Effects of Dexmedetomidine on Surgical Stress Responses at Patients Under CABG

Cardiopulmonary bypass (CPB) surgery with extracorporeal circulation produce changes in the immune system and plasma levels of inflammatory cytokines. we hypothesize that Dexmedetomidine as an adjuvant , modulates the inflammatory response after CABG. In a prospective, randomized, blind study, 31 patients were assigned to Dexmedetomidine (Dex) group and compared with control group of 30 patients. Dex was administered at a loading dose of 0.5 µg/kg for 10 min , followed by a continuous infusion of 0.5 µg/kg per hour until the completion of CABG with CPB . The endpoints used to assess inflammatory responses to mini – CPB were plasma tumor necrosis factor (TNF) – α , interleukin (IL – 6 ) and interleukin ( IL – 10) levels. The inflammatory markers (IL – 6 , IL – 10 , TNF – α ) were determined after Dex administration , before CPB and 24 hours after admission to ICU. Biochemical factors including glucose , creatinine , lactate , BUN, AST , ALT , LDH were determined before CPB, immediately after entering the ICU , 24 hr , 48 hr and 72 hr post admission to ICU. Hemodynamic variables were also determined. Dex group was associated with a significant reduction in urea and creatinine. There were no significant differences in glucose, lactate, liver enzymes, LDH , IL – 6, IL – 10 and hemodynamic variables. In contrast, the surgery – induced increase in TNF – α levels in the Dex group was significantly higher compared with the control group.