Cerebral regional oxygen saturation trends in infants with hypoxic-ischemic encephalopathy

Machine learning models of cerebral oxygenation (rcSO2) for brain injury detection in neonates with hypoxic-ischaemic encephalopathy

The present study was designed to test the potential utility of regional cerebral oxygen saturation (rcSO2) in detecting term infants with brain injury. The study also examined whether quantitative rcSO2 features are associated with grade of hypoxic ischaemic encephalopathy (HIE). We analysed 58 term infants with HIE (>36 weeks of gestational age) enrolled in a prospective observational study. All newborn infants had a period of continuous rcSO2 monitoring and magnetic resonance imaging (MRI) assessment during the first week of life. rcSO2 Signals were pre-processed and quantitative features were extracted. Machine-learning and deep-learning models were developed to detect adverse outcome (brain injury on MRI or death in the first week) using the leave-one-out cross-validation approach and to assess the association between rcSO2 and HIE grade (modified Sarnat - at 1 h). The machine-learning model (rcSO2 excluding prolonged relative desaturations) significantly detected infant MRI outcome or death in the first week of life [area under the curve (AUC) = 0.73, confidence interval (CI) = 0.59-0.86, Matthew's correlation coefficient = 0.35]. In agreement, deep learning models detected adverse outcome with an AUC = 0.64, CI = 0.50-0.79. We also report a significant association between rcSO2 features and HIE grade using a machine learning approach (AUC = 0.81, CI = 0.73-0.90). We conclude that automated analysis of rcSO2 using machine learning methods in term infants with HIE was able to determine, with modest accuracy, infants with adverse outcome. De novo approaches to signal analysis of NIRS holds promise to aid clinical decision making in the future. KEY POINTS: Hypoxic-induced neonatal brain injury contributes to both short- and long-term functional deficits. Non-invasive continuous monitoring of brain oxygenation using near-infrared- spectroscopy offers a potential new insight to the development of serious injury. In this study, characteristics of the NIRS signal were summarised using either predefined features or data-driven feature extraction, both were combined with a machine learning approach to predict short-term brain injury. Using data from a cohort of term infants with hypoxic ischaemic encephalopathy, the present study illustrates that automated analysis of regional cerebral oxygen saturation rcSO2, using either machine learning or deep learning methods, was able to determine infants with adverse outcome.

Near-infrared spectroscopy monitoring of neonatal cerebrovascular reactivity: where are we now?

Cerebrovascular reactivity defines the ability of the cerebral vasculature to regulate its resistance in response to both local and systemic factors to ensure an adequate cerebral blood flow to meet the metabolic demands of the brain. The increasing adoption of near-infrared spectroscopy (NIRS) for non-invasive monitoring of cerebral oxygenation and perfusion allowed investigation of the mechanisms underlying cerebrovascular reactivity in the neonatal population, confirming important associations with pathological conditions including the development of brain injury and adverse neurodevelopmental outcomes. However, the current literature on neonatal cerebrovascular reactivity is mainly still based on small, observational studies and is characterised by methodological heterogeneity; this has hindered the routine application of NIRS-based monitoring of cerebrovascular reactivity to identify infants most at risk of brain injury. This review aims (1) to provide an updated review on neonatal cerebrovascular reactivity, assessed using NIRS; (2) to identify critical points that need to be addressed with targeted research; and (3) to propose feasibility trials in order to fill the current knowledge gaps and to possibly develop a preventive or curative approach for preterm brain injury. IMPACT: NIRS monitoring has been largely applied in neonatal research to assess cerebrovascular reactivity in response to blood pressure, PaCO2 and other biochemical or metabolic factors, providing novel insights into the pathophysiological mechanisms underlying cerebral blood flow regulation. Despite these insights, the current literature shows important pitfalls that would benefit to be addressed in a series of targeted trials, proposed in the present review, in order to translate the assessment of cerebrovascular reactivity into routine monitoring in neonatal clinical practice.

Association between Early Basal Ganglia and Thalami Perfusion Assessed by Color Doppler Ultrasonography and Brain Injury in Infants with Hypoxic-Ischemic Encephalopathy: A Prospective Cohort Study

OBJECTIVE

To evaluate associations between neurologic outcomes and early measurements of basal ganglia (BG) and thalamic (Th) perfusion using color Doppler ultrasonography (CDUS) in infants with hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

Prospective study of infants with mild (n = 18), moderate (n = 17), and severe HIE (n = 14) and controls (n = 17). Infants with moderate-severe HIE received therapeutic hypothermia (TH). CDUS was performed at 24-36 hours and brain magnetic resonance imaging (MRI) at a median of 10 days. Development was followed through 2.5-5 years. The primary outcome was the association between BG and Th perfusion and brain MRI injury. Secondary analyses focused on associations between perfusion measurements and admission neurologic examinations, MRI scores in infants treated with TH, and motor and sensory disability, or death. An exploratory analysis assessed the accuracy of BG and Th perfusion to predict brain MRI injury in infants treated with TH.

RESULTS

Increased BG and Th perfusion on CDUS was observed in infants with severe MRI scores and those with significant motor and neurosensory disability or death through 2.5-5 years (P < .05). Infants with severe HIE showed increased BG and Th perfusion (P < .005) compared with infants with moderate HIE. No differences were identified between the between the control and mild HIE groups. Th perfusion ≥0.237 cm/second (Area under the curve of 0.824) correctly classified 80% of infants with severe MRI scores.

CONCLUSIONS

Early dynamic CDUS of the BG and Th is a potential biomarker of severe brain injury in infants with HIE and may be a useful adjunct to currently used assessments.

Altered resting-state functional connectivity in newborns with hypoxic ischemic encephalopathy assessed using high-density functional near-infrared spectroscopy

Hypoxic-ischemic encephalopathy (HIE) results from a lack of oxygen to the brain during the perinatal period. HIE can lead to mortality and various acute and long-term morbidities. Improved bedside monitoring methods are needed to identify biomarkers of brain health. Functional near-infrared spectroscopy (fNIRS) can assess resting-state functional connectivity (RSFC) at the bedside. We acquired resting-state fNIRS data from 21 neonates with HIE (postmenstrual age [PMA] = 39.96), in 19 neonates the scans were acquired post-therapeutic hypothermia (TH), and from 20 term-born healthy newborns (PMA = 39.93). Twelve HIE neonates also underwent resting-state functional magnetic resonance imaging (fMRI) post-TH. RSFC was calculated as correlation coefficients amongst the time courses for fNIRS and fMRI data, respectively. The fNIRS and fMRI RSFC maps were comparable. RSFC patterns were then measured with graph theory metrics and compared between HIE infants and healthy controls. HIE newborns showed significantly increased clustering coefficients, network efficiency and modularity compared to controls. Using a support vector machine algorithm, RSFC features demonstrated good performance in classifying the HIE and healthy newborns in separate groups. Our results indicate the utility of fNIRS-connectivity patterns as potential biomarkers for HIE and fNIRS as a new bedside tool for newborns with HIE.

Unconjugated bilirubin is correlated with the severeness and neurodevelopmental outcomes in neonatal hypoxic-ischemic encephalopathy

Unconjugated bilirubin (UB) levels during the first week after birth are related to outcomes in neonatal hypoxic-ischemic encephalopathy (HIE). Clinical Sarnat staging of HIE, brain magnetic resonance imaging (MRI), hearing outcomes, and neurodevelopmental outcomes ≥ 1 year were used to correlate UB in 82 HIE patients. The initial UB level was significantly correlated with lactic acid levels. The peak UB was higher (p < 0.001) in stage I (10.13 ± 4.03 mg/dL, n = 34) than in stages II and III (6.11 ± 2.88 mg/dL, n = 48). Among the 48 patients receiving hypothermia treatment, a higher peak UB was significantly (p < 0.001) correlated with unremarkable brain MRI scans and unremarkable neurodevelopmental outcomes at age ≥ 1 year. The peak UB were higher (P = 0.015) in patients free of seizures until 1 year of age (6.63 ± 2.91 mg/dL) than in patients with seizures (4.17 ± 1.77 mg/dL). Regarding hearing outcomes, there were no significant differences between patients with and without hearing loss. The UB level in the first week after birth is an important biomarker for clinical staging, MRI findings, seizures after discharge before 1 year of age, and neurodevelopmental outcomes at ≥ 1 year of age.

Cerebral Tissue Oxygen Saturation Measurements in Perinatal Asphyxia Cases Treated with Therapeutic Hypothermia

Cerebral tissue oxygen saturation (CrSO2) measured with near-infrared spectroscopy (NIRS) technology has recently become the subject of several research studies. The aim of this study was to investigate the diagnostic value of CrSO2 measurements in perinatal asphyxia (PA) cases. The study included a patient group of 42 PA cases, who were to be applied with therapeutic hypothermia (TH), and a control group of 42 healthy term newborns. PA cases were determined as moderate or severe encephalopathy (Sarnat score stage II or III) in clinical evaluation. In both groups, left (CrSO2L) and right (CrSO2R) NIRS measurements were taken for 10 minutes on the scalp. The arithmetic mean value of measurements was calculated and compared. The mean measurements were CrSO2R 67.38 ± 9.39 and CrSO2L 66.73 ± 7.76 in the patient group, and CrSO2R 80.28 ± 8.04 and CrSO2L 79.14 ± 8.49 in the control group. The mean CrSO2R and CrSO2L measurements of the patient group were statistically significantly lower than those of the control group (p < 0.001). In the Pearson correlation analysis, a significant correlation was determined in the patient group between cord blood gas pH and CrSO2R (r: 0.539, p < 0.001) and CrSO2L (r: 0.54, p < 0.001). For a cutoff value of CrSO2L ≤ 72%, the positive predictive value was 80 and the negative predictive value was 84.6. For a cutoff value of CrSO2R ≤ 74%, the positive predictive value was 79.5 and the negative predictive value was 82.5. Low CrSO2 measurements obtained with the NIRS method in PA cases to be applied with TH together with cord blood gas parameters can be considered a helpful parameter in diagnosis.

The Use of Cerebral Near-Infrared Spectroscopy in Neonatal Hypoxic-Ischemic Encephalopathy: A Systematic Review of the Literature

BACKGROUND

Cerebral near-infrared spectroscopy (cNIRS) is a noninvasive technology used to trend cerebral perfusion at the bedside. cNIRS has potential as a valuable tool in the evaluation of infants with suspected hypoxic-ischemic encephalopathy (HIE). Trending cerebral perfusion with cNIRS can provide information regarding cerebral metabolism as HIE is evolving, which may offer insight into the extent of brain injury.

PURPOSE

The purpose of this systematic review is to investigate the use of cNIRS as a neurocritical tool in the management of neonatal HIE by evaluating its ability to detect acute neurological compromise, including acute brain injury and seizure activity, as well as its potential to identify infants at high risk for long-term neurodevelopmental impairment.

METHODS

A literature search was conducted using PubMed, CINAHL, and Web of Science databases to review articles investigating cNIRS technology in the acute management of HIE.

RESULTS

Eight studies were identified and included in this systematic review. Correlations were observed between cNIRS trends and neurological outcomes as later detected by MRI. cNIRS has potential as a bedside neuromonitoring tool in the management of HIE to detect infants at high risk for brain injury.

IMPLICATIONS FOR PRACTICE

Existing research supports the value of trending cNIRS in HIE management. Documented normal cNIRS values for both term and preterm infants in the first few days of life is approximately 60% to 80%. A steadily increasing cNIRS reading above an infant's baseline and a value of more than 90% should prompt further evaluation and concern for significant neurological injury.

Cerebral oxygen saturation in neonates: a bedside comparison between neonatal and adult NIRS sensors

BACKGROUND

The majority of neonatal NIRS literature recommends target ranges for cerebral saturation (rScO2) based on data using adult sensors. Neonatal sensors are now commonly used in the neonatal intensive care unit (NICU). However, there is limited clinical data correlating these two measurements of cerebral oxygenation.

METHODS

A prospective observational study was conducted in two NICUs between November 2019 and May 2021. An adult sensor was placed on infants undergoing routine cerebral NIRS monitoring with a neonatal sensor. Time-synchronized rScO2 measurements from both sensors, heart rate, and systemic oxygen saturation values were collected over 6 h under varying clinical conditions and compared.

RESULTS

Time-series data from 44 infants demonstrated higher rScO2 measurements with neonatal sensors than with adult sensors; however, the magnitude of the difference varied depending on the absolute value of rScO2 (Adult = 0.63 × Neonatal + 18.2). While there was an approximately 10% difference when adult sensors read 85%, readings were similar when adult sensors read 55%.

CONCLUSION

rScO2 measured by neonatal sensors is typically higher than measured by adult sensors, but the difference is not fixed and is less at the threshold indicative of cerebral hypoxia. Assuming fixed differences between adult and neonatal sensors may lead to overdiagnosis of cerebral hypoxia.

IMPACT

In comparison to adult sensors, neonatal sensors rScO2 readings are consistently higher, but the magnitude of the difference varies depending on the absolute value of rScO2. Marked variability during high and low rScO2 readings was noted, with approximately 10% difference when adult sensors read 85%, but nearly similar (58.8%) readings when adult sensors read 55%. Estimating fixed differences of approximately 10% between adult and neonatal probes may lead to an inaccurate diagnosis of cerebral hypoxia and result in subsequent unnecessary interventions.

Association of cerebral metabolic rate following therapeutic hypothermia with 18-month neurodevelopmental outcomes after neonatal hypoxic ischemic encephalopathy

BACKGROUND

Therapeutic hypothermia (TH) is standard of care for moderate to severe neonatal hypoxic ischemic encephalopathy (HIE) but many survivors still suffer lifelong disabilities and benefits of TH for mild HIE are under active debate. Development of objective diagnostics, with sensitivity to mild HIE, are needed to select, guide, and assess response to treatment. The objective of this study was to determine if cerebral oxygen metabolism (CMRO2) in the days after TH is associated with 18-month neurodevelopmental outcomes as the first step in evaluating CMRO2's potential as a diagnostic for HIE. Secondary objectives were to compare associations with clinical exams and characterise the relationship between CMRO2 and temperature during TH.

METHODS

This was a prospective, multicentre, observational, cohort study of neonates clinically diagnosed with HIE and treated with TH recruited from the tertiary neonatal intensive care units (NICUs) of Boston Children's Hospital, Brigham and Women's Hospital, and Beth Israel Deaconess Medical Center between December 2015 and October 2019 with follow-up to 18 months. In total, 329 neonates ≥34 weeks gestational age admitted with perinatal asphyxia and suspected HIE were identified. 179 were approached, 103 enrolled, 73 received TH, and 64 were included. CMRO2 was measured at the NICU bedside by frequency-domain near-infrared and diffuse correlation spectroscopies (FDNIRS-DCS) during the late phases of hypothermia (C), rewarming (RW) and after return to normothermia (NT). Additional variables were body temperature and clinical neonatal encephalopathy (NE) scores, as well as findings from magnetic resonance imaging (MRI) and spectroscopy (MRS). Primary outcome was the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) at 18 months, normed (SD) to 100 (15).

FINDINGS

Data quality for 58 neonates was sufficient for analysis. CMRO2 changed by 14.4% per °C (95% CI, 14.2-14.6) relative to its baseline at NT while cerebral tissue oxygen extraction fraction (cFTOE) changed by only 2.2% per °C (95% CI, 2.1-2.4) for net changes from C to NT of 91% and 8%, respectively. Follow-up data for 2 were incomplete, 33 declined and 1 died, leaving 22 participants (mean [SD] postnatal age, 19.1 [1.2] month; 11 female) with mild to moderate HIE (median [IQR] NE score, 4 [3-6]) and 21 (95%) with BSID-III scores >85 at 18 months. CMRO2 at NT was positively associated with cognitive and motor composite scores (β (SE) = 4.49 (1.55) and 2.77 (1.00) BSID-III points per 10-10 moL/dl × mm2/s, P = 0.009 and P = 0.01 respectively; linear regression); none of the other measures were associated with the neurodevelopmental outcomes.

INTERPRETATION

Point of care measures of CMRO2 in the NICU during C and RW showed dramatic changes and potential to assess individual response to TH. CMRO2 following TH outperformed conventional clinical evaluations (NE score, cFTOE, and MRI/MRS) at predicting cognitive and motor outcomes at 18 months for mild to moderate HIE, providing a promising objective, physiologically-based diagnostic for HIE.

FUNDING

This clinical study was funded by an NIH grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, United States (R01HD076258).

Biomarkers of hypoxic-ischemic encephalopathy: a systematic review

BACKGROUND

Current diagnostic criteria for hypoxic-ischemic encephalopathy in the early hours lack objective measurement tools. Therefore, this systematic review aims to identify putative molecules that can be used in diagnosis in daily clinical practice (PROSPERO ID: CRD42021272610).

DATA SOURCES

Searches were performed in PubMed, Web of Science, and Science Direct databases until November 2020. English original papers analyzing samples from newborns > 36 weeks that met at least two American College of Obstetricians and Gynecologists diagnostic criteria and/or imaging evidence of cerebral damage were included. Bias was assessed by the Newcastle-Ottawa Scale. The search and data extraction were verified by two authors separately.

RESULTS

From 373 papers, 30 met the inclusion criteria. Data from samples collected in the first 72 hours were extracted, and increased serum levels of neuron-specific enolase and S100-calcium-binding protein-B were associated with a worse prognosis in newborns that suffered an episode of perinatal asphyxia. In addition, the levels of glial fibrillary acidic protein, ubiquitin carboxyl terminal hydrolase isozyme-L1, glutamic pyruvic transaminase-2, lactate, and glucose were elevated in newborns diagnosed with hypoxic-ischemic encephalopathy. Moreover, pathway analysis revealed insulin-like growth factor signaling and alanine, aspartate and glutamate metabolism to be involved in the early molecular response to insult.

CONCLUSIONS

Neuron-specific enolase and S100-calcium-binding protein-B are potential biomarkers, since they are correlated with an unfavorable outcome of hypoxic-ischemic encephalopathy newborns. However, more studies are required to determine the sensitivity and specificity of this approach to be validated for clinical practice.

Cerebral Blood Flow of the Neonatal Brain after Hypoxic-Ischemic Injury

OBJECTIVE

Hypoxic-ischemic encephalopathy (HIE) in infants can have long-term adverse neurodevelopmental effects and markedly reduce quality of life. Both the initial hypoperfusion and the subsequent rapid reperfusion can cause deleterious effects in brain tissue. Cerebral blood flow (CBF) assessment in newborns with HIE can help detect abnormalities in brain perfusion to guide therapy and prognosticate patient outcomes.

STUDY DESIGN

The review will provide an overview of the pathophysiological implications of CBF derangements in neonatal HIE, current and emerging techniques for CBF quantification, and the potential to utilize CBF as a physiologic target in managing neonates with acute HIE.

CONCLUSION

The alterations of CBF in infants during hypoxia-ischemia have been studied by using different neuroimaging techniques, including nitrous oxide and xenon clearance, transcranial Doppler ultrasonography, contrast-enhanced ultrasound, arterial spin labeling MRI, 18F-FDG positron emission tomography, near-infrared spectroscopy (NIRS), functional NIRS, and diffuse correlation spectroscopy. Consensus is lacking regarding the clinical significance of CBF estimations detected by these different modalities. Heterogeneity in the imaging modality used, regional versus global estimations of CBF, time for the scan, and variables impacting brain perfusion and cohort clinical characteristics should be considered when translating the findings described in the literature to routine practice and implementation of therapeutic interventions.

KEY POINTS

· Hypoxic-ischemic injury in infants can result in adverse long-term neurologic sequelae.. · Cerebral blood flow is a useful biomarker in neonatal hypoxic-ischemic injury.. · Imaging modality, variables affecting cerebral blood flow, and patient characteristics affect cerebral blood flow assessment..

Partial wavelet coherence as a robust method for assessment of neurovascular coupling in neonates with hypoxic ischemic encephalopathy

In neonates with hypoxic ischemic encephalopathy, the computation of wavelet coherence between electroencephalogram (EEG) power and regional cerebral oxygen saturation (rSO2) is a promising method for the assessment of neurovascular coupling (NVC), which in turn is a promising marker for brain injury. However, instabilities in arterial oxygen saturation (SpO2) limit the robustness of previously proposed methods. Therefore, we propose the use of partial wavelet coherence, which can eliminate the influence of SpO2. Furthermore, we study the added value of the novel NVC biomarkers for identification of brain injury compared to traditional EEG and NIRS biomarkers. 18 neonates with HIE were monitored for 72 h and classified into three groups based on short-term MRI outcome. Partial wavelet coherence was used to quantify the coupling between C3-C4 EEG bandpower (2-16 Hz) and rSO2, eliminating confounding effects of SpO2. NVC was defined as the amount of significant coherence in a frequency range of 0.25-1 mHz. Partial wavelet coherence successfully removed confounding influences of SpO2 when studying the coupling between EEG and rSO2. Decreased NVC was related to worse MRI outcome. Furthermore, the combination of NVC and EEG spectral edge frequency (SEF) improved the identification of neonates with mild vs moderate and severe MRI outcome compared to using EEG SEF alone. Partial wavelet coherence is an effective method for removing confounding effects of SpO2, improving the robustness of automated assessment of NVC in long-term EEG-NIRS recordings. The obtained NVC biomarkers are more sensitive to MRI outcome than traditional rSO2 biomarkers and provide complementary information to EEG biomarkers.

Newer indications for neuromonitoring in critically ill neonates

Continuous neuromonitoring in the neonatal intensive care unit allows for bedside assessment of brain oxygenation and perfusion as well as cerebral function and seizure identification. Near-infrared spectroscopy (NIRS) reflects the balance between oxygen delivery and consumption, and use of multisite monitoring of regional oxygenation provides organ-specific assessment of perfusion. With understanding of the underlying principles of NIRS as well as the physiologic factors which impact oxygenation and perfusion of the brain, kidneys and bowel, changes in neonatal physiology can be more easily recognized by bedside providers, allowing for appropriate, targeted interventions. Amplitude-integrated electroencephalography (aEEG) allows continuous bedside evaluation of cerebral background activity patterns indicative of the level of cerebral function as well as identification of seizure activity. Normal background patterns are reassuring while abnormal background patterns indicate abnormal brain function. Combining brain monitoring information together with continuous vital sign monitoring (blood pressure, pulse oximetry, heart rate and temperature) at the bedside may be described as multi-modality monitoring and facilitates understanding of physiology. We describe 10 cases in critically ill neonates that demonstrate how comprehensive multimodal monitoring provided greater recognition of the hemodynamic status and its impact on cerebral oxygenation and cerebral function thereby informing treatment decisions. We anticipate that there are numerous other uses of NIRS as well as NIRS in conjunction with aEEG which are yet to be reported.

Optimal neuromonitoring techniques in neonates with hypoxic ischemic encephalopathy

Neonates with hypoxic ischemic encephalopathy (HIE) are at significant risk for adverse outcomes including death and neurodevelopmental impairment. Neuromonitoring provides critical diagnostic and prognostic information for these infants. Modalities providing continuous monitoring include continuous electroencephalography (cEEG), amplitude-integrated electroencephalography (aEEG), near-infrared spectroscopy (NIRS), and heart rate variability. Serial bedside neuromonitoring techniques include cranial ultrasound and somatic and visual evoked potentials but may be limited by discrete time points of assessment. EEG, aEEG, and NIRS provide distinct and complementary information about cerebral function and oxygen utilization. Integrated use of these neuromonitoring modalities in addition to other potential techniques such as heart rate variability may best predict imaging outcomes and longer-term neurodevelopment. This review examines available bedside neuromonitoring techniques for the neonate with HIE in the context of therapeutic hypothermia.

Near-infrared spectroscopy in the medical management of infants

Near-infrared spectroscopy (NIRS) is a technology that is easy to use and can provide helpful information about organ oxygenation and perfusion by measuring regional tissue oxygen saturation (rSO2) with near-infrared light. The sensors can be placed in different anatomical locations to monitor rSO2 levels in several organs. While NIRS is not without limitations, this equipment is now becoming increasingly integrated into modern healthcare practice with the goal of achieving better outcomes for patients. It can be particularly applicable in the monitoring of pediatric patients because of their size, and especially so in infant patients. Infants are ideal for NIRS monitoring as nearly all of their vital organs lie near the skin surface which near-infrared light penetrates through. In addition, infants are a difficult population to evaluate with traditional invasive monitoring techniques that normally rely on the use of larger catheters and maintaining vascular access. Pediatric clinicians can observe rSO2 values in order to gain insight about tissue perfusion, oxygenation, and the metabolic status of their patients. In this way, NIRS can be used in a non-invasive manner to either continuously or periodically check rSO2. Because of these attributes and capabilities, NIRS can be used in various pediatric inpatient settings and on a variety of patients who require monitoring. The primary objective of this review is to provide pediatric clinicians with a general understanding of how NIRS works, to discuss how it currently is being studied and employed, and how NIRS could be increasingly used in the near future, all with a focus on infant management.

Prognostic value of somatosensory-evoked potentials in the newborn with hypoxic-ischemic encephalopathy after the introduction of therapeutic hypothermia

To establish the ability of somatosensory-evoked potentials (SEPs) to detect neurological damage in neonatal patients with hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia (TH). Retrospective study including 84 neonates ≥ 36 weeks of gestational age with HIE and TH with SEPs performed in the first 14 days of life. SEPs from the median nerve were performed after completion of TH. Either unilateral or bilateral absence of N20, or unilateral or bilateral latency ≥ 36 ms, was considered pathological. All newborns underwent a cerebral resonance imaging (MRI) at between days 7 and 14 of life and a neurodevelopmental evaluation using the Brunet-Lezine test at two years of age; a global Brunet-Lezine test score < 70 was considered unfavorable. The risk of moderate-to-severe alteration on basal ganglia-thalamic (BGT) and/or white matter areas on MRI for pathological SEPs was as follows: odds ratio 95% IC: 23.1 (6.9-76.9), sensitivity 78.6%, specificity 86.3%, positive predictive value 75.9%, and negative predictive value 88%. The BGT and internal capsule were the areas with the greatest risk of lesion with an altered SEPs: odds ratio 95% IC 93.1 (11.1-777.8). The risk of neurodevelopmental impairment for pathological SEPs was odds ratio 95% IC: 38.5 (4.4-335.3), sensitivity 91.7%, specificity 77.8% positive predictive value 52.4%, and negative predictive value 97.2%.

CONCLUSION

The present study demonstrates the good predictive capacity of SEPs performed in the first two weeks of life in newborns with HIE and TH to detect an increased risk of neuroimaging lesions and neurodevelopmental impairment at two years of age.

WHAT IS KNOWN

• Bilateral absence of the N20 cortical component of somatosensory evoked potentials has been associated with poor neurological outcome in neonates with hypoxic-ischemic encephalopathy.

WHAT IS NEW

• This work confirms the predictive capacity of SEPs by adding two important aspects: the value of latency when interpreting SEPs results and the absence of effect of the hypothermia method used on the results of SEPs.

Protecting brains and saving futures guidelines: A prospective, multicenter, and observational study on the use of telemedicine for neonatal neurocritical care in Brazil

Background

Management of high-risk newborns should involve the use of standardized protocols and training, continuous and specialized brain monitoring with electroencephalography (EEG), amplitude integrated EEG, Near Infrared Spectroscopy, and neuroimaging. Brazil is a large country with disparities in health care assessment and some neonatal intensive care units (NICUs) are not well structured with trained personnel able to provide adequate neurocritical care. To reduce this existing gap, an advanced telemedicine model of neurocritical care called Protecting Brains and Saving Futures (PBSF) Guidelines was developed and implemented in a group of Brazilian NICUs.

Methods

A prospective, multicenter, and observational study will be conducted in all 20 Brazilian NICUs using the PBSF Guidelines as standard-of-care. All infants treated accordingly to the guidelines during Dec 2021 to Nov 2024 will be eligible. Ethical approval was obtained from participating centers. The primary objective is to describe adherence to the PBSF Guidelines and clinical outcomes, by center and over a 3-year period. Adherence will be measured by quantification of neuromonitoring, neuroimaging exams, sub-specialties consultation, and clinical case discussions and videoconference meetings. Clinical outcomes of interest are detection of seizures during hospitalization, use of anticonvulsants, inotropes, and fluid resuscitation, death before hospital discharge, length of hospital stay, and referral of patients to specialized follow-up.

Discussion

The study will provide evaluation of PBSF Guidelines adherence and its impact on clinical outcomes. Thus, data from this large prospective, multicenter, and observational study will help determine whether neonatal neurocritical care via telemedicine can be effective. Ultimately, it may offer the necessary framework for larger scale implementation and development of research projects using remote neuromonitoring.

Trial registration

NCT03786497, Registered 26 December 2018, https://www.clinicaltrials.gov/ct2/show/NCT03786497?term=protecting+brains+and+saving+futures&draw=2&rank=1.

Does Early Cerebral Near-Infrared Spectroscopy Monitoring Predict Outcome in Neonates with Hypoxic Ischaemic Encephalopathy? A Systematic Review of Diagnostic Test Accuracy

INTRODUCTION

Hypoxic ischaemic encephalopathy (HIE) remains one of the top 10 contributors to the global burden of disease. Early objective biomarkers are required. Near-infrared spectroscopy (NIRS) may provide a valuable insight into cerebral perfusion and metabolism. We aimed to determine whether early NIRS monitoring (<6 h of age) can predict outcome as defined by grade of encephalopathy, brain MRI findings, and/or neurodevelopmental outcome at 1-2 years in infants with HIE.

METHODS

We searched PubMed, Scopus, Web of Science, Embase, and The Cochrane Library databases (July 2019). Studies of infants born ≥36+0 weeks gestation with HIE who had NIRS recording commenced before 6 h of life were included. We planned to provide a narrative of all the studies included, and if similar clinically and methodologically, the results would be pooled in a meta-analysis to determine test accuracy.

RESULTS

Seven studies were included with a combined total of 161 infants. Only 1 study included infants with mild HIE. A range of different oximeters and probes were utilized with varying outcome measures making comparison difficult. Although some studies showed a trend towards higher cSO2 values before 6 h in infants with adverse neurodevelopmental outcomes, in the majority, this was not significant until beyond 24 h of life.

CONCLUSION

Very little data currently exists to assess the use of early NIRS to predict outcome in infants with HIE. Further studies using a standardized approach are required before NIRS can be evaluated as a potential objective assessment tool for early identification of at-risk infants.

Impact of Cerebral Oxygen Saturation Monitoring on Short-term Neurodevelopmental Outcomes in Neonates with Encephalopathy - A Prospective Cohort Study

BACKGROUND

Near-infrared spectroscopy (NIRS) has been used for monitoring cerebral oxygen saturation (rSO2) in neonates. There is a lack of data from low-middle income countries (LMIC) setting of cerebral rSO2 in neonates with encephalopathy of diverse etiologies. This study aimed to monitor cerebral rSO2 using NIRS in encephalopathic neonates to maintain the rSO2 between 55 to 85 % in the first 72 hours of admission to improve short-term neurodevelopmental outcomes (NDO).

MATERIALS AND METHODS

This prospective cohort study enrolled encephalopathic neonates with hypoxic- ischemic encephalopathy (HIE) and non-HIE etiologies into 8 clinical categories. The cerebral rSO2 was monitored and targeted to be between 55 to 85 %, with predefined actions and management alterations over 72 hours. The neurodevelopmental assessment was conducted at 3, 6, and 9-12 months corrected age. Moreover, the motor and mental developmental quotients (MoDQ) (MeDQ) were recorded and compared to historical control.

RESULTS

A total of 120 neonates were enrolled and assessed for NDO. The MoDQ (mean ± SD) was 92.55 ± 14.85, 93.80 ± 13.20, 91.02 ± 12.69 and MeDQ (mean ± SD) was 91.80 ± 12.98, 91.80 ± 13.69, 88.41 ± 11.60 at 3, 6 and 9-12 months. The MoDQ and MeDQ scores of the historic cohort at 12 months were 86.35 ± 20.34 and 86.58 ± 18.27. The mean difference [MD (95 %CI)] for MoDQ was - 4.670 (- 8.48 to - 0.85) (p=0.0165) and for MeDQ was - 1.83 (- 5.26 to 1.6) (p=0.29). There was a negative correlation between the composite developmental quotient (CoDQ) with mean rSO2 and a positive correlation with cerebral fractional tissue oxygen extraction (CFTOE). Neonates with HIE and neonatal encephalopathy (NE) (n=37/120) had the lowest motor and mental DQ on neurodevelopmental assessment. Clinical categories, neonatal meningitis (NM), and intraventricular hemorrhage (IVH) improved in DQ scores over the study period.

CONCLUSION

Monitoring and maintaining cerebral rSO2 between 55-85 % through appropriate management changes improved neurodevelopmental scores at the 12-month follow-up in neonates with encephalopathy caused by varied etiologies.

Bedside and laboratory neuromonitoring in neonatal encephalopathy

Several bedside and laboratory neuromonitoring tools are currently used in neonatal encephalopathy (NE) to assess 1) brain function [amplitude-integrated electroencephalogram (aEEG) and EEG], 2) cerebral oxygenation delivery and consumption [near-infrared spectroscopy (NIRS)] and 3) blood and cerebrospinal fluid biomarkers. The aim of the review is to provide the role of neuromonitoring in understanding the development of brain injury in these newborns and better predict their long-term outcome. Simultaneous use of these monitoring modalities may improve our ability to provide meaningful prognostic information regarding ongoing treatments. Evidence will be summarized in this review for each of these modalities, by describing (1) the methods, (2) the clinical evidence in context of NE both before and with hypothermia, and (3) the research and future directions.

Near-Infrared Spectroscopy: Clinical Use in High-Risk Neonates

In this review, we describe the near-infrared spectroscopy (NIRS) technology and its clinical use in high-risk neonates in critical care settings. We searched databases (e.g., PubMed, Google Scholar, EBSCOhost) to find studies describing the use of NIRS on critically ill and high-risk neonates. Near-infrared spectroscopy provides continuous noninvasive monitoring of venous oxygen saturation. It uses technology similar to pulse oximetry to measure the oxygen saturation of hemoglobin in a tissue bed to describe the relative delivery and extraction of oxygen. Near-infrared spectroscopy can be a valuable bedside tool to provide clinicians indirect evidence of perfusion. It may prompt early interventions that promote oxygen delivery, which can improve high-risk neonatal outcomes.

Role of Optical Neuromonitoring in Neonatal Encephalopathy-Current State and Recent Advances

Neonatal encephalopathy (NE) in term and near-term infants is a significant global health problem; the worldwide burden of disease remains high despite the introduction of therapeutic hypothermia. Assessment of injury severity and effective management in the neonatal intensive care unit (NICU) relies on multiple monitoring modalities from systemic to brain-specific. Current neuromonitoring tools provide information utilized for seizure management, injury stratification, and prognostication, whilst systemic monitoring ensures multi-organ dysfunction is recognized early and supported wherever needed. The neuromonitoring technologies currently used in NE however, have limitations in either their availability during the active treatment window or their reliability to prognosticate and stratify injury confidently in the early period following insult. There is therefore a real need for a neuromonitoring tool that provides cot side, early and continuous monitoring of brain health which can reliably stratify injury severity, monitor response to current and emerging treatments, and prognosticate outcome. The clinical use of near-infrared spectroscopy (NIRS) technology has increased in recent years. Research studies within this population have also increased, alongside the development of both instrumentation and signal processing techniques. Increasing use of commercially available cerebral oximeters in the NICU, and the introduction of advanced optical measurements using broadband NIRS (BNIRS), frequency domain NIRS (FDNIRS), and diffuse correlation spectroscopy (DCS) have widened the scope by allowing the direct monitoring of oxygen metabolism and cerebral blood flow, both key to understanding pathophysiological changes and predicting outcome in NE. This review discusses the role of optical neuromonitoring in NE and why this modality may provide the next significant piece of the puzzle toward understanding the real time state of the injured newborn brain.

Theoretical basis for the use of non-invasive thermal measurements to assess the brain injury in newborns undergoing therapeutic hypothermia

The aim of this paper is to propose a new non-invasive methodology to estimate thermogenesis in newborns with perinatal asphyxia (PA) undergoing therapeutic hypothermia (TH). Metabolic heat production (with respect to either a neonate’s body mass or its body surface) is calculated from the newborn’s heat balance, estimating all remaining terms of this heat balance utilising results of only non-invasive thermal measurements. The measurement devices work with standard equipment used for therapeutic hypothermia and are equipped with the Global System for Mobile Communications (GSM), which allows one to record and monitor the course of the therapy remotely (using an internet browser) without disturbing the medical personnel. This methodology allows one to estimate thermogenesis in newborns with perinatal asphyxia undergoing therapeutic hypothermia. It also offers information about instantaneous values of the rate of cooling together with values of remaining rates of heat transfer. It also shows the trend of any changes, which are recorded during treatment. Having information about all components of the heat balance one is able to facilitate comparison of results obtained for different patients, in whom these components may differ. The proposed method can be a new tool for measuring heat balance with the possibility of offering better predictions regarding short-term neurologic outcomes and tailored management in newborns treated by TH.

Near-Infrared spectroscopy for perfusion assessment and neonatal management

Term and preterm infants often present with adverse conditions after birth resulting in abnormal vital functions and severe organ failure, which are associated or sometimes caused by low oxygen and/or blood supply. Brain injury may lead to substantial mortality and morbidity often affecting long-term outcome. Standard monitoring techniques in the NICU focus on arterial oxygen supply and hemodynamics and include respiratory rate, heart rate, blood pressure and arterial oxygen saturation as measured by pulse oximetry but provide only limited information on end organ oxygen delivery. Near-Infrared Spectroscopy can bridge this gap by displaying continuous measurements of tissue oxygen saturation, providing information on the balance of oxygen delivery and consumption in organs of interest. Future techniques using multi-wavelength devices may provide additional information on oxidative metabolism in real time adding important information.

MiR224-5p Inhibitor Restrains Neuronal Apoptosis by Targeting NR4A1 in the Oxygen-Glucose Deprivation (OGD) Model

This study was designed to investigate the molecular mechanism of stroke and to explore the effect of miR-224-5p in hypoxic cortical neurons. Firstly, we established a middle cerebral artery occlusion (MCAO) model with Sprague–Dawley rats. Triphenyltetrazolium chloride (TTC) staining showed the brain infarction of an MCAO rat. Longa scores of rats were significantly increased in 12th, 24th, and 48th hours after MCAO. Then, we found that miR-224-5p was increased after MCAO in rats by qRT-PCR. In order to investigate the effect of miR-224-5p in hypoxic neurons, we established an oxygen-glucose deprivation (OGD) model with cortical neurons. MiR-224-5p was also upregulated in neurons after OGD by qRT-PCR. After transfection of the miR-224-5p inhibitor, the number of neurons in the anti-miR-224-5p group significantly increased (P < 0.01) in comparison to the anti-NC group. Furthermore, Tuj1⁺ (neuronal marker) staining and TUNEL assay (to detect apoptotic cells) were performed in neurons. The survival of neurons in the anti-miR-224-5p group was significantly improved (P < 0.01), while the apoptosis of neurons in the anti-miR-224-5p group was significantly decreased (P < 0.01), when compared with that of the anti-NC group. In addition, we predicted that potential target genes of miR-224-5p were nuclear receptor subfamily 4 group A member 1 (NR4A1), interleukin 1 receptor antagonist (IL1RN), and ring finger protein 38 (RNF38) with bioinformatics databases, such as TargetScan, miRDB, miRmap, and miRanda. The result of qRT-PCR confirmed that NR4A1 was significantly decreased after hypoxic injury (P < 0.01). Meanwhile, luciferase reporter’s assay indicated that NR4A1 was the direct target of miR-224-5p. Compared with the anti-miR-224-5p + siNC group, the number of cortical neurons and the length of the neuron axon in the anti-miR-224-5p + si-NR4A1 group were significantly decreased (P < 0.01), and the number of neuronal apoptosis in the anti-miR-224-5p + si-NR4A1 group was increased (P < 0.01). In conclusion, miR-224-5p played a crucial role in hypoxic neuron injury through NR4A1, which might be an important regulatory mechanism in OGD injury of neurons.

Cerebral Near Infrared Spectroscopy Monitoring in Term Infants With Hypoxic Ischemic Encephalopathy-A Systematic Review

Background: Neonatal hypoxic ischemic encephalopathy (HIE) remains a significant cause of mortality and morbidity worldwide. Cerebral near infrared spectroscopy (NIRS) can provide cot side continuous information about changes in brain hemodynamics, oxygenation and metabolism in real time. Objective: To perform a systematic review of cerebral NIRS monitoring in term and near-term infants with HIE. Search Methods: A systematic search was performed in Ovid EMBASE and Medline database from inception to November 2019. The search combined three broad categories: measurement (NIRS monitoring), disease condition [hypoxic ischemic encephalopathy (HIE)] and subject category (newborn infants) using a stepwise approach as per PRISMA guidance. Selection Criteria: Only human studies published in English were included. Data Collection and Analysis: Two authors independently selected, assessed the quality, and extracted data from the studies for this review. Results: Forty-seven studies on term and near-term infants following HIE were identified. Most studies measured multi-distance NIRS based cerebral tissue saturation using monitors that are referred to as cerebral oximeters. Thirty-nine studies were published since 2010; eight studies were published before this. Fifteen studies reviewed the neurodevelopmental outcome in relation to NIRS findings. No randomized study was identified. Conclusion: Commercial NIRS cerebral oximeters can provide important information regarding changes in cerebral oxygenation and hemodynamics following HIE and can be particularly helpful when used in combination with other neuromonitoring tools. Optical measurements of brain metabolism using broadband NIRS and cerebral blood flow using diffuse correlation spectroscopy add additional pathophysiological information. Further randomized clinical trials and large observational studies are necessary with proper study design to assess the utility of NIRS in predicting neurodevelopmental outcome and guiding therapeutic interventions.

Impaired Right Ventricular Performance Is Associated with Adverse Outcome after Hypoxic Ischemic Encephalopathy

Rationale: Asphyxiated neonates with hypoxic ischemic encephalopathy (HIE) are at risk of myocardial dysfunction; however, echocardiography studies are limited and little is known about the relationship between hemodynamics and brain injury.Objectives: To analyze the association between severity of myocardial dysfunction and adverse outcome as defined by the composite of death and/or abnormal magnetic resonance imaging.Methods: Neonates with HIE undergoing therapeutic hypothermia were enrolled. Participants underwent echocardiography at 24 hours, 72 hours (before rewarming), and 96 hours (after rewarming). Cerebral hemodynamics were monitored by near-infrared spectroscopy and middle cerebral artery Doppler.Measurements and Main Results: Fifty-three patients with a mean gestation and birthweight of 38.8 ± 2.0 weeks and 3.33 ± 0.6 kg, respectively, were recruited. Thirteen patients (25%) had mild encephalopathy, 27 (50%) had moderate encephalopathy, and 13 (25%) had severe encephalopathy. Eighteen patients (34%) had an adverse outcome. Severity of cardiovascular illness (P < 0.001) and severity of neurologic insult (P = 0.02) were higher in neonates with adverse outcome. Right ventricle (RV) systolic performance at 24 hours was substantially lower than published normative data in all groups. At 24 hours, lower tricuspid annular plane systolic excursion (P = 0.004) and RV fractional area change (P < 0.001), but not pulmonary hypertension, were independently associated with adverse outcome on logistic regression. High brain regional oxygen saturation (P = 0.007) and low middle cerebral artery resistive index (P = 0.04) were associated with RV dysfunction on post hoc analysis.Conclusions: RV dysfunction is associated with the risk of adverse outcome in asphyxiated patients with HIE undergoing hypothermia. Echocardiography may be a valuable diagnostic and prognostic tool in this vulnerable population.

Retinal haemorrhage rates and resolution time of retinal haemorrhage in newborns after hypothermic treatment for hypoxic-ischemic encephalopathy

PURPOSE

The aim of this study was to evaluate retinal hemorrhages (RHs) in newborns after therapeutic hypothermia performed for hypoxic-ischemic encephalopathy (HIE).

METHODS

From 2014 January to October 2016, full-term newborns who were referred to us from the neonatal intensive care unit at our hospital for ophthalmological examination were evaluated retrospectively. Neonates diagnosed with HIE were examined with a RetCam Digital Retinal Camera (Massie Research Laboratories Inc., Pleasanton, CA) using a 130-degree or binocular indirect ophthalmoscope (Heine, Herrsching, Germany) imaging tool and were classified into three groups. Group 1 included patients without HIE, group 2 included patients with stage I HIE, and group 3 included patients with stage II or III HIE. The RH rates in cases of HIE were retrospectively reviewed.

RESULTS

A total of 148 eyes of 74 patients were included in the study. RH was detected in 36 eyes (24.3%); there were two eyes (3.7%), 14 eyes (20.6%), and 20 eyes (76.9%), in groups 1, 2, and 3, respectively. In group 3, RH was mostly seen in a widespread form. RHs involving the macula were resorbed later than haemorrhages in other locations.

CONCLUSION

RHs are frequent in neonates with HIE. RHs were seen significantly more frequently in stage II-III HIE. These haemorrhages may require treatment, especially when the macula is involved.

MicroRNA-204 may participate in the pathogenesis of hypoxic-ischemic encephalopathy through targeting KLLN

Hypoxic-ischemic encephalopathy (HIE) is a common neonatal disease that can lead to high neonatal mortality rates. Previous studies have indicated that microRNAs (miRs) may be involved in the pathogenesis of HIE; however, the specific mechanisms underlying their involvement require further investigation. The aim of the present study was to investigate the roles of miR-204 and its target gene killin p53 regulated DNA replication inhibitor (KLLN) in HIE using rat HIE models. Brain injury was induced by surgery and incubation of hypoxic incubator brain using 10-day-old pup rats. On day 3, rats were sacrificed, and the infarct size of the brain was determined using a tetrazolium chloride assay. Terminal deoxynucleotidyl transferase UTP nick-end labeling staining was performed to detect the cell death rate in the brain tissue. Following this, the brain tissues were collected, and reverse transcription-quantitative polymerase chain reaction, western blot analysis and immunohistochemistry assays were performed to examine the expression levels of miR-204 and KLLN. Furthermore, neurons were cultured and transfected with miR-204 inhibitors or mimics, and the effect of miR-204 on the proliferation and apoptosis of neurons was examined using MTT and flow cytometric assays. Finally, a dual-luciferase reporter assay was performed to confirm whether KLLN is a direct target of miR-204. The expression of miR-204 was significantly downregulated and the expression of KLLN was significantly increased in the brain tissue of HIE rats (P<0.001). In addition, the transfection with miR-204 inhibitors significantly decreased the proliferation rates and significantly increased the apoptosis rate of neurons; however, transfection with miR-204 mimics prompted the opposite results. The dual-luciferase reporter assay also confirmed that KLLN is a direct target of miR-204. Taken together, the results of the present study demonstrated that miR-204 was downregulated in HIE and that miR-204 may serve important roles in the pathogenesis of HIE through targeting KLLN.

Near-Infrared Spectroscopy in the Diagnostic Evaluation of Mitochondrial Disorders: A Neonatal Intensive Care Unit Case Series

We assessed the utility of near-infrared spectroscopy to evaluate neonates with mitochondrial disorders. We observed abnormally high cerebral oxygen saturation levels indicating insufficient tissue oxygen utilization. We propose that near-infrared spectroscopy may be an additional tool in the diagnostic evaluation of a suspected mitochondrial disorder.

Lack of Variability in Cerebral Oximetry Tendency in Infants with Severe Hypoxic-Ischemic Encephalopathy Under Hypothermia

Cerebral oximetry using near-infrared spectroscopy (NIRS) provides continuous, noninvasive assessment of the degree of hemoglobin saturation of the brain tissue. Previous studies suggest that high values of regional cerebral tissue oxygen saturation (rScO₂) during the first days in neonates with significant hypoxic-ischemic encephalopathy (HIE) are correlated with an adverse neurological outcome. However, the results are not consistent among the studies. To examine the correlation of rScO₂ values and their variability over time with HIE severity, amplitude integrated electroencephalography (aEEG) background and seizure activity, neuron-specific enolase levels in cerebrospinal fluid, magnetic resonance imaging (MRI) findings, and neurological outcome. Retrospective study that included all consecutive infants with moderate-to-severe HIE born at ≥35 weeks gestational age admitted between January 2011 and December 2014. NIRS monitoring was initiated at admission and maintained during therapeutic hypothermia up to 12 hours after rewarming. To analyze rScO₂, different periods (0-6, 6-24, 24-48, 48-72, and 72-100 hours of life) and three ranges (<55%, 55-90%, >90%) were considered. Variability in each patient was considered ≤5% when changes in rScO₂ values in all periods were ≤5%. Twenty-three newborns were included. Infants who suffered from severe HIE, seizures, abnormal aEEG background, altered MRI or death, and abnormal outcome had rScO₂ values >90% and with less variability (≤5%). rScO₂ values >90% and a lack of variability over time in infants with HIE during cooling provide useful information about the severity of neurological status.

NIRS improves hemodynamic monitoring and detection of risk for cerebral injury: cases in the neonatal intensive care nursery

Near-infrared spectroscopy (NIRS) monitoring provides a noninvasive, bedside measure of cerebral and somatic oxygenation in neonates at risk for hemodynamic instability and brain injury. This technology has been increasingly utilized in the neonatal intensive care unit, however, clinicians perceive a lack of evidence for the added value of NIRS monitoring. We present six clinical scenarios illustrating the value of NIRS monitoring for the diagnosis and management of critically ill newborns.