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Helium/oxygen gas mixtures have been used in the medical setting for over fifty years. Up until recently, usage was more often than not, limited to ear, nose and throat surgery for conditions such as laryngeal stridor or spasm. Original research undertaken in the 1950’s was for use in lower airways. In the past ten years further interest has been shown in using HELIOX21 therapy in the treatment of asthma and COPD.


Helium is a rare, chemically and physiologically inert gas that is relatively insoluble in body fluids, more viscous and eight times less dense than oxygen. HELIOX21 is typically three times less dense than air and this property allows patients with respiratory conditions to breathe more freely reducing their work of breathing and improving their comfort. (1)


Normally, when a breath is taken, the air that is inspired becomes quite turbulent and remains so until it reaches the lower airways. There it goes through a transitional stage, becoming less turbulent and laminar in its flow. When an airway is obstructed or narrowed, turbulent flow is more prominent, increasing the work of breathing which leads to shortness of breath.


Moving a turbulent flow requires greater effort than moving a laminar flow. By using HELIOX21, with its lower density, the work of breathing is reduced (1) It is known that molecules diffuse up to four times faster through a helium/oxygen mixture than through an equivalent oxygen/nitrogen mixture (air) (2,3). This further enhancing alveolar gas delivery and giving better clearance of carbon dioxide (CO2). (4)


 (1) Jean-Luc Diehl et al. Helium/Oxygen mixture reduces the work of breathing at the end of the weaning process in patients with severe chronic obstructive pulmonary disease. Critical Care Medicine 2003 Vol 31, No.5
(2) Chevrolet JC: Helium Oxygen mixtures in the intensive care unit. Crit Care Med 2001; 5: 179-181
(3) Perry R, Chilton C: Chemical Engineers’ Handbook 5th ed. McGraw Hill, New York, 1973: 220-229
(4) Gluck EH, Onorato DJ, Castriotta R: Helium-Oxygen mixtures in intubated patients with status asthmaticus and respiratory acidosis.Chest 1990; 98: 693-698 13. Chien JW, Ciufo R, Novak R,