Prediction of arterial partial pressure of oxygen with pulse oxygen saturation measurements.
OBJECTIVE
We studied 22 neonates with gestational ages from 26 to 40 weeks to determine how accurately pulse oxygen saturation (SpO2) could predict arterial partial pressure of oxygen (PaO2) and how much time and effort would be required to achieve and maintain a desired SpO2 value.


METHODS
SpO2 was maintained at 90%, 92%, 94%, 96%, and 98% by adjustment of FiO2. PaO2 was correlated with SpO2 by nonlinear mixed effects regression analysis.


RESULTS
PaO2(y) correlated positively with SpO2(x): y = (0.03). e0.08(x). Variation of PaO2 increased from a range of +/- 10 Torr at SpO2 = 90% to +/- 28 Torr at SpO2 = 98%, principally as a result of decreasing hemoglobin-oxygen affinity, with no effect of advancing gestational age, subject temperature, pH, PaCO2. Considerable time (18 +/- 14 SD minutes) and effort (5 +/- 3 SD FiO2 adjustments/min were required to achieve and maintain a desired SpO2.


CONCLUSIONS
PaO2 varied broadly with SpO2 in a clinically acceptable range of SpO2 (90% to 98%), and the variability increased at higher SpO2 values. Considerable time and effort were required to achieve and maintain desired SpO2 values.
Brockway
J
J
Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado 80262, USA.
Hay
W W
WW
D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D010092:Oximetry; D010100:Oxygen / Q000097:blood*
D010100:Oxygen