Efficacy and Safety of Dexmedetomidine in the Analgesic Prophylaxis , in Patients Undergoing Cardiovascular Surgery

Efficacy and Safety of Dexmedetomidine in the Analgesic Prophylaxis , in Patients Undergoing Cardiovascular Surgery: Randomized Clinical Trial

Acute pain is one of the complications after cardiothoracic surgeries . It can delay patients´recovery and may increase patients´morbity and mortality. This study intends to evaluate Dexmedetomidine, a highly selective α- 2 receptor agonist, that is currently applied safely and efficiently in intraoperative cardiac surgery. It has analgesic, sedative, anxiolytic and sympatholytic properties, without respiratory- depressant effect. The aim of this study is to investigate whether the intraoperative use of dexmedetomidine is better than the standard analgesia used in the intraoperative period to reduce pain and the consequences of it.

This project is a prospective, double-blinded and randomized clinical trial. Eligible participants are assigned in a 1:1 ratio to either the intervention group (Group Dexmedetomidine) or control group (Group Saline 0,9%), after written informed consent to be obtained. The patients will undergo elective cardiac surgery, with extracorporeal circulation.

In the operating room, patients will be monitored for pulse oximetry, invasive blood pressure, electrocardiograms, capnography, central venous pressure and nasopharyngeal temperature probe. Induction of anesthesia is performed with intravenous midazolam, fentanyl, etomidate and neuromuscular blocking agent. Anesthesia is maintained with sevoflurane. Dexmedetomidine, at the rate of 0,3μg/ kg/h, or placebo will be infused from the initiation of the anesthesia up to the end of the procedure, except during the cardiopulmonary by-pass. Placebo is a 0,9% saline. The follow up of the assessment of the groups will extend to the postoperative ICU, where data will be collected, during the first 24 hours after surgery.

Inclusion Criteria:

• Patients at least 18 years old and who are undergoing cardiac procedures (coronary artery bypass, valve replacement or combined procedure), with cardiopulmonary by- pass.

Exclusion Criteria:

• Congenital heart disease
• Infective endocarditis
• Acute myocardial infarction (<two weeks)
• Pregnancy
• Cancer
• Left ventricle ejection fraction < 40%
• Cardiogenic shock
• Emergent procedure
• Use of vasopressor and/or inotrope, in the preoperative
• Liver disfunction
• Renal replacement therapy
• Nephrectomy
• Previous renal transplantation
• Patients who are participating in another clinical research