Effects Of Patient-controlled Intravenous Dexmedetomidine Combined With Morphine On T Cell Subsets And NK Cells Of Peripheral Blood In Postoperative Period Of Esophageal Cancer Patients

Objective To evaluate the effect patient-controlled intravenous of dexmedetomidine combined with morphine on T-1ymphocyte subset（CD3+、CD4+、CD8+、CD4+/CD8+）and NK cells during postoperative analgesia in patients after esophageal cancer surgeries.Methods Sixty patients with ASA Physical statusⅠ～Ⅱ, both gender,undergoing elective esophageal cancer surgeries under general anesthesia were randomly allocated into Morphine group or Dexmedetomidine combined with Morphine group with30cases each.PCIA was started immediately after operation.In group M the PCIA solution contained morphine0.02mg/kg/h in150ml of normal saline(NS)，while in group MD the PCIA solution contained morphine0.02mg/kg/h+dexmedetomidine1ug/kg/d in NS150.The scores of visual analog scale (VAS)were evaluated at24,48and72h postoperatively.The total mount of morphine consumed,the number of attempts and successfully delivered doses within24,48and72h after operation were recorded．Postoperative complications including nausea，vomiting，bradycardia，hypotension，oversedation and respiratory depression were recorded．The expressions of T-lymphocyte subsets (CD3+、CD4+、CD8+、CD4+/CD8+)and natural killer cells were measured by flow cytometry at five time points: before anesthesia (baseline), during extubation,24,48and72h after operation.Results The scores of VAS had no significant differences between the two groups at24,48or72h postoperatively (P>0.05).The total amount of morphine consumed，the number of attempts and successfully delivered doses within24,48and72h after operation were significantly smaller and the incidence of nausea and vomiting and pruritus was significantly lower in group DM than in group M．No bradycardia，hypotension，oversedation respiratory depression was observed in each group． Compared with the baselines,CD3+、CD4+、CD8+、CD4+/CD8+、NK cells of the two groups began to decrease during extubation(P<0.05), and be lowest at24h after operation (P<0.05),then began to return at48,72h after operation (P<0.05).Compared with group M, group DM decreased less at24,48,72h after operation (P<0.05), CD8+of two groups had no significant difference at different time points (P>0.05).Conclusion Compared with perioperative administration of Morphine only during PCIA in patients after esophageal cancer surgeries,Dexmedetomidine combined with Morphine may reduce morphine requirements, with less adverse effects.Group DM can relief the repression effect of T-lymphocyte subsets(CD3+、CD4+、CD4+/CD8+)and NK cells after esophageal cancer surgeries on.It contributes more to recover cell mediated immunity of the patients suffering excision of esophageal cancer.