A surge of hope pushes on William's lungs.

[shootingstar]

(William and Martin in a hospital at the bedside of their terminally ill friend Colin. Colin is a tramp. William has tidied Colin up because they are expecting his ex-wife and his children)
Martin nods at Colin 'You've performed a minor miracle here today, my friend. He can't tell you himself, but it's a fact that he'd be extremely grateful for this.'
A surge of hope pushes on William's lungs. He's not sure for what, but it propels him to the foot of the bed. 'Let's make sure the sheets are tucked in at the bottom - if his wife sees the state of his toenails, we're rumbled.'

(From A Terrible Kindness by Jo Browning Wroe, Part IV Midnight Choir, scene 58)

What do you take "pushes on William's lungs" to mean in this context? I can't see a "surge of hope" has anything to do with William's lungs, and the verb "push on" doesn't really match the whole thing in my opinion. Is "push on" a phrasal verb there? I don't think so. Is "A surge of hope pushes on someone's lungs" a set phrase? Is there a synonym for "push on someone's lungs"?

 

[Skrej]

The surge of hope inspired movement. He's probably drawing a breath before moving, as we often do before sudden exertions.

Still, it seems an odd choice since pushing on someone's lungs would cause them to exhale, not inhale. Perhaps it's a reference to CPR.

 

[emsr2d2]

I think it just means that the surge of hope gives him the impetus to use energy/oxygen to move to the end of the bed to cover up Colin's feet.