60 female patients scheduled for breast cancer surgeries, allocated in 3 groups for erector spinae block with bupivacaine and erector spinae block with dexmedetomidine added to bupivacaine and control group. During anesthesia: total intraoperative fentanyl required will be recorded. After surgery the first time of request for analgesic will be recorded. after request of analgesia all patients will be connected to PCA device containing morphine solution, the amount of morphine consumed during the first 24 hours will be recorded.

60 female patients scheduled for breast cancer surgeries, allocated in 3 groups for erector spinae block with bupivacaine and erector spinae block with dexmedetomidine added to bupivacaine and control group. During anesthesia: total intraoperative fentanyl required will be recorded. After surgery the first time of request for analgesic will be recorded. after request of analgesia all patients will be connected to PCA device containing morphine solution, the amount of morphine consumed during the first 24 hours will be recorded. Other secondary outcomes are numerical rating scales and incidence of opioid side effects.

Inclusion Criteria:

• Provision of signed and dated informed consent form
• Stated willingness to comply with all study procedures and availability for the duration of the study
• Female, aged (18-70) years
• Belongs to American Society of Anaesthesiologists physical status class II.
• Scheduled for breast cancer surgeries.

Exclusion Criteria:

• Patient refusal.
• Local infection at the site of the block.
• Cardiac dysfunction (ejection fraction <45%).
• Preexisting neurological or psychiatric disease, communication difficulties, inability to use the patient-controlled analgesia (PCA) device.
• Allergy to one of the study drugs.
• Pregnancy.
• Coagulopathy (PC <60% and platelet count<100.000).