Groups A and B showed different max PEEP during the first 12 h of life ( 8.4 0.5 vs 6.7 0.6 cm H2O , P = 0.00 ) , time to lowest FiO2 ( 101 18 versus 342 128 min ; P = 0.000 ) and O2 dependency ( 7.83 2.04 vs 9.92 2.78 days ; P = 0.04 ) .