CCL4 serum levels were significantly lower in ventilated-group patients on POD-1 ( 10.9 [ 39.0 ] vs. 153.2 [ 168.1 ] ; p = 0.005 ) , POD-2 ( 16.8 [ 36.8 ] vs. 147.9 [ 165.4 ] ; p = 0.019 ) , POD-3 ( 14.2 [ 24.0 ] vs. 97.9 [ 87.1 ] ; p = 0.005 ) , and POD-5 ( 6.5 [ 25.0 ] vs. 33.6 [ 38.4 ] ; p = 0.045 ) .