Magnesium Sulfate Versus Dexmedetomidine on Anesthesia Awakening. Randomized Clinical Trial.

INTRODUCTION Magnesium sulfate (MS) and dexmedetomidine have already demonstrated the ability to reduce intra and postoperative consumption of anesthetics and analgesics, among others advantages, such as blood pressure control and intraoperative bleeding8,9. The MS has also been shown to be useful in pre-eclampsia and eclampsia control, pulmonary hypertension, asthma, cardiac arrhythmias and pheochromocytoma). Despite these advantages in the use of these important adjuncts, there is a concern about the quality and awakening time of the patients who use them. The purpose of this trial is to compare the time and quality of awakening in patients submitted to general anesthesia and receiving MS or dexmedetomidine as adjuncts in the intraoperative analgesia.

The main objective of this trial is to compare the quality and the awakening time in patients receiving MS or dexmedetomidine. The secondary objective is the comparison of postoperative analgesia in the postoperative hospitalization period. Our hypothesis is that patients present a faster awakening when receive MS an analgesic adjunct, when compared to patients who receive dexmedetomidine.

Drawing: this is a prospective, controlled, covert trial with random distribution for noninferiority trialing.

Key words: general anesthesia, long awakening from anesthesia. METHODS Participants and endpoints Scenario: The study will be carried out at "Hospital da Sociedade Portuguesa de Beneficência de Santos - Angiocorpore" (Portuguese Charity Society Hospital). Eligibility: Patients scheduled for video laparoscopic cholecystectomy, between 18 and 70 years old, physical status I or II in the American Society of Anesthesiology classification, who have no allergy or contraindication to the study protocol substances and who voluntarily agree to participate in the trial and sign the informed consent form (TCLE), will be invited to participate in the study.

Coronary disease patients, patients with heart block > atrioventricular block > I, patients with renal failure, those with brain disease past history, dementia or other psychiatric diseases, and patients with body mass index > 35 kg/m², will be excluded. Also excluded patients with Portuguese language limitations and in preoperative use of opioid or corticosteroids.