title: Influence of tube-spacer on aerosol efficacy.
mesh_terms: D000336:Aerosols; D000402:Airway Obstruction / Q000188:drug therapy*; D006801:Humans; D012138:Respiratory Therapy / Q000295:instrumentation*; D013726:Terbutaline / Q000008:administration & dosage*
chemical_list: D000336:Aerosols; D013726:Terbutaline