Perioperative pain

Abstract

Incisional pain remains underevaluated and undermanaged while evidence is growing that perioperative treatments strongly influence patients' outcome. The present review examines the recent developments in mechanisms underlying perioperative pain and questions current understanding of incisional pain features observed in patients. Experimental models of incisional pain have highlighted specific mechanisms underlying perioperative pain plasticity, i.e. sensitization of sensory processing, clinically expressed by the development of hyperalgesia. In patients, however, the long-term impact of sensory system sensitization, e.g. development of residual pain, as well as the effects of perioperative pain management on sensitization, are still poorly understood, partly because most of the trials assess only the subjective experience of pain (by evaluation of either pain intensity or analgesic needs) instead of directly measuring objective changes (i.e. hyperalgesia) with quantitative sensory testing. Experimental studies and recent clinical trials using objective measures of sensory processing sensitization induced by surgical incision have shown the importance of hyperalgesia in perioperative pain. Effective perioperative block of nociceptive inputs from the wound as well as use of antihyperalgesic and analgesic drugs in combination seem the best way to control postoperative pain and specifically to prevent central sensitization.