Chronic Pain, Postoperative

Acute appendicitis is one of the most common emergency general surgical conditions worldwide and represents the leading cause of emergency abdominal surgery in children. In some cases, appendectomy may result in persistent or recurrent pain in the right iliac fossa, which may negatively affect quality of life, particularly in children. The primary aim of this study is to determine the prevalence of chronic pain at the third postoperative month in pediatric patients who underwent appendectomy. The age, sex, body mass index, and comorbidities of patients aged 8-18 years who underwent appendectomy will be recorded. Pain in children who met the inclusion criteria was assessed using the Numeric Rating Scale (NRS). To evaluate the effects of pain on quality of life, the child and parent versions of the Pediatric Quality of Life Inventory (PedsQL) were administered at the third postoperative month. In addition, the Functional Disability Inventory (FDI) was used at the third postoperative month to assess the impact of pain on the patient's functional status.

Chronic post-sternotomy pain (CPSP) is a common complication after cardiac surgery, with a reported prevalence between 30% and 50%. Several studies show that a significant proportion of patients experience persistent pain long after cardiac surgery, often with a neuropathic component. Internal mammary artery harvesting is known to cause intercostal nerve injury. Recent data suggest that early neuropathic pain, assessed using the DN4 score, may predict the chronicization of postoperative pain. This study is a prospective observationnal study to evaluate the association between early neuropathic pain (DN4-i ≥ 3/7 on postoperative day 5) and the occurrence of chronic post-sternotomy pain at 3 months in patients who underwent median sternotomy for coronary artery bypass grafting with internal mammary artery harvesting

The goal of this clinical trial is to learn if the administration of oxycodone for preventive analgesia works to reduce the chronification of acute postoperative pain in adult participants undergoing major abdominal surgery. The main question it aims to answer is: • Does administration of oxycodone before surgical incision reduce the occurrence of chronic pain or relieve the chronic pain symptoms 3 months after the operation? Researchers will compare oxycodone + parecoxib sodium to placebo + parecoxib sodium combinations to see if oxycodone works to reduce the chronification of acute postoperative pain. Participants will: * Take oxycodone + parecoxib sodium or placebo + parecoxib sodium combinations before the surgical incision * Cooperate with the follow-up staffs and complete some checkups or tests within 3 months after the operation.