Prospective observational study on assessing the hemodynamic relevance of patent ductus arteriosus with frequency domain near-infrared spectroscopy

Abstract

BackgroundWhat constitutes a hemodynamically relevant patent ductus arteriosus (hrPDA) in preterm infants is unclear. Different clinical and echocardiographic parameters are used, but a gold standard definition is lacking.Our objective was to evaluate associations between regional cerebral tissue oxygen saturation (rcStO2), fraction of tissue oxygen extraction (rcFtO2E) measured by frequency domain near-infrared spectroscopy (fd-NIRS) and their correlation to echocardiographic, Doppler-ultrasound, and clinical parameters in preterm infants with and without a hrPDA.MethodsIn this prospective observational study, 22 infants < 1500 g (mean [± SD]: gestational age 28.6 [±1.8] weeks, birth weight 1076 [±284] g, median (interquartile range) postnatal age at measurement 7.6 (4.6–12.9) d) with a clinical suspicion of hrPDA were analysed.Twelve infants had left-to-right shunt through PDA, and in 6 of these the PDA was classified as hrPDA based on pre-defined clinical and echocardiographic criteria. fd-NIRS, echocardiographic and Doppler-ultrasound examinations were performed. After identification of blood hemoglobin (Hb) as confounding factor, rcStO2 and rcFtO2E were corrected for this effect.ResultsOverall mean ± standard deviation (normalised to a median Hb of 13.8 mg/dl) was 57 ±5% for rcStO2 and 0.39 ±0.05 for rcFtO2E. Comparing no-hrPDA with hrPDA infants, there were no significant differences in mean rcStO2 (58 ±5% vs. 54 ±5%; p = .102), but in mean rcFtO2E (0.38 ±0.05 vs. 0.43 ±0.05; p = .038). Echocardiographic parameter and Doppler indices did not correlate with cerebral oxygenation.ConclusionOxygen transport capacity of the blood may confound NIRS data interpretation. Cerebral oxygenation determined by fd-NIRS provided additional information for PDA treatment decisions not offered by routine investigations. Whether indicating PDA therapy based on echocardiography complemented by data on cerebral oxygenation results in better outcomes should be investigated in future studies.

Interpretation of Cerebral Oxygenation Changes in the Preterm Infant

“…However, other studies report stable cNIRS values despite showing differences in mean arterial blood pressure (MABP) and abdominal rSO 2 values. It is recognised that with preservation of cerebral autoregulation, perfusion may be maintained in the face of a hsPDA [ 39 , 40 , 41 , 42 , 43 ].…”

“…There are many physiological variables that influence the haemodynamic significance of a PDA including the oxygen carrying capacity of the blood, fluid and respiratory status, shunt severity, and autoregulatory capacity of the infant. Additionally, echocardiographic indices may not correlate directly with impaired cerebral oxygenation [ 39 , 41 ]. Therefore a thorough evaluation of the entire physiological status of the infant is required to determine the haemodynamic significance of a PDA.…”

Clinical Application of Near-Infrared Spectroscopy in Neonates

“…How ever, the interpretation of cerebral rSO2 values in relation to ductus arteriosus remains controversial. Schwarz et al 33) found higher cerebral FTOE (0.43± 0.05 vs. 0.38±0.05, P=0.038) but no difference in cerebral rSO2 (54%±5% vs. 58%±5%, P=0.102) when they compared preterm infants with HSDA to those without HSDA.…”

Frequency-Domain Techniques for Cerebral and Functional Near-Infrared Spectroscopy

“…Multi-distance methods (see Section "Multi-Distance Methods") have been employed for absolute measurements of cerebral concentration and/or saturation of hemoglobin in newborn piglets (Fantini et al, 1999;Zhang et al, 2000), in rats (Culver et al, 2003), in newborn and infants (Franceschini et al, 2007;Grant et al, 2009;Roche-Labarbe et al, 2010Lin et al, 2013b, Lin T.-Y. et al, 2016Dehaes et al, 2014Dehaes et al, , 2015Demel et al, 2014bDemel et al, , 2015Farzam et al, 2017;Ferradal et al, 2017;Schwarz et al, 2018), and in adults under normal conditions (Fantini et al, 2003;Gatto et al, 2006Gatto et al, , 2007McIntosh et al, 2010;Hallacoglu et al, 2012Hallacoglu et al, , 2013Scholkmann et al, 2013a;Clancy et al, 2015;Kainerstorfer et al, 2015;Yang and Dunn, 2015;Moreau et al, 2016;Davies et al, 2017;Blaney et al, 2019;Pham et al, 2019), under anesthesia (Paisansathan et al, 2007;Meng et al, 2012a,b), hypoxia (Davies et al, 2017), pathological conditions such as multiple sclerosis (Yang and Dunn, 2015), stroke (Moreau et al, 2016), traumatic brain injury (Davies et al, 2019), before and during electro-convulsive therapy (ECT) (Fabbri et al, 2003), during neurovascular surgery …”