Multiple breath washout (MBW) using Sulphur hexafluoride (SF6) has the potential to reveal ventilation heterogeneity in obstructive lung disease which is frequent in patients with small airway disease. However, it is missed by commonly used tests with reference data being scarce and mostly restricted to younger collectives. We aimed to evaluate the influence of anthropometric parameters on SF6-MBW reference values in pulmonary healthy adults.

Inclusion Criteria:

non-smoker

• no history of pulmonary disease

• absence of dyspnoea, cough, thoracic pain

• no self-reported smoking history

• normal lung function testing

  • normal shape of flow-volume curve
  • normal shape of flow-pressure curve
  • FEV1/FVC >70% (forced expiratory volume in 1 second / forced vital capacity)
  • TLC > 80% of predicted (total lung capacity)
  • TLCO/VA > 80% of predicted (transfer factor corrected for ventilated alveolar volume)
  • R5 < 150% of predicted (resistance at 5Hz, impulse oscillometry)

smoker

- as above, but with self-reported smoking history >10 pack years

Exclusion Criteria:

• unwilling or unable to give informed consent
• history of any respiratory disease

healthy volunteers including never, active and former smokers

Sharing of individual participant data is prohibited by data protection regulations. Summarized data including the models will be made available thru an online repository (GitHub).