Perioperative depressive symptoms (PDS) are common in population undergoing surgery, and this
would be sharpened especially for complicated, high-risk major surgery. However, None of
treatments could resolve this clinical problem during limited perioperative period. The
remarkable effects of ketamine on treatment resistant depression have been verified by
several clinical trials and the enantiomer S-ketamine (esketamine) showed similar
antidepressant efficacy with better safety in recent studies. The efficacy and safety of
esketamine administrated intra-operatively for PDS will be verified in this study. Other
secondary outcomes such as anxiety, postoperative pain and psychiatric symptoms will also be
investigated.