Regional anesthesia, your anesthesiologist injects medication near a cluster of nerves to numb only the area of your body that needs surgery. You may remain awake otherwise you could also be given a sedative. Spinal and epidural blocks involve interrupting sensation from the legs or abdomen by injecting local anaesthetic medication in or near the vertebral canal . Other blocks are often performed for surgery on your extremities, or limbs, blocking sensations from the arm or leg.