His lungs seemed to be processing it just fine.
His breath was like frost, and his lungs seemed to be under water.
His lungs didn't seem to want to work.
His lungs seemed to shrink within him, and he had a hard time taking a breath.
Now his lungs didn't seem to be operating, either.
Even her new, larger lungs didn't seem to have enough capacity.
Each time he took a breath of air, his lungs seemed to explode.
Her lungs seemed to have collapsed like small crumpled paper sacks.
She was breathing heavily and her lungs seemed as though they might collapse.
He drew breath and his lungs seemed to freeze.