Am J Perinatol 2018; 35(14): 1411-1418
DOI: 10.1055/s-0038-1660458
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Regional Tissue Oxygen Extraction and Severity of Anemia in Very Low Birth Weight Neonates: A Pilot NIRS Analysis

Jonathan P. Mintzer
1  Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Stony Brook Children's Hospital, Stony Brook, New York
,
Boriana Parvez
2  Division of Newborn Medicine, Department of Pediatrics, Maria Fareri Children's Hospital, Westchester Medical Center, Valhalla, New York
,
Edmund F. La Gamma
2  Division of Newborn Medicine, Department of Pediatrics, Maria Fareri Children's Hospital, Westchester Medical Center, Valhalla, New York
› Author Affiliations
Funding This study was supported in part by an unrestricted equipment use grant from Somanetics (now Medtronic, Boulder, CO).
Further Information

Publication History

08 January 2018

30 April 2018

Publication Date:
15 June 2018 (online)

Abstract

Objective Anemia causes blood flow redistribution and altered tissue metabolic behavior to sustain homeostatic oxygen consumption. We hypothesized that anemia severity would correlate with increased regional fractional tissue oxygen extraction among premature neonates.

Study Design Regional oxygen extraction was calculated using pulse oximetry and near-infrared spectroscopy data among neonates <1,250 g during their first 10 postnatal days. Oxygen extraction was assessed for correlations with raw hematocrit levels and following grouping into hematocrit quartiles.

Results Twenty-seven neonates with gestational age 27 ± 2 weeks and birth weight 966 ± 181 g underwent 116 hematocrit determinations. Cerebral and flank oxygen extraction inversely correlated with hematocrit (cerebral r = −0.527, p = 0.005; flank r = −0.485, p = 0.01). Increased cerebral oxygen extraction was observed for the lowest three hematocrit quartiles (Q1 0.26 ± 0.08, p = 0.004; Q2 0.24 ± 0.09, p = 0.01; Q3 0.25 ± 0.09, p = 0.03; all compared with Q4 0.18 ± 0.10). Increased flank oxygen extraction occurred for the lowest two quartiles (Q1 0.36 ± 0.12, p < 0.001; Q2 0.35 ± 0.11, p < 0.001; compared with Q4 0.22 ± 0.13). Splanchnic oxygen extraction demonstrated no similar correlations.

Conclusion Increases in tissue oxygen extraction may indicate early pathophysiologic responses to nascent anemia in premature neonates.