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Published on: December 31, 2015
Perfusion Index in Very Low Birth Weight Premature Infants During Their First 2 Weeks of Life
Robin B Knobel-Dail1,2, David T Tanaka2, Diane Holditch-Davis1
11 Duke University School of Nursing, Durham, NC, USA.
Insights
Extremely premature infants show increased peripheral blood flow when foot temperature rises. Perfusion index (PI) can track this trend in the first two weeks of life.
Area of Science:
- Neonatal physiology
- Perinatal circulation
- Infant thermal regulation
Background:
- Extremely premature infants exhibit periods where foot temperature exceeds central temperature.
- Understanding peripheral perfusion in this population is crucial for thermal and circulatory stability.
- Clinical indicators like Perfusion Index (PI) lack established data in premature infants.
Purpose of the Study:
- To describe foot Perfusion Index (PI) values in premature infants during the first two weeks of life.
- To examine the relationship between foot temperature (FT) and PI over time in this cohort.
Main Methods:
- Exploratory case study design.
- Longitudinal monitoring of foot temperature (FT) and Perfusion Index (PI).
- Study included 17 infants born at <29 weeks' gestation and <1,200 g birth weight for 14 days post-birth.
Main Results:
- Mean PI across all infants was 1.04 (SD=0.79) over 14 days.
- Infants averaged 851 g birth weight and 24-29 weeks' gestational age.
- A positive relationship was confirmed between FT and PI using multilevel modeling.
Conclusions:
- Elevated foot temperature correlates with increased peripheral perfusion in extremely premature infants.
- Perfusion Index (PI) serves as a reliable trend indicator for peripheral perfusion.
- PI values demonstrated an increasing trend in the first two weeks for infants >750 g.
Background:
Our program of research focuses on thermal and circulatory stability in extremely premature infants. In prior studies, we found that infants have long periods of time in which foot temperature (FT) is higher than central temperature. We thus wanted to determine whether blood flow in the foot is increased when FT is elevated. Perfusion index (PI) can be used as a clinical indicator of peripheral perfusion, but reports on use of PI in premature infants are lacking. We employed exploratory methodology to examine foot perfusion and temperature in very low birth weight infants.
Aims:
For premature infants after birth: (1) describe foot PI values for the first 2 weeks of life and (2) describe the relationship of longitudinal FT and PI.
Study Design:
Case study design with longitudinal FT and PI in 17 infants born at <29 weeks' gestation with birth weight < 1,200 g for 2 weeks after birth.
Results:
Infants averaged 851 g at birth and were 24-29 weeks' gestational age. The mean PI across all infants for 14 days was 1.04, SD = 0.79. Using a repeated measures multilevel model approach confirmed that FT and PI were positively related in these infants.
Conclusions:
These findings demonstrate that perfusion is increased in the periphery in extremely premature infants when FT is increased. PI measures can be used as a trend for peripheral perfusion, and these values increase over the first 2 weeks of life in infants weighing more than 750 g.
