Was changing the bandage (6)
I believe the answer is:
swathe
'bandage' is the definition.
(swathe is a kind of bandage)
'was changing the' is the wordplay.
'changing' is an anagram indicator.
'was' anagrammed gives 'swa'.
'swa'+'the'='SWATHE'
(Other definitions for swathe that I've seen before include "Swaddle - cut strip" , "Envelop" , "Broad strip or area of something" , "Wrap in layers of, say, bandages" , "A broad strip as of cut grass" .)