Background
Lung elasticity can be assessed by pulmonary compliance using the esophageal pressure method, but this technique is invasive and time-consuming. Impulse oscillometry has been established as a non-invasive method to describe mechanical properties of the respiratory system and preliminary data suggest that it may be used as a marker of lung elasticity. Therefore we compared impulse oscillometry and pulmonary compliance in healthy subjects.
Material and Method
In 31 healthy male volunteers aged 20 to 25 years we performed pulmonary function tests including spirometry, bodyplethysmography and pulmonary compliance by the esophageal pressure method. Impulse oscillometry (IOS) was used to determine capacitance (X 5 Hz) and resistance (R 5 Hz and R 20 Hz).
Results
Mean dynamic pulmonary compliance was 2.53+/-0.58 l/kPa and mean static pulmonary compliance was 2.82+/-0.85 l/kPa. R 5 Hz and R 20 Hz were between 0.14 and 0.49 kPa/(l/s), while mean X 5 Hz was -0.08+/-0.02 kPa/(l/s). There was demonstrated a highly significant correlation between impulse oscillometric capacitance X 5 Hz and pulmonary compliance parameters.
Conclusions
The results of the present study suggest that impulse oscillometry may be used as an alternative for the invasive esophageal pressure method in determining pulmonary elasticity.

Keywords: Reference Values, Pressure, Oscillometry - methods, Lung Compliance, Health, Esophagus - physiology, Electric Capacitance, Anthropometry, Respiratory Function Tests, Respiratory Mechanics - physiology