Effects Of Anesthetic Techniques On The Glucose Metabolism And Lipid Fluidity Of RBC In Patients Undergoing Esophageal Cancer Thoracic Surgery

Objective Our previous studies have shown that glycolysis in RBC is depressed entirely in patients undergoing major surgery, while pentose phosphorate pathway(PPP) is activated at the same time. We have known that polyol pathway as the third pathway in RBC can be activated underwent major surgery. We still do not know how polyol pathway changes during stress response to thoracic surgical injury and the effects of different anesthetic techniques. In the present study, we investigated the changes of limited-enzyme antivities of Phosphofructokinase, Glucose-6-phasphate dehydrogenase and aldose reductase and related factors in patients undergoing open thoracic surgery for esophageal cancer, whether the change of glucose metabolism is related to oxidative stress, and what are the effects of anesthetics and different anesthetic techniques on glucose metabolism and oxidative stress.Methods 60 ASA physical status â…  and â…¡ patients, undergoing elective open thoracic surgery for esophageal cancer were randomly allocated to four groups with 15 cases each. Anesthesia was maintained with propofol 3-4 mg/kg/h infusion combined epidural block ( group â…  ) or 0.6-0.8 MAC end-tidal isoflurane inhalation with epidural block ( group â…¡ ) , or propofol 4-6 mg/kg/h infusion(group â…¢), or combined 1.1-1.5 MAC end-tidal isofluraneinhalation with epidural block ( group â…£ ) . The venous samples were collected to measure the plasma levels of glucose, insulin, TNF- a and superoxide dismutase( SOD ), glutathione peroxidase( GSH-Px ), catalase ( CAT ) activities in RBC and phosphofructokinase ( PFK ) , glucose-6-phasphate dehydrogenase( G-6PD ), aldose reductase( AR ) activities in RBC and lipid fluidity of RBC at 30min before anesthesia( T1 ) ,90 min after incision ( T2 ) ,60 min after surgery ( T3 ) and on the 1st, 2nd postoperative days ( T4, T5 ) .Results (1) The levels of plasma glucose were increased significantly at 90min after incision and kept at a high level till on the 2st postoperative day in all four groups(P<0.05) as compared with those before anesthesia. (2) Plasma insulin level was increased significantly on the 1st to 2nd postoperative day as compared with the value before anesthesia(P<0.05), but no significant difference occurred among three groups ( P>0.05 ) . (3) Plasma TNF- a level was increased markedly at 90 min after incision and on the 1st postoperative day in group â…¢ and group â…£ as compared with that before anesthesia, in group I and group II it was increased on the 1st postoperative day( P<0.05 ) and was less than that in group â…¢ and group â…£(P<0.05). (4) Compared with the values before anesthesia, SOD activity was dereased markedly on the 1st postoperative day in group â…¡ and group â…£(P<0.05), but no significant difference occurred in group â…  and group â…¢. (5) GSH-Px and CAT activity was increased at 90min after incision and kept at a high level till on the 2st postoperative day in group â…¢ and group â…£ as compared with those before anesthesia(P<0.05), but not significant in group â…  and group III( P>0.05 ) . (6) The activity of PFK was decreased significantly and the activities of G-6PD and AR in RBC were increased markedly on the 1st postoperative day in group â…¢ and group â…£ (P<0.05 or P<0.01) , but not in group â…  and â…¡ ( P>0.05 ) . (7) The degree offluorescence polarization of RBC membrane increased slightly at 90 min after incision to 2nd postoperative day, but there was no significant difference in four groups.Conclusions (1) In patients undergoing thoracic surgery, polyol pathway activates, while plasma glucose is increased, with a depression in glycolysis of RBC and activation of the pentose phosphorate pathway. Oxidative stress related factors change at the same time. These changes suggest that oxidative stress occurrs and the change of glucose metabolism in RBC is one of the oxidative stress responses to surgery. (2) On the 1st postoperative day, the extent of changes in rate-limited enzyme actitivities of RBC gloucose metabolism and oxidative stress markers in group I and gr...