Hypoperfusion, or inadequate blood flow to tissues and organs, is life-threatening and a leading cause of death in a critically ill person. Research presented in September at the American Association for the Surgery of Trauma’s annual meeting in New Orleans shows that a near-IR spectroscopy system can detect hypoperfusion in trauma patients. The InSpectra StO2 system, created by Hutchinson Technology Inc., uses near-IR spectroscopy to provide a direct, continuous measurement of the amount of oxygenated hemoglobin in skeletal muscle tissue. Dr. Stephen M. Cohn, chairman of the department of surgery at the University of Texas Health Science Center in San Antonio, and his colleagues at Hutchinson Technology used the system to determine whether local tissue oxygen saturation measurements on the thenar eminence (the muscle at the base of the thumb) could adequately indicate hypoperfusion. The researchers took the measurements on 383 severely injured patients, enrolled from seven trauma centers located throughout the US. They discovered that 78 percent of the patients who developed multiple organ dysfunction syndrome (an indicator of hypoperfusion) and 83 percent of patients who died had local tissue oxygen saturation levels below 75 percent in the first hour after arrival in the emergency department. And trauma patients who maintained local tissue oxygen saturation levels above 75 percent within the first hour had an 88 percent chance of multiple organ dysfunction syndrome-free survival. The researchers believe their results indicate that measurements of local tissue oxygen saturation can be used to provide important noninvasive information about trauma patients.