• Assess the intensity of pain: Pain Scores on the Visual Analog Scale [ Time Frame: Through study completion, an average of 6 to 9 month ]
  Pain Scores on the Visual Analog Scale, from zero to 10: 0 being represented by absence of pain and 10 being the worst possible pain
• Identify possible risk factors [ Time Frame: Through study completion, an average of 6 to 9 month ]
  Incidence analysis using a questionnaire applied to patients in the late postoperative period.
• Stratify the possible types of pain [ Time Frame: Through study completion, an average of 6 to 9 month ]
  Application of a questionnaire to identify the characteristics of pain (Neuropatic or non-neuropatic pain)

• Drug: Control
  Patients who underwent mastectomy under standard general anesthesia
• Drug: Esmolol
  Patients who underwent mastectomy under general anesthesia with esmolol infusion

• Control

  Patients who underwent mastectomy under standard general anesthesia

  Patients in placebo group received general balanced inhaled anesthesia with sevoflurane and remifentanil and a saline 0,9% infusion pump.

  Intervention: Drug: Control
• Esmolol
  Patients in esmolol group received general balanced inhaled anesthesia with sevoflurane and a bolus infection of esmolol 500 mgc/kg followed by a continuous infusion of esmolol 100 mcg/kg/min
  Intervention: Drug: Esmolol

Inclusion Criteria:

- Patients previously submitted to the study Analgesic Effect of Intraoperative Esmolol in Mastectomies: a randomized placebo controlled trial

Exclusion Criteria:

• Patient aged less than 18 years and over 65 years;
• Patients who refuse to participate in the study;
• Patients with pulmonary disease;
• Patients with cardiac, renal or hepatic disease;
• Use of psychoactive drug;
• Patients with sinus bradycardia;
• Pregnant women;
• Patients with allergy to dipyrone, morphine;
• Patients with chronic pain prior to the surgical procedure;
• Patients with neurological disorders;
• Patients undergoing surgical resurfacing