There were 24 factors relating to PPC in univariate logistic analysis. And multivariate logistic analysis identified 5 independent risk factors associated with PPC, including perioperative aerosol therapy (OR = 5.906), duration of postoperative antacidstherapy (OR = 1.145), duration of operation (OR = 1.011), preoperative serum albumin (OR = 0.689), postoperative analgesia (OR = 0.059), Logistic regression equation for predicting the risk of PPC was P(1) = 1/[1 + e-(- 9.803 + 1.776 x A + 0.135 x B + 0.011 x C - 0.372 x D - 2.835 x E)].