Application of controlled arterial hypotension in endoscopic rhinosurgery.

Intraoperative bleeding is one of the major problems in endoscopic surgery of sinuses. In the case of the expanded process, still more numerous interventions are performed with general anesthesia. The objective of research is to compare intraoperative hemorrhage and the visibility of the operative field during normotension and hypotension anesthesia caused by nitroglycerin and captopril when performing endoscopic operations of accessory nasal sinuses. Fifty-two patients of physical health state 1-2 according to ASA were examined: for 32 the controlled hypotension (Group H) was applied, 20 patients underwent operations in normotension (Group N). All patients on the eve of the operation were premedicated with diazepam; Group H patients on the day of operation received 6.25 mg of captopril. Anesthesia was carried out with fentanyl and halothane steam in the 50:50% mixture of oxygen and laughing gas. In Group H arterial blood pressure was lowered by nitroglycerin infusion. The average arterial blood pressure was maintained in GroupH within the limits of 50-60 mmHg. Hypotension was coordinated with the rising of the head-bed of the operating table at 5 degrees. Hemorrhage was measured by collecting blood with the pump graded with the precision of 25 ml. The visibility of the operative field was evaluated subjectively every 15 minutes according to the scale of 5 points proposed by Fromm. In both groups the average arterial blood pressure values as well as the values of the frequency of heart contractions differed statistically significantly. In the hypotensive group, hemorrhage during operation was less, on the average, (208 ml) than in Group N (349.2 ml). The visibility of the operative field was by one point, on the average, better than in Group H. No anesthetic complications were observed during investigation. In summary, it is possible to state that the controlled arterial hypotension caused by captopril and nitroglycerin reduced significantly intraoperative hemorrhage and improved the visibility of the operative field in endoscopic rhinosurgery.