Automatic adjustment was associated with lower airway occlusion pressure after 0.1 second ( P0 .1 ) ( 1.80.9 cm H2O vs 2.41 cm H2O ; P < .01 ) , lower pressure-time product to trigger the ventilator , and lower subjective discomfort ( visual analog scale , 3.71.3 vs 4.51.2 ; P < .001 ) .