Whatever happens with whichever patient (2,3,4)
I believe the answer is:
in any case
'whatever happens' is the definition.
(I've seen this before)
'with whichever patient' is the wordplay.
'with' becomes 'in' (I can't explain this - if you can you should give a lot more credence to this answer).
'whichever' becomes 'any' (I've seen this before).
'patient' becomes 'case' ('case' can be a synonym of 'patient').
'in'+'any'+'case'='IN ANY CASE'
Can you help me to learn more?
(Other definitions for in any case that I've seen before include "Where a customs officer may search" , "Whatever the facts are, one way or the other" , "Where customs officers may search" , "No matter what" , "Lawyers may be so employed" .)