Limb RIPC significantly increased PaO2/FIO2 compared with control at 30 and 60 min after one-lung ventilation , 30 min after re-expansion , and 6 h after operation ( 238 52 vs. 192 67 , P = 0.03 ; 223 66 vs. 184 64 , P = 0.01 ; 385 61 vs. 320 79 , P = 0.003 ; 388 52 vs. 317 46 , P = 0.001 , respectively ) .