Effect of Transversus Abdominis Plane (TAP) Block Using Magnesium Sulfate Added to Dexamethasone on Quality of Recovery and Chronic Post Operative Pain Following Open Abdominal Cancer Surgery.

Patients will receive bilateral ultrasound-guided TAP block using:20ml of 0.5% Bupivacaine 100mg mixed with 8mg dexamethasone (2ml) and diluted to 40ml with normal saline (18ml),20ml per side.

Drug: Bupivacaine · Drug: Dexamethasone

Patients will receive bilateral ultrasound-guided TAP block using:20ml of 0.5% Bupivacaine 100mg mixed with 8mg dexamethasone (2ml),250mg magnesium sulfate (2.5ml) and diluted to 40ml with normal saline (15.5ml),20ml per side

Drug: Bupivacaine · Drug: Dexamethasone · Drug: Magnesium sulfate

Patients will receive bilateral ultrasound-guided TAP block using:20ml of 0.5% Bupivacaine 100mg total volume 40ml ,20ml volume per side in both groups.

Dexamethasone 8 mg will be administered as an adjunct to TAP block in both groups

Magnesium sulfate 250 mg will be administered as an adjunct to TAP block in DM group only

Plazo: 24 hours postoperatively

The Quality of Recovery-15 questionnaire will be used to assess the quality of postoperative recovery 24 hours after surgery, evaluating five dimensions: physical comfort, emotional state, psychological support, physical independence, and pain, resulting in a total score ranging from 0 to 150 (higher scores indicate better recovery).

Plazo: Through 6 months postoperatively

Assessing the presence or absence of chronic postoperative pain and its intensity using the Visual Analogue Scale (VAS)ranging from 0 (no pain) to 10 (worst imaginable pain)minimum value of 0, maximum value of 10, where higher scores mean a worse outcome.

Plazo: At arrival to Post- Anesthesia Care Unit (PACU) (0 hour), 2, 4, 6, 12, and 24 hours postoperatively.]

Evaluating postoperative pain intensity using the Visual Analogue Scale (VAS) ranging from 0 (no pain) to 10 (worst imaginable pain).

Plazo: Within the first 24 hours postoperatively

Recording the duration from the end of surgery until the patient first requests rescue analgesia (when Visual Analogue Scale (VAS)is 4 or more).

Plazo: At 24 hours postoperatively

Evaluating patient satisfaction with postoperative pain management using a 5-point Likert scale (ranging from very dissatisfied to very satisfied)(minimum value of 1, maximum value of 5, where higher scores mean a better outcome).

Plazo: Intraoperatively and throughout the 24-hour postoperative period

Evaluating the overall incidence of any block-related complications or adverse events (including block failure, local anesthetic systemic toxicity, hematoma, infection, pneumothorax, nerve injury, or magnesium-related side effects), reported as the percentage of affected patients out of the total study population

Plazo: Intraoperatively (during the surgical procedure)

Measuring the total intraoperative consumption of fentanyl.

Plazo: During the first 24 hours postoperatively

Recording the incidence of postoperative nausea episodes

Plazo: During the first 24 hours postoperatively

Recording the incidence of postoperative vomiting episodes.

Plazo: During the first 24 hours postoperatively

Measuring the total morphine consumption required by the patient as rescue analgesia.

Plazo: At baseline, after block, every 15 minutes intraoperatively, and at the end of surgery (extubation period)

Assessing heart rate values.

Plazo: At baseline, after block, every 15 minutes intraoperatively, and at the end of surgery (extubation period).

Assessing Mean Arterial Pressure (MAP) values

Plazo: At baseline, after block, every 15 minutes intraoperatively, and at the end of surgery (extubation period)

Assessing peripheral oxygen saturation levels.

Effect of Magnesium Sulfate Added to Dexamethasone-Augmented Ultrasound-Guided Transversus Abdominis Plane (TAP) Block on Early Quality of Recovery and Chronic Post Operative Pain Following Open Abdominal Cancer Surgery: A Prospective Randomized Double-Blind Controlled Trial