Contrast and Anesthetic Level With Lumbar Erector Spinae Plan (ESP) Block

The block solution will consist of 1% ropivacaine 3 mg/Kg ideal body weight (IBW) mixed with dexmedetomidine 0.5 mcg/Kg IBW and diluted with 10 mL iohexol 300 mg/mL and normal saline for a total volume of 40 mL. All medications used are standard of care

The block solution will consist of 1% ropivacaine 3 mg/Kg ideal body weight (IBW) mixed with dexmedetomidine 0.5 mcg/Kg IBW and diluted with 10 mL iohexol 300 mg/mL and normal saline for a total volume of 40 mL. All medications used are standard of care

The block solution will consist of 1% ropivacaine 3 mg/Kg ideal body weight (IBW) mixed with dexmedetomidine 0.5 mcg/Kg IBW and diluted with 10 mL iohexol 300 mg/mL and normal saline for a total volume of 40 mL. All medications used are standard of care except for iohexol which is used for study purposes.

The QST procedure (test of buzzing sensation and temperature sensation through pads applied to your skin) to assess the numb areas.