This prospective observational study investigates the impact of preoperative regional anesthesia on postoperative sleep quality in patients undergoing mastectomy. Sleep quality will be assessed using two validated tools: the Richards-Campbell Sleep Questionnaire (RCSQ) for all participants, and the Pittsburgh Sleep Quality Index (PSQI) in a subgroup. The study also examines the relationship between sleep quality and postoperative pain, patient satisfaction, and psychological status measured by the Hospital Anxiety and Depression Scale (HADS). Patients will be grouped based on anesthesia technique-general anesthesia alone or general anesthesia combined with regional block-and sleep outcomes will be compared. The study aims to provide evidence on how anesthetic technique and psychological factors affect recovery and sleep quality after breast cancer surgery.

Inclusion Criteria:

• Female patients aged 18 years or older
• Undergoing elective mastectomy surgery
• ASA physical status I to III
• Willing and able to provide written informed consent
• Expected to remain hospitalized for at least 24 hours postoperatively

Exclusion Criteria:

• History of major psychiatric or neurological disorders
• Regular use of antidepressants, anxiolytics, or hypnotics
• Difficult airway management during anesthesia (e.g., intubation or ventilation complications)
• Reoperation within the first 24 hours after surgery
• Inability to complete questionnaires due to deep sedation or visual/auditory impairment

The study population will consist of adult female patients (≥18 years old) scheduled for elective mastectomy surgery at a single academic hospital