What modality is most suitable for administering helium-oxygen therapy at a mixture of 70/30%?

Helium-oxygen therapy, commonly referred to as heliox, is beneficial in managing certain respiratory conditions, particularly those involving airway obstruction. The optimal method for delivering this therapy should ensure that the gas mixture is preset to achieve the desired proportions effectively.

Using a nonrebreather mask is most suitable for administering the helium-oxygen mixture at a concentration of 70% helium and 30% oxygen. This type of mask has a reservoir bag that allows for high-flow delivery of the gas, ensuring that the patient receives a consistent and concentrated mixture without atmospheric air dilution. This is crucial when precise concentrations of the therapeutic gas are needed, as any mixing with ambient air could disrupt the intended heliox therapy effectiveness.

In contrast, other options such as the air-entrainment mask, simple mask, and nasal cannula do not provide the same level of control over the gas mixture. These devices may not be able to maintain the correct proportions of helium and oxygen due to their design, which can lead to inhalation of room air, diluting the therapy. Consequently, the nonrebreather mask remains the preferred choice for delivering a high concentration of heliox effectively.