Evidence-based management of postoperative pain in adults undergoing open inguinal hernia surgery

Background: Open inguinal hernia repair is associated with moderate postoperative pain, but optimal analgesia remains controversial. The aim of this systematic review was to evaluate the available literature on the management of pain after open hernia surgery. Methods: Randomized studies, in English, published between January 1966 and March 2009, assessing analgesic and anaesthetic interventions in adult open hernia surgery, and reporting pain scores, were retrieved from the Embase and MEDLINE databases. In addition to published evidence, clinical practice was taken into account to ensure that the recommendations had clinical validity. Results: Of the 334 randomized studies identified, 79 were included. Quantitative analysis suggested that regional anaesthesia was superior to general anaesthesia for reducing postoperative pain. Spinal anaesthesia was associated with a higher incidence of urinary retention and increased time to home-readiness compared with regional anaesthesia. Conclusion: Field block with, or without wound infiltration, either as a sole anaesthetic/analgesic technique or as an adjunct to general anaesthesia, is recommended to reduce postoperative pain. Continuous local anaesthetic infusion of a surgical wound provides a longer duration of analgesia. Conventional non-steroidal anti-inflammatory drugs or cyclo-oxygenase 2-selective inhibitors in combination with paracetamol, administered in time to provide sufficient analgesia in the early recovery phase, are optimal. In addition, weak opioids are recommended for moderate pain, and strong opioids for severe pain, on request.