Median survival time to extubation was similar between the groups ( T 67 h [ 95 % CI 51 , 84 ] vs P 52 h [ 95 % CI 43 , 65 ] ; P = 0.4 ) , and similar numbers were extubated by 96 h ( T 69 % vs P 77 % ; difference -8 % , 95 % CI -28 , 13 % ) .