CLASS
- Heliox is a mixture of helium and oxygen
- Helium is an inert gas with a significantly lower density (and specific gravity) than room air (1.42g/L for O2 vs 0.17g/L for He)
MECHANISM OF ACTION
- by substituting helium for nitrogen -> reduction in density of the gas -> reduction in Reynolds number -> more laminar flow
-> reduces airflow resistance, work of breathing and dynamic hyperinflation
PHARMACEUTICS
- gas administered via a mask with a reservoir bag or via endotracheal tube
- supplied at 137 bar as either Heliox (79% He, 21% O2) in white cylinders with white/brown shoulders or as 100% helium in brown cylinders (size C, D, E and G cylinders (410, 1400, 3500 and 7300L nominal capacity respectively)
- can be used as the driving gas for nebulisation
DOSE
- helium:oxygen mix of 80:20 or 70:30, which are 1.8 and 1.6 times less dense than pure oxygen, respectively.
INDICATIONS
- lower airways disorders – e.g. severe asthma, severe COPD, bronchiolitis, bronchiectasis, lung cancer
- extrathoracic or tracheal obstruction – e.g. croup, epiglottitis, foreign body, tumour, tracheal stenosis, tracheomalacia
- FRC assessment (helium dilution technique)
- decompression sickness
ADVERSE EFFECTS
- expensive (10x the cost of oxygen)
- lack of availability
- can’t use on those with a high FiO2 (>0.4)
- ventilators require recalibration for FiO2 and TV – interferes with valve function
- requires heated humidified circuits as helium conducts heat 6x faster than nitrogen
- alteration of vocal pitch
- may reduce the efficiency of coughing
PHARMACOKINETICS
- near instantaneous onset an offset
- eliminated within a few breaths
EVIDENCE
- anecdotal evidence of avoiding need for intubation in upper airway obstruction
- little evidence of benefit in lower airways obstructive lung disease – the common theme is that heliox is a temporising measure but is not a treatment
References and Links
Journal articles and textbooks
- Fink JB. Opportunities and risks of using heliox in your clinical practice. Respir Care. 2006 Jun;51(6):651-60. Review. PubMed PMID: 16723042. [Free fulltext]
- Gentile MA. Inhaled medical gases: more to breathe than oxygen. Respir Care. 2011 Sep;56(9):1341-57; discussion 1357-9. Review. PubMed PMID: 21944684. [free fulltext]
- Hess DR, Fink JB, Venkataraman ST, Kim IK, Myers TR, Tano BD. The history and physics of heliox. Respir Care. 2006 Jun;51(6):608-12. Review. PubMed PMID: 16723037. [free fulltext]
- Kim IK, Saville AL, Sikes KL, Corcoran TE. Heliox-driven albuterol nebulization for asthma exacerbations: an overview. Respir Care. 2006 Jun;51(6):613-8. Review. PubMed PMID: 16723038. [free fulltext]
- McGarvey JM, Pollack CV. Heliox in airway management. Emerg Med Clin North Am. 2008 Nov;26(4):905-20, viii. Review. PMID: 19059090.
- Reuben AD, Harris AR. Heliox for asthma in the emergency department: a review of the literature. Emerg Med J. 2004 Mar;21(2):131-5. Review. PubMed PMID: 14988333; PubMed Central PMCID: PMC1726290.
- Vorwerk C, Coats T. Heliox for croup in children. Cochrane Database Syst Rev. 2010 Feb 17;(2):CD006822. doi: 10.1002/14651858.CD006822.pub2. Review. Update in: Cochrane Database Syst Rev. 2012;10:CD006822. PubMed PMID: 20166089.
- Wigmore T, Stachowski E. A review of the use of heliox in the critically ill. Crit Care Resusc. 2006 Mar;8(1):64-72. Review. PubMed PMID: 16536724. [free fulltext]
Thanks Haney
Great to have the insight of someone who actually has access to this stuff in clinical practice!
Chris
great review ….really helpful….thank you,,,
On the BOC website accessed July 2015 it lists Heliox28 (28% oxygen and 71% helium). Wondering if this has changed from 21% oxygen in recent years or are there now two formulations of Heliox in Australia?