Postoperative Pain and Systemic Inflammatory Stress Response (SIRS) After Preoperative Analgesia With Clonidine or Levobupivacaine

Investigations showed that upregulation of prostaglandin E2 and interleukin-6 at central sites is an important component of surgery induced inflammatory response in patients. Postoperative period is associated with an increased production of cytokines, which augment pain sensitivity. With adequate perioperative pain control it is possible to control central and peripheral inflammatory response to surgery, and influence on patient outcomes. Use of analgetics before the pain stimulus (preventive analgesia) prevent development of neuroplastic changes in central nervous system, and reduces pain. Clonidine is an alpha2-adrenergic agonist with sedative, analgesic and hemodynamic properties. It inhibits transmission of nociceptive stimuli in the dorsal horn of the spinal cord, acting on the inhibitory descending pathways. According to recent experimental investigations clonidine lowers proinflammatory cytokine level, and prevents hypersensitization acting through adrenoreceptors alpha-2A.

Levobupivacaine is a long-acting local anesthetic, S-enantiomer of bupivacaine, with identical anesthetic potency. When administered intraperitoneally or by local infiltration of operation site, levobupivacaine produced analgesia and reduction of proinflammatory cytokines. Investigations of epidural and intrathecal levobupivacaine provide evidence for improved postoperative analgesia with reduced analgesic consumption. But, it remains unknown if that analgesia is sufficient enough to blockade inflammatory stress response during perioperative time.We want to investigate and compare analgesic and immunomodulation efficacy of this two frequently used analgesics.