Erector Spinae Plane Block Versus Local Wound Infiltration After Modified Radical Mastectomy

patients will be placed in the lateral decubitus position. The ESP block is usually performed at the level of fourth transvers process. The ultrasound probe should be placed in a cephalo-caudal orientation over the midline of the back at the desired level.Under aseptic conditions, the block needle will be inserted in plane at an angle of 30-40° in cranial-to-caudal direction until the tip contacted the T4 transverse process at erector spinae plane. After hydro-dissection with 2-3 mL of isotonic saline solution to confirm the correct needle tip position and after negative aspiration to prevent intra vascular injection or position, (20 ml) of plain bupivacaine 0.25% will be injected deep to the erector spinae muscle.

after the surgeon complete the surgery and insert the surgical drains (pectoral and axillary drains) we will inject 20ml of plain bupivacaine 0.25% in each surgical drain, the drains will be clamped for 20 minutes then declamped.