Detection pulmonary disorders using impulse oscillometry in patients with extrinsic allergic alveolitis L.D.Kiryukhina, G.P.Orlova, M.Y.Kameneva Research Institute of Pulmonology at Saint-Petersburg State Medical University
Introduction: Changes of impulse oscillometry (IO) parameters were well studied in patients with obstructive disorders. Investigations of lung mechanics using IO meet less often in patients with combined restrictive and obstructive disorders. Current tests of lung function demand performance of forced and maximal breathing maneuvers and they are difficultly feasible for patients with severe dyspnoea. IO has been developed as a measure of lung function that requires only passive cooperation and may be used with success in patients with severe pulmonary disorders.
Aim of the study: To evaluate the possibility of the impulse oscillometry to detect the pulmonary disorders in patients with mixed lung function abnormalities.
Materials : We observed 57 healthy volunteers (30 M/27F, mean age 47 ± 1 years) and 17 patients with extrinsic allergic alveolitis (8M/9F, mean age 45±3 years).
Methods: • Spirometry • Bodyplethysmography • Investigation of lung elastic properties with oesophagus catheter (MasterLab, E. Jaeger). • IMPULSE OSCILLOMETRY (MasterScreen IOS, E. Jaeger)
Parameters IO: • Zrs – total respiratory impedance • R5 – respiratory resistance at 5 Hz • R20 – respiratory resistance at 20 Hz • FD Rrs – frequency dependence of respiratory resistance: FD Rrs = R5 – R20 • X5– respiratory resistance at 5 Hz • X5 – deviation X5 from predicted value: X5 = |X5 – X5pred.| • RF – resonant frequency
Lung mechanic parameters (M±SEM) in healthy and patients with EAA (p<0.01)
Respiratory resistance Rrs in healthy (n=57) and patients with EAA(n=17) kPa/l/c Hz
Frequency dependence of respiratory resistance FD Rrs in healthy (n=57) and patients with EAA (n=17)
Respiratory reactance Xrs in healthy (n=57) and patients with EAA(n=17) kPa/l/s Hz
Deviation X5 from predicted valueX5 in healthy (n=57) and patients with EAA (n=17)
Correlation coefficients (p<0,03) between lung mechanic parameters and IO parameters in patients with EAA
Conclusion: The changes of IO parameters were not specific to detect the changes of elastic properties in patients with mixed lung disorders. IO may be more useful to detect airway disorders in such patients.