Near-Infrared Spectroscopy Monitoring of Cerebral Oxygenation and Influencing Factors in Neonates from High-Altitude Areas

Abstract

<b><i>Background:</i></b> Accurate detection of cerebral oxygen saturation (rSO<sub>2</sub>) may be useful for neonatal brain injury prevention, and the normal range of rSO<sub>2</sub> of neonates at high altitude remained unclear. <b><i>Objective:</i></b> To compare cerebral rSO<sub>2</sub> and cerebral fractional tissue oxygen extraction (cFTOE) at high-altitude and low-altitude areas in healthy neonates and neonates with underlying diseases. <b><i>Methods:</i></b> 515 neonates from low-altitude areas and 151 from Tibet were enrolled. These neonates were assigned into the normal group, hypoxic-ischemic encephalopathy (HIE) group, and other diseases group. Near-infrared spectroscopy was used to measure rSO<sub>2</sub> in neonates within 24 h after admission. The differences of rSO<sub>2</sub>, pulse oxygen saturation (SpO<sub>2</sub>), and cFTOE levels were compared between neonates from low- and high-altitude areas. <b><i>Results:</i></b> (1) The mean rSO<sub>2</sub> and cFTOE levels in normal neonates from Tibet were 55.0 ± 6.4% and 32.6 ± 8.5%, significantly lower than those from low-altitude areas (<i>p</i> < 0.05). (2) At high altitude, neonates with HIE, pneumonia (<i>p</i> < 0.05), anemia, and congenital heart disease (<i>p</i> < 0.05) have higher cFTOE than healthy neonates. (3) Compared with HIE neonates from plain areas, neonates with HIE at higher altitude had lower cFTOE (<i>p</i> < 0.05), while neonates with heart disease in plateau areas had higher cFTOE than those in plain areas (<i>p</i> < 0.05). <b><i>Conclusions:</i></b> The rSO<sub>2</sub> and cFTOE levels in normal neonates from high-altitude areas are lower than neonates from the low-altitude areas. Lower cFTOE is possibly because of an increase in blood flow to the brain, and this may be adversely affected by disease states which may increase the risk of brain injury.

Predictive Utility of Near-Infrared Spectroscopy for the Outcomes of Hypoxic-Ischemic Encephalopathy: A Systematic Review and Meta-Analysis

“…Study characteristics and quality assessment: Nine studies published between 2012 and 2021 were included in the present study. Seven studies were prospective, and two were retrospective chart reviews [16,17]. The studies mainly included patients with moderate-to-severe HIE, with a sample size ranging from 10 to 666 patients.…”

Global Neonatal Research

“…In this issue of Neonatology, we have introduced a new section of the journal, Global Neonatal Research and published the first article from Tibet on near infrared spectroscopy monitoring of cerebral oxygen at high altitude [1]. Why have we decided to do this now?…”