The Pecs block will be performed while the patient in the supine position with the ipsilateral upper limb abducted 90 degree with an 80 mm 21 G needle (Pajunk®SonoPlex Stim cannula U.S.A) using linear array ultrasound probe of high frequency (Sonosite®, Inc. U.S.A) starting from the lateral third of the clavicle and moving distally and laterally to the mid axillary line .

Patients will be given ultrasound guided, modified Pecs block with 30 mL of 0.25% bupivacaine hydrochloride (Markyrene ®Sigma Tec, Egypt) plus ketamine hydrochloride (1 mg/kg) (Ketamine® Sigma-Tec, Egypt) injected between the pectoralis minor and the serratus anterior muscles , and skin incision will be performed 15 minutes after the block was given.

After surgical hemostasis before wound closure Patients will receive 1 mg/kg ketamine hydrochloride plus 30 mL of 0.25% bupivacaine hydrochloride which will be put in asterile syringe and irrigated onto the surgical field at the end of surgery .

On arrival to the operating room, an intravenous line will be inserted in the contralateral upper limb to the side of surgery. Anesthesia will be induced for all participating patients with 2 μg/kg fentanyl, 2 - 3 mg/kg propofol and 1.5 mg/kg lidocaine. Endotracheal intubation will be facilitated by 0.15 mg/kg cis-atracurium.The patients will be randomly assigned into 2 groups ( pecs block group , topical instillation group) using a randomization-computer program . Anesthesia will be maintained by 1 - 1.5 MAC isoflurane in 50% oxygen/ air mixture and 0.03 mg/kg cisatrcurium, respectively, in ventilation parameters that maintain normocapnia. At the end of surgery, a reversal of the muscle relaxant will be done using neostigmine (0.04 mg/kg) and atropine (0.01 mg/kg). After extubation, all patients will be transmitted to the post anesthesia care unit (PACU) for follow up .