Background: Phantom limb pain is a frequent complication after limb amputation, its pathophysiology is complex and includes changes in the peripheral nerve, dorsal root ganglia, spinal cord, cerebral cortex, and thalamus. At this time, there is not an effective drug for treatment and prevention of phantom limb pain. Perineural local anesthetic infiltration has obtained different results in the prevention of phantom limb pain, so we propose to combine an α2 agonist in peripheral nerve block to assess its effectiveness in preventing postoperative pain.
Background: Phantom limb pain is a frequent complication after limb amputation, its pathophysiology is complex and includes changes in the peripheral nerve, dorsal root ganglia, spinal cord, cerebral cortex, and thalamus. At this time, there is not an effective drug for treatment and prevention of phantom limb pain. Perineural local anesthetic infiltration has obtained different results in the prevention of phantom limb pain, so we propose to combine an α2 agonist in peripheral nerve block to assess its effectiveness in preventing postoperative pain. Methods: This was a prospective, double-blind, controlled, and simple randomized study. We included 30 patients undergoing surgery for supracondylar femoral amputation, older than 18 years, ASA I-III, in a sample calculation of 95% in Confidence Interval and 80% of statistical power. We included 15 patients per group managed with subarachnoid neuraxial block, and a perineural infiltration before the sciatical nerve section with 10 ml of 0.5% ropivacaine + 50 mcg dexmedetomidine (RD Group), or 0.5% ropivacaine + 0.9% saline solution (Group RS), in both groups We continued a perineural infusion with 0.15% ropivacaine using an elastomeric pump for 24 hours; We evaluated stump pain and phantom limb pain, upon admission to recovery, 8 hrs, 24 hrs, 30 days and 3 months. The data analysis was carried out using the SPSS version 21 program; In all cases, we defined statistical significance when obtaining p