Fig. 2.

Oxygen index in mild, moderate and severe NARDS. a mild NARDS; b moderate NARDS; c severe NARDS; d total. The overall p value for within patients comparisons: in Calsurf treatment group, OI decreased significantly after 4 h surfactant given (7.23 ± 2.73 at 4 h, 14.89 ± 11.44 at 0 h, P < 0.001) and 12 h given (7.53 ± 3.13 at 12 h, 14.89 ± 11.44 at 0 h, P < 0.001), while the same change pattern can be seen in control group, although the decline is not as obvious as control group. The between-group patients’ comparisons: Calsurf administration significantly decreased the OI in mild, moderate, and severe cases of NARDS, especially moderate and severe cases. Data shown are mean values; error bars indicate SEM. *P < 0.05for the significant difference between groups