A systematic review of therapeutic interventions to reduce acute and chronic post-surgical pain after amputation, thoracotomy or mastectomy*

BACKGROUND Perioperative neuropathic pain is under-recognized and often undertreated. Chronic pain may develop after any routine surgery, but it can have a far greater incidence after amputation, thoracotomy or mastectomy. The peak noxious barrage due to the neural trauma associated with these operations may be reduced in the perioperative period with the potential to reduce the risk of chronic pain. DATABASES AND DATA TREATMENT A systematic review of the evidence for perioperative interventions reducing acute and chronic pain associated with amputation, mastectomy or thoracotomy. RESULTS Thirty-two randomized controlled trials met the inclusion criteria. Gabapentinoids reduced pain after mastectomy, but a single dose was ineffective for thoracotomy patients who had an epidural. Gabapentinoids were ineffective for vascular amputees with pre-existing chronic pain. Venlafaxine was associated with less chronic pain after mastectomy. Intravenous and topical lidocaine and perioperative EMLA (eutectic mixture of local anaesthetic) cream reduced the incidence of chronic pain after mastectomy, whereas local anaesthetic infiltration appeared ineffective. The majority of the trials investigating regional analgesia found it to be beneficial for chronic symptoms. Ketamine and intercostal cryoanalgesia offered no reduction in chronic pain. Total intravenous anaesthesia (TIVA) reduced the incidence of post-thoracotomy pain in one study, whereas high-dose remifentanil exacerbated chronic pain in another. CONCLUSIONS Appropriate dose regimes of gabapentinoids, antidepressants, local anaesthetics and regional anaesthesia may potentially reduce the severity of both acute and chronic pain for patients. Ketamine was not effective at reducing chronic pain. Intercostal cryoanalgesia was not effective and has the potential to increase the risk of chronic pain. TIVA may be beneficial but the effects of opioids are unclear.