Heliox for Croup in Children

This week, as part of the Child Health Emergency Medicine Social Media Campaign, we are highlighting a Cochrane summary on heliox for the treatment of croup in children. This review was selected for the TREKK Evidence Repository on croup.

Key Messages:


Related TREKK Resources:

Cochrane Summary:

Helium-oxygen (heliox) treatment for croup in children

Croup is an acute illness commonly seen in children up to six years of age but mostly by the age of two. It is triggered by viral infections causing upper airway obstruction with varying degrees of respiratory distress. Mostly, it is mild and transient and resolves with supportive care. Croup is characterised by a barking cough, hoarseness, varying degrees of inspiratory stridor (abnormal breathing sound) and chest wall retractions and is usually preceded by one to three days of upper respiratory tract infection symptoms. The peak croup seasons are autumn and winter but can occur at any time.

Corticosteroids are an accepted treatment for moderate to severe croup, supplemented in more severe cases by nebulised epinephrine and oxygen. Epinephrine is often effective and safe but can have undesired effects (such as increased heart rate and anxiety). Corticosteroids improve croup symptoms but it takes time for their full effect to be achieved. In the meantime the child remains at risk of deterioration. This may rarely result in the development of respiratory failure, which may require emergency intubation and ventilation. Therefore, finding a safe and effective treatment to bridge the gap between the administration and effectiveness of the corticosteroids is important for clinical practice.

Some studies have shown a benefit of using heliox in children with croup. Heliox, a gas with lower density than air or oxygen, is believed to reduce the resistance to gas flow in narrowed upper airways, potentially improving symptoms and signs of respiratory distress. This review found three randomised controlled trials (RCTs) assessing the effect of heliox in 91 children with croup. Heliox did not appear to be more effective than administration of 30% oxygen in children with mild croup. In children with moderate to severe croup who had been administered oral or intramuscular corticosteroids, heliox appeared to be at least as effective as continuous 100% oxygen with one to two doses of nebulised racaemic epinephrine (adrenaline as a fine spray) in one study. It was slightly more effective than no treatment in another study. There were no adverse effects or outcomes reported. The included trials were small and had a number of methodological limitations. Further methodologically well-designed RCTs with more participants are needed to further assess the role of heliox in managing children with moderate to severe croup. The evidence is current to November 2013.

Authors’ Conclusions:

There is some evidence to suggest a short-term benefit of heliox inhalation in children with moderate to severe croup who have been administered oral or intramuscular dexamethasone. In one study, the benefit appeared to be similar to a combination of 100% oxygen with nebulised epinephrine. In another study there was a slight change in croup scores between heliox and controls, with unclear clinical significance. In another study in mild croup, the benefit of humidified heliox was equivalent to that of 30% humidified oxygen, suggesting that heliox is not indicated in this group of patients provided that 30% oxygen is available. Adequately powered RCTs comparing heliox with standard treatments are needed to further assess the role of heliox in children with moderate to severe croup.

Check Out the Full Cochrane Systematic Review Below:

Moraa, I., Sturman, N., McGuire, T., van Driel, M.L. (2012). Heliox for croup in children. Cochrane Database Syst Rev, 12, CD006822. doi: 10.1002/14651858.CD006822.pub4


This post is part of a weekly blog series highlighting pediatric emergency medicine (PEM) focused Cochrane summaries and other key resources selected by TREKK.

Published by arrangement with John Wiley & Sons.