From the Research
Heliox is a beneficial adjunctive therapy for moderate to severe pediatric croup, providing short-term relief from respiratory distress by reducing airway resistance, and should be used in conjunction with standard treatments like dexamethasone. The most recent and highest quality study, 1, published in 2018, suggests that heliox may be beneficial in the short term for children with moderate to severe croup treated with dexamethasone, with its effect similar to 100% oxygen given with one or two doses of adrenaline. Heliox consists of a mixture of helium (typically 70-80%) and oxygen (20-30%), administered via a non-rebreather mask or through a ventilator circuit at flow rates of 8-15 L/min.
Key Points to Consider
- Heliox should be used as a temporizing measure while waiting for corticosteroids to take effect, usually for 1-2 hours or until clinical improvement occurs.
- The scientific basis for heliox's effectiveness lies in helium's lower density compared to nitrogen, which creates less turbulent airflow through narrowed airways, reducing the work of breathing and improving gas exchange.
- Heliox therapy requires specialized equipment and monitoring, including a helium-oxygen blender and appropriate flow meters calibrated for helium.
- Patients should be continuously monitored for respiratory status and oxygen saturation during administration.
- While heliox provides symptomatic relief, it does not treat the underlying inflammation, so concurrent administration of standard croup therapies like dexamethasone (0.6 mg/kg, maximum 16 mg) remains essential.
Administration and Monitoring
- Heliox should be administered with caution, considering the potential for adverse effects, although none were reported in the included studies 1.
- The evidence for all outcomes in the comparisons was of low quality, downgraded for serious imprecision, highlighting the need for adequately powered RCTs comparing heliox with standard treatments to further assess its role in the treatment of children with moderate to severe croup.
Clinical Decision Making
- In clinical practice, the decision to use heliox should be based on the individual patient's condition, the availability of heliox, and the clinical judgment of the healthcare provider, considering the potential benefits and limitations of heliox therapy, as suggested by 1 and supported by earlier studies like 2 and 3.