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

IntroductionIntroduction::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: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)

ParametersParameters IO IO::

ZrsZrs – total respiratory impedance R5 R5 – respiratory resistance at 5 Hz R20 R20 – respiratory resistance at 20 Hz FD Rrs FD Rrs – frequency dependence of respiratory resistance:

FD Rrs = R5 – R20 X5X5 – respiratory resistance at 5 Hz X5X5 – deviation X5 from predicted value:

X5 = |X5 – X5pred.| RFRF – resonant frequency

Lung mechanic parameters (M±SEM) in Lung mechanic parameters (M±SEM) in healthy and patients with healthy and patients with EAAEAA (p<0.01) (p<0.01)

Parameters Healthy (n=57)

Patients with EAA (n= 17)

TLC, % pred. 1061 794

VC, % pred. 1072 724

RV, % pred. 993 1006

Raw, kPa/l/s 0,200,01 0,580,06

FEV1, % pred. 1082 614

FEV1/FVC, % 891 722

СL, % pred. 974 475

CR, kPa/l 0,410,01 0,960,12

Respiratory resistance Rrs in healthy (n=57) and patients with EAA (n=17))

00,20,4

0,60,8

1

5 10 15 20 25 35

healthy

EAA

kPa/l/c

Hz

Frequency dependence of Frequency dependence of respiratory respiratory resistance resistance FD Rrs FD Rrs in healthy (in healthy (n=57) andn=57) and

patients with patients with EAAEAA ( (n=1n=177))

0,03

0,22

0

0,05

0,1

0,15

0,2

0,25

FD Rrs, kPa/l/c

HealthyEAA

Respiratory reactance Xrs in healthy (n=57) and patients with

EAA (n=17))

-0,3-0,25

-0,2-0,15

-0,1-0,05

00,05

0,10,15

0,2

5 10 15 20 25 35

healthy EAA

kPa/l/s

Hz

Deviation X5 from predicted valueDeviation X5 from predicted value X5 in X5 in healthy (healthy (n=57) andn=57) and patients with patients with EAAEAA

((n=1n=177))

0,07

0,24

0

0,05

0,1

0,15

0,2

0,25

X5, kPa/l/c

HealthyEAA

Correlation coefficients (p<0,0Correlation coefficients (p<0,033) between lung ) between lung mechanic parameters and IO parameters mechanic parameters and IO parameters

in patients with in patients with EAAEAA

Zrs R5 R20 ЧЗ Rrs X5 RF

FEV1-0,38 - - - -0,57 -0, 44

FEV1/FVC -0,38 -0,40 - -0,42 - -0,57

Raw 0,74 0,68 0,37 0,71 0,71 0,65

CR - - - - - -

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.

Thank you for your attention