Perioperative Oral Decontamination and ImmunoNuTrition (POINT) in Elderly

The goal of this multicenter randomized controlled trial is to explore the efficacy of perioperative oral decontamination and immunonutrition supplement to prevent postoperative pulmonary complications in elderly patients(≥65 years) receiving elective non-cardiac operations. Participants will be either given immunonutrition supplement versus routine nutrition advice, and oral chlorhexidine decontamination versus routine oral care randomly. The two interventions will be compared with control groups separately regarding postoperative pulmonary complications and other outcomes.