Efficacy and Safety of Dexmedetomidine Added to Modified Pectoral's Block in Breast Cancer Patients

60 patients (age ≥29 years) who scheduled for modified radical mastectomy surgery under general anesthesia. Group I (Bupivacaine group): patients underwent modified radical mastectomy were given preoperative ultrasound guided modified Pecs block with 30 mL of 0.25% bupivacaine divided into 10 ml injected between the pectoralis muscles on the interfasial plane, and 20 ml injected between the Pectoralis minor muscle and the serratus muscle.Group II (Bupivacaine + Dexmedetomidine group) : preoperative ultrasound guided modified Pecs block with 30 mL of 0.25% bupivacaine plus Dexmedetomidine (1 µg/kg) divided into 20 ml injected between the pectoralis muscles on the interfasial plane , and 10 ml injected between the Pectoralis minor muscle and the serratus muscle.