Impact of hypotension and low cerebral perfusion pressure on outcomes in children treated with hypothermia therapy following severe traumatic brain injury: a post hoc analysis of the Hypothermia Pediatric Head Injury Trial

Brief oxygen exposure after traumatic brain injury speeds recovery and promotes adaptive chronic endoplasmic reticulum stress responses

Traumatic brain injury (TBI) is a major public health concern particularly in adolescents who have a higher mortality and incidence of visual pathway injury compared to adult patients. Likewise, we have found disparities between adult and adolescent TBI outcomes in rodents. Most interestingly, adolescents suffer a prolonged apneic period immediately post injury leading to higher mortality; so, we implemented a brief oxygen exposure paradigm to circumvent this increased mortality. Adolescent male mice experienced a closed-head weight-drop TBI then were exposed to 100% O ₂ until normal breathing returned or recovered in room air. We followed mice for 7- and 30-days and assessed their optokinetic response; retinal ganglion cell loss; axonal degeneration; glial reactivity; and retinal ER stress protein levels. O ₂ reduced adolescent mortality by 40%, improved post-injury visual acuity, and reduced axonal degeneration and gliosis in optic projection regions. ER stress protein expression was altered in injured mice, and mice given O ₂ utilized different ER-stress pathways in a time dependent manner. Finally, O ₂ exposure may be mediating these ER stress responses through regulation of the redox-sensitive ER folding protein ERO1α, which has been linked to a reduction in the toxic effects of free radicals in other animal models of ER stress.

Development and internal validation of a nomogram for predicting outcomes in children with traumatic subdural hematoma

Background

A subdural hematoma (SDH) following a traumatic brain injury (TBI) in children can lead to unexpected death or disability. The nomogram is a clinical prediction tool used by physicians to provide prognosis advice to parents for making decisions regarding treatment. In the present study, a nomogram for predicting outcomes was developed and validated. In addition, the predictors associated with outcomes in children with traumatic SDH were determined.

Methods

In this retrospective study, 103 children with SDH after TBI were evaluated. According to the King’s Outcome Scale for Childhood Head Injury classification, the functional outcomes were assessed at hospital discharge and categorized into favorable and unfavorable. The predictors associated with the unfavorable outcomes were analyzed using binary logistic regression. Subsequently, a two-dimensional nomogram was developed for presentation of the predictive model.

Results

The predictive model with the lowest level of Akaike information criterion consisted of hypotension (odds ratio [OR], 9.4; 95% confidence interval [CI], 2.0–42.9), Glasgow coma scale scores of 3–8 (OR, 8.2; 95% CI, 1.7–38.9), fixed pupil in one eye (OR, 4.8; 95% CI, 2.6–8.8), and fixed pupils in both eyes (OR, 3.5; 95% CI, 1.6–7.1). A midline shift ≥5 mm (OR, 1.1; 95% CI, 0.62–10.73) and co-existing intraventricular hemorrhage (OR, 6.5; 95% CI, 0.003–26.1) were also included.

Conclusions

SDH in pediatric TBI can lead to mortality and disability. The predictability level of the nomogram in the present study was excellent, and external validation should be conducted to confirm the performance of the clinical prediction tool.

Pediatric Severe Traumatic Brain Injury : Updated Management

Traumatic brain injury (TBI) is the leading cause of death and disability in children. Survivors of severe TBI are more susceptible to functional deficits, resulting in disability, poor quality of life, cognitive decline, and mental health problems. Despite this, little is known about the pathophysiology of TBI in children and how to manage it most effectively. Internationally, efforts are being made to expand knowledge of pathophysiology and develop practical clinical treatment recommendations to improve outcomes. Here we discuss recently updated evidence and management of severe pediatric TBI.

The management of pediatric severe traumatic brain injury: Italian Guidelines

INTRODUCTION

The aim of the work was to update the "Guidelines for the Management of Severe Traumatic Brain Injury" published in 2012, to reflect the new available evidence, and develop the Italian national guideline for the management of severe pediatric head injuries to reduce variation in practice and ensure optimal care to patients.

EVIDENCE ACQUISITION

MEDLINE and EMBASE were searched from January 2009 to October 2017. Inclusion criteria were English language, pediatric populations (0-18 years) or mixed populations (pediatric/adult) with available age subgroup analyses. The guideline development process was started by the Promoting Group that composed a multidisciplinary panel of experts, with the representatives of the Scientific Societies, the independent expert specialists and a representative of the Patient Associations. The panel selected the clinical questions, discussed the evidence and formulated the text of the recommendations. The documentarists of the University of Florence oversaw the bibliographic research strategy. A group of literature reviewers evaluated the selected literature and compiled the table of evidence for each clinical question.

EVIDENCE SYNTHESIS

The search strategies identified 4254 articles. We selected 3227 abstract (first screening) and, finally included 67 articles (second screening) to update the guideline. This Italian update includes 25 evidence-based recommendations and 5 research recommendations.

CONCLUSIONS

In recent years, progress has been made on the understanding of severe pediatric brain injury, as well as on that concerning all major traumatic pathology. This has led to a progressive improvement in the clinical outcome, although the quantity and quality of evidence remains particularly low.

Determinants of outcomes for acute encephalopathy with reduced subcortical diffusion

Acute encephalopathy with reduced subcortical diffusion (AED), characterised by seizure onset and widespread reduced apparent diffusion coefficient in the cortex/subcortical white matter, is one of the most common acute encephalopathies in children in East Asia. This 14-year single-centre retrospective study on 34 patients with AED showed that therapeutic hypothermia was used for patients with more severe consciousness disturbance after the first seizure or second phase initiation, extrapolating from neonatal hypoxic encephalopathy and adult post-cardiac arrest syndrome. The basal ganglia/thalamus lesions and the Tada score were the poor outcome determinants in the multivariate analysis. The correlation between the worse outcomes and the duration from the first seizure to the initiation of therapeutic hypothermia was observed only in the patients with AED cooled before the second phase. This correlation was not observed in the overall AED population. There was a moderate negative association between the worse outcomes and the duration between the first seizure and the second phase. Therefore, the basal ganglia/thalamus lesions and the Tada score were the outcome determinants for patients with AED. Further investigation is required to examine the efficacy of therapeutic hypothermia in this population while considering the timing of the therapeutic hypothermia initiation and the second phase.

Guidelines for the Management of Pediatric Severe Traumatic Brain Injury, Third Edition: Update of the Brain Trauma Foundation Guidelines, Executive Summary

The purpose of this work is to identify and synthesize research produced since the second edition of these Guidelines was published and incorporate new results into revised evidence-based recommendations for the treatment of severe traumatic brain injury in pediatric patients. This document provides an overview of our process, lists the new research added, and includes the revised recommendations. Recommendations are only provided when there is supporting evidence. This update includes 22 recommendations, 9 are new or revised from previous editions. New recommendations on neuroimaging, hyperosmolar therapy, analgesics and sedatives, seizure prophylaxis, temperature control/hypothermia, and nutrition are provided. None are level I, 3 are level II, and 19 are level III. The Clinical Investigators responsible for these Guidelines also created a companion algorithm that supplements the recommendations with expert consensus where evidence is not available and organizes possible interventions into first and second tier utilization. The complete guideline document and supplemental appendices are available electronically (https://doi.org/10.1097/PCC.0000000000001735). The online documents contain summaries and evaluations of all the studies considered, including those from prior editions, and more detailed information on our methodology. New level II and level III evidence-based recommendations and an algorithm provide additional guidance for the development of local protocols to treat pediatric patients with severe traumatic brain injury. Our intention is to identify and institute a sustainable process to update these Guidelines as new evidence becomes available.

Management of Pediatric Severe Traumatic Brain Injury: 2019 Consensus and Guidelines-Based Algorithm for First and Second Tier Therapies

OBJECTIVES

To produce a treatment algorithm for the ICU management of infants, children, and adolescents with severe traumatic brain injury.

DATA SOURCES

Studies included in the 2019 Guidelines for the Management of Pediatric Severe Traumatic Brain Injury (Glasgow Coma Scale score ≤ 8), consensus when evidence was insufficient to formulate a fully evidence-based approach, and selected protocols from included studies.

DATA SYNTHESIS

Baseline care germane to all pediatric patients with severe traumatic brain injury along with two tiers of therapy were formulated. An approach to emergent management of the crisis scenario of cerebral herniation was also included. The first tier of therapy focuses on three therapeutic targets, namely preventing and/or treating intracranial hypertension, optimizing cerebral perfusion pressure, and optimizing partial pressure of brain tissue oxygen (when monitored). The second tier of therapy focuses on decompressive craniectomy surgery, barbiturate infusion, late application of hypothermia, induced hyperventilation, and hyperosmolar therapies.

CONCLUSIONS

This article provides an algorithm of clinical practice for the bedside practitioner based on the available evidence, treatment protocols described in the articles included in the 2019 guidelines, and consensus that reflects a logical approach to mitigate intracranial hypertension, optimize cerebral perfusion, and improve outcomes in the setting of pediatric severe traumatic brain injury.

Guidelines for the Management of Pediatric Severe Traumatic Brain Injury, Third Edition: Update of the Brain Trauma Foundation Guidelines, Executive Summary

OBJECTIVES

The purpose of this work is to identify and synthesize research produced since the second edition of these Guidelines was published and incorporate new results into revised evidence-based recommendations for the treatment of severe traumatic brain injury in pediatric patients.

METHODS AND MAIN RESULTS

This document provides an overview of our process, lists the new research added, and includes the revised recommendations. Recommendations are only provided when there is supporting evidence. This update includes 22 recommendations, nine are new or revised from previous editions. New recommendations on neuroimaging, hyperosmolar therapy, analgesics and sedatives, seizure prophylaxis, temperature control/hypothermia, and nutrition are provided. None are level I, three are level II, and 19 are level III. The Clinical Investigators responsible for these Guidelines also created a companion algorithm that supplements the recommendations with expert consensus where evidence is not available and organizes possible interventions into first and second tier utilization. The purpose of publishing the algorithm as a separate document is to provide guidance for clinicians while maintaining a clear distinction between what is evidence based and what is consensus based. This approach allows, and is intended to encourage, continued creativity in treatment and research where evidence is lacking. Additionally, it allows for the use of the evidence-based recommendations as the foundation for other pathways, protocols, or algorithms specific to different organizations or environments. The complete guideline document and supplemental appendices are available electronically from this journal. These documents contain summaries and evaluations of all the studies considered, including those from prior editions, and more detailed information on our methodology.

CONCLUSIONS

New level II and level III evidence-based recommendations and an algorithm provide additional guidance for the development of local protocols to treat pediatric patients with severe traumatic brain injury. Our intention is to identify and institute a sustainable process to update these Guidelines as new evidence becomes available.

Targeted Temperature Management in Pediatric Neurocritical Care

Targeted temperature management encompasses a range of clinical interventions to regulate systemic temperature, and includes both induction of varying degrees of hypothermia and fever prevention ("targeted normothermia"). Targeted temperature management plays a key role in the contemporary management of critically ill neonates and children with acute brain injury. Yet, many unanswered questions remain regarding optimal temperature management in pediatric neurocritical care. The introduction highlights experimental studies that have evaluated the neuroprotective efficacy of therapeutic hypothermia and explored possible mechanisms of action in several brain injury models. The next section focuses on three major clinical conditions in which therapeutic hypothermia has been evaluated in randomized controlled trials in pediatric populations: neonatal hypoxic-ischemic encephalopathy, postcardiac arrest encephalopathy, and traumatic brain injury. Clinical implications of targeted temperature management in pediatric neurocritical care are also discussed. The final section examines some of the factors that may underlie the limited neuroprotective efficacy of hypothermia that has been observed in several major pediatric clinical trials, and outlines important directions for future research.

Brain metabolism and severe pediatric traumatic brain injury

Age-dependent changes in brain metabolism may influence the response to and tolerance of secondary insults, potentially affecting outcomes. More complete characterization of brain metabolism across the clinical trajectory of severe pediatric TBI is needed to improve our ability to measure and better mitigate the impact of secondary insults. Better management of secondary insults will impact clinical care and the probability of success of future neuroprotective clinical trials. Improved bedside monitoring and imaging technologies will be required to achieve these goals. Effective and sustained integration of brain metabolism information into the pediatric critical care setting will be equally challenging and important.

Hypothermia for traumatic brain injury

BACKGROUND

Hypothermia has been used in the treatment of brain injury for many years. Encouraging results from small trials and laboratory studies led to renewed interest in the area and some larger trials.

OBJECTIVES

To determine the effect of mild hypothermia for traumatic brain injury (TBI) on mortality, long-term functional outcomes and complications.

SEARCH METHODS

We ran and incorporated studies from database searches to 21 March 2016. We searched the Cochrane Injuries Group's Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE (OvidSP), Embase Classic+Embase (OvidSP), PubMed, ISI Web of science (SCI-EXPANDED, SSCI, CPCI-S & CPSI-SSH), clinical trials registers, and screened reference lists. We also re-ran these searches pre-publication in June 2017; the result from this search is presented in 'Studies awaiting classification'.

SELECTION CRITERIA

We included randomised controlled trials of participants with closed TBI requiring hospitalisation who were treated with hypothermia to a maximum of 35 ºC for at least 12 consecutive hours. Treatment with hypothermia was compared to maintenance with normothermia (36.5 to 38 ºC).

DATA COLLECTION AND ANALYSIS

Two review authors assessed data on mortality, unfavourable outcomes according to the Glasgow Outcome Scale, and pneumonia.

MAIN RESULTS

We included 37 eligible trials with a total of 3110 randomised participants; nine of these were new studies since the last update (2009) and five studies had been previously excluded but were re-assessed and included during the 2017 update. We identified two ongoing studies from searches of clinical trials registers and database searches and two studies await classification.Studies included both adults and children with TBI. Most studies commenced treatment immediately on admission to hospital or after craniotomies and all treatment was maintained for at least 24 hours. Thirty-three studies reported data for mortality, 31 studies reported data for unfavourable outcomes (death, vegetative state or severe disability), and 14 studies reported pneumonia. Visual inspection of the results for these outcomes showed inconsistencies among studies, with differences in the direction of effect, and we did not pool these data for meta-analysis. We considered duration of hypothermia therapy and the length of follow-up in collected data for these subgroups; differences in study data remained such that we did not perform meta-analysis.Studies were generally poorly reported and we were unable to assess risk of bias adequately. Heterogeneity was evident both in the trial designs and participant inclusion. Inconsistencies in results may be explained by heterogeneity among study participants or bias introduced by individual study methodology but we did not explore this in detail in subgroup or sensitivity analyses. We used the GRADE approach to judge the quality of the evidence for each outcome and downgraded the evidence for mortality and unfavourable outcome to very low. We downgraded the evidence for the pneumonia outcome to low.

AUTHORS' CONCLUSIONS

Despite a large number studies, there remains no high-quality evidence that hypothermia is beneficial in the treatment of people with TBI. Further research, which is methodologically robust, is required in this field to establish the effect of hypothermia for people with TBI.

Neurologic Outcomes Following Care in the Pediatric Intensive Care Unit

Purpose of review

With increasing survival of children requiring admission to pediatric intensive care units (PICU), neurodevelopmental outcomes of these patients are an area of increased attention. Our goal was to systematically review recently published literature on neurologic outcomes of PICU patients.

Recent Findings

Decline in neurofunctional status occurs in 3%-20% of children requiring PICU care. This proportion varies based on primary diagnosis and severity of illness, with children admitted for primary neurologic diagnosis, children who suffer cardiac arrest or who require invasive interventions during the PICU admission, having worse outcomes. Recent research focuses on early identification and treatment of modifiable risk factors for unfavorable outcomes, and on long-term follow-up that moves beyond global cognitive outcomes and is increasingly including tests assessing multidimensional aspects of neurodevelopment.

Summary

The pediatric critical care research community has shifted focus from survival to survival with favorable neurologic outcomes of children admitted to the PICU.

Targeted temperature management in the ICU: Guidelines from a French expert panel

Over the recent period, the use of induced hypothermia has gained an increasing interest for critically ill patients, in particular in brain-injured patients. The term "targeted temperature management" (TTM) has now emerged as the most appropriate when referring to interventions used to reach and maintain a specific level temperature for each individual. TTM may be used to prevent fever, to maintain normothermia, or to lower core temperature. This treatment is widely used in intensive care units, mostly as a primary neuroprotective method. Indications are, however, associated with variable levels of evidence based on inhomogeneous or even contradictory literature. Our aim was to conduct a systematic analysis of the published data in order to provide guidelines. We present herein recommendations for the use of TTM in adult and paediatric critically ill patients developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. These guidelines were conducted by a group of experts from the French Intensive Care Society (Société de réanimation de langue française [SRLF]) and the French Society of Anesthesia and Intensive Care Medicine (Société francaise d'anesthésie réanimation [SFAR]) with the participation of the French Emergency Medicine Association (Société française de médecine d'urgence [SFMU]), the French Group for Pediatric Intensive Care and Emergencies (Groupe francophone de réanimation et urgences pédiatriques [GFRUP]), the French National Association of Neuro-Anesthesiology and Critical Care (Association nationale de neuro-anesthésie réanimation française [ANARLF]), and the French Neurovascular Society (Société française neurovasculaire [SFNV]). Fifteen experts and two coordinators agreed to consider questions concerning TTM and its practical implementation in five clinical situations: cardiac arrest, traumatic brain injury, stroke, other brain injuries, and shock. This resulted in 30 recommendations: 3 recommendations were strong (Grade 1), 13 were weak (Grade 2), and 14 were experts' opinions. After two rounds of rating and various amendments, a strong agreement from voting participants was obtained for all 30 (100%) recommendations, which are exposed in the present article.

Targeted temperature management in the ICU: guidelines from a French expert panel

Over the recent period, the use of induced hypothermia has gained an increasing interest for critically ill patients, in particular in brain-injured patients. The term “targeted temperature management” (TTM) has now emerged as the most appropriate when referring to interventions used to reach and maintain a specific level temperature for each individual. TTM may be used to prevent fever, to maintain normothermia, or to lower core temperature. This treatment is widely used in intensive care units, mostly as a primary neuroprotective method. Indications are, however, associated with variable levels of evidence based on inhomogeneous or even contradictory literature. Our aim was to conduct a systematic analysis of the published data in order to provide guidelines. We present herein recommendations for the use of TTM in adult and paediatric critically ill patients developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. These guidelines were conducted by a group of experts from the French Intensive Care Society (Société de Réanimation de Langue Française [SRLF]) and the French Society of Anesthesia and Intensive Care Medicine (Société Francaise d’Anesthésie Réanimation [SFAR]) with the participation of the French Emergency Medicine Association (Société Française de Médecine d’Urgence [SFMU]), the French Group for Pediatric Intensive Care and Emergencies (Groupe Francophone de Réanimation et Urgences Pédiatriques [GFRUP]), the French National Association of Neuro-Anesthesiology and Critical Care (Association Nationale de Neuro-Anesthésie Réanimation Française [ANARLF]), and the French Neurovascular Society (Société Française Neurovasculaire [SFNV]). Fifteen experts and two coordinators agreed to consider questions concerning TTM and its practical implementation in five clinical situations: cardiac arrest, traumatic brain injury, stroke, other brain injuries, and shock. This resulted in 30 recommendations: 3 recommendations were strong (Grade 1), 13 were weak (Grade 2), and 14 were experts’ opinions. After two rounds of rating and various amendments, a strong agreement from voting participants was obtained for all 30 (100%) recommendations, which are exposed in the present article.

Pediatric neurocritical care in the 21st century: from empiricism to evidence

PURPOSE OF REVIEW

Approximately one in five children admitted to a pediatric ICU have a new central nervous system injury or a neurological complication of their critical illness. The spectrum of neurologic insults in children is diverse and clinical practice is largely empirical, as few randomized, controlled trials have been reported. This lack of data poses a substantial challenge to the practice of pediatric neurocritical care (PNCC). PNCC has emerged as a novel subspecialty, and its presence is expanding within tertiary care centers. This review highlights the recent advances in the field, with a focus on traumatic brain injury (TBI), cardiac arrest, and stroke as disease models.

RECENT FINDINGS

Variable approaches to the structure of a PNCC service have been reported, comprising multidisciplinary teams from neurology, critical care, neurosurgery, neuroradiology, and anesthesia. Neurologic morbidity is substantial in critically ill children and the increased use of continuous electroencephalography monitoring has highlighted this burden. Therapeutic hypothermia has not proven effective for treatment of children with severe TBI or out-of-hospital cardiac arrest. However, results of studies of severe TBI suggest that multidisciplinary care in the ICU and adherence to guidelines for care can reduce mortality and improve outcome.

SUMMARY

There is an unmet need for clinicians with expertise in the practice of brain-directed critical care for children. Although much of the practice of PNCC may remain empiric, a focus on the regionalization of care, creating defined training paths, practice within multidisciplinary teams, protocol-directed care, and improved measures of long-term outcome to quantify the impact of such care can provide evidence to direct the maturation of this field.

Therapeutic hypothermia brings favorable neurologic outcomes in children with near drowning

A 1-year-10-month-old boy was admitted to our pediatric intensive care unit due to near drowning with pulmonary edema. A conventional ventilator with 100% oxygen supplementation was used initially, but was shifted to high frequency oscillatory ventilation as his oxygen saturation was around 84–88%. Therapeutic hypothermia was applied due to hypoxic ischemic encephalopathy with severe acidosis. His respiratory condition improved and he was extubated successfully on the 6^th hospital day. The patient had no obvious neurological defects and he was discharged in a stable condition after 17 days of hospitalization. Our case report demonstrates the advantages of therapeutic hypothermia on survival and neurological outcomes in treating pediatric near drowning patients.

Management of the Pediatric Neurocritical Care Patient

Pediatric neurocritical care is a growing subspecialty of pediatric intensive care that focuses on the management of acute neurological diseases in children. A brief history of the field of pediatric neurocritical care is provided. Neuromonitoring strategies for children are reviewed. Management of major categories of acute childhood central neurologic diseases are reviewed, including treatment of diseases associated with intracranial hypertension, seizures and status epilepticus, stroke, central nervous system infection and inflammation, and hypoxic-ischemic injury.

A State-of-the-Science Overview of Randomized Controlled Trials Evaluating Acute Management of Moderate-to-Severe Traumatic Brain Injury

Moderate-to-severe traumatic brain injury (TBI) remains a major global challenge, with rising incidence, unchanging mortality and lifelong impairments. State-of-the-science reviews are important for research planning and clinical decision support. This review aimed to identify randomized controlled trials (RCTs) evaluating interventions for acute management of moderate/severe TBI, synthesize key RCT characteristics and findings, and determine their implications on clinical practice and future research. RCTs were identified through comprehensive database and other searches. Key characteristics, outcomes, risk of bias, and analysis approach were extracted. Data were narratively synthesized, with a focus on robust (multi-center, low risk of bias, n > 100) RCTs, and three-dimensional graphical figures also were used to explore relationships between RCT characteristics and findings. A total of 207 RCTs were identified. The 191 completed RCTs enrolled 35,340 participants (median, 66). Most (72%) were single center and enrolled less than 100 participants (69%). There were 26 robust RCTs across 18 different interventions. For 74% of 392 comparisons across all included RCTs, there was no significant difference between groups. Positive findings were broadly distributed with respect to RCT characteristics. Less than one-third of RCTs demonstrated low risk of bias for random sequence generation or allocation concealment, less than one-quarter used covariate adjustment, and only 7% employed an ordinal analysis approach. Considerable investment of resources in producing 191 completed RCTs for acute TBI management has resulted in very little translatable evidence. This may result from broad distribution of research effort, small samples, preponderance of single-center RCTs, and methodological shortcomings. More sophisticated RCT design, large multi-center RCTs in priority areas, increased focus on pre-clinical research, and alternatives to RCTs, such as comparative effectiveness research and precision medicine, are needed to fully realize the potential of acute TBI research to benefit patients.

Proteomic Profiling Reveals Adaptive Responses to Surgical Myocardial Ischemia-Reperfusion in Hibernating Arctic Ground Squirrels Compared to Rats

BACKGROUND

Hibernation is an adaptation to extreme environments known to provide organ protection against ischemia-reperfusion (I/R) injury. An unbiased systems approach was utilized to investigate hibernation-induced changes that are characteristic of the hibernator cardioprotective phenotype, by comparing the myocardial proteome of winter hibernating arctic ground squirrels (AGS), summer active AGS, and rats subjected to I/R, and further correlating with targeted metabolic changes.

METHODS

In a well-defined rodent model of I/R by deep hypothermic circulatory arrest followed by 3 or 24 h of reperfusion or sham, myocardial protein abundance in AGS (hibernating summer active) and rats (n = 4 to 5/group) was quantified by label-free proteomics (n = 4 to 5/group) and correlated with metabolic changes.

RESULTS

Compared to rats, hibernating AGS displayed markedly reduced plasma levels of troponin I, myocardial apoptosis, and left ventricular contractile dysfunction. Of the 1,320 rat and 1,478 AGS proteins identified, 545 were differentially expressed between hibernating AGS and rat hearts (47% up-regulated and 53% down-regulated). Gene ontology analysis revealed down-regulation in hibernating AGS hearts of most proteins involved in mitochondrial energy transduction, including electron transport chain complexes, acetyl CoA biosynthesis, Krebs cycle, glycolysis, and ketogenesis. Conversely, fatty acid oxidation enzymes and sirtuin-3 were up-regulated in hibernating AGS, with preserved peroxisome proliferator-activated receptor-α activity and reduced tissue levels of acylcarnitines and ceramides after I/R.

CONCLUSIONS

Natural cardioprotective adaptations in hibernators involve extensive metabolic remodeling, featuring increased expression of fatty acid metabolic proteins and reduced levels of toxic lipid metabolites. Robust up-regulation of sirtuin-3 suggests that posttranslational modifications may underlie organ protection in hibernating mammals.

Monitoring intracranial pressure utilizing a novel pattern of brain multiparameters in the treatment of severe traumatic brain injury

The aim of the study was to evaluate the clinical value of multiple brain parameters on monitoring intracranial pressure (ICP) procedures in the therapy of severe traumatic brain injury (sTBI) utilizing mild hypothermia treatment (MHT) alone or a combination strategy with other therapeutic techniques. A total of 62 patients with sTBI (Glasgow Coma Scale score <8) were treated using mild hypothermia alone or mild hypothermia combined with conventional ICP procedures such as dehydration using mannitol, hyperventilation, and decompressive craniectomy. The multiple brain parameters, which included ICP, cerebral perfusion pressure, transcranial Doppler, brain tissue partial pressure of oxygen, and jugular venous oxygen saturation, were detected and analyzed. All of these measures can control the ICP of sTBI patients to a certain extent, but multiparameters associated with brain environment and functions have to be critically monitored simultaneously because some procedures of reducing ICP can cause side effects for long-term recovery in sTBI patients. The result suggested that multimodality monitoring must be performed during the process of mild hypothermia combined with conventional ICP procedures in order to safely target different clinical methods to specific patients who may benefit from an individual therapy.

Advances in neurocritical care

The neurologically injured child, whether from trauma or other causes, is a common admission into any Pediatric critical care unit. Whatever the cause, the risk for death and life long disability remains very high. Unlike the adult population, neurological diseases in children are diverse and arise from a variety of factors that vary greatly in age and presentation. Nervous system dysfunction is often a complication of critical illness and interventions. While neurointensive care units may be ideal for the at-risk child, in mixed units, 40 % of admissions may be neurological or have neurological complications. Improved quality of care and the application of protocols and bundles, appear to have contributed significantly to improved outcomes. Since we are constantly facing an uphill task of dealing with deterioration while trying to preserve function, detection of early shifts of any nature would be deemed helpful. The intensivist must focus not only on saving life but also on preventing disability with full awareness that responsibility does not end with discharge from the pediatric intensive care unit (PICU). Outcome audits should include not only deaths and discharge from PICU but also one year mortality and even degree of disability at the end of one year from discharge.

Therapeutic Hypothermia in Children and Adults with Severe Traumatic Brain Injury

Great expectations have been raised about neuroprotection of therapeutic hypothermia in patients with traumatic brain injury (TBI) by analogy with its effects after heart arrest, neonatal asphyxia, and drowning in cold water. The aim of this study is to review our present knowledge of the effect of therapeutic hypothermia on outcome in children and adults with severe TBI. A literature search for relevant articles in English published from year 2000 up to December 2013 found 19 studies. No signs of improvement in outcome from hypothermia were seen in the five pediatric studies. Varied results were reported in 14 studies on adult patients, 2 of which reported a tendency of higher mortality and worse neurological outcome, 4 reported lower mortality, and 9 reported favorable neurological outcome with hypothermia. The quality of several trials was low. The best-performed randomized studies showed no improvement in outcome by hypothermia-some even indicated worse outcome. TBI patients may suffer from hypothermia-induced pulmonary and coagulation side effects, from side effects of vasopressors when re-establishing the hypothermia-induced lowered blood pressure, and from a rebound increase in intracranial pressure (ICP) during and after rewarming. The difference between body temperature and temperature set by the biological thermostat may cause stress-induced worsening of the circulation and oxygenation in injured areas of the brain. These mechanisms may counteract neuroprotective effects of therapeutic hypothermia. We conclude that we still lack scientific support as a first-tier therapy for the use of therapeutic hypothermia in TBI patients for both adults and children, but it may still be an option as a second-tier therapy for refractory intracranial hypertension.

Age-specific cerebral perfusion pressure thresholds and survival in children and adolescents with severe traumatic brain injury*

OBJECTIVES

Evidence-based traumatic brain injury guidelines support cerebral perfusion pressure thresholds for adults at a class 2 level, but evidence is lacking in younger patients. The purpose of this study is to identify the impact of age-specific cerebral perfusion pressure thresholds on short-term survival among patients with severe traumatic brain injury.

DESIGN

Institutional review board-approved, prospective, observational cohort study.

SETTING

Level I or II trauma centers in New York State.

PATIENTS

Data on all patients with a postresuscitation Glasgow Coma Score less than 9 were added in the Brain Trauma Foundation prospective New York State TBI-trac database.

MEASUREMENTS AND MAIN RESULTS

We calculated the survival rates and relative risks of mortality for patients with severe traumatic brain injury based on predefined age-specific cerebral perfusion pressure thresholds. A higher threshold and a lower threshold were defined for each age group: 60 and 50 mm Hg for 12 years old or older, 50 and 35 mm Hg for 6-11 years, and 40 and 30 mm Hg for 0-5 years. Patients were stratified into age groups of 0-11, 12-17, and 18 years old or older. Three exclusive groups of CPP-L (events below low cerebral perfusion pressure threshold), CPP-B (events between high and low cerebral perfusion pressure thresholds), and CPP-H (events above high cerebral perfusion pressure threshold) were defined. As an internal control, we evaluated the associations between cerebral perfusion pressure events and events of hypotension and elevated intracranial pressure. Survival was significantly higher in 0-11 and 18 years old or older age groups for patients with CPP-H events compared with those with CPP-L events. There was a significant decrease in survival with prolonged exposure to CPP-B events for the 0-11 and 18 years old and older age groups when compared with the patients with CPP-H events (p = 0.0001 and p = 0.042, respectively). There was also a significant decrease in survival with prolonged exposure to CPP-L events in all age groups compared with the patients with CPP-H events (p< 0.0001 for 0- to 11-yr olds, p = 0.0240 for 12- to 17-yr olds, and p < 0.0001 for 18-yr old and older age groups). The 12- to 17-year olds had a significantly higher likelihood of survival compared with adults with prolonged exposure to CPP-L events (< 50 mm Hg). CPP-L events were significantly related to systemic hypotension for the 12- to 17-year-old group (p = 0.004) and the 18-year-old and older group (p < 0.0001). CPP-B events were significantly related to systemic hypotension in the 0- to 11-year-old group (p = 0.014). CPP-B and CPP-L events were significantly related to elevated intracranial pressure in all age groups.

CONCLUSIONS

Our data provide new evidence that cerebral perfusion pressure targets should be age specific. Furthermore, cerebral perfusion pressure goals above 50 or 60 mm Hg in adults, above 50 mm Hg in 6- to 17-year olds, and above 40 mm Hg in 0- to 5-year olds seem to be appropriate targets for treatment-based studies. Systemic hypotension had an inconsistent relationship to events of low cerebral perfusion pressure, whereas elevated intracranial pressure was significantly related to all low cerebral perfusion pressure events across all age groups. This may impart a clinically important difference in care, highlighting the necessity of controlling intracranial pressure at all times, while targeting systolic blood pressure in specific instances.

Viral encephalitis in the ICU

Viral encephalitis causes an altered level of consciousness, which may be associated with fever, seizures, focal deficits, CSF pleocytosis, and abnormal neuroimaging. Potential pathogens include HSV, VZV, enterovirus, and in some regions, arboviruses. Autoimmune (eg, anti-NMDA receptor) and paraneoplastic encephalitis are responsible for some cases where no pathogen is identified. Indications for ICU admission include coma, status epilepticus and respiratory failure. Timely initiation of anti-viral therapy is crucial while relevant molecular and serological test results are being performed. Supportive care should be directed at the prevention and treatment of cerebral edema and other physiological derangements which may contribute to secondary neurological injury.

Is therapeutic hypothermia beneficial for pediatric patients with traumatic brain injury? A meta-analysis

PURPOSE

Hypothermia therapy shows its unique potential for reducing mortality in animal study and improving neurologic outcome in patients with traumatic brain injury. However, therapeutic hypothermia for pediatric traumatic brain injury remains a controversial issue. To determine the effectiveness and safety of hypothermia treatment for pediatric traumatic brain injury patients, we conducted this meta-analysis.

PATIENTS AND METHODS

We analyzed the data from MEDLINE, Pubmed, EMBASE, and Cochrane Library by electronic searching. No limitation of language was selected for analysis. We extracted the mortality and adverse events from the published trials.

RESULTS

Six clinical trials and 366 pediatric patients met our inclusion criteria. Pediatric patients with traumatic brain injury treated with hypothermia had more unfavorable outcome than those in the normothermia group (RR 1.73, 95 % CI 1.06 to 2.84), and this increased risk is statistically significant. Patients with therapeutic hypothermia are slightly likely to be induced by cardiac arrhythmia, and the likelihood is also significant (RR 2.57, 95 % CI 1.01 to 6.54). Risk of pneumonia has no statistical difference between normothermia and hypothermia arms (RR 0.90, 95 % CI 0.73 to 1.12). Two of the included trials have reported their detail randomization assignment.

CONCLUSIONS

Hypothermia may slightly increase the risk of mortality in children with traumatic brain injury and the ratio of cardiac arrhythmia after this hypothermia therapy is slightly higher than that in normothermia groups. In the future, more randomized controlled trials and multicenter studies on the mechanism of therapeutic hypothermia are required.

High-dose barbiturates for refractory intracranial hypertension in children with severe traumatic brain injury

OBJECTIVES

To evaluate high-dose barbiturates as a second-tier therapy for pediatric refractory intracranial hypertension complicating severe traumatic brain injury.

DESIGN

This is a retrospective cohort study of children with refractory intracranial hypertension treated with high-dose barbiturates.

SETTING

A single center level I pediatric trauma from 2001 to 2010.

PATIENTS

Thirty-six children with refractory intracranial hypertension defined as intracranial pressure greater than 20 mm Hg despite standard management treated with high-dose barbiturates after severe traumatic brain injury.

INTERVENTIONS

High-dose barbiturates were administered for refractory intracranial hypertension for a minimum duration of 6 hours and monitored by continuous electroencephalography.

MEASUREMENTS AND MAIN RESULTS

Exposure was control of refractory intracranial hypertension defined as > 20 mm Hg within 6 hours after starting barbiturates. Pediatric cerebral performance category scores at hospital discharge and at 3 months (or longer) follow-up were the primary outcomes. Ten of 36 patients (28%) had control of refractory intracranial hypertension. Neither demographic nor injury characteristics were associated with refractory intracranial hypertension control. Children who responded received barbiturates significantly later after injury (76 vs. 29 median hours). Overall, 14 children died, 13 without control of intracranial pressure. Survival was more common in those who responded compared with those who did not respond to high-dose barbiturates, although this did not reach statistical significance (relative risk of death 0.2; 95% confidence interval; [0.03-1.3]). Of the 22 survivors, 19 had an acceptable survival (pediatric cerebral performance category less than 3) at 3 months or longer after injury; however, only three returned to normal function. Among survivors, control of refractory intracranial hypertension was associated with significantly better pediatric cerebral performance category scores and over two-fold likelihood of acceptable long-term outcome (relative risk 2.3; 95% confidence interval [1.4-4.0]) compared with uncontrolled refractory intracranial hypertension despite high-dose barbiturates.

CONCLUSIONS

Addition of high-dose barbiturates achieved control of refractory intracranial hypertension in almost 30% of treated children. Control of refractory intracranial hypertension was associated with increased likelihood of an acceptable long-term outcome.

Perioperative management of the pediatric patient with traumatic brain injury

TBI and its sequelae remain a major healthcare issue throughout the world. With an improved understanding of the pathophysiology of TBI, refinements of monitoring technology, and ongoing research to determine optimal care, the prognosis of TBI continues to improve. In 2003, the Society of Critical Care Medicine published guidelines for the acute management of severe TBI in infants, children, and adolescents. As pediatric anesthesiologists are frequently involved in the perioperative management of such patients including their stabilization in the emergency department, familiarity with these guidelines is necessary to limit preventable secondary damage related to physiologic disturbances. This manuscript reviews the current evidence-based medicine regarding the care of pediatric patients with TBI as it relates to the perioperative care of such patients. The issues reviewed include those related to initial stabilization, airway management, intra-operative mechanical ventilation, hemodynamic support, administration of blood and blood products, positioning, and choice of anesthetic technique. The literature is reviewed regarding fluid management, glucose control, hyperosmolar therapy, therapeutic hypothermia, and corticosteroids. Whenever possible, management recommendations are provided.

Pediatric neurocritical care

Pediatric neurocritical care is an emerging multidisciplinary field of medicine and a new frontier in pediatric critical care and pediatric neurology. Central to pediatric neurocritical care is the goal of improving outcomes in critically ill pediatric patients with neurological illness or injury and limiting secondary brain injury through optimal critical care delivery and the support of brain function. There is a pressing need for evidence based guidelines in pediatric neurocritical care, notably in pediatric traumatic brain injury and pediatric stroke. These diseases have distinct clinical and pathophysiological features that distinguish them from their adult counterparts and prevent the direct translation of the adult experience to pediatric patients. Increased attention is also being paid to the broader application of neuromonitoring and neuroprotective strategies in the pediatric intensive care unit, in both primary neurological and primary non-neurological disease states. Although much can be learned from the adult experience, there are important differences in the critically ill pediatric population and in the circumstances that surround the emergence of neurocritical care in pediatrics.

Quo vadis 2010? - carpe diem: challenges and opportunities in pediatric traumatic brain injury

Traumatic brain injury (TBI) in infants and children remains a public health problem of enormous magnitude. It is a complex and heterogeneous condition that presents many diagnostic, therapeutic and prognostic challenges. A number of investigative teams are studying pediatric TBI both in experimental models and in clinical studies at the bedside. This review builds on work presented in a prior supplement to Developmental Neuroscience that was published in 2006, and addresses several active areas of research on this topic, including (1) the application of novel imaging methods, (2) the use of serum and/or CSF biomarkers of injury, (3) advances in neuromonitoring, (4) the development and testing of novel therapies, (5) developments in modeling pediatric TBI, (6) the consideration of a new approach to classification of pediatric TBI, and (7) assessing the potential impact of the development of pediatric and neonatal neurocritical care services on the management and outcome of pediatric TBI.