Analisi avanzata dello washout di gas inerti

Transcription

1 Analisi avanzata dello washout di gas inerti (relation to models & imaging) Sylvia Verbanck

2 Volume (L) Flow (L/s) R, X (kpa.l -.s) volume (L) volume (L) Non-invasive lung function testing spirometry impedance airways alveloi You are here Volume (L) diffusing capacity time (s) N conc (%) time (s) multiple breath washout 6 8 time (s) Firenze, sep6

3 N conc (%) flow (L/s) Non-invasive lung function testing : interpretation spirometry Quantification 6 5 forced expiratory flow single breath washout forced expired volume (L) Lung Model 5 N phase III slope expired volume (L) Firenze, sep6

4 Flow (L/s) Non-invasive lung function testing : models () spirometry Volume (L) Firenze, sep6

5 N conc (%) Non-invasive lung function testing : models () single breath washout 5 N phase III slope Expired volume (L) Firenze, sep6

6 MBW in the beginning sensitive / heterogeneity 95 Lung Clearance Index Firenze, sep6

7 MBW in the beginning mechanism/periphery 959 Nitrogen Helium Firenze, sep6

8 Z MBW now : avanzata?. gas transport mechanimsms at different lung depths convection diffusion airways alveloi ~6. ~.. O N conductive airways DIFFUSION FRONT. effect of airway changes at different lung depths acinar airways proximal or peripheral vs diffusion front Firenze, sep6

9 vol (L) N MBW analysis O N (%) n= n= time (s) washout concentration curve : all air spaces normalized N phaseiii slope : conductive vs acinar air spaces (diffusion front) Firenze, sep6

10 N conc (%) N conc (%) Z Z MBW : washout N concentration () O N conductive airways acinar airways conductive airways acinar airways,, hypoventilated comp hyperventilated comp combination,,, breath number or lung turnover, breath number or lung turnover Firenze, sep6

11 N conc (%) Z (%) 9 vol (L) N MBW : washout N concentration () time (s),, conductive airways acinar airways, lung turnover Firenze, sep6

12 vol (L) N MBW : normalized N phase III slope () (%) n= n= time (s) Diffusion-Convection equation C s C (sd) C Q C = D + - t S x S x x S x Firenze, sep6

13 Z Structural homogeneity : zero N slope! Convection Diffusion N S= exhaled volume conductive airways acinar airways C s C (sd) C Q C = D + - t S x S x x S x Firenze, sep6

14 Z Structural heterogeneity in Acinar Lung Zone N S> exhaled volume conductive airways acinar airways C s C (sd) C Q C = D + - t S x S x x S x Interaction: diffusion & convection / asymmetry Firenze, sep6

15 Z Structural heterogeneity in Conductive Lung Zone N S> exhaled volume conductive airways acinar airways specific ventilation heterogeneity & flow asynchrony (best ventilated unit empties first!) Firenze, sep6

16 A normal subject Normalized phase III slope (L - ) vol (L) N Structural heterogeneity in Conductive & Acinar Lung Zone (%) n= n= n= time (s) lung turnover Firenze, sep6

17 Normalized phase III slope (L - ) Z Structural heterogeneity in Acinar Lung Zone n= n=.5 conductive airways acinar airways lung turnover Firenze, sep6

18 Normalized phase III slope (L - ) Z Structural heterogeneity in Conductive Lung Zone n= n=.5 conductive airways acinar airways lung turnover Firenze, sep6

19 A normal subject Normalized phase III slope (L - ) MBW : normalized N phase III slope (),5,,, Scond, Sacin 5 6 lung turnover Firenze, sep6

20 Sn (L - ) Sn (L - ) Scond & Sacin S cond.8.6 S acin lung turnover 5 6 lung turnover Firenze, sep6

21 MBW : histamine provocation Sacin - Scond J Appl Physiol 997; 8: Firenze, sep6

22 mean expired conc (%alv) normalized slope (L - ) MBW ffwd: adult Cystic Fibrosis,,8,6,,,,8,6,, Sacin Scond , lung turnover, TO lung turnover, TO Eur Respir J ; : 8-8. Respir Physiol Neurobiol ; 88: -. Firenze, sep6

23 mean expired conc (%alv) normalized slope (L - ) MBW in COPD,,8,6,,,,8,6,, Sacin Scond , lung turnover, TO lung turnover, TO Am J Respir Crit Care Med. ;7():-9. Firenze, sep6

24 mean expired conc (%alv) normalized slope (L - ) MBW in adult asthma,,8,6,,,,8,6,, Sacin Scond , lung turnover, TO lung turnover, TO Downie SR et al. Thorax 7; 6: Thompson BR et al. J Allergy Clin Immunol ; : -8. Firenze, sep6

25 COPD and asthma S cond S acin o Asthma : o asthma severity linked to increased S acin [inflammation] o COPD : o o even in absence of emphysema : increased S acin [inflammation] with emphysema : additional S acin increase [parenchymal architecture] both: S cond relatively insensitive to disease severity [airway remodelling] Firenze, sep6

26 N conc (%) Relationship MBW to imaging : expansion () CT,,, lung turnover De Backer JW et al. Radiology. Dec;57():85-6. Choi S et al. J Appl Physiol. Sep;5(5):7-. Firenze, sep6

27 N conc (%) Relationship MBW to imaging : expansion () D-CT,,, lung turnover Jahani N et al. J Appl Physiol 5;9():6-7. Verbanck S, Paiva M ; J Appl Physiol 6;(): Firenze, sep6

28 N conc (%) Relationship MBW to imaging : ventilation () MRI,,, lung turnover Kirby M et al Acad Radiol Feb;9():-5. Deppe MH et al, Magn Reson Med. Apr;65():75-8. Firenze, sep6

29 Relationship MBW to imaging : ventilation () MRI Horn FC, J Appl Physiol ;6:9-9. simulated Curv experimental Curv (M/F approx yrs) Eur Respir J. 6;7(): J Appl Physiol ;6(9):57. Firenze, sep6

30 Relationship MBW to imaging : diffusion MRI Apparent Diffusion Coefficient (ADC) normal emphysema Wang C et al; J Magn Reson Imaging 56:96 9,6. J Appl Physiol 7;():9-5. J Appl Physiol ;8():79-9. Firenze, sep6

31 MBW now : avanzata? (via modelling) airways alveloi better understanding of type of information that can be gained from MBW and what cannot be obtained! (eg, Scond=genX) success of quantitative link between metrics derived from MBW and (functional) imaging at the right resolution! Firenze, sep6