Τίτλος:
Expiratory flow limitation detected by forced oscillation and negative
expiratory pressure
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
The within-breath change in reactance (Delta(X) over bar rs) measured by
forced oscillation technique (FOT) at 5 Hz reliably detects expiratory
flow limitation in chronic obstructive pulmonary disease (COPD). The
present study compared this approach to the standard negative expiratory
pressure (NEP) method.
In total, 21 COPD patients were studied by applying both techniques to
the same breath and in 15 patients the measurements were repeated after
bronchodilator. For each patient and condition five NEP tests were
performed and independently scored by three operators unaware of the FOT
results.
In 180 tests, FOT classified 53.3% as flow limited. On average, the
operators scored 27.6% of tests flow limited and 47.6% non-flow
limited, but could not score 24.8%. The methods disagreed in 7.9% of
cases; in 78% of these the NEP scores differed between operators.
Bronchodilation reduced NEP and Delta(X) over bar rs scores, with only
the latter achieving significance. Averaging the operators’ NEP scores,
a threshold between 24.6-30.8% of tidal volume being flow limited by
NEP produced 94% agreement between methods.
In conclusion, when negative expiratory pressure and forced oscillation
technique were both available they showed good agreement. As forced
oscillation technique is automatic and can measure multiple breaths over
long periods, it is suitable for monitoring expiratory flow limitation
continuously and identifying patients’ breathing close to the onset of
expiratory flow limitation, where intermittent sampling may be
unrepresentative.
Συγγραφείς:
Dellaca, R. L.
Duffy, N.
Pompilio, P. P.
Aliverti, A. and
Koulouris, N. G.
Pedotti, A.
Calverley, P. M. A.
Περιοδικό:
The European respiratory journal
Εκδότης:
EUROPEAN RESPIRATORY SOC JOURNALS LTD
Λέξεις-κλειδιά:
chronic obstructive pulmonary disease; forced oscillation technique;
respiratory system reactance; within-breath impedance
DOI:
10.1183/09031936.00038006
