Pulse Oximetry at Moderate Altitude

Abstract

Pulse oximetry is commonly used in both outpatient and inpatient settings to assess children with respiratory illness. This study was designed to obtain reference values for oxygen saturations in young children living at moderate altitude and to assess the impact of upper respiratory infection (URI) on oxygen saturation. We hypothesized that oxygen saturations of sick children at the University of Utah, Salt Lake City (1,500 meters above sea level), would be lower than oxygen saturations of those who were well. Eighty well children and 74 children with URI and nasal congestion were recruited from the University of Utah Pediatric Clinic. Subjects were 2 to 23 months of age. Oxygen saturations were recorded at 1-minute intervals for 5 minutes, and an average value was then calculated for each child. Mean oxygen saturation for well children (range 96% to 100%, mean 98.9%) corresponded to reported values at sea level. Oxygen saturations of children with URI were significantly lower (mean 97.5%, P<.001). Although the difference between well and sick children was statistically significant, given the small difference, URI cannot be considered the cause of clinically significant oxygen desaturation in previously healthy children at moderate altitude.