Adding regional analgesia to general anaesthesia: increase of risk or improved outcome?

Although it is clear that regional analgesia in association with general anaesthesia substantially reduces postoperative pain, the benefits in terms of overall perioperative outcome are less evident. The aim of this nonsystematic review was to evaluate the effect on middle and long-term postoperative outcomes of adding regional perioperative analgesia to general anaesthesia. This study is based mostly on systematic reviews, large epidemiological studies and large or high-quality randomized controlled trials that were selected and evaluated by the author. The endpoints that are discussed are perioperative morbidity, cancer recurrence, chronic postoperative pain, postoperative rehabilitation and risk of neurologic damage. Epidural analgesia may have a favourable but very small effect on perioperative morbidity. The influence of other regional anaesthetic techniques on perioperative morbidity is unclear. Preliminary data suggest that regional analgesia might reduce the incidence of cancer recurrence. However, adequately powered randomized controlled trials are lacking. The sparse literature available suggests that regional analgesia may prevent the development of chronic postoperative pain. Rehabilitation in the immediate postoperative period is possibly improved, but the advantages in the long term remain unclear. Permanent neurological damage is extremely rare. In conclusion, while the risk of permanent neurologic damage remains extremely low, evidence suggests that regional analgesia may improve relevant outcomes in the long term. The effect size is mostly small or the number-needed-to-treat is high. However, considering the importance of the outcomes of interest, even minor improvement probably has substantial clinical relevance.