Improving postoperative pain management: Continuous wound infusion and postoperative pain

Despite various analgesic drugs and techniques, relieving acute postoperative pain remains a challenge. An actual state of the question indicates that there is imperative need for further improvements. After a surgical incision, nociceptive inputs originating from the wound play a major role in both the initiation and the maintenance of postoperative pain. Continuous infiltration of analgesics into the surgical wound is a rational approach, a simple and safe technique which has gained in popularity. Local intrawound analgesics are mainly local anesthetics which block the nociceptive transmission. Non-steroidal anti-inflammatory drugs which modulate the local inflammatory reaction sensitizing the peripheral nociceptors represent an interesting alternative. Moreover, both local anesthetics and anti-inflammatory drugs possess a variety of modes of action, beside those which are conventionally recognized, mechanisms which may participate to their local analgesic effect. However, clinical reports published to date have brought conflicting results regarding the efficacy of intrawound analgesic techniques. These studies have pointed out several important issues like the place of the catheter, choice and dose of the analgesic drug, potential local toxicity. These issues need to be solved to better determine the right place of the technique in postoperative multimodal analgesia.