critical care medicine
Monitoring and Testing the Critical Care Patient
Near Infrared Spectroscopy (NIRS)
NIRS is a noninvasive method of continuously monitoring end organ oxygenation and perfusion. NIRS sensors are usually placed on the skin above the target tissue to monitor mitochondrial cytochrome redox states, which reflect tissue perfusion. NIRS may help diagnose acute compartment syndromes (eg, in trauma) or ischemia after free tissue transfer and may be helpful in postoperative monitoring of lower-extremity vascular bypass grafts. NIRS monitoring of small-bowel pH may be used to gauge the adequacy of resuscitation. 