Approaches to Multimodality Monitoring in Pediatric Traumatic Brain Injury

Cerebral autoregulation in paediatric and neonatal intensive care: A scoping review

Deranged cerebral autoregulation (CA) is associated with worse outcome in adult brain injury. Strategies for monitoring CA and maintaining the brain at its 'best CA status' have been implemented, however, this approach has not yet developed for the paediatric population. This scoping review aims to find up-to-date evidence on CA assessment in children and neonates with a view to identify patient categories in which CA has been measured so far, CA monitoring methods and its relationship with clinical outcome if any. A literature search was conducted for studies published within 31st December 2022 in 3 bibliographic databases. Out of 494 papers screened, this review includes 135 studies. Our literature search reveals evidence for CA measurement in the paediatric population across different diagnostic categories and age groups. The techniques adopted, indices and thresholds used to assess and define CA are heterogeneous. We discuss the relevance of available evidence for CA assessment in the paediatric population. However, due to small number of studies and heterogeneity of methods used, there is no conclusive evidence to support universal adoption of CA monitoring, technique, and methodology. This calls for further work to understand the clinical impact of CA monitoring in paediatric and neonatal intensive care.

Accuracy of Early Neuroprognostication in Pediatric Severe Traumatic Brain Injury

BACKGROUND

Children with severe traumatic brain injury (sTBI) are at risk for neurological sequelae impacting function. Clinicians are tasked with neuroprognostication to assist in decision-making. We describe a single-center study assessing clinicians' neuroprognostication accuracy.

METHODS

Clinicians of various specialties caring for children with sTBI were asked to predict their patients' functioning three to six months postinjury. Clinicians were asked to participate in the study if their patient had survived but not returned to baseline between day 4 and 7 postinjury. The outcome tool utilized was the functional status scale (FSS), ranging from 6 to 30 (best-worst function). Predicted scores were compared with actual scores three to six months postinjury. Lin concordance correlation coefficients were used to estimate agreement between predicted and actual FSS. Outcome was dichotomized as good (FSS 6 to 8) or poor (FSS ≥9). Positive and negative predictive values for poor outcome were calculated. Pessimistic prognostic prediction was defined as predicted worse outcome by ≥3 FSS points. Demographic and clinical variables were collected.

RESULTS

A total of 107 surveys were collected on 24 patients. Two children died. Fifteen children had complete (FSS = 6) or near-complete (FSS = 7) recovery. Mean predicted and actual FSS scores were 10.8 (S.D. 5.6) and 8.6 (S.D. 4.1), respectively. Predicted FSS scores were higher than actual scores (P < 0.001). Eight children had collective pessimistic prognostic prediction.

CONCLUSIONS

Clinicians predicted worse functional outcomes, despite high percentage of patients with near-normal function at follow-up clinic. Certain patient and provider factors were noted to impact accuracy and need to be studied in larger cohorts.

Update in Pediatric Neurocritical Care: What a Neurologist Caring for Critically Ill Children Needs to Know

Currently nearly one-quarter of admissions to pediatric intensive care units (PICUs) worldwide are for neurocritical care diagnoses that are associated with significant morbidity and mortality. Pediatric neurocritical care is a rapidly evolving field with unique challenges due to not only age-related responses to primary neurologic insults and their treatments but also the rarity of pediatric neurocritical care conditions at any given institution. The structure of pediatric neurocritical care services therefore is most commonly a collaborative model where critical care medicine physicians coordinate care and are supported by a multidisciplinary team of pediatric subspecialists, including neurologists. While pediatric neurocritical care lies at the intersection between critical care and the neurosciences, this narrative review focuses on the most common clinical scenarios encountered by pediatric neurologists as consultants in the PICU and synthesizes the recent evidence, best practices, and ongoing research in these cases. We provide an in-depth review of (1) the evaluation and management of abnormal movements (seizures/status epilepticus and status dystonicus); (2) acute weakness and paralysis (focusing on pediatric stroke and select pediatric neuroimmune conditions); (3) neuromonitoring modalities using a pathophysiology-driven approach; (4) neuroprotective strategies for which there is evidence (e.g., pediatric severe traumatic brain injury, post-cardiac arrest care, and ischemic stroke and hemorrhagic stroke); and (5) best practices for neuroprognostication in pediatric traumatic brain injury, cardiac arrest, and disorders of consciousness, with highlights of the 2023 updates on Brain Death/Death by Neurological Criteria. Our review of the current state of pediatric neurocritical care from the viewpoint of what a pediatric neurologist in the PICU needs to know is intended to improve knowledge for providers at the bedside with the goal of better patient care and outcomes.

The State of the Field of Pediatric Multimodality Neuromonitoring

BACKGROUND

The use of multimodal neuromonitoring in pediatrics is in its infancy relative to adult neurocritical care. Multimodal neuromonitoring encompasses the amalgamation of information from multiple individual neuromonitoring devices to gain a more comprehensive understanding of the condition of the brain. It allows for adaptation to the changing state of the brain throughout various stages of injury with potential to individualize and optimize therapies.

METHODS

Here we provide an overview of multimodal neuromonitoring in pediatric neurocritical care and its potential application in the future.

RESULTS

Multimodal neuromonitoring devices are key to the process of multimodal neuromonitoring, allowing for visualization of data trends over time and ideally improving the ability of clinicians to identify patterns and find meaning in the immense volume of data now encountered in the care of critically ill patients at the bedside. Clinical use in pediatrics requires more study to determine best practices and impact on patient outcomes. Potential uses include guidance for targets of physiological parameters in the setting of acute brain injury, neuroprotection for patients at high risk for brain injury, and neuroprognostication. Implementing multimodal neuromonitoring in pediatric patients involves interprofessional collaboration with the development of a simultaneous comprehensive program to support the use of multimodal neuromonitoring while maintaining the fundamental principles of the delivery of neurocritical care at the bedside.

CONCLUSIONS

The possible benefits of multimodal neuromonitoring are immense and have great potential to advance the field of pediatric neurocritical care and the health of critically ill children.

"Roberto Rodríguez" General Teaching Hospital of Moron, Ciego De Avila, Cuba, Neurosurgery and Pediatric Intensive Care Services Pediatric Neuromonitoring in Severe Head Trauma

Among all types of trauma in children, traumatic brain injury has the greatest potential for the development of devastating consequences, with nearly three million affected each year in the world. A controlled, nonrandomized experimental study was carried out in pediatric patients with severe traumatic brain injury, whose objective was to evaluate the use of continuous multimodal neuromonitoring (MMN) of intracranial parameters as a guide in the treatment of children of different age-groups. The patients were divided into two groups according to the treatment received; clinical and imaging monitoring was performed in both. Group I included those whose treatment was guided by MMN of intracranial parameters such as intracranial pressure, cerebral perfusion pressure, and intracranial compliance, and group II included those who had only clinical and imaging monitoring. Eighty patients were studied, 41 in group I and 39 in group II. There were no significant differences between the groups with respect to the sociodemographic variables and the results; as a consequence, both forms of treatment were outlined, for patients with MMN and for those who only have clinical and imaging monitoring. It is concluded that both treatment schemes can be used depending on technological availability, although the scheme with MMN is optimal.

Ictal-Interictal Continuum in the Pediatric Intensive Care Unit

BACKGROUND

The ictal-interictal continuum (IIC) consists of several electroencephalogram (EEG) patterns that are common in critically ill adults. Studies focused on the IIC are limited in critically ill children and have focused primarily on associations with electrographic seizures (ESs). We report the incidence of the IIC in the pediatric intensive care unit (PICU). We then compare IIC patterns to rhythmic and periodic patterns (RPP) not meeting IIC criteria looking for associations with acute cerebral abnormalities, ES, and in-hospital mortality.

METHODS

This was a retrospective review of prospectively collected data for patients admitted to the PICU at Children's National Hospital from July 2021 to January 2023 with continuous EEG. We excluded patients with known epilepsy and cerebral injury prior to presentation. All patients were screened for RPP. The American Clinical Neurophysiology Society standardized Critical Care EEG terminology for the IIC was applied to each RPP. Associations between IIC and RPP not meeting IIC criteria, with clinical and EEG variables, were calculated using odds ratios (ORs).

RESULTS

Of 201 patients, 21% (42/201) had RPP and 12% (24/201) met IIC criteria. Among patients with an IIC pattern, the median age was 3.4 years (interquartile range (IQR) 0.6-12 years). Sixty-seven percent (16/24) of patients met a single IIC criterion, whereas the remainder met two criteria. ESs were identified in 83% (20/24) of patients and cerebral injury was identified in 96% (23/24) of patients with IIC patterns. When comparing patients with IIC patterns with those with RPP not qualifying as an IIC pattern, both patterns were associated with acute cerebral abnormalities (IIC OR 26 [95% confidence interval {CI} 3.4-197], p = 0.0016 vs. RPP OR 3.5 [95% CI 1.1-11], p = 0.03), however, only the IIC was associated with ES (OR 121 [95% CI 33-451], p < 0.0001) versus RPP (OR 1.3 [0.4-5], p = 0.7).

CONCLUSIONS

Rhythmic and periodic patterns and subsequently the IIC are commonly seen in the PICU and carry a high association with cerebral injury. Additionally, the IIC, seen in more than 10% of critically ill children, is associated with ES. The independent impact of RPP and IIC patterns on secondary brain injury and need for treatment of these patterns independent of ES requires further study.

Quantitative Electroencephalographic Changes Associated With Brain Tissue Hypoxia After Pediatric Traumatic Brain Injury: A Retrospective Exploratory Analysis

PURPOSE

Brain tissue hypoxia is associated with poor outcomes after pediatric traumatic brain injury. Although invasive brain oxygenation (PbtO 2 ) monitoring is available, noninvasive methods assessing correlates to brain tissue hypoxia are needed. We investigated EEG characteristics associated with brain tissue hypoxia.

METHODS

We performed a retrospective analysis of 19 pediatric traumatic brain injury patients undergoing multimodality neuromonitoring that included PbtO 2 and quantitative electroencephalography(QEEG). Quantitative electroencephalography characteristics were analyzed over electrodes adjacent to PbtO 2 monitoring and over the entire scalp, and included power in alpha and beta frequencies and the alpha-delta power ratio. To investigate relationships of PbtO 2 to quantitative electroencephalography features using time series data, we fit linear mixed effects models with a random intercept for each subject and one fixed effect, and an auto-regressive order of 1 to model between-subject variation and correlation for within-subject observations. Least squares (LS) means were used to investigate for fixed effects of quantitative electroencephalography features to changes in PbtO 2 across thresholds of 10, 15, 20, and 25 mm Hg.

RESULTS

Within the region of PbtO 2 monitoring, changes in PbtO 2 < 10 mm Hg were associated with reductions of alpha-delta power ratio (LS mean difference -0.01, 95% confidence interval (CI) [-0.02, -0.00], p = 0.0362). Changes in PbtO 2 < 25 mm Hg were associated with increases in alpha power (LS mean difference 0.04, 95% CI [0.01, 0.07], p = 0.0222).

CONCLUSIONS

Alpha-delta power ratio changes are observed across a PbtO 2 threshold of 10 mm Hg within regions of PbtO 2 monitoring, which may reflect an EEG signature of brain tissue hypoxia after pediatric traumatic brain injury.

Intracranial Pressure and Brain Tissue Oxygen Multimodality Neuromonitoring in Gunshot Wounds to the Head in Children

OBJECTIVE

Gunshot wounds to the head (GSWH) are a cause of severe penetrating traumatic brain injury (TBI). Although multimodal neuromonitoring has been increasingly used in blunt pediatric TBI, its role in the pediatric population with GSWH is not known. We report on 3 patients who received multimodal neuromonitoring as part of clinical management at our institution and review the existing literature on pediatric GSWH.

METHODS

We identified 3 patients ≤18 years of age who were admitted to a quaternary children's hospital from 2005 to 2021 with GSWH and received invasive intracranial pressure (ICP) and Pbto2 (brain tissue oxygenation) monitoring with or without noninvasive near-infrared spectroscopy (NIRS). We analyzed clinical and demographic characteristics, imaging findings, and ICP, Pbto2, cerebral perfusion pressure, and rSo2 (regional cerebral oxygen saturation) NIRS trends.

RESULTS

All patients were male with an average admission Glasgow Coma Scale score of 4. One patient received additional NIRS monitoring. Episodes of intracranial hypertension (ICP ≥20 mm Hg) and brain tissue hypoxia (Pbto2 <15 mm Hg) or hyperemia (Pbto2 >35 mm Hg) frequently occurred independently of each other, requiring unique targeted treatments. rSo2 did not consistently mirror Pbto2. All children survived, with favorable Glasgow Outcome Scale-Extended score at 6 months after injury.

CONCLUSIONS

Use of ICP and Pbto2 multimodality neuromonitoring enabled specific management for intracranial hypertension or brain tissue hypoxia episodes that occurred independently of one another. Multimodality neuromonitoring has not been studied extensively in pediatric GSWH; however, its use may provide a more complete picture of patient injury and prognosis without significant added procedural risk.

Electrical bioimpedance measurement and near-infrared spectroscopy in pediatric postoperative neurocritical care: a prospective observational study

Background

To investigate the clinical significance of the disturbance coefficient (DC) and regional cerebral oxygen saturation (rSO₂) as obtained through the use of electrical bioimpedance and near-infrared spectroscopy (NIRS) in pediatric neurocritical care.

Participants and methods

We enrolled 45 pediatric patients as the injury group and 70 healthy children as the control group. DC was derived from impedance analysis of 0.1 mA-50 kHz current via temporal electrodes. rSO₂ was the percentage of oxyhemoglobin measured from reflected NIR light on the forehead. DC and rSO₂ were obtained at 6, 12, 24, 48 and 72 h after surgery for the injury group and during the health screening clinic visit for the control group. We compared DC and rSO₂ between the groups, their changes over time within the injury group and their correlation with intracranial pressure (ICP), cerebral perfusion pressure (CPP), Glasgow coma scale (GCS) score, Glasgow outcome scale (GOS) score, and their ability to diagnose postoperative cerebral edema and predict poor prognosis.

Results

DC and rSO₂ were significantly lower in the injury group than in the control group. In the injury group, ICP increased over the monitoring period, while DC, CPP and rSO₂ decreased. DC was negatively correlated with ICP and positively correlated with GCS score and GOS score. Additionally, lower DC values were observed in patients with signs of cerebral edema, with a DC value of 86.5 or below suggesting the presence of brain edema in patients aged 6-16 years. On the other hand, rSO₂ was positively correlated with CPP, GCS score, and GOS score, with a value of 64.4% or below indicating a poor prognosis. Decreased CPP is an independent risk factor for decreased rSO₂.

Conclusion

DC and rSO₂ monitoring based on electrical bioimpedance and near-infrared spectroscopy not only reflect the degree of brain edema and oxygenation, but also reflect the severity of the disease and predict the prognosis of the patients. This approach offers a real-time, bedside, and accurate method for assessing brain function and detecting postoperative cerebral edema and poor prognosis.

Approaches to neuroprotection in pediatric neurocritical care

Acute neurologic injuries represent a common cause of morbidity and mortality in children presenting to the pediatric intensive care unit. After primary neurologic insults, there may be cerebral brain tissue that remains at risk of secondary insults, which can lead to worsening neurologic injury and unfavorable outcomes. A fundamental goal of pediatric neurocritical care is to mitigate the impact of secondary neurologic injury and improve neurologic outcomes for critically ill children. This review describes the physiologic framework by which strategies in pediatric neurocritical care are designed to reduce the impact of secondary brain injury and improve functional outcomes. Here, we present current and emerging strategies for optimizing neuroprotective strategies in critically ill children.

Invasive Neuromonitoring Modalities in the Pediatric Population

Invasive neuromonitoring has become an important part of pediatric neurocritical care, as neuromonitoring devices provide objective data that can guide patient management in real time. New modalities continue to emerge, allowing clinicians to integrate data that reflect different aspects of cerebral function to optimize patient management. Currently, available common invasive neuromonitoring devices that have been studied in the pediatric population include the intracranial pressure monitor, brain tissue oxygenation monitor, jugular venous oximetry, cerebral microdialysis, and thermal diffusion flowmetry. In this review, we describe these neuromonitoring technologies, including their mechanisms of function, indications for use, advantages and disadvantages, and efficacy, in pediatric neurocritical care settings with respect to patient outcomes.

Cerebrovascular dynamics after pediatric traumatic brain injury

Objective: We aimed to investigate model-based indices of cerebrovascular dynamics after pediatric traumatic brain injury (TBI) using transcranial Doppler ultrasound (TCD) integrated into multimodality neurologic monitoring (MMM). Methods: We performed a retrospective analysis of pediatric TBI patients undergoing TCD integrated into MMM. Classic TCD characteristics included pulsatility indices and systolic, diastolic and mean flow velocities of the bilateral middle cerebral arteries. Model-based indices of cerebrovascular dynamics included the mean velocity index (Mx), compliance of the cerebrovascular bed (Ca), compliance of the cerebrospinal space (Ci), arterial time constant (TAU), critical closing pressure (CrCP) and diastolic closing margin (DCM). Classic TCD characteristics and model-based indices of cerebrovascular dynamics were investigated in relation to functional outcomes and intracranial pressure (ICP) using generalized estimating equations with repeated measures. Functional outcomes were assessed using the Glasgow Outcome Scale-Extended Pediatrics score (GOSE-Peds) at 12 months, post-injury. Results: Seventy-two separate TCD studies were performed on twenty-five pediatric TBI patients. We identified that reduced Ci (estimate -5.986, p = 0.0309), increased CrCP (estimate 0.081, p < 0.0001) and reduced DCM (estimate -0.057, p = 0.0179) were associated with higher GOSE-Peds scores, suggestive of unfavorable outcome. We identified that increased CrCP (estimate 0.900, p < 0.001) and reduced DCM (estimate -0.549, p < 0.0001) were associated with increased ICP. Conclusion: In an exploratory analysis of pediatric TBI patients, increased CrCP and reduced DCM and Ci are associated with unfavorable outcomes, and increased CrCP and reduced DCM are associated with increased ICP. Prospective work with larger cohorts is needed to further validate the clinical utility of these features.

Invasive brain tissue oxygen and intracranial pressure (ICP) monitoring versus ICP-only monitoring in pediatric severe traumatic brain injury

OBJECTIVE

Severe traumatic brain injury (TBI) is a leading cause of disability and death in the pediatric population. While intracranial pressure (ICP) monitoring is the gold standard in acute neurocritical care following pediatric severe TBI, brain tissue oxygen tension (PbtO2) monitoring may also help limit secondary brain injury and improve outcomes. The authors hypothesized that pediatric patients with severe TBI and ICP + PbtO2 monitoring and treatment would have better outcomes than those who underwent ICP-only monitoring and treatment.

METHODS

Patients ≤ 18 years of age with severe TBI who received ICP ± PbtO2 monitoring at a quaternary children's hospital between 1998 and 2021 were retrospectively reviewed. The relationships between conventional measurements of TBI were evaluated, i.e., ICP, cerebral perfusion pressure (CPP), and PbtO2. Differences were analyzed between patients with ICP + PbtO2 versus ICP-only monitoring on hospital and pediatric intensive care unit (PICU) length of stay (LOS), length of intubation, Pediatric Intensity Level of Therapy scale score, and functional outcome using the Glasgow Outcome Score-Extended (GOS-E) scale at 6 months postinjury.

RESULTS

Forty-nine patients, including 19 with ICP + PbtO2 and 30 with ICP only, were analyzed. There was a weak negative association between ICP and PbtO2 (β = -0.04). Conversely, there was a strong positive correlation between CPP ≥ 40 mm Hg and PbtO2 ≥ 15 and ≥ 20 mm Hg (β = 0.30 and β = 0.29, p < 0.001, respectively). An increased number of events of cerebral PbtO2 < 15 mm Hg or < 20 mm Hg were associated with longer hospital (p = 0.01 and p = 0.022, respectively) and PICU (p = 0.015 and p = 0.007, respectively) LOS, increased duration of mechanical ventilation (p = 0.015 when PbtO2 < 15 mm Hg), and an unfavorable 6-month GOS-E score (p = 0.045 and p = 0.022, respectively). An increased number of intracranial hypertension episodes (ICP ≥ 20 mm Hg) were associated with longer hospital (p = 0.007) and PICU (p < 0.001) LOS and longer duration of mechanical ventilation (p < 0.001). Lower minimum hourly and average daily ICP values predicted favorable GOS-E scores (p < 0.001 for both). Patients with ICP + PbtO2 monitoring experienced longer PICU LOS (p = 0.018) compared to patients with ICP-only monitoring, with no significant GOS-E score difference between groups (p = 0.733).

CONCLUSIONS

An increased number of cerebral hypoxic episodes and an increased number of intracranial hypertension episodes resulted in longer hospital LOS and longer duration of mechanical ventilator support. An increased number of cerebral hypoxic episodes also correlated with less favorable functional outcomes. In contrast, lower minimum hourly and average daily ICP values, but not the number of intracranial hypertension episodes, were associated with more favorable functional outcomes. There was a weak correlation between ICP and PbtO2, supporting the importance of multimodal invasive neuromonitoring in pediatric severe TBI.

Transcranial Doppler in a child: A most valuable imaging modality

Introduction

Pediatric brain injury is a common cause of emergency department (ED) referral. Although severe traumatic brain damage is less frequent, it could be primarily managed by non-pediatric critical care physicians called in for advice. Clinical evaluation is important, but radiology is of particular value in the case of severe brain injury. Transcranial Doppler may help the physician through neuromonitoring.

Case Report

We report the case of a 3-year-old male child brought into the pediatric ED for a moderate head injury. His neurological status deteriorated rapidly, making endotracheal intubation and mechanical ventilation necessary. Computed tomography (CT) of the head revealed brain contusion and post-traumatic subarachnoidal hemorrhage.

Discussion

Transcranial Doppler was performed at the standard transtemporal evaluation window, and it showed normal vascularization of the entire anterior brain. This result permitted performance of the control CT scan to be postponed. In this case, basic knowledge of transcranial ultrasound proved to be useful, and we believe it could also be useful to other colleagues faced with similar situations even if they are not dedicated to pediatric critically ill patients.

Conclusion

Doppler ultrasound in the pediatric population is a valuable bedside tool. Together with clinical evaluation and radiology, it completes the set of techniques necessary for continuous neuromonitoring.

A Survey of Neuromonitoring Practices in North American Pediatric Intensive Care Units

BACKGROUND

Neuromonitoring is the use of continuous measures of brain physiology to detect clinically important events in real-time. Neuromonitoring devices can be invasive or non-invasive and are typically used on patients with acute brain injury or at high risk for brain injury. The goal of this study was to characterize neuromonitoring infrastructure and practices in North American pediatric intensive care units (PICUs).

METHODS

An electronic, web-based survey was distributed to 70 North American institutions participating in the Pediatric Neurocritical Care Research Group. Questions related to the clinical use of neuromonitoring devices, integrative multimodality neuromonitoring capabilities, and neuromonitoring infrastructure were included. Survey results were presented using descriptive statistics.

RESULTS

The survey was completed by faculty at 74% (52 of 70) of institutions. All 52 institutions measure intracranial pressure and have electroencephalography capability, whereas 87% (45 of 52) use near-infrared spectroscopy and 40% (21/52) use transcranial Doppler. Individual patient monitoring decisions were driven by institutional protocols and collaboration between critical care, neurology, and neurosurgery attendings. Reported device utilization varied by brain injury etiology. Only 15% (eight of 52) of institutions utilized a multimodality neuromonitoring platform to integrate and synchronize data from multiple devices. A database of neuromonitoring patients was maintained at 35% (18 of 52) of institutions. Funding for neuromonitoring programs was variable with contributions from hospitals (19%, 10 of 52), private donations (12%, six of 52), and research funds (12%, six of 52), although 73% (40 of 52) have no dedicated funds.

CONCLUSIONS

Neuromonitoring indications, devices, and infrastructure vary by institution in North American pediatric critical care units. Noninvasive modalities were utilized more liberally, although not uniformly, than invasive monitoring. Further studies are needed to standardize the acquisition, interpretation, and reporting of clinical neuromonitoring data, and to determine whether neuromonitoring systems impact neurological outcomes.

Neuromonitoring in Rare Disorders of Metabolism

Inborn errors of metabolism (IEM) are a unique class of genetic diseases due to mutations in genes involved in key metabolic pathways. The combined incidence of IEM has been estimated to be as high as 1:1000. Urea Cycle disorders (UCD), one class of IEM, can present with cerebral edema and represent a possible target to explore the utility of different neuromonitoring techniques during an hyperammonemic crisis. The last two decades have brought advances in the early identification and comprehensive management of UCD, including further understanding of neuroimaging patterns associated with neurocognitive function. Nonetheless, very important questions remain about the potential acute neurotoxic effects of hyperammonemia to better understand how to treat and prevent secondary brain injury. In this review, we describe existing neuromonitoring techniques that have been used in rare metabolic disorders to assess and allow amelioration of ongoing brain injury. Directions of future research should be focused on identifying new diagnostic approaches in the management of metabolic crises to optimize care and reduce long term morbidity and mortality in patients with IEM.

Physiologic Characteristics of Hyperosmolar Therapy After Pediatric Traumatic Brain Injury

All work was performed at the Barrow Neurological Institute at Phoenix Children's Hospital.

Objective: Investigate injury severity, neuroimaging, physiology, and outcomes with bolus hyperosmolar therapy (HT) of 3% hypertonic saline or mannitol.

Methods: Retrospective cohort analysis was performed. Physiologic variables included intracranial pressure (ICP), arterial blood pressure (ABP), and heart rate (HR). Volume-pressure compensation (PVC) indices included ICP pulse amplitude (AMP) and correlation of AMP and ICP (RAP). Cerebrovascular pressure reactivity (CVPR) indices included pressure reactivity index (PRx), pulse amplitude index (PAx), wavelet PRx (wPRx), and correlation of AMP and cerebral perfusion pressure (RAC). Heart rate variability (HRV) indices included heart rate standard deviation (HRsd), heart rate root mean square of successive differences (HRrmssd) and low-high frequency ratio (LHF). Outcome was assessed using Glasgow Outcomes Scale Extended Pediatrics, 12-months post-injury. Generalized estimating equations was applied to investigate associations of physiologic changes and pre-treatment indices with HT efficacy. Repeated measures analysis of variance was applied to investigate changes after HT without intracranial hypertension (ICH). Wilcoxon rank-sum was applied to investigate HT responsiveness with age, injury severity, neuroimaging, and outcomes.

Results: Thirty children received bolus HT. ICH reduction after HT was associated with reduced ICP (p = 0.0064), ABP (p = 0.0126), PRx (p = 0.0063), increased HRsd (p = 0.0408), and decreased pretreatment RAC (p = 0.0115) and wPRx (p = 0.0072). HT-responsive patients were older and had improved outcomes (p = 0.0394). HT without ICH was associated with increased ICP (P < 0.0001) and ABP (P < 0.0001), increases in all HRV indices and decreases in all PVC indices.

Conclusion: After pediatric TBI, efficacious HT is associated with decreased ICP and ABP, pre-treatment indices suggesting efficient CVPR, and potentially improved outcomes.

How much oxygen for the injured brain - can invasive parenchymal catheters help?

PURPOSE OF REVIEW

Each year in the United States there are over 2.5 million visits to emergency departments for traumatic brain injury (TBI), 300,000 hospitalizations, and 50,000 deaths. TBI initiates a complex cascade of events which can lead to significant secondary brain damage. Great interest exists in directly measuring cerebral oxygen delivery and demand after TBI to prevent this secondary injury. Several invasive, catheter-based devices are now available which directly monitor the partial pressure of oxygen in brain tissue (PbtO2), yet significant equipoise exists regarding their clinical use in severe TBI.

RECENT FINDINGS

There are currently three ongoing multicenter randomized controlled trials studying the use of PbtO2 monitoring in severe TBI: BOOST-3, OXY-TC, and BONANZA. All three have similar inclusion/exclusion criteria, treatment protocols, and outcome measures. Despite mixed existing evidence, use of PbtO2 is already making its way into new TBI guidelines such as the recent Seattle International Brain Injury Consensus Conference. Analysis of high-fidelity data from multimodal monitoring, however, suggests that PbtO2 may only be one piece of the puzzle in severe TBI.

SUMMARY

While current evidence regarding the use of PbtO2 remains mixed, three ongoing clinical trials are expected to definitively answer the question of what role PbtO2 monitoring plays in severe TBI.

Implementation of Multimodality Neurologic Monitoring Reporting in Pediatric Traumatic Brain Injury Management

Background/Objective

Multimodality neurologic monitoring (MMM) is an emerging technique for management of traumatic brain injury (TBI). An increasing array of MMM-derived biomarkers now exist that are associated with injury severity and functional outcomes after TBI. A standardized MMM reporting process has not been well described, and a paucity of evidence exists relating MMM reporting in TBI management with functional outcomes or adverse events.

Methods

Prospective implementation of standardized MMM reporting at a single pediatric intensive care unit (PICU) is described that included monitoring of intracranial pressure (ICP), cerebral oxygenation and electroencephalography (EEG). The incidence of clinical decisions made using MMM reporting is described, including timing of neuroimaging, ICP monitoring discontinuation, use of paralytic, hyperosmolar and pentobarbital therapies, neurosurgical interventions, ventilator and CPP adjustments and neurologic prognostication discussions. Retrospective analysis was performed on the association of MMM reporting with initial Glasgow Coma Scale (GCS) and Pediatric Risk of Mortality III (PRISM III) scores, duration of total hospitalization and PICU hospitalization, duration of mechanical ventilation and invasive ICP monitoring, inpatient complications, time with ICP > 20 mmHg, time with cerebral perfusion pressure (CPP) < 40 mmHg and 12-month Glasgow Outcome Scale—Extended Pediatrics (GOSE-Peds) scores. Association of outcomes with MMM reporting was investigated using the Wilcoxon rank-sum test or Fisher’s exact test, as appropriate.

Results

Eighty-five children with TBI underwent MMM over 6 years, among which 18 underwent daily MMM reporting over a 21-month period. Clinical decision-making influenced by MMM reporting included timing of neuroimaging (100.0%), ICP monitoring discontinuation (100.0%), timing of extubation trials of surviving patients (100.0%), body repositioning (11.1%), paralytic therapy (16.7%), hyperosmolar therapy (22.2%), pentobarbital therapy (33.3%), provocative cerebral autoregulation testing (16.7%), adjustments in CPP thresholds (16.7%), adjustments in PaCO2 thresholds (11.1%), neurosurgical interventions (16.7%) and neurologic prognostication discussions (11.1%). The implementation of MMM reporting was associated with a reduction in ICP monitoring duration (p = 0.0017) and mechanical ventilator duration (p = 0.0018). No significant differences were observed in initial GCS or PRISM III scores, total hospitalization length, PICU hospitalization length, total complications, time with ICP > 20 mmHg, time with CPP < 40 mmHg, use of tier 2 therapy, or 12-month GOS-E Peds scores.

Conclusion

Implementation of MMM reporting in pediatric TBI management is feasible and can be impactful in tailoring clinical decisions. Prospective work is needed to understand the impact of MMM and MMM reporting systems on functional outcomes and clinical care efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01190-8.

Edaravone Improves the Post-traumatic Brain Injury Dysfunction in Learning and Memory by Modulating Nrf2/ARE Signal Pathway

OBJECTIVES

To investigate the molecular mechanism of edaravone (EDA) in improving the post-traumatic brain injury (TBI) dysfunction in learning and memory.

METHODS

In vitro and in vivo TBI models were established using hydrogen peroxide (H2O2) treatment for hippocampal nerve stem cells (NSCs) and surgery for rats, followed by EDA treatment. WST 1 measurement, methylthiazol tetrazolium assay, and flow cytometry were performed to determine the activity, proliferation, and apoptosis of NSCs, and malondialdehyde (MDA), lactic dehydrogenase (LDH), and reactive oxygen species (ROS) detection kits were used to analyze the oxides in NSCs.

RESULTS

Following EDA pretreatment, NSCs presented with promising resistance to H2O2-induced oxidative stress, whereas NSCs manifested significant increases in activity and proliferation and a decrease in apoptosis. Meanwhile, for NSCs, EDA pretreatment reduced the levels of MDA, LDH, and ROS, with a significant upregulation of Nrf2/antioxidant response element (ARE) signaling pathway, whereas for EDA-treated TBI rats, a significant reduction was observed in the trauma area and injury to the hippocampus, with improvement in memory and learning performance and upregulation of Nrf2/ARE signaling pathway.

CONCLUSIONS

EDA, by regulating the activity of Nrf2/ARE signal pathway, can improve the TBI-induced injury to NSCs and learning and memory dysfunction in rats.