title: Effect of tramadol on perioperative immune function in patients undergoing gastric cancer surgeries.
abstract: BACKGROUND
  A prospective randomized controlled trial was designed to observe the effect of tramadol on T-lymphocyte subsets, activated T cell and natural killer (NK) cells of patients undergoing gastric cancer surgeries.
  
  
  METHODS
  Thirty patients undergoing elective gastric cancer surgeries under general anesthesia were randomly divided into two groups. Before anesthesia induction, Group I did not receive any drugs and Group II received intramuscular tramadol 1 mg/kg. Peripheral venous blood samples were taken before anesthesia, 1 h after incision and postoperation. CD3(+), CD3(+) CD4(+), CD3(+) CD8(+), CD3(-)CD16(+) CD56(+) (NK) cells and CD3(+) human leukocyte antigen (HLA)-DR(+) (activated T cell) were measured by flow cytometer.
  
  
  RESULTS
  One hour after incision, CD3(+), CD3(+) CD4+, CD3(+) CD4(+)/CD3(+) CD8(+), CD3(-)CD16(+) CD56(+), and CD3(+) HLA-DR(+) cells in the experimental and control group were significantly decreased compared with their baselines (P < 0.05), while the values of Group I were lower than those of Group II (P < 0.05). After surgery, the values of Group I were lower than their baselines (P < 0.05). But the values of Group II had no significant difference compared with their baselines.
  
  
  CONCLUSIONS
  Tramadol can reduce the decrease of T-lymphocytes subsets and NK cells, thus improve the cellular immune function in the perioperation of gastric cancer.
authors.affiliation: Department of Anesthesiology, Xiangyang Central Hospital, Hubei University of Arts and Science, Hubei Province, China.
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Zhou
authors.affiliation: Department of Anesthesiology, Xiangyang Central Hospital, Hubei University of Arts and Science, Hubei Province, China.
authors.forename: Han-Lin
authors.initials: HL
authors.lastname: Ding
authors.affiliation: Department of Anesthesiology, Xiangyang Central Hospital, Hubei University of Arts and Science, Hubei Province, China.
authors.forename: Ming-Qiang
authors.initials: MQ
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Xiangyang Central Hospital, Hubei University of Arts and Science, Hubei Province, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Jin
authors.affiliation: Department of Anesthesiology, Xiangyang Central Hospital, Hubei University of Arts and Science, Hubei Province, China.
authors.forename: Xue-Song
authors.initials: XS
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Xiangyang Central Hospital, Hubei University of Arts and Science, Hubei Province, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Ji
keywords: Gastric cancer; T-lymphocyte subsets; killer cells; natural; tramadol