Investigation of Effects of Epidural Anaesthesia Combined with General Anaesthesia on the Stress Response in Patients Undergoing Hip and Knee Arthroplasty.

OBJECTIVE To investigate the effects of general anaesthesia and general+epidural anaesthesia on the stress response which was evaluated with the adrenocorticotrophic hormone (ACTH), cortisol, insulin, and glucose levels and the haemodynamic parameters. METHODS Forty two, American Society of Anesthesiologists physiologic status I-II, patients undergoing hip and knee arthroplasty were randomized into two groups; general anaesthesia (Group G) and general anaesthesia+epidural anaesthesia (Group E). Epidural anaesthesia: patients in Group E received epidural anaesthesia with 0.5% bupivacaine, a lumbar epidural catheter was placed and after achieving sensorial block at T10 dermatome, general anaesthesia was commenced. General anaesthesia was standardized in both groups. Further, plasma ACTH, cortisol, insulin and glucose levels were determined at preoperative=t1, after the surgical incision=t2, postoperative 2(nd) hour=t3 and postoperative 24(th) hour=t4. Perioperative heart rate, blood pressures, pain scores and morphine consumption were also determined. RESULTS ACTH levels were higher in Group G than Group E [Group G, t2: 71.4±39.9 pg mL(-1), t3: 578.6±566.1 pg mL(-1), Group E, t2: 20.2±16.2 pg mL(-1), t3: 56.3±73.6 pg mL(-1) (p<0.001)]. Cortisol, was higher in Group G compared with Group E [Group G, t3: 33.4±13.1 μg dL(-1), t4: 34.1±22.5 μg dL(-1), Group E, t3: 19.1±10.3 μg dL(-1), t4: 21.3±8.1 μg dL(-1) (p=0.001 and p=0.002)]. The insulin levels were higher compared with the baseline values at t3, and glucose was higher at t3 and t4 in both groups. Haemodynamic parameters were stable in Group E, and pain scores and morphine consumption were higher in Group G than in Group E. CONCLUSION Our results suggest that epidural anaesthesia combined with general anaesthesia suppressed the stress response, which was evaluated with ACTH, cortisol levels and haemodynamic parameters; however, this method was ineffective to attenuate the increase in glucose and insulin levels.