in our study, we will investigate the impact of adding dexmedetomidine to bupivacaine for the potency of the obturator nerve block and prevention of the postoperative pain associated with transurethral surgery in comparison of obturator nerve block with bupivacaine alone

• After history taking and examination of the labs and airway of the patient , An intravenous catheter will be secured in the dorsum of the hand of non dominant hand and patients will be monitored for heart rate, noninvasive blood pressure, and oxygen saturation.
• All patients after aseptic preparation will receive subarachnoid block in lumber 3-4 or 4-5 space in sitting position.
• About 3 ml (15mg) of heavy 0.5% bupivacaine will be injected into subarachnoid space.
• After the completion of the block, patients will be laid in the supine position and subsequently waited for 5 min for fixation of drug and assessed for sensorimotor block.
• Further procedure will be performed as per the group allocation.
• ONB will be performed by classic technique 1.5cm lateral and 1.5cm caudal to the pubic tuberacle . after contact with the pubic ramus is made , the needle is redirected laterally to a point 2-3 cm deeper than the pubic ramus.(15)
• A waiting period 20 min will be allowed for the full effect of the block and then resection will be allowed to perform
• Hemodynamics (heart rate, mean arterial blood pressure) will be recorded intraoperatively and postoperative at 0, 2 and 6 hours .
• VAS score at 0,2 and 6 hours post-operatively will be assessed.
• Time to first call for analgesic requirements (duration of analgesia) will be measured.
• Total postoperative analgesic consumption in the first 24 hours post-operative will be measured.
• Incidence of complications such as nerve injury, hematoma formation, local anesthetic toxicity, intravascular injection, bleeding and bladder perforation will be assessed.

Inclusion Criteria:

• Participants will be adults (above 18 years) scheduled to undergo transurethral surgery under regional anesthesia.
• ASA1, ASA2

Exclusion Criteria:

• American Society of Anesthesiologists (ASA) physical class 3,4, severe cardiac comorbidity (impaired contractility with ejection fraction less than 50%, heart block, significant arrhythmias, tight valvular lesions), allergy to any study's drugs