Peripheral perfusion index in well newborns at 6 to 72 h of life at different altitudes: a multi-center study in China
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Published on: March 4, 2022
Wei Hua1, Conway Niu2, Yan Xuan3
1Children's Hospital of Fudan University, Shanghai, China.
Insights
Peripheral perfusion index (PPI) in newborns increases with altitude. This study provides crucial reference values for healthy infants at varying altitudes, suggesting adjustments for accurate hemodynamic monitoring.
Area of Science:
- Neonatal physiology
- Altitude medicine
- Hemodynamic monitoring
Background:
- Monitoring hemodynamics is critical for neonates.
- Peripheral Perfusion Index (PPI) is a reliable, non-invasive index for early detection of tissue perfusion and oxygenation issues.
- Existing PPI reference ranges may not account for altitude variations.
Purpose of the Study:
- To establish reference ranges for peripheral perfusion index (PPI) in asymptomatic newborns.
- To investigate the influence of different altitudes on PPI values in neonates.
- To provide altitude-specific PPI reference values for improved neonatal care.
Main Methods:
- A prospective cohort study involving 4257 asymptomatic newborns across various altitudes (4 to 4200m) in China.
- Peripheral Perfusion Index (PPI) was measured pre- and post-ductal at 6, 12, 24, 48, and 72 hours after birth.
- Statistical analysis, including Lambda Mu Sigma method and linear mixed-effects regression, was used to generate reference curves and assess altitude's impact.
Main Results:
- Peripheral Perfusion Index (PPI) values, both pre- and post-ductal, demonstrated a statistically significant increase with rising altitude.
- Reference curves for PPI in newborns at low, mild, moderate, and high altitudes showed relative similarity, except for significantly different values at higher altitudes (≥4000m).
- The study successfully obtained comprehensive PPI reference values for newborns aged 6 to 72 hours across a wide range of altitudes.
Conclusions:
- Newborn peripheral perfusion index (PPI) values increase significantly with altitude.
- Altitude-specific reference values for PPI are necessary for accurate interpretation of hemodynamic status in neonates.
- Clinical thresholds for PPI in asymptomatic neonates should be adapted based on local altitude to ensure optimal patient management.
Abstract:
The purpose of this study is to obtain the reference range of peripheral perfusion index (PPI) of asymptomatic well newborns at 6 to 72 h of life at different altitudes. A population-based prospective cohort study was conducted in cities at different altitudes in China. Asymptomatic well newborns were enrolled consecutively from six hospitals with an altitude of 4 to 4200 m between February 1, 2020, and April 15, 2021. PPI was measured at 6, 12, 24, 48, and 72 h after birth on the right hand (pre-ductal) and either foot (post-ductal) using a Masimo SET Radical-7 oximeter. Fiftieth percentile reference curves of the pre- and post-ductal PPI values at 6-72 h after birth were generated using the Lambda Mu Sigma method. Linear mixed-effects regression was performed to determine the influence of different altitude levels on PPI values over different measurement time points. A total of 4257 asymptomatic well newborns were recruited for analysis. The median and quartile pre- and post-ductal PPI values at 6-72 h of life at different altitudes were 1.70 (1.20, 2.60) and 1.70 (1.10, 2.70) for all infants, 1.30 (1.10, 1.90) and 1.10 (0.88, 1.80) for infants at low altitude, 1.40 (1.00, 2.00) and 1.30 (0.99, 2.00) at mild altitudes, 1.90 (1.30, 2.50) and 1.80 (1.20, 2.70) at moderate altitudes, 1.80 (1.40, 3.50) and 2.20 (1.60, 4.30) for high altitudes, 3.20 (2.70, 3.70), and 3.10 (2.10, 3.30) for higher altitudes, respectively. Overall, both pre- and post-ductal PPI increased with altitude. The 50th percentile curves of pre- and post-ductal PPI values in well newborns at mild, low, moderate, and high altitudes were relatively similar, while the difference between the PPI curves of infants at higher altitudes and other altitudes was significantly different. Conclusions: With the increase of altitude, pre- and post-ductal PPI of newborns increases. Our study obtained the PPI reference values of asymptomatic well newborns at 6 to 72 h after birth at different altitudes from 4 to ≥ 4000 m. What is Known: • Monitoring hemodynamics is very important to neonates. As an accurate and reliable hemodynamic monitoring index, PPI can detect irreversible damage caused by insufficient tissue perfusion and oxygenation early, directly, noninvasively, and continuously. What is New: • Our study obtained the PPI reference values of asymptomatic well newborns at 6 to 72 h after birth at different altitudes from 4 to ≥ 4000 m. With the increase of altitude, pre- and post-ductal PPI of newborns increase with statistical significance. Therefore, the values and disease thresholds of PPI for asymptomatic neonates should be modified according to altitudes.
