Pulse oximetry curves in healthy children living at moderate altitude: a cross-sectional study from the Ecuadorian Andes

Abstract

Background In populations above 3000 meters above sea level (m a.s.l.) normal values of oxygen saturation (SpO2) above 90% have been reported. Few studies have been conducted in cities of moderate altitude (between 2500 and 3000 m a.s.l.) We set out to describe the range of SpO2 values measured with a pulse oximeter in healthy children between 1 month and 12 years of age living in an Ecuadorian Andean city. Methods A cross-sectional study was carried out in Quito, Ecuador, located at 2800 m a.s.l. SpO2 measurement in healthy children of ages ranging from 1 month to 12 years of age living in the city were recorded by pulse oximetry. Age and gender were recorded, and 2.5th and 5th percentile were drawn. Nonparametric tests were used to compare differences in SpO2 values by age and gender. Results 1378 healthy children were eligible for the study, 719 (52.2%) males. Average SpO2 for the entire population was 94.5% (SD 1.70; 95%CI 94.41–94.59). No differences were observed between SpO2 values by age and gender. The SpO2 2.5 percentile value in the whole was 90%, in children under 5 years of age was 91% and it was 90% in children older than 7. Conclusions In cities of moderate altitude, the SpO2 percentile measures developed in healthy children may contribute to an improved decision-making process, especially in cases where resource availability is limited.