I checked the CDC website and the websites of a number of medical organizations. All mention that social distancing, hand washing and avoiding crowds as well as sick persons are important to staying healthy and that a face mask is not a substitute for these measures. There is no endorsement of a “best mask” for patients with chronic lung diseases. Cloth masks are recommended for non-healthcare personnel. Fabric selection must balance sufficient capacity to trap viral particles with comfort. Recommended fabrics include cotton blends, 100% cotton T-shirt fabric and sheets/pillowcases with high thread counts. Two layers of fabric or one layer of fabric plus a filter layer are most commonly recommended. Too many layers will result in a mask that makes breathing difficult. Make sure that you cannot see daylight through the mask. If someone is having trouble breathing, they should probably avoid wearing a mask as this could paradoxically lead to worsening of their respiratory status. The CDC recommends wearing a bandana, which may be the most comfortable approach for persons with lung conditions since it is not constricting. It is important to keep in mind that the purpose of the mask is to reduce transmission of viral particles to other persons.
I hope this information is helpful to you and your patient.
Jacqueline A. Pongracic, MD, FAAAAI