The infant received CPAP briefly but then was intubated because of poor air movements.
 The infant was breathing on room air 
(ROOT (S (NP (DT The) (NN infant)) (VP (VP (VBD received) (NP (NNP CPAP) (NN briefly))) (CC but) (S (ADVP (RB then)) (VP (VBD was) (VP (VBN intubated) (PP (IN because) (IN of) (NP (JJ poor) (NN air) (NNS movements))))))) (. .)))
(ROOT (S (NP (DT The) (NN infant)) (VP (VBD was) (VP (VBG breathing) (PP (IN on) (NP (NN room) (NN air)))))))
( ( The infant ) ( ( ( ( received ( CPAP briefly ) ) but ) ( then ( was ( intubated ( because ( of ( poor ( air movements ) ) ) ) ) ) ) ) . ) )
( ( The infant ) ( was ( breathing ( on ( room air ) ) ) ) )