Heliox for asthma in the emergency department: a review of the literature.

January 2002 saw the relaunch by BOC of Heliox, a gaseous mixture of helium and oxygen, for the use in a wide range of respiratory conditions. Despite a lapse of over 65 years since it was first used, and a large number of studies and case reports advocating its use, it remains an enigma, its use sporadic, and its role undefined. This paper reviews the discovery of helium and early medical use of helium oxygen mixtures and outlines areas where Heliox already has confirmed benefit as well as one or two areas that are currently under investigation. It will also look specifically at the use of Heliox in acute exacerbations of asthma and perform a thorough review of the current literature.