Reliability of rSO2 to Measure CO2 Reactivity of Cerebral Vasculatures during Desflurane-N2O Anesthesia

Abstract

Background: Near infrared spectroscopy (NIRS) to monitor regional cerebral oxygen saturation () is a noninvasive and simple modal ity in clinical use. The ability of r as an index of cerebral oxygenation has been well demonstrated. However, the reliability of to reflect the changes of cerebral vascular reactivity in the changes of arterial partial pressure of () has not been established. The aim of this study was to verify the reliability of to measure the reactivity of cerebral vasculatures. Methods: Twenty healthy adult patients undergoing general anesthesia were enrolled in this study. Anesthesia was induced with propofol and maintained with desflurane/. Respiration was mechanically controlled. The radial artery and jugular bulb were cannulated. The sensor of the NIRS was attached to the ipsilateral forehead. During normocapnia ( 40 1.3 mmHg) and hypocapnia ( 30 2.4 mmHg), blood was obtained from the radial artery and jugular bulb and analyzed. was compared with (estimated field oxygen satuation), and the gold standard of tissue oxygen saturation. was calculated from the following equation: = 0.75 + 0.25 . Results: significantly correlated with (P = 0.000, = 0.56). A bias of - 5.8% with a precision 12.94% was found. Conclusions: We concluded that can be a reliable predictor to measure reactivity of cerebral vasculatures during normocapnia and hypocapnia.