A402 Estimation of Jugular Venous O Sub 2 Saturation From Cerebral Oximetry or Arterial O Sub 2 Saturation During Isocapnic Hypoxia

Near Infrared Spectroscopy Monitoring During Carotid Endarterectomy: Which Threshold Value is Critical?

“…As reported by others utilizing this device 8,16 -19 the definition of 'normal values' for rSO 2 is highly questionable because of the wide variation of preclamp baseline saturation. Like the variability found in jugular venous oxygen saturation in healthy volunteers 20 rSO 2 has been found to exhibit a similar but even wider variability. The results of our study confirmed the variability of this parameter and the necessity to focus attention on individual changes of rSO 2 and to normalize the preclamp value to make easier the calculation of the percentage decrease.…”

A noninvasive estimation of mixed venous oxygen saturation using near‐infrared spectroscopy by cerebral oximetry in pediatric cardiac surgery patients

“…Various sources estimate between 70 (4) and 90% (27) venous blood by volume. Although these volumes cannot be measured in vivo , INVOS cerebral oximeter values correlate well when a 75% venous volume is assumed during volume changes which occur as a result of changes in PaCO 2 (28). The compartment ratio of 75% venous and 25% arterial is likely not constant, but changes continuously in response to changes in cerebral vascular resistance, pulmonary vascular resistance, and tissue oxygen demands.…”

Who Fails the Iowa Gambling Test (IGT)? Personality, Neuropsychological, and Near-Infrared Spectroscopy Findings in Healthy Young Controls

“…However, as head size varies, the exact localization of the tissue being assessed cannot be precisely determined. The INVOS 5100 Cerebral Oximeter assumes a strict ratio of 3:1 for venus:arterial blood, based on the studies of cerebral circulation (Henson, Cartwright, & Chlebowski, 1997) and therefore uses this ratio when calculating values for regional blood oxygenation saturation (rSO 2 ). Light absorption data were collected 15 times per second and a new average rSO 2 value was calculated every 3 -4 s. The NIRS-dependent variables for the current study were right and left frontal lobe change scores during performance of each task (average resting rSO 2 values during a 5-min pre-task baseline subtracted from average rSO 2 values during task performance), summed across tasks separately for left and right hemispheres.…”