Comparative study of the effect of two different doses of remifentanil on bleeding control in lumbar fusion surgery: A randomized clinical trial

•Spinal fusion surgery completely prevents movement or friction between the two vertebrae.•Remifentanil, a selective drug agonist, suppresses and decreases the vasomotor system.•0.3 μg/kg/min remifentanil was associated with significantly lower systolic blood pressure.•Patients that received 0.1 μg/kg/min remifentanil had significantly higher duration of surgeries.