Suicidal asphyxiation with helium: report of three cases.

Helium is an inert gas that among other things is used medically to alleviate the symptoms of airway obstruction, as part of a diving mix in deep-sea diving or as balloon gas. In recent years the so-called right-to-die literature has suggested suffocation with inhaled helium as an effective and peaceful means of self-deliverance for terminally ill patients. Helium displaces oxygen and carbon dioxide and can thus lead to asphyxia. We report three cases of suicidal asphyxiation with helium gas that were examined at the Department of Forensic Medicine Vienna within three months in 2006. In all three cases, autopsy was unrewarding from the point of view of gross pathology. Special autopsy techniques and devices are required for collection of the gas from the lungs. Gas-chromatography is used to examine the gas for helium; however, this requires replacement of the carrier gas, which is itself usually helium. The fact that three people in Vienna committed suicide using this method within a short period of time, together with the abundance of detailed how-to literature on the Internet, suggests a possible future increase in the number of deaths associated with the inhalation of inert gases, particularly helium. Because of the diagnostic obstacles involved, it is necessary to rely on good death-scene investigation for situational evidence when the body is discovered.