Murkin, J. M., & Arango, M. (2009). Near-infrared spectroscopy as an index of brain and tissue oxygenation. BJA: British Journal of Anaesthesia, 103(suppl_1), i3–i13. https://doi.org/10.1093/bja/aep299
Continuous real-time monitoring of the adequacy of cerebral perfusion can provide important therapeutic information in a variety of clinical settings. The current clinical availability of several non-invasive near-infrared spectroscopy (NIRS)-based cerebral oximetry devices represents a potentially important development for the detection of cerebral ischaemia. In addition, a number of preliminary studies have reported on the application of cerebral oximetry sensors to other tissue beds including splanchnic, renal, and spinal cord. This review provides a synopsis of the mode of operation, current limitations and confounders, clinical applications, and potential future uses of such NIRS devices.
Near-infrared spectroscopy (NIRS) is a relatively new tool that allows continuous noninvasive monitoring of in vivo oxygenation in selected tissues such as muscle and brain. Since hemoglobin, myoglobin, and cytochrome c oxidase are the only biological compounds to exhibit variable absorption of near-infrared (NIR) light in response to changes in oxygen availability, NIRS can determine changes in tissue oxygenation. NIRS can measure regional blood volume, local oxyhemoglobin and deoxyhemoglobin contents, and reduction-oxidation state of cellular mitochondrial cytochrome a, a3. As a comprehensive monitor of regional oxygen metabolism, NIRS has been applied in certain clinical and research settings. Despite technical limitations and the lack of definite "gold standards" to allow validation of results, NIRS remains a promising technology with applications in both the critical care environment and the research laboratory studying mechanisms of oxygen metabolism.