Perineural Methylene Blue Infusion in Lower Limb Amputation Surgery

"Patients in this group will receive the following regimen through the perineural catheter:~Bolus dose of 1 ml methylene blue 1% (10 mg) plus 19 ml bupivacaine 0.25% will be given intraoperatively before wound closure, and perineural infusion of methylene blue plus bupivacaine 0.25% (1 ml of methylene blue added to each 49 ml of bupivacaine 0.25%) will be started in the recovery room at a rate of 2-5 ml/hour for 72 hours postoperatively"

"Patients in this group will receive the following regimen through the perineural catheter:~Bolus dose of 1 ml normal saline plus 19 ml bupivacaine 0.25% will be given intraoperatively before wound closure, and perineural infusion of bupivacaine 0.25% will be started in the recovery room at a rate of 2-5 ml/hour for 72 hours postoperatively"