic Antidepressant Ventricular Fibrillation Other Problems to be Considered Other causes for altered mental status: * Intracranial Pathology * Electrolyte abnormality * Hepatic encephalopathy * Encephalitis Comorbidities: * Multidrug ingestion * Other illicit drugs of abuse * Sexually transmitted diseases WORKUP Section 5 of 10 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic � * Authors and Editors * Introduction * Clinical * Differentials * Workup * Treatment * Medication * Follow-up * Miscellaneous * References Lab Studies * When solvent-inhalant abuse is suspected, specific solvent identification should be requested from the laboratory because solvent inhalants are infrequently included in routine toxicologic screening tests. * o A complete toxicology screen should be performed because patients who abuse one drug can be simultaneously abusing others. o Obtain serologic investigation of renal and hepatic dysfunction, as well as blood and urine testing for rhabdomyolysis. o Obtain serum electrolyte levels to diagnose hypokalemia, hypophosphatemia, hypercalcemia, and acidosis from distal renal tubular acidosis caused by chronic hydrocarbon abuse. o If indicated from the history and physical examination, laboratory tests should be performed for sexually transmitted disease and, possibly, pregnancy, because of disinhibition and poor judgment. o Pregnancy testing should be done for all solvent-abusing females of reproductive age because of the risk of toluene embryopathy. Other Tests * ECG and echocardiography * o Identify pulmonary hypertension o Evaluate for cardiomyopathy o Identify and document dysrhythmias * Pulmonary function testing to look for evidence of restrictive disease * Neurophysiologic and neuropsychiatric tests for patients with evidence of chronic inhalant use * Neuromotor testing in patients with symptoms of peripheral neuropathy TREATMENT Section 6 of 10 Click here to go to the previous section in this topic Click here to go to the top of this page Click here to go to the next section in this topic � * Authors and Editors * Introduction * Clinical * Differentials * Workup * Treatment * Medication * Follow-up * Miscellaneous * References Medical Care The care of patients with inhalation abuse is mainly supportive. Because many potential complications involving the pulmonary, cardiovascular, and neurologic systems may be present, careful assessment and stabilization of the "ABCs" should be paramount in the initial management. In addition to acute medical treatment, patients suspected of chronic solvent-inhalant use should be carefully evaluated by a team trained in the treatment of childhood substance abuse. * Acute inhalant abuse * o Medical care of patients following acute decompensation from hydrocarbon inhalation is primarily supportive. Those with significant neurologic impairment who are unable to protect their airway should undergo endotracheal intubation and mechanical ventilation to prevent aspiration and respiratory deterioration. Hypoxic injury to other organ systems, particularly the heart, should be sought and treated accordingly. o Because of the sensitization of the myocardium to catecholamines, inotropic agents and bronchodilators should be avoided. Some authors suggest the use of amiodarone to treat ventricular arrhythmias if used early in treatment. Epinephrine administration during resuscitation may be harmful and can lead to recurrence of ventricular fibrillation. o Electrolyte abnormalities should be corrected. * Chronic inhalant abuse * o Management of chronic solvent-inhalant abuse should be directed at preventing further abuse. o Therapy for commonly involved organs, including the central and peripheral nervous systems, kidneys, liver, lungs, heart, and bone marrow, is primarily supportive. o In patients with significant electrolyte abnormalities, typically from distal renal tubular acidosis, parenteral fluid and electrolyte repletion may be necessary. Correction of potassium and phosphorus deficiency may result in rapid improvement in muscle strength. Hypocalcemia is frequently encountered during fluid and electrolyte repletion. Consultations Patients who are suspected of solvent-inhalant abuse should be carefully evaluated by experts who are trained in the treatment of childhood substance abuse. Consultation with specialists, including cardiologists and neurologists, depending on the individual needs of the patient, may also be warranted. Any patient who has unstable hemodynamics or cardiac arrhythmias or who has significantly altered mental status should be admitted to and observed in the pediatric intensive care unit. Diet Patients should remain on nothing by mouth (NPO) until muscle weakness clearly will not necessitate institution of mechanical ventilation. Also, because of the risk of hypocalcemic seizures, patients should remain NPO during initial fluid and electrolyte repletion.