Near-infrared spectroscopy for the in vivo study of cerebral hemodynamics and oxygenation.

With the advent of near-infrared spectroscopy (NIRS), it has become possible for the first time to make continuous measurements of in vivo cerebral oxygenation and hemodynamic changes at the bedside, in the intensive care unit, and in the operating room. NIRS has shown immense potential as a noninvasive technique for monitoring real-time cerebrovascular and oxygenation changes in the critically ill child. To date, clinical applications of the technique have included cerebral measurements in the intrapartum fetus, the high-risk newborn, and the infant undergoing extracorporeal membrane oxygenation and hypothermic cardiac surgery. Despite these advances in the clinical application of the NIRS technique, several basic controversies persist and are the focus of intense research in the area. This review provides an update on recent clinical studies using NIRS and outlines the likely future directions of the technique.