OBJECTIVE: To explore the effects of long-term intravenous infusion of dexmedetomidine combined with oxycodone on postoperative inflammatory response and immune function in patients with breast cancer. METHODS: A total of 87 patients with breast cancer admitted to the hospital from Jan. 2020 to Jan. 2021 were selected and randomly divided into observation group（43 cases） and control group（44 cases）. Patients in the control group were given continuous infusion of oxycodone during general anesthesia

and patients in the observation group were given continuous infusion of dexmedetomidine on the basis of patients in the control group.The general conditions of patients in 2 groups before operation（including age

course of disease

weight

the level of serum albumin）

immune function（including mHLA-DR

sE-cad）

inflammatory response（including TNF-α

IL-6） and visual analogue scale（VAS） before and after treatment

and adverse reactions were recorded. RESULTS: Compared with before operation

the levels of mHLA-DR in two groups were increased significantly

while the levels of sE-cad were decreased significantly at the end of operation

1 day and 3 days after operation; the level of mHLA-DR in observation group was significantly higher than control group

while the level of sE-cad was significantly lower than control group at the same period

with statistical significance（P<0.05）. At the end of operation

1 day and 3 days after operation

the content of TNF-α in observation group was significantly lower than control group

with statistical significance（P<0.05）. VAS scores of 2 groups 6 and 12 h after operation were significantly decreased compared with 1 h after operation; VAS scores of observation groups were significantly lower than that of control group

with statistical significance（P<0.05）. There was no serious irreversible adverse reaction in two groups

and there was no significant difference in the incidence of adverse drug reactions（P>0.05）. CONCLUSIONS: Continuous intravenous infusion of dexmedetomidine combined with oxycodone can effectively reduce postoperative inflammatory response

improve postoperative immune function and reduce postoperative pain in patients with breast cancer.