Lumbar epidural analgesia and sciatic and femoral peripheral nerve blocks attenuate the stress-induced response in patients during the early postoperative period following total knee replacement

Invasive surgical procedures cause immune system downregulation by inducing a profound proinflammatory response. Establishing the most effective type of postoperative analgesia is crucial to maintain the equilibrium of the immune system. The purpose of this research was to evaluate the influence of epidural analgesia, peripheral nerve blockade as well as systemic analgesia on stress response in patients during the early postoperative period following total knee replacement. In total, 60 patients undergoing total knee replacement were allocated into three groups (n = 20, per group) in this prospective randomized study. Group 1, Group 2 and Group 3 received epidural analgesia, sciatic and femoral peripheral nerve blocks and systemic analgesia, respectively. Intensity of pain was measured at rest and upon movement. Blood samples were collected at baseline (T0), immediately before (T1) and after (T2) surgery, and 24 (T3) and 72 (T4) h postoperatively. The absolute number of leukocytes, concentrations of catecholamine, cortisol and C-reactive protein were determined. Patients in Group 1 and Group 2 exhibited lower pain scores than Group 3. Concentrations of cortisol and norepinephrine, but not epinephrine, were significantly lower in Group 1 and Group 2 at T2 than in Group 3. Significantly lower interleukin-1 beta concentrations were observed in Group 1 and Group 2 at T3 and T4 than in Group 3. Interleukin-6 concentrations were minor in Group 1 and Group 2 at T2 than in Group 3. Lumbar epidural analgesia and sciatic and femoral peripheral nerve blocks are effective analgesic techniques that reduce the acute inflammatory stress response in patients during the early postoperative period following total knee replacement.