EFFECT OF FETAL HEMOGLOBIN ON THE DETERMINATION OF NEONATAL CEREBRAL OXYGENATION BY NEAR-INFRARED SPECTROSCOPY

Near-infrared spectroscopy has been applied to the study of cerebral o xygenation and hemodynamics in the newborn. Fetal Hb is present in hig h concentrations in these infants. Because spectral absorption curves in the near-infrared range for fetal Hb are not identical to those for adult Hb, there is a potential for the measurements to be affected. T his possibility has not previously been investigated. A quantitative a nalysis of cerebral oxygenation was undertaken in six newborn infants. The analysis used near-infrared spectroscopy multiplier coefficients derived from the absorption coefficients of both fetal and adult deoxy genated and oxygenated Hb. The results of both analyses were compared. It was concluded that the error in near-infrared spectroscopy analysi s of neonatal cerebral oxygenation arising from the use of absorption coefficients derived from adult Hb is inconsequential, even in the pre sence of high concentrations of fetal Hb.