[Evaluation the metoprolol effects in controlled hypotension and reduction of bleeding during head and neck surgery]

ABSTRACT

Intraoperative bleeding, which reduces visibility in the operative field, is one of the major problems of head and neck surgeries. Improvement of intraoperative visibility and reduction of bleeding is an important task for an anesthetist during head and neck surgery. It has been shown that preoperative beta-blockade decreases bleeding during the operation. In a 18 month period, 88 patients, who were candidate for nasal procedures in hazrat Rasul medical complex, were selected in a randomized open clinical trial study. They were divided to 4 groupes 50 mg metoprolol at night before surgery 50 mg metoprolol in the morning of the surgery 50 mg metoprolol at night before surgery and in the morning of the surgery placebo Heart rate, Systolic and diastolic blood pressure was measured in a non-invasive way just both upon arrival on the operation bed and after induction of anesthesia during operation. For evaluation of the visibility of the operative field during operation the quality scale proposed by Fromm and Boezzart was used. SPSS 13 was used for assessment. There was significant relationship between metoprolol administration and bleeding during the operation. All patients who received two doses of metoprolol one in the last night and another in the morning of the operation day had only mild bleeding. There was statistically significant relation between agitation and time of administration of metoprolol. Nowadays, there are growing evidences that not only decrease in systolic blood pressure but also a low heart rate [< 60 beats per minute] can minimize surgical bleeding. Both of the above mentioned effects could be induced by beta blockers. In this study, two doses of metoprolol could decrease the amount of bleeding and improve the operation field significantly and also could decrease the agitation in recovery room