Chronic Pain After Surgery

Chronic Pain After Surgery

Session took place on Saturday 2 June

This three-part session addressing pain, held during the Saturday sessions of Euroanaesthesia, was opened by Professor Valeria Martinez, Hôpital Raymond Poincaré, Garches, France, who presented on “perioperative hyperalgesia as a predictor of chronic pain after surgery”.

“Over the past ten years there has been recognition that chronic post-surgical pain (CPSP) is a significant medical problem,” said Professor Martinez. “Every year, surgery is performed on millions patients in the world, therefore the number of patients potentially exposed to CPSP is large and CPSP may represent a major, largely unrecognised clinical problem.”

A high prevalence of persistent pain after common surgical procedures has been reported in follow-up studies, as well as in the general population. In most cases, CPSP is neuropathic and difficult to treat once it is established. These findings highlight the importance of identifying potential risk factors and prevention measures. Several important risk factors involved in chronic pain development after tissue injury have been identified, underlining how much the phenomenon is complex and multifaceted.

Professor Martinez said: “Hyperalgesia is a symptom defined by an increase pain sensitivity. Preoperative and postoperative hyperalgesia have been more and more reported as a common sign of several predictive factors of pain becoming chronic. Central sensitisation is a key mechanism in the development and maintenance of hyperalgesia. Anesthesiologists are involved in all of the stages of the operative care of patients and play a decisive role in the evaluation of the risk, the development of a preventive strategy, and in the detection of early warning.”

“Chronic pain after surgery: neuropathic or nociceptive how to diagnose and treat” was then presented by Dr Massimo Allegri, University of Parma, Italy. “Chronic pain after surgery is a complex and multidimensional issue,” he said. “It has to be carefully evaluated in order to prevent and treat successfully. In fact, as for chronic pain in general, it is mandatory to establish a mechanism-based treatment for chronic pain after surgery to face all different mechanisms that can sustain it.”

He explained that first, it is necessary to exclude that a surgical problem is still present. Then, it must be investigated if the pain has a nociceptive or neuropathic component. The Pain Detect Questionnaire and DN4 are the two most used and easiest questionnaires proposed in the literature. If a neuropathic component is found, the type of fibre involved must be defined.

Finally, once the type of pain is defined, the treatment must be chosen. For nociceptive pain, NSAIDs and steroids are the best drugs if there is an inflammatory response that has to be controlled and solved. Alternatively, opioids could be useful. In peripheral neuropathic pain, anticonvulsants and antidepressants are the drugs of choice to treat this problem but it is important to define which nerve fibre is involved.

For central sensitisation, this mechanism is often present in chronic postoperative pain. It is important to define if it is still a reversible or definitive process. In this case, peripheral nerve blocks could be helpful in defining it and in helping to treat this pain mechanism.

Dr Allegri concluded: “Chronic neuropathic pain needs a careful evaluation in order to treat specifically all the underlining mechanisms that sustain it.”

The final talk in this session, on interventional techniques for chronic postsurgical pain, was delivered by Professor Jan van Zundert, Ziekenhuis Oost‐Limburg, Genk, Belgium.