Effects Of Dexmedetomidine On Perioperative Cellular Immune Function Of Colorectal Cancer Patients

ObjectiveThe celluar immune function in tumor patients was always inhibited. The level of T-lymphocyte subsets was lower and the activity of NK cells was down-regulated in those who suffered malignant tumor, especially in advanced stage. This situation was exacerbated by surgical injury and anesthesia. Dexmedetomidine(Dex) is a highly selectiveα2-adrenergic agonist (α2AR). Dex has anα2:α1 receptor affinity ratio of 1600:1, its affinity toα2AR is 8 times more specific than that of clonidine. A list of benefits includes, (1) The effects of sedation, hypnosis and anxiolysis, normal non-rapid-eye-movement sleep induced by theα2AR can be awakening during the operation, which was different from other sedative and hypnotic drugs. (2) Dex can reduce the consumption of opioids during operation for the effect of analgesia. (3) Dex has been shown to reduce sympathetic nervous system activity, may reduce the blood pressure and heart rate during stress, reduce the consumption of oxygen of heart muscle, stabilize the blood pressure, (4) sedation without respiratory depression or significant cognitive impairment. Recent study showed that sedative drugs modify immune cell functions, and Dex limited apoptosis. While it is not clear that the effects of Dex on perioperative cellular immune function, especially that of colorectal cancer patients under anesthesia. It is the research focus at present. The purpose of this study is to investigate the influence of Dex on the immune function in patients with colorectal cancer during the perioperative period. If the experiment can achieve the expected purpose, it will provide theoretical basis of security application for cancer patients using Dex undergoing general anesthesia. It will be useful for improving further anesthetic quality, particularly protecting the immune function of cancer patients and improving the curative effect and prognosis.Material and methods 40 patients undergoing radical resection for colorectal cancer under general anesthesia were selected and randomly divided into control group (n=20) and experimental group (n=20). After the induction of anesthesia with midazolam 0.06mg/kg, propofol 1.5mg/kg, fentanyl 3μg/kg and rocuronium 0.9mg/kg intravenously, intubation was performed and the patient was on volume-controlled mechanical ventilation. In contral group, the anesthesia was maintained with sevoflurane inhaled, propofol and fentanyl pump intravenously, and continual intravenous injection of rocuronium. In experimental group, the anesthesia was maintained with sevoflurane inhaled, Dex (0.2-0.3μg/kg/h) and fentanyl pump intravenously, and continual intravenous injection of rocuronium. 1.5ml of samples of the patient peripheral blood was collected 1 day before the surgery, when the operation was finished and 72h after the operation respectively for the detection.After immunofluorescence staining, the samples were analyzed for the absolute counts of the immunocyte(T cell subpopulations, NK cell and B cell) using FCM(Flow Cytometry).ResultBoth the absolute counts of T cell subpopulations, NK cell and B cell immediate and 72h post operation were lower than that before surgery in control group and experimental group (P<0.05). The absolute counts of T cell subpopulations, NK cell and B cell immediate and 72h post operation were lower in control group than that in experimental group (P<0.05).The absolute counts of T cell subpopulations, NK cell and B cell in control group is lower than experimental group after operation. And the change of the absolute counts before operation and postoperation is smaller in experimental group (p<0.05).Conclusions1. Dex can suppress effectively the perioperative reduction of T cell subpopulations in patients undergoing colorectal carcinectomy.2. Dex can suppress effectively the perioperative reduction of NK cell in patients undergoing colorectal carcinectomy.3. Dex can suppress effectively the perioperative reduction of B cell in patients undergoing colorectal carcinectomy.4. Dex can attenuate the perioperative suppression of immune function in colorectal cancer patients.5. Dex can attenuate the perioperative suppression of immune function in cancer patients, particularly during the general anesthesia. And there is hardly any literature published in home and abroad relative to the result of our study.