Noninvasive arterial hemoglobin oxygen saturation versus transcutaneous oxygen tension monitoring in the preterm infant.

We found that results from a transcutaneous arterial hemoglobin oxygen-saturation monitor correlated well with those from a co-oximeter. The monitor was not disturbed by differing hematocrit levels, the presence of fetal hemoglobin, or hypotension. We also found that the results of simultaneous transcutaneous arterial hemoglobin oxygen saturation (StcaO2) and transcutaneous oxygen tension (PtcO2) monitoring were predictably correlated over a wide range of hemoglobin saturations in preterm infants. When StcaO2 was between 80% and 95%, PtcO2 was at a safe level of 40 to 80 torr in 94% of the patients studied. StcaO2 monitoring as an index of arterial oxygenation has several advantages for the preterm infant.