Poate fi inlocuita spirometria?

Traian Mihaescutraian@mihaescu.eu

www.pneumo-iasi.ro

Spirometria

Cel mai utilizat test de masurare a functiei respiratorii!

Asigurarea calitatii!

Variabilitatea (“zgomotul”) este mai mare in spirometrie decit in majoritatea altor teste de laborator clinic, datorita inconsistentei eforturilor pacientilor.

Becklake MR. Am J Med 1986; 80: 1158-1164

Asigurarea calitatii!

In 1990, in SUA, numai 57% din spirometre intruneau standardele ATS!

Nelson SB et al. Chest 1990; 97: 288-297

+ alti factori perturbatori

Procedurile de testare? Program permanent de asigurare a

calitatii? Valori de referinta corespunzatoare? Algoritmi corecti de interpretare a

rezultatelor?

…

National Asthma Education Program: spirometria este esentiala pentru diagnosticul si ingrijirea astmului deoarece atit medicii, cit si pacientii au o perceptie gresita asupra severitatii astmului ceea ce duce la erori de tratament.

NIH publication no.91-3042

…

Medicii nu pot identifica patternul obstructiv sau restrictiv din istoric si examenul fizic. Cind incearca sa o faca gresesc in 61% din cazuri!

Russell NJ et al. Thorax 1986; 41: 360-363

…

Subestimarea obstructiei cailor aeriene se asociaza cu o crestere a mortalitatii in astm!

Sly MR. J Allergy Clin Immunol 1989; 84: 421-434

Dar…

Spirometria la batrini, de ex.

59% din pacientii cu astm pot avea spirometrie normala!

Enright PL et al. Chest 1999; 116: 603-613

Obstructive airways disease in old age

Dr Stephen Allen

The Royal Bournemouth Hospital

Spirometry in old age - myths

‘Most old people can’t do a meaningful PEFR, FEV1 and FVC’

FALSE

‘Almost all old people can do spirometry if encouraged’

FALSE

Spirometry in old age - facts

* >80% of 65-94 year olds can meet the ATS’94 criteria

* performance is related to cognitive scores, functional scores and educational attainment

* not independently related to age, BMI, or GDS

* the proportion of incompetent patients rose with age, to about 40% at age 85 or over

Pezzoli et al Age Ageing(2003);32:43-46

Bellia et al Am J Respir Crit Care Med(2000);161:1094-99

Spirometry in old age - how?

* screen for cognitive impairment (? thresholds)

* High level of operator skill, patience, enthusiasm

* use the ATS’94 criteria for quality control

* if ATS’94 criteria not met, consider using PEFR, Slow VC

* if in doubt, try to do spirometry

ATS’94 criteria

* 3 curves acceptable, 2 of which reproducible

* acceptable curve has - no artefact, an acceptable start (back extrap. Vol <5%), FVC time of 6s or more, final plateau 1s

* reproducible curves have - difference of 200ml or less in FEV1 and FVC

Alternatives to spirometry

* respiratory impedance by forced oscillation

* whole body plethysmography

* helium dilution volumetry

* inspiratory ‘impedance’ (ratio of dP/dtmax to Vt/Ti)

* cross-sectional radiography

All these limited by complexity, cost, unavailability or lack of data for elderly patients

Punctaj total 15

+3

+2

+3

+3

+4

Valoarea limita pentruValoarea limita pentru ACT ACT – controlat sau nu ? – controlat sau nu ?

Pacientii cu scor ACT Pacientii cu scor ACT ≤ ≤ 1919 sunt necontrolati sunt necontrolati

ACT asigura o valoare predictiva mai buna in evaluarea controlului astmului comparativ cu VEMS ; cea mai buna strategie este cea care le combina pe ambele

Contributia ACT si spirometriei in Contributia ACT si spirometriei in evaluarea controlului astmului evaluarea controlului astmului

Monitorizare BPOC

Sintem obsedati de VEMS!... Dar

Imbunatatirea simptomelor poate apare fara modificarea VEMS si schimbarea VEMS poate avea loc fara repercursiuni clinice!

Monitorizare BPOC

Consecintele bolii includ simptomele, pierderea in greutate, intoleranta la effort, exacerbarile, calitatea vietii, utilizarea resurselor sanitare si decesul.

VEMS nu poate fi utilizat ca un marker global si sint necesari alti markeri!

Jones PW. Eur Respir J 2006; 27: 822-832

Monitorizare BPOC

Spirometria nu este adecvata pentru a descrie impactul BPOC sau a evalua eficacitatea interventiilor terapeutice!

Jones PW. Eur Respir J 2006; 27: 822-832

Markeri biologici

Celule inflamatorii in expectoratie Markeri solubili in expectoratie Gaze expirate Condensat aerian expirat Markeri periferici sanguini Nivelurile din sputa proteaze/antiproteaze etc.

Markeri fiziologici

Testul de mers la 6 min Functia muschilor sheletici Rata si tipul exacerbarilor Imagistica: CT, PET etc.

Markeri simptomatici

Simptome: chestionarul MRC Dispnee: scala de dispnee MRC, Borg,

UCSD Calitatea vietii legata de boala: SGRQ,

CRDQ, BPQ, PFSDQ, PFSS, CCQ Calitatea vietii generica: SF-36, NHP,

EQ-5D Functia cognitiva

Markeri compoziti

BODE index

Concluzie:

Ce vine mai intii este intotdeauna istoricul!

“Spirometry helps confirm the diagnosis and establishes the initial severity of the disease, but you are usually 95% of the way there with the history”

Pownall M. Airways J 2003; 2: 191-2

“How are you?”

“What would you like to be able to do”?

“How far can you walk?”

Pownall M. Airways J 2003; 2: 191-2