Development of a combined broadband near-infrared and diffusion correlation system for monitoring cerebral blood flow and oxidative metabolism in preterm infants.

Mamadou Diop,Vladislav Toronov,Jessica Kishimoto,David S C Lee,Keith St Lawrence

doi:10.1364/boe.6.003907

Abstract

Neonatal neuromonitoring is a major clinical focus of near-infrared spectroscopy (NIRS) and there is an increasing interest in measuring cerebral blood flow (CBF) and oxidative metabolism (CMRO2) in addition to the classic tissue oxygenation saturation (StO2). The purpose of this study was to assess the ability of broadband NIRS combined with diffusion correlation spectroscopy (DCS) to measured changes in StO2, CBF and CMRO2 in preterm infants undergoing pharmaceutical treatment of patent ductus arteriosus. CBF was measured by both DCS and contrast-enhanced NIRS for comparison. No significant difference in the treatment-induced CBF decrease was found between DCS (27.9 ± 2.2%) and NIRS (26.5 ± 4.3%). A reduction in StO2 (70.5 ± 2.4% to 63.7 ± 2.9%) was measured by broadband NIRS, reflecting the increase in oxygen extraction required to maintain CMRO2. This study demonstrates the applicability of broadband NIRS combined with DCS for neuromonitoring in this patient population.

Highlights

Preterm infants born at a very low birth weight (≤ 1500 g) are at high risk of brain injury, with 5-10% developing major disabilities such as cerebral palsy and 40-50% having longterm cognitive and behavioral deficits [1]
Acquisition of the near-infrared spectroscopy (NIRS) and diffusion correlation spectroscopy (DCS) data sets were coordinated around the pharmacological treatment of patent ductus arteriosus (PDA), which involved the infusion of intravenous indomethacin over 30 min at a dose of 0.2 mg/kg
The reduction in StO2 observed in the current study agrees with the concept of a compensatory adjustment in oxygen extraction, and these results demonstrate the ability of broadband NIRS to track changes in StO2 in a patient population

Summary

Introduction

Preterm infants born at a very low birth weight (≤ 1500 g) are at high risk of brain injury, with 5-10% developing major disabilities such as cerebral palsy and 40-50% having longterm cognitive and behavioral deficits [1]. There is a growing interest in alternative methods that can directly measure CBF and the cerebral metabolic rate of oxygen (CMRO2) since these are likely more sensitive markers of brain health than StO2 alone [10]. This has been shown in an animal model of neonatal brain injury in which CMRO2, and not tissue oxygenation, correlated with the duration of cerebral ischemia [11]

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Conclusion