• Comparing the analgesic effects of Anterior subcostal versus Posterior approach in ultrasound guided Quadratus Lumborum Block by using the Numeric Rating Scale. [ Time Frame: baseline ]
  : to compare the efficacy of Anterior subcostal versus Posterior approach in ultrasound guided Quadratus Lumborum Block by The Numeric rating scale (NRS) both resting and ambulatory which measures pain as felt by the patient every two hours for the first 24 hours then every six hours for the second day. the Numeric rating scale is a scale from 0 to 10 with '0' being lowest pain or no pain and '10' is the worst pain felt.
• Comparing the analgesic effects of Anterior subcostal versus Posterior approach in ultrasound guided Quadratus Lumborum Block by using the Revised American Pain Society Patient Outcome Questionnaire. [ Time Frame: baseline ]
  to compare the efficacy of Anterior subcostal versus Posterior approach in ultrasound guided Quadratus Lumborum Block by the Revised American Pain Society Patient Outcome Questionnaire which is a set of questions answered by the patient to evaluate the patient's satisfaction and for quality improvement of pain management in hospitalized patients

• Primary outcome: to compare the efficacy of Anterior subcostal versus Posterior approach in ultrasound guided Quadratus Lumborum Block.
• Secondary outcome: to evaluate the efficacy of Quadratus Lumborum Block in the control of postoperative pain in patients undergoing Nephrectomy surgery, hemodynamics, any complications and patients' satisfaction..

A variant of the ultrasound-guided transversus abdominis plane (TAP) block was first described in an abstract, in which local anesthetic injection occurs at the point where the internal oblique and transversus abdominis muscles taper off and adjoin the lateral border of quadratus lumborum (QL) muscle.

Currently, the QL block is performed as one of the perioperative pain management procedures for all generations (pediatrics, pregnant, and adult) undergoing abdominal surgery.

However, there is large disagreement regarding the best approach for administering the block because of unclear mechanisms responsible for the effects and complicated nomenclature system. Nephrectomy for patients with renal cell carcinoma (RCC) was first described in 1969. Surgical treatment varies with the pathology. Simple nephrectomy is the preferred option for those with non-neoplastic disease (e.g. trauma, non-functioning kidney with chronic infection) with radical nephrectomy being preferred in those with neoplastic disease. Radical nephrectomy implies resection of the whole of Gerota's fascia, including the perinephric fat, lymphatics, and the ipsilateral adrenal gland. Here the investigators are going to compare the Anterior (subcostal) approach to the Posterior approach to determine their level of spread and their value in controlling postoperative pain in patients scheduled for Nephrectomy surgery.

• Active Comparator: Quadratus Lumborum Block anterior subcostal (QLa)
  Patients in this group will receive Anterior subcostal Quadratus Lumborum block postoperative with 30 ml of 0.125 bupivacaine.
  Intervention: Procedure: Quadratus Lumborum block
• Active Comparator: Quadratus Lumborum Block posterior (QLp)
  Patients in this group will receive Posterior Quadratus Lumborum block postoperative with 30 ml of 0.125 bupivacaine.
  Intervention: Procedure: Quadratus Lumborum block
• Placebo Comparator: Quadratus Lumborum Block anterior subcostal control (QLca)
  Patients in this group will receive Anterior subcostal Quadratus Lumborum block postoperative with 30 ml of 0.9% normal saline.
  Intervention: Procedure: Quadratus Lumborum block
• Placebo Comparator: Quadratus Lumborum Block posterior control (QLcp)
  Patients in this group will receive Anterior subcostal Quadratus Lumborum block postoperative with 30 ml of 0.9% normal saline.
  Intervention: Procedure: Quadratus Lumborum block

Inclusion Criteria:

• Both sex
• Age: 18-60 years.
• ASA I and II
• Elective surgery

Exclusion Criteria:

• Patient's refusal.
• Allergy to local anesthetics.
• Peripheral neuropathy.
• Bleeding diathesis.
• Inflammation or infection over injection site.
• Morbid obesity.
• Patients on previous opioid therapy.
• Psychiatric disorders.
• Emergency surgery