Near infrared spectroscopy (NIRS) of the thenar eminence in anesthesia and intensive care

Here we review of current knowledge of the application of NIRSth in anesthesia and intensive care.We performed an analytical and descriptive review of the literature using the terms “near-infrared spectroscopy” combined with “anesthesia,” “anesthesiology,” “intensive care,” “critical care,” “sepsis,” “bleeding,” “hemorrhage,” “surgery,” and “trauma” with particular focus on all NIRS studies involving measurement at the thenar eminence.We found that NIRSth has been applied as clinical research tool to perform both static and dynamic assessment of StO2. Specifically, a vascular occlusion test (VOT) with a pressure cuff can be used to provide a dynamic assessment of the tissue oxygenation response to ischemia. StO2 changes during such induced ischemia-reperfusion yield information on oxygen consumption and microvasculatory reactivity. Some evidence suggests that StO2 during VOT can detect fluid responsiveness during surgery. In hypovolemic shock, StO2 can help to predict outcome, but not in septic shock. In contrast, NIRS parameters during VOT increase the diagnostic and prognostic accuracy in both hypovolemic and septic shock. Minimal data are available on static or dynamic StO2 used to guide therapy.Although the available data are promising, further studies are necessary before NIRSth can become part of routine clinical practice.