Compared with group I , extubation time ( 5.5 1.4 vs 7.1 1.7 ) and residence time in ICU ( 17.3 4.2 vs 21.4 5.8 ) were shortened significantly in group P ( P < 0.05 ) , and there were no significant difference in length of stay after operation ( 10.5 2.6 vs 11.7 2.8 , P > 0.05 ) .