Bronchodilator aerosols are commonly delivered through nebulizers or metered dose inhalers (MDI) to treat bronchospasm. Although the clinical results obtained with both these devices are comparable, the use of MDI offers several advantages like lower drug dose, reduced risk of complications, reliability of dosing, ease of administration, less personnel time and reduced cost. However, in non-intubated, spontaneously breathing patients, the amount of drug inhaled depends on the coordination of the inspiratory phase and delivery of the drug. In severely dyspnoeic or disoriented patients in the casualty department or intensive care settings, this is often not possible. Valved spacers and breath-actuated inhalers may not be easily available in such situations. Also, the spacer devices cannot be connected to the anatomical facemask and the need to discontinue oxygenation for aerosol delivery further limits their use.