Effects of Premedication with Metoprolol on Bleeding and Induced Hypotension in Nasal Surgery

BACKGROUND One of the major problems in surgery is intraoperative bleeding which reduces visibility in the operative field. An important task for an anesthetist during head and neck surgery is to improve intraoperative visibility. OBJECTIVES The purpose of this study was to compare the amount of bleeding using different doses of oral metoprolol during three common types of nasal operation; rhinoplasty, septoplasty and functional endoscopic sinus surgery, as this is one of the complications during head and neck surgery. PATIENTS AND METHODS In a randomized, controlled, open clinical trial, 88 patients who were candidates for nasal operations were studied. Patients entering the study were divided into four groups and randomly assigned to receive 50 mg metoprolol a night before the operation, 50 mg metoprolol on the day of operation, 50 mg metoprolol on the night and on the day of operation, or a placebo. Following the patient's preparation on the operating table and after intubation, systolic and diastolic blood pressures were measured in a non-invasive oscillometric way, and their pulse rate was recorded simultaneously. All the data were recorded during the surgery as well. Bleeding was measured by the quality scale proposed by Formme and Boezaart. RESULTS There was a statistical significance between using metoprolol and the amount of intraoperative bleeding. All patients who received metoprolol the night before surgery and on the day of surgery had slight bleeding during the surgery. In addition, there was a statistical significance between patients' agitation levels and the time they received metoprolol. CONCLUSIONS Decreases in both systolic blood pressure and heart rate to less than 60 beats per minute reduces intraoperative bleeding. These rates can be achieved by using beta-blocker drugs. In this study, using a double-dose of metoprolol significantly reduced intraoperative bleeding and improved the quality of the operative field. It also reduced patients' agitation in the recovery room.