“今夜が峠だな。” -- I think emotion (closeness) is part of this expression. If two doctors are talking about a patient, they may not use such an expression (euphemism). Their conversation may be strictly in medical and technical terms.
Are there any similar expressions in English?
峠を越えた http://www.thesaurus.com/browse/over%20the%20hump (turned the corner)
over the hump
out of the woods !
on the comeback trail
on the mend
on the road to recovery
峠 http://www.thesaurus.com/browse/crisis -- (the hump?), dire straits, turning point, moment of truth, ... ((the proverbial) Cape Horn?)
What have i missed ?