Breathing Skills 4:
Heliox
Helium is an inert gas that has very low density and viscosity higher than that of oxygen. These properties cause it to flow smoothly and easily around obstructing objects. The gas mixture that is most practical in clinical medicine is 80% helium and 20% oxygen (Heliox). This premixed gas is readily available from medical gas suppliers at low cost. The only equipment needed is a pressure reducing and flow valve for the Heliox tank. An E tank of Heliox will last about 1 hour at 10 L/min and a G tank about 9 hours.
Clinical indications include:
- Severe viral croup or tracheitis resulting in respiratory distress, (PEDS) especially in small children.
- Acute severe asthma with poor response to treatment with nebulized albuterol.
- Upper airway obstruction, as in acute epiglottitis, and laryngeal edema.
- Tracheal and main stem bronchus obstruction with a foreign body, tumor mass, hematoma, etc.
- Follow oxygen saturation and arterial blood gases to monitor the effects of the Heliox. Observe for improvement in the work of breathing with less rib retractions, stridor, etc.
- Administer the gas per a face mask at a high flow rate (10 to 15 L/min). This rapid flow rate will deplete the Heliox tank quickly, so use a tight fitting non-rebreathing mask with a reservoir and one-way valves. Adjust the flow so that the reservoir does not empty completely with each breath.
- If the patient's oxygen saturation falls below 89% add additional oxygen by placing a nasal cannula under the mask for the administration of low flow oxygen.
- The Heliox will need to be continued until other forms of treatment become effective. Plan ahead for obtaining additional tanks of Heliox or transfer the patient to a center with a large inventory of the gas.
Reference
- Smith SW, Biros M. Relief of imminent respiratory failure from upper airway obstruction by use of helium-oxygen: a case series and brief review. Acad Emerg Med. 1999;6(9):953-956.