The inhalation of vapours such as anaesthetic agents for their pleasurable effects has been recognized for many years, but the practice spread in the 1950s with the use of petrol fumes as intoxicants,' to be followed in the next decade by "glue sniffing".2 A variety of products have subsequently been sniffed in the quest for pleasure and elation, the most popular being solvents, cleaners, paints, thinners, lacquers, and recently pressurized aerosols.Glue sniffing, rarely reported in Great Britain,34 has been the most popular sniffing syndrome in America. The practice has caused serious cerebral damage, aplastic anaemia, and even death from asphyxiation by a plastic bag used for inhalation. Other varieties of the sniffing syndrome may be equally dangerous. The inhalation of petrol fumes has caused severe hepatic damage and lead encephalopathy.5 Sniffing of a popular spot remover containing trichlorethylene has resulted in acute renal tubular necrosis and acute hepatic necrosis.' Possibly the most dangerous practice is the inhalation of fluorinated hydrocarbons from aerosol containers. A recent review8 reported 110 cases of sudden death during the last decade in American teenage sniffers. These sudden deaths from sniffing differed from previously reported fatalities due to asphyxiation by a plastic bag in that death was usually preceded by a period of hyperactivity or emotional stress. At necropsy no physical abnormalities were found. Deaths followed the sniffing of vapours of glue, solvents, and petrol, but the largest number occurred after inhalation of aerosols in which the fluorinated hydrocarbons act as agents for propelling ingredients out of the can. Severe cardiac arrhythmias, intensified by hypercapnia, stress, or activity, were considered the most likely explanation for sudden death.The "inert" propellant gases from pressurized nebulizers, which are also fluorinated hydrocarbons, have been shown to sensitize the hearts of mice to asphyxia-induced sinus bradycardia, atrioventricular block, and ventricular T-wave depression.9 Sensitization is rapid in onset, long-lasting, and potentially lethal. The question has been raised whether sudden death in young people who inhale aerosols and in asthmatics using pressurized nebulizers could be due to a similar cardiotoxic effect, with perhaps sensitization of the heart to endogenous catecholamines, the release of which may be enhanced by such factors as hypoxia and hypercapnia. Moreover, fluorinated hydrocarbons have recently been found in the blood of volunteers using nebulizers.20 These findings may not only have a bearing on the sudden death of some asthmatics but also raise questions about the effect on persons with asthma and cardiac disease of aerosol dispensers used for cosmetic, household, and other purposes.Diagnosis of a sniffing syndrome can be difficult, and, as O'Brien and his colleagues stress, there may be no clinical abnormality when the patient is first seen. The differential diagnosis includes alcoholic intoxication, cerebral disease, gastroenteri...
