Carboxyhemoglobinemia caused by inhalation of methylene chloride.

Spray-paint inhalation, once a common and inexpensive source of drug abuse, is now rare. Newer organic solvents, such as methylene chloride, were thought to decrease the toxicity of aerosol solvents, but they carry unique toxicities of their own. Methylene chloride toxicity is difficult to diagnose, as early symptoms are similar to those associated with many intoxicants; however, a rising carboxyhemoglobin level, despite removal of the patient from the source of exposure, is pathognomonic. In dealing with industrial exposures or organic aerosol abuse, a carboxyhemoglobin level should be part of the initial diagnostic workup, and treatment with oxygen is mandatory until toxicity resolves.