IRCT20220111053694N1 IRCT 2022-08-07 Mashhad University of Medical Sciences The effect of adding a very low dose of naloxone to remifentanil infusion on pain Addition of a very low dose of naloxone to remifentanil infusion on postoperative pain in patients undergoing total hip replacement surgery 2021-02-19 anticipated 80 Complete https://irct.ir/trial/61362 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: In this randomized clinical trial study, patients are randomly divided into groups with a ratio of 1:1 in two equal parts and using block randomization and sealed envelopes. allocation Concealment is done with a sealed envelope. The envelope method is that the envelopes will be prepared and printed by a member of the research team and random numbers with the help of Randomaize.com and placed inside the envelope. The lid of the envelopes will be closed and its contents will not be visible from the outside, Blinding description: In this study, patients and outcome assessors were unaware of the intervention and control groups. 2-3 Patients undergoing complete hip replacement surgery. Intervention 1: Intervention group: In the intervention group, naloxone (Caspian tamin pharmaceutical co) with a very low dose (0.05 μg/kg/h) was added to remifentanil (Exir pharmaceutical co) infusion (with a dose of 0.3 μg/kg/min) as IV and through a continuous injection pump until the end of the operation in Patients undergoing total hip replacement surgery. The treatment method is based on the effect of narcotics on peripheral and central µu receptors and the effect of naloxone agonists and antagonists on these receptors. Intervention 2: Control group: Only remifentanil (Exir pharmaceutical co) infusion at a dose of 0.3 μg/kg/min as IV and through a continuous injection pump until the end of the operation was prescribed for patients undergoing total hip replacement surgery. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is Respecting the privacy of the participants in the study and ethical principles according to the Declaration of Helsinki