Surgeons' initially positive response about call for medical instruments (8)
I believe the answer is:
syringes
'medical instruments' is the definition.
(syringe is a kind of medical instrument)
'surgeons' initially positive response about call' is the wordplay.
'initially' says to take the initial letters.
'positive response' becomes 'yes' (I've seen this before).
'about' is an insertion indicator.
'call' becomes 'ring' ('ring' can be a synonym of 'call'**).
The initial letter of 'surgeons' is 's'.
'yes' going around 'ring' is 'yringes'.
's'+'yringes'='SYRINGES'
'for' acts as a link.
(Other definitions for syringes that I've seen before include "Injecting devices" , "Instruments for injections" , "Fluid-injecting devices" , "Instruments for injecting or drawing off liquid" .)