Effects of Intraoperative Esmolol on Post-mastectomy Pain Syndrome

Study Overview
=================
Brief Summary
-----------------
Chronic postoperative pain is an entity that is usually neglected by anesthetists, but several studies show that the choice of anesthetic technique may interfere with this prevalence. Esmolol is a selective beta-blocker of ultra fast duration that has been studied as a perioperative venous adjuvant with antihyperalgesic and opioid sparing action. The investigators ventured the possibility of this anti-hyperalgesic effect attenuating the chronic pain syndrome post-mastectomy.

Official Title
-----------------
Effects of Intraoperative Esmolol on Post-mastectomy Pain Syndrome: a Cross-sectional Study

Conditions
-----------------
Post-mastectomy Pain Syndrome

Intervention / Treatment
-----------------
* Drug: Control
* Drug: Esmolol


Participation Criteria
=================
Eligibility Criteria
-----------------
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

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Control<br>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. | Drug: Control<br>* Patients who underwent mastectomy under standard general anesthesia<br>|
| Esmolol<br>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 | Drug: Esmolol<br>* Patients who underwent mastectomy under general anesthesia with esmolol infusion<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of post-mastectomy chronic pain syndrome | Incidence analysis using a questionnaire applied to patients in the late postoperative period. | Through study completion, an average of 6 to 9 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assess the intensity of pain: Pain Scores on the Visual Analog Scale | 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 | Through study completion, an average of 6 to 9 month | 
| Identify possible risk factors | Incidence analysis using a questionnaire applied to patients in the late postoperative period. | Through study completion, an average of 6 to 9 month | 
| Stratify the possible types of pain | Application of a questionnaire to identify the characteristics of pain (Neuropatic or non-neuropatic pain) | Through study completion, an average of 6 to 9 month | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Post-mastectomy Pain Syndrome, Esmolol, Perioperative