Risk factors for chronic postoperative pain after elective nephrectomy

Objective: The aim of our study is to assess pain at the first hour, 3rd month, and 1st year postoperatively in patients undergoing nephrectomy, and to identify factors risk affecting acute and chronic pain. Materials and Methods: In our study, the data of 204 patients with age of 18- 90 years and ASA I-IV who underwent elective nephrectomy between January 2020 and December 2023 were reviewed. Data from the first hour were recorded, and patients were contacted by phone for data at the 3rd month and 1st year. Patients were divided into two groups at postoperative 1st hour, 3rd month, and 1st year: those with NRS<4 (pain-free) and those with NRS≥4 (painful). Pain at the first hour was defined as "Acute postoperative pain," while pain at the 3rd month and 1st year was defined as "Post-surgical chronic pain (PSCP)." Various patient, surgical, and anesthetic factors affecting pain were analyzed. Results: Postoperative pain was observed in 42.6% of patients at the 1st hour, 33.3% at the 3rd month, and 27.9% at the 1st year. A positive correlation was found between pain at the 1st hour and pain at the 3rd month and 1st year. Pain at the first hour was associated with higher ASA classification, comorbidities, diabetes mellitus (DM), preoperative analgesic use, postoperative opioid use, epidural analgesia, and the administration of epidural drugs or blocks. Pain at the 3rd month was associated with female gender, high body mass index (BMI), comorbidities, hypertension (HT), a history of chronic pain, preoperative analgesic use, and postoperative opioid use. Pain at the 1st year was associated with female gender, higher ASA classification, high BMI, comorbidities, HT, a history of chronic pain, preoperative analgesic use, postoperative opioid use, surgery duration, and open surgery. Conclusion: Acute pain was found to be positively correlated with chronic pain. The presence of comorbidities, preoperative analgesic use, and postoperative opioid use were identified as risk factors for both acute and chronic pain. Keywords: Post-surgical chronic pain, nephrectomy, acute pain, postoperative pain risk factors, chronic pain