At similar BIS40-60 [ 79 ( 67-86 ) % vs 76 ( 65-85 ) % ] , N2O slightly decreased propofol consumption [ 4.5 ( 3.7-5 .5 ) vs 4.8 ( 4.0-5 .9 ) mg kg ( -1 ) h ( -1 ) , P = 0.032 ] , but not remifentanil consumption [ 0.17 ( 0.12-0 .23 ) vs 0.18 ( 0.14-0 .24 ) g kg ( -1 ) min ( -1 ) ] .