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Updated: Mar 8, 2026
Hemodynamic Precision in the Neonatal Intensive Care Unit using Targeted Neonatal Echocardiography
Published on: January 27, 2023
Relationship between perfusion index and patent ductus arteriosus in preterm infants
Enrique Gomez-Pomar1, Majd Makhoul2, Philip M Westgate3
1Division of Neonatology, Department of Pediatrics, University of Kentucky, Lexington, Kentucky.
Insights
Continuous monitoring of the difference in perfusion index (ΔPI) can effectively detect a hemodynamically significant patent ductus arteriosus (PDA) in preterm infants. This noninvasive method offers a promising bedside tool for early diagnosis.
Area of Science:
- Neonatal Physiology
- Cardiovascular Monitoring
- Medical Diagnostics
Background:
- Perfusion index (PI) is a noninvasive measure of tissue perfusion.
- The difference between pre- and postductal PI (ΔPI) may identify hemodynamically significant patent ductus arteriosus (PDA).
- Previous studies were limited by brief, intermittent ΔPI sampling.
Purpose of the Study:
- To assess the diagnostic value of continuous, high-resolution ΔPI monitoring for PDA in preterm infants.
- To evaluate the relationship between ΔPI measures and PDA diagnosis confirmed by echocardiography.
Main Methods:
- Continuous ΔPI monitoring was performed prospectively in preterm infants using high-resolution pulse oximeters.
- Analysis included ΔPI mean and variability, and pre- and postductal PI over a 4-hour period before echocardiography.
- A cardiologist blinded to PI results diagnosed PDA via echocardiography; linear mixed regression models were used.
Main Results:
- Lower mean ΔPI (-0.23 vs. 0.16; P < 0.05) and mean pre-PI (0.86 vs. 1.26; P < 0.05) were observed in infants with PDA.
- Higher ΔPI variability (0.39 vs. 0.61; P = 0.05) was associated with the absence of PDA.
- These measures, taken 4 hours prior to echocardiography, differentiated infants with and without PDA.
Conclusions:
- Continuous ΔPI monitoring, including mean values and variability, effectively detects PDA in preterm infants.
- The dynamic nature of PI necessitates continuous assessment.
- Perfusion index monitoring is a promising, noninvasive bedside tool for identifying PDA in this population.
Background:
Perfusion index (PI) is a noninvasive measure of perfusion. ΔPI (difference between pre- and postductal PI) may identify hemodynamically significant PDA. However, studies are limited to brief and intermittent ΔPI sampling. Our objective is to assess the value of continuous high resolution ΔPI monitoring in the diagnosis of PDA.
Methods:
Continuous ΔPI monitoring in preterm infants was prospectively performed using two high-resolution pulse oximeters. Perfusion Index measures (ΔPI mean and variability, pre- and postductal PI) were analyzed over a 4-h period prior to echocardiography. A cardiologist blinded to the results evaluated for PDA on echocardiography. Linear mixed regression models were utilized for analyses.
Results:
We obtained 31 echocardiography observations. Mean ΔPI (-0.23 vs. 0.16; P < 0.05), mean pre-PI (0.86 vs. 1.26; P < 0.05), and ΔPI variability (0.39 vs. 0.61; P = 0.05) were lower in infants with PDA compared to infants without PDA at the time of echocardiography.
Conclusion:
Mean ΔPI, ΔPI variability, and mean pre-PI measured 4 h prior to echocardiography detect PDA in preterm infants. PI is dynamic and should be assessed continuously. Perfusion index is a promising bedside measurement to identify PDA in preterm infants.
