Obstructive sleep apnea on C-PAP, 12 mm HG.
 The patient does not require ventilatory support while sleeping. 
(ROOT (NP (NP (JJ Obstructive) (NN sleep) (NN apnea)) (PP (IN on) (NP (NN C-PAP))) (, ,) (NP (CD 12) (NN mm) (NNP HG)) (. .)))
(ROOT (S (NP (DT The) (NN patient)) (VP (VBZ does) (RB not) (VP (VB require) (NP (JJ ventilatory) (NN support)) (SBAR (IN while) (NP (VBG sleeping))))) (. .)))
( ( ( ( ( Obstructive ( sleep apnea ) ) ( on C-PAP ) ) , ) ( 12 ( mm HG ) ) ) . )
( ( The patient ) ( ( ( does not ) ( ( require ( ventilatory support ) ) ( while sleeping ) ) ) . ) )