Inclusion Criteria:  Female patients with an American Society of Anesthesia (ASA) physical status I-II Scheduled for elective breast cancer surgery  Exclusion Criteria:  Patients unable to understand the study procedure or unable to give informed consent with concurrent analgesic or sedative medication, with history of chronic pain with history of psychiatric disorders with history of alcohol or drug abuse with an allergy to the study medication who are pregnant or breast feeding with a BMI >30 and <18 kg/m^2 with severe cardiac, pulmonary, hepatic or renal dysfunction with intracranial hypertension