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Transcutaneous Microcirculatory Imaging in Preterm Neonates
Published on: December 31, 2015
Perfusion Index in Preterm Infants during the First 3 Days of Life: Reference Values and Relation with Clinical
Thomas Alderliesten1, Petra M A Lemmers, Willem Baerts
1Department of Neonatology, Wilhelmina Children's Hospital/University Medical Center Utrecht, Utrecht, The Netherlands.
Insights
Perfusion index (PI) in neonates varies with clinical factors. This study establishes reference values for PI, showing its potential for monitoring neonatal hemodynamics and guiding interventions.
Area of Science:
- Neonatal physiology
- Cardiovascular monitoring
- Medical device technology
Background:
- Perfusion index (PI) from pulse oximetry reflects pulsatile arterial blood flow.
- PI correlates with cardiac performance and is readily available.
- Reference values and clinical associations for PI in neonates are currently lacking.
Purpose of the Study:
- Establish reference values for PI in premature infants.
- Determine the influence of common clinical conditions on PI.
Main Methods:
- Prospective monitoring of PI on the lower limb for 72 hours in 311 neonates (<32 weeks gestational age).
- Utilized longitudinal mixed-effects modeling, exploring linear, quadratic, and cubic models.
- Investigated main effects and interactions of clinical factors on PI.
Main Results:
- PI followed a squared model (0-24h) then linear (24-72h), lowest at 12-18h, increasing thereafter.
- Positive associations found with female gender, gestational age, and pulse pressure.
- Negative associations with SIMV/HFOV ventilation, dopamine, MAP, and SpO2; positive with PDA.
Conclusions:
- PI demonstrates variability influenced by multiple clinical conditions in neonates.
- The identified associations suggest PI's utility for monitoring neonatal hemodynamics.
- PI may serve as an additional tool to guide clinical interventions.
Background:
The perfusion index (PI) derived from pulse oximetry readings represents the ratio of pulsatile (arterial blood) and nonpulsatile contributors to infrared light absorption. PI has been shown to correlate with cardiac performance. In theory, PI is readily available on every pulse oximeter; therefore, no additional sensors or infant handling are required. Currently, reference values are lacking in (preterm) neonates and the association with common clinical conditions is unclear.
Objectives:
To establish reference values for the PI in premature infants and at the same time determine the influence of common clinical conditions.
Methods:
PI was prospectively monitored on the lower limb for 72 h in 311 neonates born with a gestational age <32 weeks between January 2011 and December 2013. Longitudinal mixed-effects modeling was used. Linear, quadratic, and cubic models were explored. Main effects and interactions were investigated.
Results:
A squared model (0-24 h) followed by a linear model (24-72 h) provided the best fit of the data. PI was lowest around 12-18 h after birth and showed a steady increase thereafter. PI was positively related with female gender, gestational age, and pulse pressure. Negative associations were found with SIMV/HFOV ventilation, dopamine administration, mean arterial blood pressure, and arterial oxygen saturation. Although more complex, the general association with a patent ductus arteriosus was positive.
Conclusion:
PI varied according to several clinical conditions. The association with common clinical factors suggests that PI might be used for monitoring neonatal hemodynamics and possibly as an additional guidance for interventions.
