Nebulizer

In medicine, a nebulizer (or nebuliser) is a drug delivery device used to administer medication in the form of a mist inhaled into the lungs. Nebulizers are commonly used for the treatment of cystic fibrosis, asthma, COPD and other respiratory diseases.

(google.com)

regular nebulised normal saline helps to loosen tenacious secretions

(patient.co.uk)