To observe the effect of dexmedetomidine combined with oxycodone in immune function of patients undergoing gastrectomy.

Sixty patients undergoing elective radical resection of gastric carcinoma were randomized into two groups from People's Hospital of Xinjiang Uygur Autonomous Region between June 2015 to March 2016: Group O treated with oxycodone and Group DO dexmedetomidine combined with oxycodone, with 30 cases in each group. All patients received intravenous general anesthesia with 4-6 mg·kg^-1·h^-1 propofol and target controlled infusion of 3-4 μg/ml remifentanil. Group O were injected through veins 0.04 mg/kg oxycodone 30 min before the end of surgery, and patients in Group DO were give intravenous injection of 0.5 μg·kg^-1·h^-1 dexmedetomidine consistently till 30 min before the end of the operation. The patient-controlled intravenous analgesia (PCIA) was used for postoperative analgesia. Before surgery (T0), at the end of surgery (T1), 4 days (T2) and 8 days (T3) after surgery, venous blood samples were collected for detection of T lymphocyte subsets CD3+, CD4+, CD8+ and natural killer (NK) cell CD16+/CD56+ levels by flow cytometry. CD4+/CD8+ ratio was calculated. The occurrence of postoperative VAS score and adverse reactions such as nausea, vomiting, headache and respiratory expression were recorded after surgery.

Compared with the value at T0, the levels of CD3+, CD4+, CD4+/CD8+, and CD16+/CD56+ were significantly decreased at T1 and T2, and the CD8+ level was increased (P<0.01). Compared with group O, the levels of CD3+, CD4+, CD4+/CD8+, and CD16+/CD56+ in group DO were significantly increased at T1 and T2 (P<0.01), and there was no significant difference in the incidence of adverse reactions after surgery in the two groups.

The effect of dexmedetomidine combined with oxycodone is better than oxycodone alone on immune function in patients undergoing radical resection of gastric carcinoma.