Prevalence of Chronic Pain After an Emergency Department Visit for Severe Acute Pain

The presence of pain is the most frequent reason for a patient to visit the emergency department. the investigators know that severe acute pain can be a risk factor for developing chronic pain. Chronic pain is a symptom, devoid of biological utility, that persists despite the absence of nociceptive stimulus, even after a reasonable period of time that would have allowed the tissue lesion to heal. It is therefore a public health problem with a negative impact on patients' lives. Chronic pain has been studied in anesthesia and surgery in recent years. In 2006, a study showed the appearance of chronic pain (incidence between 10-50%) in patients who had undergone routine surgery. On the other hand, few studies have looked at the occurrence of chronic pain in patients who came to the emergency department for acute pain. It is in this context that the investigators find it relevant to assess the prevalence of moderate to severe chronic pain after an emergency department consultation for severe acute pain. The physiological mechanisms of pain are better identified and the activation of N-methyl-D-aspartate (NMDA) receptors contributes to the onset of hyperalgesia. These receptors are activated under certain conditions, such as during intense and prolonged pain or exposure to high doses of opioids. In addition, the hyperalgesic effect of opioids is known and widely described in the literature. Finally, in the perioperative period, it is now accepted that the administration of a low dose of ketamine can combat these hyperalgesic effects thanks to its NMDA receptor inhibitory action. This effect may have an impact on pain at six months after surgery. On the basis of these data, it seems relevant to question the prevalence of chronic pain in the course of an emergency department consultation, all the more so in patients with severe initial pain, in whom there is an initial indication for morphine titration, based on the recommendations of the French Society of Emergency Medicine (SFMU). In addition, the investigators need to question the effects of initial analgesia administered in the emergency department for patients with severe acute pain. Is there a link between the use of certain molecules or the combination of molecules on the onset of chronic pain?