Effect of dexmedetomidine and tramadol on perioperative insulin resistance in patients undergoing radical resection of rectal carcinoma

Abstract

Objective To evaluate the effect of dexmedetomidine and tramadol on perioperative insulin resistance in patients undergoing radical resection of rectal carcinoma. Methods Sixty ASA I or II patients undergoing radical resection of rectal carcinoma were randomly divided into 3 groups(n=20 each): dexmedetomidine group(group D), tramadol group(group T), control group(group C). Group D was given dexmedetomidine intravenously at 1μg/kg 15min before induction of anesthesia followed by a continuous infusion of 0.5μg·kg-1·h-1 until the abdomen was closed,and group T was given tramadol intravenously at 1.5mg/kg 15min before induction of anesthesia followed by a continuous infusion of 0.5mg·kg-1·h-1 until the abdomen was closed, whereas group C received the same volume of normal saline. Venous blood samples were taken at 30min before anesthesia induction(T1),1 h after the beginning of the operation(T2),1h after operation(T3),24h after operation(T4)for determination of blood concentrations of glucose(BG), insulin(INS), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α). Insulin resistance(HOMAIR)and insulin sensitivity index(QUICKI)were calculated.The numbers of patients with PONV were studied respectively. Results The serum IL-6,TNF-α,BG,INS concentrations and HOMA-IR were significantly lower while ISI was significantly higher in both group D[t=7.71,3.37,8.78,8.73,11.45,2.82(T 2),3.04,2.95, 12.75,10.73,16.09,2.92(T3),11.26,2.45,11.40,5.10,14.5,2.51(T4),all P<0.05]and group T[t= 3.02,2.59,2.93,7.76,6.32,2.03(T 2),8.78,2.27,4.14,8.83,7.68,2.12(T 3),6.10,2.05,3.71,2.35,7.12,2.09 (T4),all P<0.05]at T 2,T 3 and T4 than those in group C. The serum TNF-αconcentration and HOMA-IR were significantly lower while ISI was significantly higher in group D[t=6.68,4.58,2.05(T2),9.01,6.66,2.23 (T3),7.54,5.5,2.02(T4),all P<0.05]at T 2,T3 and T 4 than those in group T. The numbers of patients with PONV were significantly higher in group T than those in group D and group C(χ2=26.13,18.75,all P<0.05). Conclusion Both dexmedetomidine and tramadol can attenuate perioperative insulin resistance in patients undergoing Radical Resection of Rectal Carcinoma, and the decrease the consentrations of IL-6 and TNF-α may be involved in the mechanism. The roles of prevention of perioperative insulin resistance in dexmedetomidine group are superior to tramadol group. The incidence of PONV is less in a dexmedetomidine group than that in a tramadol group. Key words: Insulin resistance; Interleukin-6; Tumor necrosis factor-α; Dexmedetomidine; Tramadol