Evaluating a Targeted Bedside Measure of Cerebral Perfusion in a Nonhuman Primate Model of Neonatal Hypoxic-Ischemic Encephalopathy

Hypoxic Ischemic Encephalopathy Indicators of Sarnat and Sarnat Scoring in Neonatal Subjects with Perinatal Asphyxia

Objectives

Hypoxic-ischemic encephalopathy (HIE) is still a relevant cause of neonatal mortality and morbidity. HIE severity can predict long-term outcomes. Sarnat staging is one of the most common methods used to evaluate HIE severity. However, an ongoing urge exists to find other accurate and affordable ways to accompany this clinical staging for HIE. This study aimed to evaluate the relationship between cerebral arteries' resistive indices and other hypoxic-ischemic encephalopathy indicators using Sarnat scoring of newborns subjected to perinatal asphyxia.

Materials & Methods

In this retrospective study, 76 neonates with gestational age ≥34 weeks affected with HIE were investigated. The patients were categorized into three groups according to Sarnat staging: I, II, and III. Initially, perinatal data were analyzed to assess the correlation between HIE severity and various factors such as gestational age, type of delivery, Apgar scores, necessity for resuscitation, and requirement for respiratory assistance. Notably, these relationships were significant.

Results

Examining various symptoms in different HIE stages showed that the incidence of coagulopathy was significantly higher in severe HIE neonates than in mild neonates. Eventually, proposedly, cranial arterial Doppler indices, i.e., the anterior cerebral artery's resistive index (RI), significantly differed between HIE stage groups.

Conclusion

This study represented a combination of available and affordable data to achieve early HIE staging, including perinatal data, clinical symptoms, and a bedside Doppler ultrasonography of cerebral perfusion. Higher cranial artery RI was associated with severe HIE and could be considered for therapeutic hypothermia, which may reduce HIE mortality and morbidity.

Neonatal neurosonography practices: a survey of active Society for Pediatric Radiology members

BACKGROUND

While neonatal brain US is emerging as an imaging modality with greater portability, widespread availability and relative lower cost compared to MRI, it is unknown whether US is being maximized in infants to increase sensitivity in detecting intracranial pathology related to common indications such as hemorrhage, ischemia and ventriculomegaly.

OBJECTIVE

To survey active members of the Society for Pediatric Radiology (SPR) regarding their utilization of various cranial US techniques and reporting practices in neonates.

MATERIALS AND METHODS

We distributed an online 10-question survey to SPR members to assess practice patterns of neonatal cranial US including protocol details, use of additional sonographic views, perceived utility of spectral Doppler evaluation, and germinal matrix hemorrhage and ventricular size reporting preferences.

RESULTS

Of the 107 institutions represented, 90% of respondents were split evenly between free-standing children's hospitals and pediatric departments attached to a general hospital. We found that most used template reporting (72/107, 67%). The anterior fontanelle approach was standard practice (107/107, 100%). We found that posterior fontanelle views (72% sometimes, rarely or never) and high-frequency linear probes to evaluate far-field structures (52% sometimes, rarely or never) were seldom used. Results revealed a range of ways to report germinal matrix hemorrhage and measure ventricular indices to assess ventricular dilatation. There was substantial intra-institutional protocol and reporting variability as well.

CONCLUSION

Our results demonstrate high variability in neurosonography practice and reporting among active SPR members, aside from the anterior fontanelle views, template reporting and linear high-resolution near-field evaluation. Standardization of reporting germinal matrix hemorrhage and ventricular size would help ensure a more consistent application of neonatal US in research and clinical practice.

Does abnormal Doppler on cranial ultrasound predict disability in infants with hypoxic-ischaemic encephalopathy? A systematic review

AIM

To evaluate whether abnormal resistive index or cerebral blood flow velocity (CBFV) on cranial ultrasound predicts disability (≥1 year) in infants with hypoxic-ischaemic encephalopathy (HIE).

METHOD

This was a systematic review and meta-analysis of studies comparing developmental outcomes of infants with HIE with normal versus abnormal resistive index or CBFV.

RESULTS

Twenty-six studies were included (pre-therapeutic hypothermia era, 20; therapeutic hypothermia era, six). Data from 15 studies (pre-therapeutic hypothermia, 10; therapeutic hypothermia, five) were available for meta-analysis. Pooled sensitivity and specificity, summary area under the receiver operating characteristic curve, and diagnostic odds ratio of resistive index or CBFV for predicting 'death or severe disability' were as follows. Pre-therapeutic hypothermia era: 0.83 (95% confidence interval [CI] 0.45-0.97) and 0.92 (95% CI 0.74-0.98), 0.94 (95% CI 0.92-0.96), 54 (95% CI 7-391). Therapeutic hypothermia era (measurements before therapeutic hypothermia): 0.62 (95% CI 0.41-0.80) and 0.96 (95% CI 0.88-0.99), 0.93 (95% CI 0.89-0.94), 23 (95% CI 6-91). Therapeutic hypothermia era (measurements during/after therapeutic hypothermia): 0.51 (95% CI 0.24-0.78) and 0.83 (95% CI 0.73-0.90), 0.81 (95% CI 0.78-0.85), 5 (95% CI 2-13). Overall Grading of Recommendations Assessment, Development and Evaluation (GRADE) rating of evidence was 'low' or 'very low'.

INTERPRETATION

Low-level evidence suggests that abnormal resistive index or CBFV can predict death or disability with high sensitivity and specificity in infants with HIE who are not cooled. The specificity of these tests was high when performed before starting cooling in infants who received therapeutic hypothermia.

WHAT THIS PAPER ADDS

Cerebral doppler ultrasound may be useful in predicting death or disability in infants with hypoxic-ischaemic encephalopathy who are not cooled. Cerebral doppler ultrasound may also be useful in infants who are cooled, if done before starting cooling. Cerebral doppler ultrasound may not be useful when performed during or after completing cooling.

Pathophysiology of Perinatal Asphyxia in Humans and Animal Models

Perinatal asphyxia is caused by lack of oxygen delivery (hypoxia) to end organs due to an hypoxemic or ischemic insult occurring in temporal proximity to labor (peripartum) or delivery (intrapartum). Hypoxic–ischemic encephalopathy is the clinical manifestation of hypoxic injury to the brain and is usually graded as mild, moderate, or severe. The search for useful biomarkers to precisely predict the severity of lesions in perinatal asphyxia and hypoxic–ischemic encephalopathy (HIE) is a field of increasing interest. As pathophysiology is not fully comprehended, the gold standard for treatment remains an active area of research. Hypothermia has proven to be an effective neuroprotective strategy and has been implemented in clinical routine. Current studies are exploring various add-on therapies, including erythropoietin, xenon, topiramate, melatonin, and stem cells. This review aims to perform an updated integration of the pathophysiological processes after perinatal asphyxia in humans and animal models to allow us to answer some questions and provide an interim update on progress in this field.

Point-of-care ultrasound in the neonatal ICU

PURPOSE OF REVIEW

Point-of-care ultrasound (POCUS) is an emerging clinical tool in the neonatal intensive care unit (NICU). Recent literature describing the use of POCUS for various applications in the NICU has garnered increased interest among neonatologists.

RECENT FINDINGS

Diagnostic applications for POCUS in the NICU include the evaluation and serial monitoring of common pulmonary diseases, hemodynamic instability, patent ductus arteriosus (PDA), persistent pulmonary hypertension of the newborn (PPHN), necrotizing enterocolitis (NEC), and intraventricular hemorrhage (IVH), among others. Procedural applications include vascular access, endotracheal intubation, lumbar puncture, and fluid drainage.

SUMMARY

Experience with POCUS in the NICU is growing. Current evidence supports the use of POCUS for a number of diagnostic and procedural applications. As use of this tool increases, there is an urgent need to develop formal training requirements specific to neonatology, as well as evidence-based guidelines to standardize use across centers.