( ( The ( last ( blood gas ) ) ) ( ( indicates ( a ( severe ( respiratory acidosis ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ last) (NN blood) (NN gas)) (VP (VBZ indicates) (NP (DT a) (JJ severe) (NN respiratory) (NNS acidosis))) (. .)))
The last blood gas indicates a severe respiratory acidosis.
(ROOT (S (NP (JJ Respiratory) (NNS acidosis)) (VP (VBZ is) (VP (VBN considered) (S (VP (TO to) (VP (VB be) (ADJP (JJ problematic) (PP (IN because) (NP (NP (JJ excess) (NNS co2)) (PP (IN in) (NP (NN blood))))))))))) (. .)))