Shortens the course of disease, improves the treatment efficiency, reduces incidence rate of antibiotic resistance, reduces occurrence of double infection, further improves the prognosis and reduces the mortality rate (Zhang and Wang, 2015). Reduces leukocytes, improve oxygen index, lower CPIS score, promotes absorption of pulmonary inflammation, shortens the duration of mechanical ventilation and length of stay in ICU, and improves clinical effect (Yang et al., 2014).