The aim of this study is to assess the efficacy of Mg sulfate ( 10% ) as an adjuvant to Bupivacain ( 0.25 % ) in an U.S guided QLB for postoperative analgesia and postoperative Morphine consumption in lower abdominal cancer surgeries.

It is vital to apply adequate postoperative analgesia following lower abdominal surgeries of cancer because Postoperative pain not only affects the patients' rest but also produces a series of pathological reactions. Postoperative analgesia, including regional anesthesia, is very important which not only provides effective postoperative analgesia but also reduces the need for postoperative opioids.In recent years, various ultrasound-guided regional anethetic techniques have been extensively used. One of them is Quadratus lumborum block which can provide postoperative analgesia of the segmental innervation from T6 to L1. In which the Local anesthetics can spread through the thoracolumbar fascia to the paravertebral space, thereby blocking part of the sympathetic nerves . Clinical studies have shown that compared with the current widely used transverse abdominal block, QLB provides longer analgesia and wider block levels when the same dose of local anesthetic is used unlike traditional trunk block, QLB cannot use the sense of falling during puncture and can only be performed under ultrasound guidance, which has the advantages of being real-time and dynamic. Ultrasound-guided nerve block provides more accurate positioning and benefits for patients with less injury. Magnesium sulfate plays an important role in the physiological function of the human body. A large number of studies have reported the safety and effectiveness of adding magnesium sulfate as an adjuvant in various regional anethetic techniques . Therefore, we designed a prospective randomized controlled trial to compare the analgesic efficacy of combining magnesium sulfate with bupivacaine in QLB.

Inclusion Criteria:

1. Age from 18 to 80 years old
2. Both gender
3. Weight from 55 to 85 kg
4. ASA groups 2 and 3
5. Lower abdominal cancer surgeries

Exclusion Criteria:

• 1. Patient refusal 2. True local anesthetic allergy 3. Coagulopathy 4. Local infection at the procedure site 5. Psychic patients 6. Patient on chronic opioid use