The effect of exhalation flow on endogenous particle emission and phospholipid composition

• Published in: Respiratory physiology & neurobiology Vol. 243; pp. 39 - 46
• Main Authors: Larsson, Per, Bake, Björn, Wallin, Anita, Hammar, Oscar, Almstrand, Ann-Charlotte, Lärstad, Mona, Ljungström, Evert, Mirgorodskaya, Ekaterina, Olin, Anna-Carin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2017
• Subjects: 1994; Adult; Aged; Airway re-opening; asthma; Breath Tests; clearance; cough; Cough - metabolism; Cough - physiopathology; european respiratory journal; Exhalation - physiology; Exhaled particles; Female; Forced expiration; Functional Residual Capacity; Health Sciences; Healthy Volunteers; Humans; Hälsovetenskap; Inhalation; limitation; lung; Lung Volume Measurements; Male; Mass Spectrometry; mass-spectrometric analysis; Medical Education; metabolism; Middle Aged; Non-invasive technique; p1616; PEx; phosphatidylcholine; Phospholipids - analysis; Physiology; Pulmonary surfactant; Pulmonary Surfactants - analysis; Pulmonary/Respiratory; Respiration; Respiratory System; Respiratory System - metabolism; sanctis gt; surfactant protein-a; Non-invasive technique; PEx; Exhaled particles; Forced expiration; Pulmonary surfactant; Airway re-opening
• ISSN: 1569-9048; 1878-1519; 1878-1519
• DOI: 10.1016/j.resp.2017.05.003

[Display omitted] •Exhaled particles have potential as a tool for monitoring respiratory disease.•This potential would increase if particle formation was better understood.•Maximal forced exhalation generate particles mainly in central or upper airways.•Deep exhalations and inhalations generate particles mainly in small airways.•Particles from small airways contain a higher concentration of alveolar surfactant. Exhaled particles constitute a micro-sample of respiratory tract lining fluid. Inhalations from low lung volumes generate particles in small airways by the airway re-opening mechanism. Forced exhalations are assumed to generate particles in central airways by mechanisms associated with high air velocities. To increase knowledge on how and where particles are formed, different breathing manoeuvres were compared in 11 healthy volunteers. Particles in the 0.41–4.55μm diameter range were characterised and sampled. The surfactant lipid dipalmitoylphosphatidylcholine (DPPC) was quantified by mass spectrometry. The mass of exhaled particles increased by 150% (95% CI 10–470) for the forced exhalation and by 470% (95% CI 150–1190) for the airway re-opening manoeuvre, compared to slow exhalations. DPPC weight percent concentration (wt%) in particles was 2.8wt% (95%CI 1.4–4.2) and 9.4wt% (95%CI 8.0–10.8) for the forced and the airway re-opening manoeuvres, respectively. In conclusion, forced exhalation and airway re-opening manoeuvres generate particles from different airway regions having different DPPC concentration.