Comparative Study of Ketamine Added to Bupivacaine in PECS Block Versus Topical Wound Instillation on Post Operative Analgesia in Modified Radical Mastectomy 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 .