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.
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http://dx.doi.org/10.1016/j.resp.2017.05.003 | DOI Listing |
Physiol Rep
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Multidisciplinary Medical Centre, MedImprove BV, Kontich, Belgium.
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FLUIDDA Inc., New York City, New York, USA.
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Since the SARS-CoV-2 pandemic onset, many routine medical activities have been put on hold and this has deeply affected the management of patients with chronic diseases such as obstructive sleep apnea. Untreated OSA is associated with increased mortality and difficulties in social functioning. A delay in initiating treatment may therefore have harmful consequences.
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