Comparison of oxygen saturation levels by pulse oximetry in healthy children aged 1 month to 5 years residing at an altitude of 1500 metres and at sea level

Abstract

To compare oxygen saturation levels (SaO(2)) by pulse oximetry among healthy Indian children aged from 1 month to 5 years age residing at two different altitudes, Chennai and the Shervaroy hills. Prospective observational study with a control group at sea level. SETTING 1: Chennai city which is at sea level (data published previously). SETTING 2: The Shervaroy hills (Yercaud, Salem district, Tamil Nadu) about 1500 metres above sea level (this study). 328 healthy children aged 1 month to 5 years living in the Shervaroy hills. After assessment of anthropometry and heart and respiratory rates, oxygen saturation was recorded by pulse oximetry. The mean SaO(2) values of children in the Shervaroy hills in the age groups 1 month to 3 years and 3-5 years were 97% and 98%, respectively. The mean -2 SD O(2) saturation values for the 1 month to 5 years age group was 93%. The overall mean and median values of oxygen saturation were 97% in the Shervaroy hills vs 99% for children in Chennai city (p<0.01). When compared with their counterparts in Chennai, the Shervaroy hills subjects had significantly lower mean weight and height and higher heart and respiratory rates (p<0.01). The reference value for mean SaO(2) in healthy children aged 1 month to 5 years in the Shervaroy hills (1500 m) was 97%, with the (-2 SD) values having a mean of 93% which is significantly lower than those living in Chennai (sea level), 99% of whom had a -2 SD mean of 96.6%.