After matching and multivariable adjustment , EEG suppression was not associated with mortality [ OR ( 95 % CI ) = 0.83 ( 0.55-1 .25 ) ] ; however , the interaction between EEG suppression and mean arterial pressure ( MAP ) < 55 mm Hg was [ OR ( 95 % CI ) = 2.96 ( 1.34-6 .52 ) ] .