IRCT20180303038923N1 IRCT 2022-07-05 Tehran University of Medical Sciences Comparison of Remifentanil use in spinal surgery with and without ANI monitoring guidance Comparison of Remifentanil use in spinal surgery with and without ANI(analgesia nociception Index) monitoring guidance 2018-05-21 anticipated 60 Complete https://irct.ir/trial/60528 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: The eligible patients were randomly assigned to the treatment and control groups using balanced block randomization with a block size of four. For this purpose, the treatment and control groups were randomly assigned to letters A and B. Thus, for each block of four patients, two sequence different assignments were made for each treatment. Six sheets of paper were used. In the papers were written all the possible states, i.e. Paper No. 1 for AABB, Paper No. 2 for ABAB, Paper No. 3 for ABBA, Paper No. 4 for BBAA, Paper No. 5 for BABA, and Paper No. 6 or BAAB. Then the number were selected randomly via table of random numbers. According to number of selected papers, the patients respectively were in the treatment or control groups. 3 Remifentanil use in surgery with Analgesia Nociception Index. Intervention 1: Control group: Patients who are candidates for spinal surgery who undergo general anesthesia without ANI monitoring. Intervention 2: Intervention group: Patients who are candidates for spinal surgery who undergo general anesthesia under the guidance of ANI monitoring. 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 There is no more information.