The time of stay in the ICU and the time of mechanical ventilation of lactic group were shorter that those of control group , but there was no statistical difference [ ICU time ( days ) : 8.95 5.19 vs. 9.45 6.18 , t = 0.605 , P = 0.652 ; mechanical ventilation time ( hours ) : 101.15 11.50 vs. 110.63 13.26 , t = 0.631 , P = 0.564 ] .