Effect of Esketamine on Perioperative Negative Emotions in Patients Undergoing Breast Cancer Surgery

Inclusion Criteria:

1. Age ≥ 18 years.
2. Scheduled to undergo elective breast cancer resection surgery.
3. American Society of Anesthesiologists (ASA) physical status classification of I-III.
4. Clearly understand and voluntarily agree to participate in the study, and sign the informed consent form.
5. Anticipated anesthesia duration greater than 90 minutes.

Exclusion Criteria:

1. Patients with significant preoperative abnormalities in cardiac, pulmonary, hepatic, or renal function, or coagulation disorders .
2. Patients taking antipsychotics, antidepressants, or glucocorticoids, or with a history of alcohol abuse or illicit drug use .
3. Patients with an MMSE score \<18, dementia, intellectual disability, or those unable to communicate (e.g., coma, severe dementia, hearing or language impairment) .
4. Patients with a history of psychiatric or neurological disorders (e.g., schizophrenia, epilepsy, Parkinson's disease, or severe myasthenia gravis) .
5. Patients with poorly controlled or untreated hypertension (≥180/110 mmHg) .
6. Patients with elevated intracranial or intraocular pressure.
7. Patients with untreated or inadequately treated hyperthyroidism .
8. Patients with a known allergy to the drugs involved in this study .
9. Patients unable to complete the assessment scales required by this study.
10. Patients who are currently participating in other clinical trials