To compare mean duration of postoperative analgesia following the administration of bupivacaine with and without magnesium sulphate in erector spinae plane block in modified radical mastectomy patients.

There is a difference in mean duration of analgesia following the administration of bupivacaine with and without magnesium sulphate in erector spinae plane block in modified radical mastectomy patients.

Inclusion Criteria:

• Female patients having ASA 1 and Il being aged 2 5 - 60 years and undergoing one sided breast cancer surgery * Patients who sign written informed consent to participate in the study.

Exclusion Criteria:

• Patients having contraindications for regional blocks (c.g., infection a t the injection site, coagulopathy), allergy to the drugs used i n the study Patients who received radiotherapy, and patients need axillary dissection • Patients with known hypersensitivity to local anesthetic drug (Bupivacaine). Patients with coagulation disorders or receiving anti-coagulant therapy (INR>2.0).