Use of early dexmedetomidine did not improve NIV tolerance ( score , 1 of 4 ; OR , 1.44 ; 95 % CI , 0.44-4 .70 ; P = .54 ) nor , vs. placebo , led to a greater median ( interquartile range ) percent time either tolerating NIV ( 99 % [ 61 % -100 % ] vs. 67 % [ 40 % -100 % ] , P = .56 ) or remaining at the desired sedation level ( SAS score = 3 or 4 , 100 % [ 86 % -100 % ] vs. 100 % [ 100 % -100 % ] , P = .28 ] , or fewer intubations ( P = .79 ) .