IRCT20190719044274N1 IRCT 2019-09-28 Tehran University of Medical Sciences Goal directed fluid therapy in spine surgery Effects of goal-directed fluid therapy using LiDCOrapid system in postoperative outcomes and comparison with standard fluid therapy for patients undergoing spine surgery 2019-10-11 anticipated 40 Complete https://irct.ir/trial/41072 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Crossover, Purpose: Supportive, Randomization description: Simple randomization After providing explanations about the goals of the research and obtaining informed consent, 40 patients undergoing Spine surgery will be selected with a simple random sampling method. Then they are divided into the case and control groups by simple randomization method, Blinding description: people who were responsible for making assessments on postoperative outcomes or gathering data on outcome variables were blinded Also the people who analysed the data collected during this trial were blinded. N/A Patients with spine surgery due to Spinal canal stenosis, spondylopathies and etc with past medical history of Hypertension or Diabetes mellitus, Ischemic heart disease, Chronic obstructive pulmonary disease. Intervention 1: Intervention group: Fluid therapy based on Hemodynamic Monitoring such as Stroke Volume Variation, Cardiac Output, Systemic Vascular Resistance and etc given by LidcoRapid Hemodynamic monitoring. Serum type will be crystalloid (lactated ringer). Intervention 2: Control group: In Control group fluid therapy would be based on standard protocols which is 4 cc/kg/h. If bleeding reaches to the maximum allowable blood loss blood transfusion will be started. Serum type will be crystalloid (lactated ringer). No - There is not a plan to make this available Justification or reason for not sharing IPD is After completion of the study, if necessary, the encoded data will be published along with the article.