Cerebral Oxygen Saturation Measured by Near-infrared Spectroscopy and Jugular Venous Bulb Oxygen Saturation during Arthroscopic Shoulder Surgery in Beach Chair Position under Sevoflurane-Nitrous Oxide or Propofol-Remifentanil Anesthesia Hyejin Jeong, M.D.,* Seongtae Jeong, M.D., Ph.D.,† Hoi J. Lim, Ph.D.,‡ JongUn Lee, M.D., Ph.D.,§ Kyung Y. Yoo, M.D., Ph.D. ABSTRACT Background: We examined the effects of different anesthet- ics on cerebral oxygenation and systemic hemodynamics in patients undergoing surgery in beach chair position (BCP). Jugular venous bulb oxygen saturation (SjvO 2 ) and regional cerebral tissue oxygen saturation (SctO 2 ) were determined while patients were placed from the supine to BCP. Whether SctO 2 and SjvO 2 are interchangeable in assessing the cerebral oxygenation was also examined. Methods: Forty patients undergoing shoulder surgery in BCP were randomly assigned to receive sevoflurane-nitrous oxide (S/N) or propofol-remifentanil (P/R) anesthesia. Four patients taking angiotensin II receptor antagonists were ex- cluded post hoc. Mean arterial pressure and heart rate, as well as SjvO 2 and SctO 2 , were measured before (postinduction baseline in supine position) and after BCP. Results: Mean arterial pressure decreased by BCP in both groups. It was, however, significantly higher in S/N (n = 19) than in P/R group (n = 17) at 7 to 8 min after the position- ing. SjvO 2 also significantly decreased after BCP in both groups, the magnitude of which was lower in S/N than in P/R group (11  10% vs. 23  9%, P = 0.0006). The incidences of SjvO 2 50% and mean arterial pressure less than 50 mmHg were lower in S/N group, but SctO 2 and the incidence of cerebral desaturation (more than 20% decrease from baseline) did not significantly differ between the groups. SctO 2 and SjvO 2 were only weakly correlated ( = 0.218, r 2 = 0.133). Bland-Altman analysis showed a mean difference of -7.2% with 95% limit of agreement between -38.2% and 23.8%. Conclusions: The margin of safety against impaired cerebral oxygenation is greater and SjvO 2 is more preserved with S/N than with P/R anesthesia. SctO 2 may not be reliable in de- tecting a low SjvO 2 during the surgery in BCP. T HE beach chair position (BCP) is commonly used in arthroscopic and open shoulder procedures because of its numerous advantages, such as reduced direct neurovascu- lar trauma, excellent intraarticular visualization, and ease of conversion to an open approach if needed compared with the lateral decubitus approach. 1,2 However, it is associated with reductions in cardiac output, mean arterial pressure (MAP), and cerebral perfusion pressure because of the gravitational effect of positioning the head above the level of the heart. 3,4 Sudden profound hypotensive and bradycardic events have been reported in more than 20% of patients undergoing shoulder arthroscopy in BCP. 5 Systemic hypotension may compromise cerebral perfusion, resulting in a neurologic in- jury when the episode is prolonged. Brain and spinal cord ischemia, 6,7 transient visual loss, opthalmoplegia, 8 and se- * Clinical Fellow, † Assistant Professor,  Professor, Department of Anesthesiology and Pain Medicine, § Professor, Department of Physiology, ‡ Assistant Professor, Department of Orthodontics, School of Dentistry, Chonnam National University Medical School, Chonnam, Gwangju, South Korea. Received from the Department of Anesthesiology and Pain Med- icine, Chonnam National University Medical School, Chonnam, Gwangju, South Korea. Submitted for publication August 25, 2011. Accepted for publication February 3, 2012. Supported by grant no. CRI11026-1 from Chonnam National University Hospital Research Institute of Clinical Medicine, Gwangju, Chonnam, South Korea. Address correspondence to Dr. Yoo: Department of Anesthesiol- ogy and Pain Medicine, Chonnam National University Medical School, 8 Hak-dong, Gwangju 501-757, South Korea. kyyoo@jnu.ac.kr. Infor- mation on purchasing reprints may be found at www.anesthesiology. org or on the masthead page at the beginning of this issue. ANESTHESI- OLOGY’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue. Copyright © 2012, the American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins. Anesthesiology 2012; 116:1047–56 What We Already Know about This Topic • The beach chair position (BCP) carries a risk of cerebral ischemia What This Article Tells Us That Is New • Using jugular venous bulb oxygen saturation (SjvO 2 ) and re- gional cerebral tissue oxygen saturation (SctO 2 ) monitoring in patients changed from the supine to BCP, the margin of safety against impaired cerebral oxygenation was greater and SjvO 2 better preserved with sevoflurane-nitrous oxide than with propofol-remifentanil anesthesia. SctO 2 may not be reliable in detecting a low SjvO 2 during the surgery in BCP Anesthesiology, V 116 • No 5 May 2012 1047 Downloaded from anesthesiology.pubs.asahq.org by guest on 05/29/2020