OBJECTIVE: To probe into the efficacy of acetylcysteine combined with budesonide aerosol inhalation in children with congenital heart disease（ CHD） after cardiopulmonary bypass（ CPB）.METHODS: Totally 102 children from 1 to 3 years with CHD undergoing CPB admitted into the First Affiliated Hospital of Air Force Military Medical University from Jan.2018 to Jun.2019 were extracted to be divided into the study group and the control group via the random number table

with 51 cases in each group.The control group was given budesonide aerosol inhalation after CPB

while the study group received acetylcysteine combined with budesonide aerosol inhalation.Differences of general treatment and postoperative pulmonary function

airway resistance and inflammation indexes of two groups were compared.RESULTS:（ 1） The disappearance time of lung phlegm sound

ventilator ventilation time

length of stay in ICU and length of stay after CPB in the study group were significantly shorter than those in the control group

and the differences were statistically significant（ P<0.05）.（ 2） After treatment of 24 and 48 h

the respiratory index（ RI）

the alveolar-arterial oxygen differential pressure（ A-aDO2） of two groups were lower than those before treatment

while the oxygenation index（ OI） was significantly higher; RI of the study group at 48 h and A-aDO2 at 24 h and 48 h after treatment were significantly lower than those in the control group

OI at 24 and 48 h after treatment was significantly higher than that of the control group

and the differences were statistically significant（ P < 0.05）.（ 3） The airway resistance of two groups after treatment was lower than that before treatment

while the airway resistance of the study group was significantly lower than that of the control group after treatment of 24 h and 48 h

and the differences were statistically significant（ P < 0.05）.（ 4） The levels of glutathione peroxidase in the study group after treatment were significantly higher than those of the control

the levels of intercellular adhesion molecule-1 and interleukin 8 were significantly lower than those of the control group

and the differences were statistically significant（ P < 0.05）.CONCLUSIONS: Acetylcysteine combined with budesonide aerosol inhalation in children with CHD after CPB is more beneficial to the recovery of pulmonary function than simple aerosol inhalation of budesonide

and can synergistically improve the inflammatory response.