Reference Interval for Pulse Oxygen Saturation in Neonates at Different Altitudes: A Systematic Review

Area of Science:

• Neonatal Medicine
• Environmental Physiology
• Public Health

Background:

• Establishing accurate reference intervals for pulse oxygen saturation (SpO2) in neonates is crucial for clinical assessment.
• High-altitude environments present unique physiological challenges for newborns, necessitating altitude-specific SpO2 guidelines.
• Current reference intervals for neonatal SpO2 have not been defined for high-altitude populations.

Approach:

• A systematic review of published literature was conducted to identify studies reporting SpO2 in healthy neonates at varying altitudes.
• Multiple databases (PubMed, Embase, Cochrane Library, etc.) were searched from inception to August 2021.
• Data from seven cross-sectional studies were analyzed using Python v3.8 to establish prediction equations and determine reference intervals.

Key Points:

• Seven studies from diverse geographical locations (US, Mexico, Israel, Ecuador, China) were included, with quality ratings of high or moderate.
• Mean SpO2 values were collected for neonates across a wide range of altitudes (25 to 3,100 meters).
• A prediction equation was developed to calculate the lower limit of the SpO2 reference interval, which was then determined for different altitudes.

Conclusions:

• The lower limit of the reference interval for SpO2 in healthy neonates demonstrates a downward trend with increasing altitude.
• The findings provide a basis for understanding neonatal SpO2 at high altitudes.
• Further high-quality prospective studies are recommended to validate these established reference intervals.