Oxygen saturation by pulse oximetry in healthy infants at an altitude of 1610 m (5280 ft). What is normal?
E. H. Thilo, B. Park-Moore, E. R. Berman and B. S. Carson
Department of Pediatrics, University of Colorado School of Medicine, Children's Hospital, Denver 80218.
Pulse oximetry is a valuable, noninvasive technique for assessing oxygen
saturation that has gained wide clinical acceptance despite little
available information concerning normal values in the newborn, especially
at an altitude different than sea level. We performed serial pulse oximetry
studies on 150 term, appropriate-weight-for-gestational-age, clinically
healthy infants at an altitude of 1610 m (5280 ft) at 24 to 48 hours, 1
month, and 3 months of age to define a reference range for oxygen
saturation as a guideline in clinical care. We found that mean oxygen
saturation at 24 to 48 hours of age is 92% to 93% and varies little with
infant activity. With increasing postnatal age, there is a tendency for
increased oxygen saturation during the awake states to 93% to 94%, while
oxygen saturation during sleep stays the same or even decreases slightly.
The lower end of the reference range (2 SDs below the mean) is as low as
85% during feeding at 24 to 48 hours of age, and as low as 86% during quiet
sleep at 1 and 3 months of age, with 88% to 89% the lower limit in other
activities at all ages.
