Statistical methods for characterizing transfusion-related changes in regional oxygenation using Near-infrared spectroscopy (NIRS) in preterm infants

TL;DR

This paper introduces new statistical methods to analyze NIRS data for assessing intestinal oxygenation changes in preterm infants during blood transfusions, improving detection accuracy and power.

Contribution

The paper develops novel statistical measures and estimation techniques for analyzing mesenteric rSO2, enhancing the reliability of NIRS data interpretation in neonatal care.

Findings

Proposed MAUC and slope measures effectively characterize rSO2 levels and trends.

Methods show improved accuracy over standard approaches in simulations.

Application to clinical data demonstrates practical utility in detecting transfusion-related changes.

Abstract

Near infrared spectroscopy (NIRS) is an imaging-based diagnostic tool that provides non-invasive and continuous evaluation of regional tissue oxygenation in real-time. In recent years, NIRS has show promise as a useful monitoring technology to help detect relative tissue ischemia that could lead to significant morbidity and mortality in preterm infants. However, some issues inherent in NIRS technology use on neonates, such as wide fluctuation in signals, signal dropout and low limit of detection of the device, pose challenges that may obscure reliable interpretation of the NIRS measurements using current methods of analysis. In this paper, we propose new statistical methods to analyse mesenteric rSO2 (regional oxygenation) produced by NIRS to evaluate oxygenation in intestinal tissues and investigate oxygenation response to red blood cell transfusion (RBC) in preterm infants. We present a mean area under the curve (MAUC) measure and a slope measure to capture the mean rSO2 level and temporal trajectory of rSO2, respectively. Estimation methods are developed for these measures and nonparametric testing procedures are proposed to detect RBC-related changes in mesenteric oxygenation in preterm infants. Through simulation studies, we show that the proposed methods demonstrate improved accuracy in characterizing the mean level and changing pattern of mesenteric rSO2 and also increased statistical power in detecting RBC-related changes, as compared with standard approaches. We apply our methods to a NIRS study in preterm infants receiving RBC transfusion from Emory Univerity to evaluate the pre- and post-transfusion mesenteric oxygenation in preterm infants.