Revised threshold values for neonatal oxygen saturation at mild and moderate altitudes

The aim of this study was to determine reference values for oxygen saturation (SpO₂ ) in neonates at mild and moderate altitudes.

Our study included 41 097 consecutively born, asymptomatic neonates from 35 hospitals, located in Yunnan, China, with altitudes ranging from 267 to 2202 m. Pre-and post-ductal SpO₂ of each neonate was measured at 24 hours of age and before hospital discharge. All study participants, according to the altitude of birth, were categorised into three groups: low (0-500 m), mild (500-1500 m) and moderate altitude (1500-2500 m).

Every 1000-m increase in altitude was associated with a 1.54 per cent decrease in mean SpO₂ . The means of pre-ductal SpO₂ at low, mild and moderate groups were 97.9%, 96.4% and 95.5%, respectively. We used the 2.5th percentile of SpO₂ distribution as the cut-off for neonatal SpO₂ screening and defined new cut-off values of ≤93% for mild altitudes, ≤92% for moderate altitudes and no adjustment for low altitudes.

We recommend revised cut-off values for neonatal SpO₂ at mild and moderate altitudes and provide new values for paediatricians to refer to when screening neonates for severe congenital heart or lung diseases.