Assessment ofreversibility ofairway obstruction inpatients withchronic obstructive airways disease

Spirometry beforeandafteraninhaled betaagonist or acourseoforalprednisolone iswidelyusedtodetect reversibleairflow limitation inpatients with chronicobstructive lungdisease. How many ofthesepatients havea response andhow theresponsetobetaagonists relates totheresponse tocorticosteroids isnotclear. In127outpatients (mean(SD) FEV,0-92(0-38) 1)who hada clinical diagnosis ofchronicobstructive lung disease (continuous breathlessness for morethansixmonthsandanFEV,lforced vital capacity (FVC)ratio< 60%)and whoappeared tobestable, thechangein FEV,was measuredaftersalbutamol 200pgfromametereddoseinhaler and 5mg froma nebuliser. Symptomsand spirometric values wererecorded before andafter twoweeksoforalprednisolone 30mg.Reversibility wasdefined asares