Am J Perinatol
DOI: 10.1055/s-0041-1735870
Original Article

Correlation between Perfusion Index and Left Ventricular Output in Healthy Late Preterm Infants

Ayça Aytekin*
1  Department of Pediatrics, Sıtkı Koçman University School of Medicine, Muğla, Turkey
Nilay Hakan*
2  Department of Neonatology, Sıtkı Koçman University School of Medicine, Muğla, Turkey
Özkan İlhan
2  Department of Neonatology, Sıtkı Koçman University School of Medicine, Muğla, Turkey
Mustafa Aydin
3  Neonatology Department, Firat University School of Medicine, Elazig, Turkey
Haşim Olgun
4  Department of Pediatric Cardiology, Sıtkı Koçman University School of Medicine, Muğla, Turkey
› Author Affiliations
Funding None.


Aim The perfusion index (PI) is a noninvasive marker derived from photoelectric plethysmographic signals in pulse oximetry in the evaluation of peripheral perfusion. This study was aimed to determine the correlation between PI and left ventricular output (LVO) in healthy late preterm infants at 48th hour of life.

Methods With new generation pulse oximeter (MASIMO Rad 7 Oximeter) pre- and post-ductal PI values were recorded from healthy late preterm babies at the 48th hour of life. PI was determined simultaneously with LVO as measured by transthoracic echocardiography.

Results A total of 50 late preterm babies were included in the study. The mean gestational age of the cases was 35.4 ± 0.7 weeks and the birth weight was 2,586 ± 362 g. Mean pre- and post-ductal PI values at the postnatal 48th hour of babies' life were found to be 2.0 ± 0.9 and 1.7 ± 1.1. The mean LVO value was 438 ± 124, LVO/kg 175 ± 50. When the LVO value was normalized according to the babies' body weight, there was no statistically significant correlation between the pre- and post-ductal PI and the LVO/kg value (r <0.2, p >0.05 in both comparisons).

Conclusion There was no correlation between pre- and post-ductal PI and LVO values in healthy late preterm infants. This may be due to the failure of the LVO, a systemic hemodynamic parameter, to accurately reflect microvascular blood flow due to incomplete maturation of the sympathetic nervous system involved in the regulation of peripheral tissue perfusion in preterm babies.

Key Points

  • No correlation found between PI and LOV in preterm babies.

  • LVO cannot adequately reflect peripheral blood flow.

  • Sympathetic nervous system is immature in preterm infants.

Authors' Contributions

N.H. and H.O. contributed toward concept of the study. N.H. and A.A. designed the study. M.A. and H.O. did the supervision. Ö.İ. and A.A. collected the materials. A.A., Ö.İ., and H.O. did the data collection and/or processing. A.A., Ö.İ., and M.A. did the literature review. A.A., N.H., and Ö.İ wrote the manuscript. H.O. did the echocardiographic evaluation. and N.H., M.A., and H.O. did the critical review.

Ethics Approval

The study was approved by our faculty of ethics committee (date: May 02, 2019 and decision no: 08/II).

Consent to Participate

Formal and written consents were obtained from the study subjects' parent.

Consent for Publication

All authors would like to publish their manuscript in American Journal of Perinatology.

* Both authors contributed equally to the article.

Publication History

Received: 24 May 2021

Accepted: 27 July 2021

Publication Date:
20 September 2021 (online)

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