For 50% of medics, bandaging is guaranteed (8)
I believe the answer is:
promised
'guaranteed' is the definition.
(thesaurus)
'for 50 of medics bandaging is' is the wordplay.
'for' becomes 'pro' (I've seen this before).
'50 of medics' becomes 'med' (I can't explain this - if you can you should believe this answer much more).
'bandaging' indicates putting letters inside.
'med' placed around 'is' is 'mised'.
'pro'+'mised'='PROMISED'
Can you help me to learn more?
(Other definitions for promised that I've seen before include "Undertook (to do something)" , "Gave one's word, pledged" , "undertaken" , "swore" , "Betrothed" .)