IRCT20200825048515N66 IRCT 2023-04-24 Esfahan University of Medical Sciences The effect of bupivacaine on pain reduction after hysterectomy surgery. The effect of bupivacaine (Marcaine) intraperitoneal instillation on pain reduction after open hysterectomy surgery. 2023-05-21 anticipated 110 Complete https://irct.ir/trial/69515 interventional Randomization: Randomized, Blinding: Triple blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: Before starting the study, letter A is written on 55 sheets, letter B is written on 55 sheets, and each is placed in an envelope. Then, each eligible patient who consented to participate in the study is asked to choose an envelope from among the envelopes. In this way, the patient will be randomly assigned to one of the two groups according to the envelope selected without the interference of the researcher, Blinding description: In order to comply with the condition of triple-blindness of the study, two drugs, bupivacaine and normal saline, will be prepared by the operating room nurse (without the knowledge of the researcher) in equal volumes (40 mg) in syringes covered with labels A, B and will be prepared and placed in the bag daily. And it is given to the researcher daily. Therefore, the researcher, the patient, the person recording the clinical and basic information of the patients, as well as the statistical analyst, will not be aware of the type of intervention. 3 Hysterectomy surgery. Intervention 1: Intervention group: After surgery, before closing the peritoneum, 40 ml of bupivacaine 0.25% is sprayed into the peritoneal cavity. Intervention 2: Control group: After surgery, before closing the peritoneum, 40 ml of normal saline will be sprayed into the peritoneal cavity. No - There is not a plan to make this available Justification or reason for not sharing IPD is There is no further information