Comparison Between Ultrasound-guided Erector Spinae Block and Transverse Abdominis Plane Block in Obese Patients Undergoing Sleeve Gasterectomy.

Primary outcomes

• Cumulative opioid consumption during the first 24 h postoperatively. For the purpose of comparison, all opioids administered postoperatively will be converted to IV morphine equivalent doses using standard opioid dosage conversion tables.

Secondary outcome parameters

1. Pain assessment by the aid of Visual analogue scale (VAS), which is consisted of a "10 cm" line with one end labeled no pain and other end labeled worst intolerable pain. The patients marked the line at the point that best describing the pain intensity. The preoperative assessment included training of the patients about (VAS) for postoperative pain. The length of the line to the patient's mark will be measured and recorded postoperative after 30 min., 4, 6, 8, and 24 hours.
2. Failure rate of the block will be calculated, where the block will be considered a failed block if the patient requires more than two doses of rescue analgesia in the first hour postoperatively.
3. Duration of surgery (from skin incision till skin closure) and general anesthesia (from induction of GA till extubation).
4. Incidence of complications, such as: Nerve injury, Hematoma formation, LA toxicity, and intravascular injection.