NEAR-INFRARED SPECTROSCOPY - LIMITATIONS AND PROBLEMS IN THE INTENSIVE-CARE UNIT

Near infrared spectroscopy is a non-invasive method of calculating cha nges in cerebral oxygenation. We have now evaluated a new near infrare d spectroscope, the NIRO-500 (Hamamatsu Photonics, japan), in an inten sive care unit setting. The influence of extracerebral and intracerebr al physical-technical, physiological and pathophysiological parameters was investigated. The results showed that the method is very sensitiv e to changes in oxygenation and perfusion in the cerebral vasculature. However, the influence of other factors can be considerable and not a lways easy to detect and interpret.