Time to extubation was 17 minutes ( 95 % CI , 14-20 minutes ) in the lorazepam group , 12 minutes ( 95 % CI , 11-13 minutes ) for the no premedication group , and 13 minutes ( 95 % CI , 12-14 minutes ) for the placebo group ( P < .001 ) and the rate of early cognitive recovery was 51 % ( 95 % CI , 45 % -56 % ) , 71 % ( 95 % CI , 66 % -76 % ) , and 64 % ( 95 % CI , 59 % -69 % ) , respectively ( P < .001 ) .