The Clinical Applications Of Dexmedetomidine And Its Effects On Postoperative Cognitiye Dysfunction After Colorectal Cancer Surgery In Elder Patients

Background:The present study was designed to observe the influence of dexmedetomidine on the hemodynamics, propofol consumption, inflammatory factor, and postoperative cognitive dysfunction when dexmedetomidine had been used in general anesthesia in elder patients undergoing colorectal cancer surgery.Methods:Thirty elder patients aged60-80years old, ASA Ⅰ-Ⅲ were randomized into two groups:A(Control group), B(ExPeriment group), each group included15cases. The patients of experiment group received load dosage (1ug/kg) dexmedetomidine before anesthesia induction,and this Process must last more than10minutes, then the dexmedetomidine was maintained at a speed of0.5ug/(kg·h)during the operation. The patients of control group were given the same dosage normal saline in the same way instead. All cases had been choosen total intravenous anesthesia, and received midazolam0.04mg/kg, cisatracurium besilate0.3mg/kg, fentany5ug/kg, etomidate0.25mg/kg, esmolol0.5mg/kg for induction, after that trachea intubation were performed. Maintenance of anesthesia:fentany2ug/kg was given to the patients at the beginning and the following each hour, cisatracurium besilate was given to at0.1mg/(kg·h), propofol was also pumped and the speed was determined by the NI (the NI should be controlled between D1and E1).Note the MAP and HR at T0(arriving operating room),Tl (after giving the load dosage),T2(trachea intubation),T3(skin incision),T4(skin suture),T5(trachea extubation.) The plasma levels of IL-6, TNF-a and s-100β protein were measured by ELISE at Ta(before surgery), Tb(1hours after surgery)and Tc(6hours after surgery).MMSE and SDS were measured one day before surgery. WAIS and WMS were measured at one day before surgery, one day after surgery, three days after surgery, seven days after surgery. Z-combined score recommended by most experts was applied to diagnosis of cognitive dysfunction.Result:1. There were no significant differences in the aspects of fundamental state, MMSE and SDS test.2. There were significant differences in the aspects of MAP and HR at different time points between the two groups, P<0.05. AT T1the MAP of group B were higher than group A, the HR were lower in group B than group A, P<0.05. Group A, the MAP and HR of T2-T5were significantly different from T0, P<0.05, while group B did not, P>0.05.4. The operative propofol requirements were significantly lower in experiment group than the control group[5.3±0.7mg/(kg’h) vs8.1±0.6mg/(kg·h)].5. There were significant differences in plasma levels of IL-6, S-100protein between the2groups before or after operation, P<0.05. There were no significant differences in plasma levels of TNF-α between the2groups before or after operation, P>0.05.6. The POCD incidence of experiment group was significantly lower than the control group especially one day after operation., P<0.05.Conclusion:In colorectal cancer surgery in elder patients, the dexmedetomidine can maintan hemodynamic stability, cut down the dosage of propofol, inhibit IL-6and s-100β protein plasma level, and it also could reduce the incidence of postoperative cognitive dysfunetion.