( ( ( A decrease ) ( in ( ( blood pH ) ( due ( to ( respiratory depression ) ) ) ) ) ) ( ( is ( called ( respiratory acidosis ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN decrease)) (PP (IN in) (NP (NP (NN blood) (NN pH)) (ADJP (JJ due) (PP (TO to) (NP (JJ respiratory) (NN depression))))))) (VP (VBZ is) (VP (VBN called) (NP (JJ respiratory) (NNS acidosis)))) (. .)))
A decrease in blood pH due to respiratory depression is called 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))))))))))) (. .)))