Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 11 1 2025 01 01 84 88 Seyed Babak Mojaveraghili Department of Anesthesiology, 5 Azar Hospital, Golestan University of Medical Sciences, Gorgan, Iran. Sina Hassannasab Department of Anesthesiology and Pain Medicine, Imam Hossain Hospital,, Shahid Beheshti Medical University, Tehran, Iran. Mansour Deylami Department of Anesthesiology, 5 Azar Hospital, Golestan University of Medical Sciences, Gorgan, Iran. Tahereh Chavoshi Department of Anesthesiology, Ali Asghar Hospital, Iran University of Medical Sciences, Tehran, Iran. Avasadat Mirkatouli Department of Anesthesiology, 5 Azar Hospital, Golestan University of Medical Sciences, Gorgan, Iran. Nasser Behnampour Department of Biostatistics and Epidemiology, Health Management and Social Development Research Center, Faculty of Health, Golestan University of Medical Sciences, Golestan, Iran. 2024 06 22 2024 07 01 Background: The use of regional anesthesia for lower limb orthopedic surgery is preferable to general anesthesia. In some studies comparing regional anesthesia and general anesthesia, the one-month mortality of patients undergoing regional surgery was significantly lower. Given the relative advantages observed about intrathecal injection of pethidine, including fewer side effects, and longer postoperative analgesia, in combination with effective sensory, motor, and sympathetic blocks, we sought to compare the influence of intrathecal injection of pethidine and bupivacaine on the hemodynamics of patients. Methods: In this double blind randomized parallel trial, patients undergoing surgery with femoral and hip fractures, were divided into two groups. In the first group bupivacaine and in the second group pethidine were used for spinal anesthesia. Hemodynamic changes were examined and recorded during surgery. The results were analyzed by SPSS18 software Results: 67 patients undergoing surgery with femoral and hip fractures, were divided into two groups of 30 and 37 individuals. The mean heart rate in patients with a high risk of surgery was higher in the group receiving pethidine compared to the group of bupivacaine, with a Cohen's effect size of 0.294. This effect size is evaluated as average, while the rate of mean arterial pressure with Cohen's effect size of 0.511 was evaluated as large. Conclusion: Pethidine can be a good alternative to bupivacaine, especially in patients at high risk of surgery, given its hemodynamic stability. https://aacc.tums.ac.ir/index.php/aacc/article/view/1027