Range of S-100β levels during functional endoscopic sinus surgery with moderately controlled hypotension

The aim of this study is to determine the range of S-100β levels during functional endoscopic sinus surgery (FESS) when the mean arterial pressure (MAP) was controlled within 60-70 mmHg. After anesthesia induction with propofol and remifentanil, the patient was positioned in the reverse Trendelenburg position and MAP was controlled within 60-70 mmHg during surgery. For the S-100β assay, blood was taken from a radial arterial catheter before (baseline) and at 20 (T ₂₀) and 60 (T ₆₀) min after setting the reverse Trendelenburg position and controlled hypotension, and at 60 (T _post60) min after the end of the operation. In total, 34 patients completed the study. Baseline S-100β was 0.00837 ± 0.00785 ng/mL. The levels at T ₂₀ and T ₆₀ were 0.02057 ± 0.01739 and 0.01987 ± 0.01145 ng/mL, respectively. The level of T _post60 was 0.05436 ± 0.02318 ng/mL. The level at T ₂₀ increased significantly versus the baseline level (P < 0.001); there were no significant differences between T ₂₀ and T ₆₀. The level at T _post60 was significantly different versus T ₂₀ and T ₆₀ (P < 0.001). However, all S-100β levels were within the normal range. S-100β-a sensitive biomarker of cerebral ischemia-was within the normal range during FESS when moderate hypotension (MAP >60 mmHg) was provided. Thus, moderate hypotension would be seemed to be a safe and effective anesthetic technique for FESS without risk for cerebral ischemia.