Role of near-infrared spectroscopy in neuroanesthesia

Abstract

Near-infrared spectroscopy (NIRS) provides information on regional tissue oxygen saturation (rSO2) by measuring absorption of near-infrared light. Values of rSO2 reflect the balance between oxygen supply and demand in the monitored region. The clinical application of NIRS has been frequently studied in the context of neuroanesthesia, such as assessment of cerebral ischemia during carotid endarterectomy or early detection of cerebral hyperperfusion. In addition, when a bolus of indocyanine green is injected and analyzed using specific NIRS software, blood flow index can be calculated, which indicates the relative measurement of cerebral blood flow. While NIRS has technical limitations and requires further development, it is noninvasive and relatively simple, thus providing advantages over other modalities. It has the potential to provide helpful information on cerebral function and improve perioperative outcomes in neuroanesthesia.