Introduction: Dexmedetomidine is a drug used widely in recent years to reduce complications during and after surgery, but there is a disagreement about the optimal dose of this drug. The aim of present study was to compare the effects of infusion of two doses of 0.3 and 0.6 μg / kg dexmedetomidine during surgery on changes in hemodynamic parameters and pain in patients undergoing spinal surgery under general anesthesia.

Methods: In a clinical trial study, 81 patients, who were candidates for spinal surgery, were randomly assigned to three groups (27 patients in each group). The first group received 0.3 μg / kg dexmedetomidine and the second group received 0.6 μg / kg dexmedetomidine intravenously and the third group (control) received normal saline. Hemodynamic parameters during surgery and recovery and postoperative stage complications such as pain severity and the first time of receiving opioids were evaluated and compared in three groups.

Results: Patients who received 0.6 μg / kg dexmedetomidine had lower blood pressure, lower heart rate and lower oxygen saturation during surgery. Also, the severity of postoperative pain was lower in this group. However, the first time of receiving opioid, received drug, length of stay in recovery and extubation time were not significantly different among the three groups.

Conclusion: The use of 6 μg / kg dexmedetomidine intravenously is associated with reduced postoperative pain and appropriate hemodynamic stability during surgery. Therefore, it seems that this dose of drug to be effective in preventing acute postoperative pain.

Keywords: Postoperative pain, Hemodynamics, Dexmedetomidine