title: Potential limitations of a conical spacer device in severe asthma.
mesh_terms: D000328:Adult; D000336:Aerosols; D001249:Asthma / Q000188:drug therapy*; D004868:Equipment Failure; D005260:Female; D006801:Humans; D013726:Terbutaline / Q000008:administration & dosage*
chemical_list: D000336:Aerosols; D013726:Terbutaline