The Effect of Different Doses of Isoflurane on Hemodynamic Changes and Bleeding in Patients Undergoing Endoscopic Sinus Surgery under General Anesthesia.

Background: Nowadays, endoscopic sinus surgery is one of the most common surgeries in the field of ear, nose, and throat. This surgery has always been followed by bleeding and can cause hemodynamic disorders due to the direct effect of the endoscopic sinus surgery.

Objectives: This study aimed to investigate the hemodynamic changes with different doses of isoflurane during endoscopic sinus surgery.

Methods: In a randomized clinical trial, 90 patients were selected based on ASA class I and II, and divided into three groups of 30 people. The method of anesthesia induction in groups was alike. After induction anesthesia, isoflurane with percentages of 1%, 1.2%, and 1.5% was used in the groups of 1, 2, and 3, respectively and remifentanil was fixed and used in the groups in a dose of 0.1 g/kg/min during the surgery.

Results: There was a significant difference in changes in mean of arterial pressure (MAP) after induction in the 3 groups (P < 0.001) that the reduction in mean of arterial pressure between 1 and 3 groups and between 2 and 3 groups were significantly different. There was a significant difference in heart rate per 30, 45, and 60 minutes between 1 and 2 groups (P < 0.001).

Conclusions: Isoflurane percentages of 1.5% versus 1.2% and 1% affected generally a considerable reduction rate of 1% in bleeding and better control of mean arterial blood pressure. In addition, the mean heart rate in several minutes in group 2 with 1.2% isoflurane was less than other groups.