The aim of this study was to compare the hemodynamic changes in patients undergoing lumbar discopathy surgery between two continuous infusions of Dexmedetomidine and remifentanil during anesthesia with controlled low blood pressure, which was designed as a randomized, triple-blind clinical trial. In this study, the patient, clinician and the person responsible for the statistical analysis will be blind regarding the study groups. Inclusion criteria are patients undergoing lumbar discopathy surgery in physical conditions I and II, and exclusion criteria including any kind of bleeding or coagulation disorders, history of uncontrolled or severe hypertension, use of anticoagulant drugs, history of lumbar discopathy surgery and history of trauma to the lumbar spine. A total of 60 patients aged 20-65 years will be randomly assigned to control and intervention groups. computerized random numbers will be used for randomization. The study method is that for the general anesthesia, the same drug regimen will be used for both groups, and in the intervention group, the dose of Dexmedetomidine is 0.7-0.3 micrograms per kilogram body weight per hour plus propofol of 150-50 micrograms per kilogram of body weight per minute will be continuously injected. In the control group, 1-0.1 μg of Remifentanil per kg body weight per minute plus the same amount of propofol is injected with the same quality. The primary variables of this study are changes in the patient's blood pressure, the amount of patient's bleeding during surgery, and the amount of urinary output. Secondary variables are the time interval between extubation and complete consciousness, the duration of the surgery, and the time that there is a need to administer analgesic drugs after surgery.