Chronic post-surgical pain: Epidemiology and clinical implications for acute pain management

Chronic post-surgical pain (CPSP) is an under-recognised and prevalent healthcare problem associated with significant morbidity and potential economic costs. Risk factors include the type of surgery, pre-existing pain, re-operation, nerve damage, moderate-to-severe acute post-operative pain, neurotoxic radio or chemotherapy and psycho-social factors.CPSP has a multifactorial aetiology, principally nerve injury and wound inflammatory response, leading to peripheral and central sensitisation. The extent of wound hyperalgesia following abdominal surgery correlates with the incidence of CPSP but not with acute pain outcomes, reflecting the relative importance of central sensitisation in the development of CPSP. The contributions of genetics, gender, age, opioid-induced hyperalgesia, pre-existing pain disorders and psycho-social factors to the pathogenesis of CPSP have yet to be clarified.The prevention of CPSP includes limiting nerve and tissue injury at the time of surgery and in some cases using preventive analgesia techniques such as regional neural blockade or low-dose ketamine infusion. Other strategies such as education, patient surveillance, management of psycho-social factors and functional rehabilitation may also be beneficial, although there are no data to support this. Further research is required to develop ‘predictive tools’ and to examine the effects of multimodal “protective” analgesia and multidisciplinary approaches in the prevention and treatment of CPSP.