Aerosol Drug Administration with Helium-Oxygen (Heliox) Mixtures: An Overview

Aerosol drug administration using helium-oxygen mixtures as a carrier gas has been advocated in the treatment of severe airway obstruction. Helium's low density has been shown to reduce resistance of gas flow through restricted airways passages, work of breathing, and minute ventilation requirements. Thus, it improves aerosol delivery in patients with acute airway obstruction, during both spontaneous breathing and mechanical ventilation. Although heliox has been shown to improve deposition of particles into the lung, the clinical evidence supporting the benefit of heliox is mixed. This review of the literature from 1934 - 2009 includes a brief review of the history of use of heliox in respiratory medicine, its physical properties and how they relate to the potential effects, limitations, and practical considerations associated with heliox-driven aerosol drug administration in acute and critically ill patients.