The infant was admitted to the NICU for respiratory distress.
 The infant had difficulty breathing 
(ROOT (S (NP (DT The) (NN infant)) (VP (VBD was) (VP (VBN admitted) (PP (TO to) (NP (NP (DT the) (NNP NICU)) (PP (IN for) (NP (JJ respiratory) (NN distress))))))) (. .)))
(ROOT (S (NP (DT The) (NN infant)) (VP (VBD had) (NP (NN difficulty) (NN breathing)))))
( ( The infant ) ( ( was ( admitted ( to ( ( the NICU ) ( for ( respiratory distress ) ) ) ) ) ) . ) )
( ( The infant ) ( had ( difficulty breathing ) ) )