Currently, domestic and international research on dexmedetomidine as well as anxiety and depression is more focused on basic research. In terms of clinical research, dexmedetomidine is more often used in pediatrics, short surgeries, intensive care units, etc., for sedation and analgesia; while less research has been done for the relief of anxiety and depression. At present, on the one hand, the number of oncology patients is on the rise both at home and abroad, and on the other hand, anxiety and depression account for an increasing proportion of healthcare in the world. Tumor patients, as a high prevalence group of anxiety and depression, their prognosis and regression are also more complicated. Therefore, exploring the role of intranasal administration of dexmedetomidine in relieving perioperative anxiety and depression in oncology patients has a very strong practical basis and clinical significance.

Inclusion Criteria:

1. Patients with a preoperative diagnosis of colorectal cancer who were to undergo their first oncologic procedure
2. Patients who opted for general anesthesia via orotracheal intubation
3. Age ≥18 years old
4. ASA classification II-III (5) 18.0 < BMI < 30.0
5. Signed informed consent.

Exclusion Criteria:

1. Diagnosed mental illness or cognitive impairment, or taking antipsychotic, sedative-hypnotic, or anxiolytic-depressant medications
2. Serious abnormalities of liver or kidney function.
3. Prior alcohol or drug abuse
4. Second or third degree atrioventricular block, severe sinus bradycardia (<50 beats/min), sick sinus node syndrome, congenital heart disease, and other cardiac arrhythmias that severely affect hemodynamic stability
5. Grade 3 hypertension
6. Any disease of the head, such as cerebral infarcts, epilepsy, head trauma, etc.
7. Confirmed diagnosis of non-tumor-induced chronic ( ≥3 months) neuropathic pain
8. Inability to understand the meaning of the scale and complete the scoring.
9. Women preparing for pregnancy, pregnant women, or breastfeeding
10. Patients with myasthenia gravis
11. Respiratory function score ≥3