The Effects Of Depth Of General Anesthesia On Immunocytes For Patients Of Stomach Cancer During Operation Of Gastrectomy

IntroductionIt has become an important problem that how to control an appropriate depth of general anesthesia during operation . We must take it into account synthetically that we should choose a correct depth of general anesthesia , which need both guarantee the operation and think of the negative effect of general anesthesia on hemodynamics and internal environment .Immune system does not exist and perform its function solitarily , but contact tightly with nervous system and endocrine system . On some characteristic cells which regulate internal environment by immune mechanisms , there are also molecule receptors having regulation function to nervous system and endocrine system . So there is neuroimmuneology and neuroendocrinology concept at present . When nervous system and endocrine system are interfered by environment , it is inevitable to affect the function of immune system.During operation , the interference with immune system from tension , anxious , drugs , wounds , anesthesia and so on had caused our attention in the increasing of infection ratio and tumor recurrence . At present , most studies focus on the function of different drugs and methods of anesthesia which may affect immune system during operation . There are few reports about the effect of depth of general anesthesia on immune system during the operation. Nevertheless the depth of general anesthesia has directly correlation to the effect on hemodynamics and internal environment . we in the long run should consider seriously the relation between general anesthesia and effect on immune system when it come to the selection of depth of general anesthesia.ObjectiveTo observe the effects of different depth of general anesthesia on granulocyte , monocyte , lymphocyte , T - lymphocyte , B - lymphocyte , natural - killer cell and T - lymphocyte subsets for patients of stomach cancer who received inhalation intravenous anesthesia during operations of gastrectomy .Methods24 ASA Ⅰ or Ⅱ patients of stomach cancer scheduled for elective gastrectomy ( Billroth Ⅰ ) and received inhalation intravenous anesthesia were randomly divided into two groups to receive high ( Group H) or low ( Group L) depth of general anesthesia . Group H : Bispectral Index ( BIS) was 40 ( ± 10% ) ; Group L: BIS was around 60 ( ± 10% ) . All patients received midazolam 50 μg/kg and atropine 10 μg/kg intramuscular injection as premedication . Following administration of fentanyl 4 μg/kg , propofol 2mg/kg and atracurium 1mg/ kg , trachea was intubated . Then the patients were ventilated mechanically with 100 percent oxygen . The depth of anesthesia was maintained with inhalation of isoflurane in oxygen . The flow of fresh oxygen was 1 liter/ minute . The intraoperative muscle relaxant was intravenous atracurium . Measurements included BIS, electrocardiogram (ECG) , heart rate (HR) , blood pressure (BP) and oxygen saturation before and during and after surgery until endotracheal extubation . The blood sample ( 1. 5 ml) was drown respectively from centre vein at special time point such as the tenth minute before endotracheal intubation (T1) , the ninetieth minute after incision of skin(T2) , the one hundred and eightieth minute after incision of skin (T3) and was anticoagulated with EDTA .Granulocyte, monocyte, lymphocyte, T - lymphocyte, B - lymphocyte, natural - killer cell and T - lymphocyte subsets CD3 + , CD4 + , CD8 + , CD4+/ CD8 + , natural killer cell ( CD16+56 + ) was measured with FACSCalibur flow cy-tometer . Data are presented as mean ± S. E. Statistical analysis was done using Student t - test for non - paired data and using analysis of variance with q - testfor group comparison . A P <0. 05 was considered significant .ResultsNumbers and ratio of granulocyte in both group H and group L increased significantly at T2, T3 time point compared with T, time point . Monocyte numbers in group H and group L increased significantly at T3 time point compared with T1 time point. Lymphocyte ratio in group H and group L decreased significantly at T2, T3 time point . T - lymphocyte ratio in group L decreased significantly at T2, T3 time point . The tendency of change of T - lymphocyte ratio in group H was identical to group L but had no significant difference contrast pre -anesthesia ( P > 0. 05 ). B- lymphocyte of both two groups had no significant difference contrast pre - anesthesia (P > 0. 05). Natural killer cell numbers in group L increased significantly at T3 time point compared with T, time point. The tendency of change of Natural killer cell numbers in group H was identical to group L but had no significant difference contrast pre - anesthesia ( P > 0. 05). Variance of monocyte ratio and natural - killer cell ratio of both two groups increased but had no significant difference contrast pre - anesthesia ( P > 0. 05). Variance of T - lymphocyte numbers of both two groups had no significant difference contrast pre - anesthesia ( P > 0.05 ).CD4+ ratio in group L decreased significantly (P < 0.05) at T2,T3 time point compared with T1 time point . The tendency of change of CD4 + ratio in group H was identical to group L but had no significant difference contrast pre -anesthesia (P > 0.05) . CD8 + , CD4+/ CD8 + of both two groups had no significant difference contrast pre -anesthesia (P > 0.05) .ConclusionThe granulocytes and monocytes increased whereas the lymphocyte ratio decreased regardless of the depth of general anesthesia . T - lymphocyte ratio and CD4 + ratio decreased under low depth of general anesthesia , which indicated that the function of cytoimmunity was inhibited . General anesthesia has no sig-...