Time of Hypotension and Discharge Outcome in Children with Severe Traumatic Brain Injury

Cardiovascular events in children with brain injury: A systematic review

BACKGROUND

Brain injury is a leading cause of morbidity and mortality in the pediatric population. Neurogenic stunned cardiomyopathy is a complication associated with several neurological conditions that can lead to worse outcomes. It presents as alterations in blood pressure, cardiac rhythm disturbances and the increase in cardiac injury biomarkers. This systematic review aims to assess the hemodynamic consequences of brain injury in the pediatric population to identify better management strategies and improve outcomes.

METHODS

An electronic literature search was performed in Pubmed, Scopus and WebOfScience, up until October 3rd, 2022. The selected articles underwent quality assessment using the National Heart, Lung and Blood Institute tools for cohort and case-control studies.

RESULTS

This systematic review includes thirteen articles on the effects of brain injury in arterial pressure, rhythm disturbances and biomarkers of myocardial injury. These studies showed the following key results: both hypotension and hypertension are associated with worse outcomes; brain injury could be related to longer QTc intervals; neurogenic stunned cardiomyopathy was a common found after brain injury.

CONCLUSION

This is the first systematic review to report cardiovascular abnormalities arising from brain injury in children. An early arterial pressure, electrocardiographic and echocardiographic evaluation, as well as the measure of serum biomarkers for myocardial injury, can be critical in identifying poor prognostic factors. Further research is required to understand the implications of our findings in clinical practice.

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.

Management of Severe Traumatic Brain Injury in Pediatric Patients

The optimal management of severe traumatic brain injury (TBI) in the pediatric population has not been well studied. There are a limited number of research articles studying the management of TBI in children. Given the prevalence of severe TBI in the pediatric population, it is crucial to develop a reference TBI management plan for this vulnerable population. In this review, we seek to delineate the differences between severe TBI management in adults and children. Additionally, we also discuss the known molecular pathogenesis of TBI. A better understanding of the pathophysiology of TBI will inform clinical management and development of therapeutics. Finally, we propose a clinical algorithm for the management and treatment of severe TBI in children using published data.

Metrics of shock in pediatric trauma patients: A systematic search and review

INTRODUCTION

Shock-index (SI) and systolic blood pressure (SBP) are metrics for identifying children and adults with hemodynamic instability following injury. The purpose of this systematic review was to assess the quality of these metrics as predictors of outcomes following pediatric injury.

MATERIALS AND METHODS

We conducted a literature search in Pubmed, SCOPUS, and CINAHL to identify studies describing the association between shock metrics on the morbidity and mortality of injured children and adolescents. We used the data presented in the studies to calculate the sensitivity and specificity for each metric. This study was registered with Prospero, protocol CRD42020162971.

RESULTS

Fifteen articles met the inclusion criteria. seven studies evaluated SI or SIPA score, an age-corrected version of SI, as predictors of outcomes following pediatric trauma, with one study comparing SIPA score and SBP and one study comparing SI and SBP. The remaining eight studies evaluated SBP as the primary indicator of shock. The median sensitivity for predicting mortality and need for blood transfusion was highest for SI, followed by SIPA, and then SBP. The median specificity for predicting these outcomes was highest for SBP, followed by SIPA, and then SI.

CONCLUSIONS

Common conclusions were that high SIPA scores were more specific than SI and more sensitive than SBP. SIPA score had better discrimination for severely injured children compared to SI and SBP. An elevated SIPA was associated with a greater need for blood transfusion and higher in-hospital mortality. SIPA is specific enough to exclude most patients who do not require a blood transfusion.

Assessment of Non-Routine Events and Significant Physiological Disturbances during Emergency Department Evaluation after Pediatric Head Trauma

Outcomes following pediatric traumatic brain injury (TBI) are dependent on initial injury severity and prevention of secondary injury. Hypoxia, hypotension, and hyperventilation following TBI are associated with increased mortality. The purpose of this study was to determine the association of non-routine events (NREs) during the initial resuscitation phase with these physiological disturbances. We conducted a video review of pediatric trauma resuscitations of patients with suspected TBI and Glasgow Coma Scale (GCS) scores <13. NREs were rated as "momentary" if task progression was delayed by <1 min and "moderate" if delayed by >1 min. Vital sign monitor data were used to identify periods of significant physiological disturbances. We calculated the association between the rate of overall and moderate NREs per case and the proportion of cases with abnormal vital signs using multi-variate linear regression, controlling for GCS score and need for intubation. Among 26 resuscitations, 604 NREs were identified with a median of 23 (interquartile range [IQR] 17-27.8, range 5-44) per case. Moderate delay NREs occurred in 19 resuscitations (n = 32, median 1 NRE/resuscitation, IQR 0.3-1, range 0-5). Oxygen desaturation and respiratory depression were associated with a greater rate of moderate NREs (p = 0.008, p < 0.001, respectively). We observed no association between duration of hypotension, desaturation, and respiratory depression and overall NRE rate. NREs are common in the initial resuscitation of children with moderate to severe TBI. Episodes of hypoxia and respiratory depression are associated with NREs that cause a moderate delay in task progression. Conformance with resuscitation guidelines is needed to prevent physiological events associated with adverse outcomes following pediatric TBI.

Injury Causes and Severity in Pediatric Traumatic Brain Injury Patients Admitted to the Ward or Intensive Care Unit: A Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) Study

Background: Traumatic brain injury (TBI) is the leading cause of death and disability in children. It includes a range of different pathologies that differ considerably from adult TBI. Analyzing and understanding injury patterns of pediatric TBI is essential to establishing new preventive efforts as well as to improve clinical management.

Methods: The multi-center, prospectively collected CENTER-TBI core and registry databases were screened and patients were included when younger than 18 years at enrollment and admitted to the regular ward (admission stratum) or intensive care unit (ICU stratum) following TBI. Patient demographics, injury causes, clinical findings, brain CT imaging details, and outcome (GOSE at 6 months follow-up) were retrieved and analyzed. Injury characteristics were compared between patients admitted to the regular ward and ICU and multivariate analysis of factors predicting an unfavorable outcome (GOSE 1-4) was performed. Results from the core study were compared to the registry dataset which includes larger patient numbers but no follow-up data.

Results: Two hundred and twenty seven patients in the core dataset and 687 patients in the registry dataset were included in this study. In the core dataset, road-traffic incidents were the most common cause of injury overall and in the ICU stratum, while incidental falls were most common in the admission stratum. Brain injury was considered serious to severe in the majority of patients and concurrent injuries in other body parts were very common. Intracranial abnormalities were detected in 60% of initial brain CTs. Intra- and extracranial surgical interventions were performed in one-fifth of patients. The overall mortality rate was 3% and the rate of unfavorable outcome 10%, with those numbers being considerably higher among ICU patients. GCS and the occurrence of secondary insults could be identified as independent predictors for an unfavorable outcome. Injury characteristics from the core study could be confirmed in the registry dataset.

Conclusion: Our study displays the most common injury causes and characteristics of pediatric TBI patients that are treated in the regular ward or ICU in Europe. Road-traffic incidents were especially common in ICU patients, indicating that preventive efforts could be effective in decreasing the incidence of severe TBI in children.

Paediatric traumatic brain injury: prognostic insights and outlooks

PURPOSE OF REVIEW

Traumatic brain injury (TBI) is a leading cause of death and disability in children. Prognostication of outcome following TBI is challenging in this population and likely requires complex, multimodal models to achieve clinically relevant accuracy. This review highlights injury characteristics, physiological indicators, biomarkers and neuromonitoring modalities predictive of outcome that may be integrated for future development of sensitive and specific prognostic models.

RECENT FINDINGS

Paediatric TBI is responsible for physical, psychosocial and neurocognitive deficits that may significantly impact quality of life. Outcome prognostication can be difficult in the immature brain, but is aided by the identification of novel biomarkers (neuronal, astroglial, myelin, inflammatory, apoptotic and autophagic) and neuromonitoring techniques (electroencephalogram and MRI). Investigation in the future may focus on assessing the prognostic ability of combinations of biochemical, protein, neuroimaging and functional biomarkers and the use of mathematical models to develop multivariable predication tools to improve the prognostic ability following childhood TBI.

SUMMARY

Prognostication of outcome following paediatric TBI is multidimensional, influenced by injury severity, age, physiological factors, biomarkers, electroencephalogram and neuroimaging. Further development, integration and validation of combinatorial prognostic algorithms are necessary to improve the accuracy and timeliness of prognosis in a meaningful fashion.

Timely Hemodynamic Resuscitation and Outcomes in Severe Pediatric Traumatic Brain Injury: Preliminary Findings

OBJECTIVES

Early resuscitation may improve outcomes in pediatric traumatic brain injury (TBI). We examined the association between timely treatment of hypotension and hypoxia during early care (prehospital or emergency department locations) and discharge outcomes in children with severe TBI.

METHODS

Hypotension was defined as systolic blood pressure less than 70 + 2 (age in years), and hypoxia was defined as PaO2 less than 60 mm Hg or oxygen saturation less than 90% in accordance with the 2003 Brain Trauma Foundation guidelines. Timely treatment of hypotension and hypoxia during early care was defined as the treatment within 30 minutes of a documented respective episode. Two hundred thirty-six medical records of children younger than 18 years with severe TBI from 5 regional pediatric trauma centers were examined. Main outcomes were in-hospital mortality and discharge Glasgow Outcome Scale (GOS) score.

RESULTS

Hypotension occurred in 26% (60/234) during early care and was associated with in-hospital mortality (23.3% vs 8.6%; P = 0.01). Timely treatment of hypotension during early care occurred in 92% (55/60) by use of intravenous fluids, blood products, or vasopressors and was associated with reduced in-hospital mortality [adjusted relative risk (aRR), 0.46; 95% confidence interval, 0.24-0.90] and less likelihood of poor discharge GOS (aRR, 0.54; 95% confidence interval, 0.39-0.76) when compared to children with hypotension who were not treated in a timely manner. Early hypoxia occurred in 17% (41/236) and all patients received timely oxygen treatment.

CONCLUSIONS

Timely resuscitation during early care was common and associated with lower in-hospital mortality and favorable discharge GOS in severe pediatric TBI.

Intensive care treatments associated with favorable discharge outcomes in Argentine children with severe traumatic brain injury: For the South American Guideline Adherence Group

Objective

Little is known about the critical care management of children with traumatic brain injury (TBI) in low middle income countries. We aimed to identify indicators of intensive care unit (ICU) treatments associated with favorable outcomes in Argentine children with severe TBI.

Methods

We conducted a secondary analysis of data from patients previously enrolled in a prospective seven center study of children with severe TBI who were admitted to an ICU in one of the seven study centers. Severe TBI was defined by head AIS ≥ 3, head CT with traumatic lesion, and admission GCS < 9. Seven indicators of best practice TBI care were examined. The primary outcome was discharge Pediatric Cerebral Performance Category Scale [PCPC] and Pediatric Overall Performance category Scale [POPC]. We also examined variation in ICU care and in-patient mortality.

Results

Of the 117 children, 67% were male and 7.5 (4.3) years on average, 92% had isolated TBI. Hypotension (54%) was more common than hypoxia (28%) and clinical or radiographic signs of high intracranial pressure (ICP) were observed in 92%. Yet, ICP monitoring occurred in 60% and hyperosmolar therapy was used in only 36%. Adherence to indicators of best TBI practice ranged from 55.6% to 83.7% across the seven centers and adherence was associated with favorable discharge PCPC (aRR 0.98; 95% CI [0.96, 0.99]), and POPC (aRR 0.98; 95% CI [0.96, 0.99]). Compared to patients whose adherence rates were below 65%, patients whose adherence rates were higher between 75%-100% had better discharge PCPC (aRR 0.28; 95% CI [0.10, 0.83]) and POPC (aRR 0.32; 95% CI [0.15, 0.73]. Two indicators were associated with favorable discharge PCPC: Avoidance of hypoxia (aRR 0.46; 95% CI [0.23, 0.93]), and Nutrition started in 72 hours (aRR 0.45; 95% CI [0.21, 0.99]). Avoiding hypoxia was also associated with favorable discharge POPC (aRR 0.47; 95% CI [0.22, 0.99]).

Conclusion

There is variation in Argentine ICU practice in the care of children with severe TBI. Second insults are common and hyperosmolar therapy use is uncommon. Adherence to best practice TBI care by avoiding hypoxia and providing timely nutrition were associated with significantly favorable discharge outcomes. Implementing strategies that prevent hypoxia and facilitate early nutrition in the ICUs are urgently needed to improve pediatric TBI outcomes.

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.

Emergency Neurological Life Support: Traumatic Brain Injury

Traumatic Brain Injury (TBI) was chosen as an Emergency Neurological Life Support topic due to its frequency, the impact of early intervention on outcomes for patients with TBI, and the need for an organized approach to the care of such patients within the emergency setting. This protocol was designed to enumerate the practice steps that should be considered within the first critical hour of neurological injury.

The value of intraoperative intracranial pressure monitoring for predicting re-operation using salvage decompressive craniectomy after craniotomy in patients with traumatic mass lesions

BACKGROUND

The risk factors of predicting the need for postoperative decompressive craniectomy due to intracranial hypertension after primary craniotomy remain unclear. This study aimed to investigate the value of intraoperative intracranial pressure (ICP) monitoring in predicting re-operation using salvage decompressive craniectomy (SDC).

METHODS

From January 2008 to October 2014, we retrospectively reviewed 284 patients with severe traumatic brain injury (STBI) who underwent craniotomy for mass lesion evacuation without intraoperative brain swelling. Intraoperative ICP was documented at the time of initial craniotomy and then again after the dura was sutured. SDC was used when postoperative ICP was continually higher than 25 mmHg for 1 h without a downward trend. Univariate and multivariate analyses were applied to both initial demographic and radiographic features to identify risk factors of SDC requirement.

RESULTS

Of 284, 41 (14.4%) patients who underwent SDC had a higher Initial ICP than those who didn't (38.1 ± 9.2 vs. 29.3 ± 8.1 mmHg, P < 0.001), but there was no difference in ICP after the dura was sutured. The factors which have significant effects on SDC are higher initial ICP [odds ratio (OR): 1.100, 95% confidence interval (CI): 1.052-1.151, P < 0.001], older age (OR: 1.039, 95% CI: 1.002-1.077, P = 0.039), combined lesions (OR: 3.329, 95% CI: 1.199-9.244, P = 0.021) and early hypotension (OR: 2.524, 95% CI: 1.107-5.756, P = 0.028). The area under the curve of multivariate regression model was 0.771.

CONCLUSIONS

The incidence of re-operation using SDC after craniotomy was 14.4%. The independent risk factors of SDC requirement are initial ICP, age, early hypotension and combined lesions.

Pediatric head injury: a pain for the emergency physician?

The prompt diagnosis and initial management of pediatric traumatic brain injury poses many challenges to the emergency department (ED) physician. In this review, we aim to appraise the literature on specific management issues faced in the ED, specifically: indications for neuroimaging, choice of sedatives, applicability of hyperventilation, utility of hyperosmolar agents, prophylactic anti-epileptics, and effect of hypothermia in traumatic brain injury. A comprehensive literature search of PubMed and Embase was performed in each specific area of focus corresponding to the relevant questions. The majority of the head injured patients presenting to the ED are mild and can be observed. Clinical prediction rules assist the ED physician in deciding if neuroimaging is warranted. In cases of major head injury, prompt airway control and careful use of sedation are necessary to minimize the chance of hypoxia, while avoiding hyperventilation. Hyperosmolar agents should be started in these cases and normothermia maintained. The majority of the evidence is derived from adult studies, and most treatment modalities are still controversial. Recent multicenter trials have highlighted the need to establish common platforms for further collaboration.

Evidence-based assessment of severe pediatric traumatic brain injury and emergent neurocritical care

Pediatric traumatic brain injury accounts for approximately 474,000 emergency department visits, 37,000 hospitalizations, and 3,000 deaths in children 14 years and younger annually in the United States. Acute neurocritical care in children has advanced with specialized pediatric trauma centers and emergency medical services. This article reviews pediatric-specific diagnosis, management, and medical decision making related to the neurocritical care of severe traumatic brain injury.

Acute care clinical indicators associated with discharge outcomes in children with severe traumatic brain injury

OBJECTIVE

The effect of the 2003 severe pediatric traumatic brain injury (TBI) guidelines on outcomes has not been examined. We aimed to develop a set of acute care guideline-influenced clinical indicators of adherence and tested the relationship between these indicators during the first 72 hours after hospital admission and discharge outcomes.

DESIGN

Retrospective multicenter cohort study.

SETTING

Five regional pediatric trauma centers affiliated with academic medical centers.

PATIENTS

Children under 18 years with severe traumatic brain injury (admission Glasgow Coma Scale score ≤ 8, International Classification of Diseases, 9th Edition, diagnosis codes of 800.0-801.9, 803.0-804.9, 850.0-854.1, 959.01, 950.1-950.3, 995.55, maximum head abbreviated Injury Severity Score ≥ 3) who received tracheal intubation for at least 48 hours in the ICU between 2007 and 2011 were examined.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Total percent adherence to the clinical indicators across all treatment locations (prehospital, emergency department, operating room, and ICU) during the first 72 hours after admission to study center were determined. Main outcomes were discharge survival and Glasgow Outcome Scale score. Total adherence rate across all locations and all centers ranged from 68% to 78%. Clinical indicators of adherence were associated with survival (adjusted hazard ratios, 0.94; 95% CI, 0.91-0.96). Three indicators were associated with survival: absence of prehospital hypoxia (adjusted hazard ratios, 0.20; 95% CI, 0.08-0.46), early ICU start of nutrition (adjusted hazard ratios, 0.06; 95% CI, 0.01-0.26), and ICU PaCO2 more than 30 mm Hg in the absence of radiographic or clinical signs of cerebral herniation (adjusted hazard ratios, 0.22; 95% CI, 0.06-0.8). Clinical indicators of adherence were associated with favorable Glasgow Outcome Scale among survivors (adjusted hazard ratios, 0.99; 95% CI, 0.98-0.99). Three indicators were associated with favorable discharge Glasgow Outcome Scale: all operating room cerebral perfusion pressure more than 40 mm Hg (adjusted relative risk, 0.61; 95% CI, 0.58-0.64), all ICU cerebral perfusion pressure more than 40 mm Hg (adjusted relative risk, 0.73; 95% CI, 0.63-0.84), and no surgery (any type; adjusted relative risk, 0.68; 95% CI, 0.53- 0.86).

CONCLUSIONS

Acute care clinical indicators of adherence to the Pediatric Guidelines were associated with significantly higher discharge survival and improved discharge Glasgow Outcome Scale. Some indicators were protective, regardless of treatment location, suggesting the need for an interdisciplinary approach to the care of children with severe traumatic brain injury.

Update on the 2012 guidelines for the management of pediatric traumatic brain injury - information for the anesthesiologist

Traumatic brain injury (TBI) is a significant contributor to death and disability in children. Considering the prevalence of pediatric TBI, it is important for the clinician to be aware of evidence-based recommendations for the care of these patients. The first edition of the Guidelines for the Acute Medical Management of Severe Traumatic Brain Injury in Infants, Children, and Adolescents was published in 2003. The Guidelines were updated in 2012, with significant changes in the recommendations for hyperosmolar therapy, temperature control, hyperventilation, corticosteroids, glucose therapy, and seizure prophylaxis. Many of these interventions have implications in the perioperative period, and it is the responsibility of the anesthesiologist to be familiar with these guidelines.

Early cerebral perfusion pressure augmentation with phenylephrine after traumatic brain injury may be neuroprotective in a pediatric swine model

OBJECTIVE

Cerebral perfusion pressure<40 mm Hg following pediatric traumatic brain injury has been associated with increased mortality independent of age, and current guidelines recommend maintaining cerebral perfusion pressure between 40 mm Hg-60 mm Hg. Although adult traumatic brain injury studies have observed an increased risk of complications associated with targeting a cerebral perfusion pressure>70, we hypothesize that targeting a cerebral perfusion pressure of 70 mm Hg with the use of phenylephrine early after injury in the immature brain will be neuroprotective.

DESIGN

Animals were randomly assigned to injury with a cerebral perfusion pressure of 70 mm Hg or 40 mm Hg. Diffuse traumatic brain injury was produced by a single rapid rotation of the head in the axial plane. Cerebral microdialysis, brain tissue oxygen, intracranial pressure, and cerebral blood flow were measured 30 min-6 hrs postinjury. One hour after injury, cerebral perfusion pressure was manipulated with the vasoconstrictor phenylephrine. Animals were euthanized 6 hrs posttraumatic brain injury, brains fixed, and stained to assess regions of cell injury and axonal dysfunction.

SETTING

University center.

SUBJECT

Twenty-one 4-wk-old female swine.

MEASUREMENTS AND MAIN RESULTS

Augmentation of cerebral perfusion pressure to 70 mm Hg resulted in no change in axonal dysfunction, but significantly smaller cell injury volumes at 6 hrs postinjury compared to cerebral perfusion pressure 40 (1.1% vs. 7.4%, p<.05). Microdialysis lactate/pyruvate ratios were improved at cerebral perfusion pressure 70 compared to cerebral perfusion pressure 40. Cerebral blood flow was higher in the cerebral perfusion pressure 70 group but did not reach statistical significance. Phenylephrine was well tolerated and there were no observed increases in serum lactate or intracranial pressure in either group.

CONCLUSIONS

Targeting a cerebral perfusion pressure of 70 mm Hg resulted in a greater reduction in metabolic crisis and cell injury volumes compared to a cerebral perfusion pressure of 40 mm Hg in an immature swine model. Early aggressive cerebral perfusion pressure augmentation to a cerebral perfusion pressure of 70 mm Hg in pediatric traumatic brain injury before severe intracranial hypertension has the potential to be neuroprotective, and further investigations are needed.

Emergency management of increased intracranial pressure

Primary neurological injury in children can be induced by diverse intrinsic and extrinsic factors including brain trauma, tumors, and intracranial infections. Regardless of etiology, increased intracranial pressure (ICP) as a result of the primary injury or delays in treatment may lead to secondary (preventable) brain injury. Therefore, early diagnosis and aggressive treatment of increased ICP is vital in preventing or limiting secondary brain injury in children with a neurological insult. Present management strategies to improve survival and neurological outcome focus on reducing ICP while optimizing cerebral perfusion and meeting cerebral metabolic demands. Targeted therapies for increased ICP must be considered and implemented as early as possible during and after the initial stabilization of the child. Thus, the emergency physician has a critical role to play in early identification and treatment of increased ICP. This article intends to identify those patients at risk of intracranial hypertension and present a framework for the emergency department investigation and treatment, in keeping with contemporary guidelines. Intensive care management and the treatment of refractory increases in ICP are also outlined.

Pediatric traumatic brain injury: an update

PURPOSE OF REVIEW

The developing brain is particularly vulnerable to traumatic brain injury (TBI), leading to frequent disability or death. This article is an update of the pediatric specificities of TBI management.

RECENT FINDINGS

We review the evidences with regards to general management and therapeutic goals to prevent secondary injuries in pediatric TBI patients. Recent controversies in neurocritical care, such as multimodal neuromonitoring, hyperventilation, barbiturate coma, hypothermia, and decompressive surgery, are also highlighted.

SUMMARY

Many therapeutic modalities in pediatric TBI have a low level of evidence. Further research is needed to establish clear resuscitation goals. Universal objectives may not be suitable for all patients; intensive neuromonitoring may help in identifying individual therapeutic goals and guiding the selection of treatments.

Traumatic brain injury: preferred methods and targets for resuscitation

PURPOSE OF REVIEW

Severe traumatic brain injury (TBI) is the most common cause of death and disability in pediatric trauma. This review looks at the strategies to treat TBI in a temporal fashion. We examine the targets for resuscitation from field triage to definitive care in the pediatric ICU.

RECENT FINDINGS

Guidelines for the management of pediatric TBI exist. The themes of contemporary clinical research have been compliance with these guidelines and refinement of treatment recommendations developing a more sophisticated understanding of the pathophysiology of the injured brain. In the field, the aim has been to achieve routine compliance with the resuscitation goals. In the hospital, efforts have been directed at improving our ability to monitor the injured brain, developing techniques that limit brain swelling, and customizing brain perfusion.

SUMMARY

As our understanding of pediatric TBI evolves, the ambition is that age-specific and perhaps individual brain injury strategies based upon feedback from continuous monitors will be defined. In addition, vogue methods such as hypothermia, hypertonic saline, and aggressive surgical decompression may prove to impact brain swelling and outcomes.

Progenitor cell therapy for traumatic brain injury: effect of serum osmolarity on cell viability and cytokine production

INTRODUCTION

The potential translation of mesenchymal stem cell (MSC) therapy into a multimodal protocol for traumatic brain injury requires evaluation of viability and cytokine production in a hyperosmolar environment. Optimization of MSC therapy requires delivery to the target area without significant loss of cellular function or viability. No model evaluating the potential efficacy of MSC therapy at varying osmolarities currently exists.

METHODS

Rat MSCs were characterized with flow cytometric immunophenotyping. MSCs (passage 3) were placed in culture with multipotent adult progenitor cell media at varying osmolarities (250, 270, 290, 310, 330, 350 and 370 mOsm) potentially found with hypertonic saline infusion. After culture for 24 h, cellular viability was measured using flow cytometry (n = 6). Next, brain tissue supernatant was harvested from both normal rat brains and injured brains 6 h after cortical injury. Subsequently, MSCs were placed in culture with multipotent adult progenitor cell media +/- 20% normal brain or injured brain supernatant (at the aforementioned osmolarities) and allowed to remain in culture for 24 h (n = 11). At this point, media supernatant cytokine levels were measured using a multiplex cytokine assay system.

RESULTS

MSCs showed no clinically significant difference in viability at 24 h. MSCs cultured with 20% injured brain supernatant showed an decrease in proinflammatory cytokine production (IL-1alpha and IL-1beta) with increasing osmolarity. No difference in anti-inflammatory cytokine production (IL-4 and IL-10) was observed.

CONCLUSION

Progenitor cell therapy for traumatic brain injury may require survival and activity in a hyperosmolar environment. Culture of MSCs in such conditions shows no clinically significant effect on cell viability. In addition, MSC efficacy could potentially be enhanced via a decrease in proinflammatory cytokine production. Overall, a multimodal traumatic brain injury treatment protocol based upon MSC infusion and hypertonic saline therapy would not negatively affect progenitor cell efficacy and could be considered for multicenter clinical trials.

Clinical management and functional neuromonitoring in traumatic brain injury in children

PURPOSE OF REVIEW

Traumatic brain injury is the main cause of childhood disability and death. In this review, we highlight recent original findings and emerging themes from published literature on children with serious traumatic brain injury.

RECENT FINDINGS

We focus this review on lessons learned from our recent randomized clinical trial of hypothermia therapy in severe traumatic brain injury in children and on bedside neuromonitoring. We propose that integrating the measurement of biomarkers into clinical care as surrogate endpoints and as potential prognostic markers would allow us to evaluate earlier the effect of injury and clinical care in children after traumatic brain injury. Several methods are now more readily available to monitor cerebral physiology in children. These methods include indices evaluating the integrity of cerebral autoregulation, such as the pressure reactivity index derived from values obtained from intracranial pressure measurements, flow velocity measurements from transcranial Doppler ultrasonography or from cerebral oximetry. Other methods allow the evaluation of coma with the nonlinear analysis of electroencephalography or the evaluation of cerebral metabolism and cell death pathways with biomarkers from serum, cerebral spinal fluid, and cerebral microdialysis.

SUMMARY

We suggest expanding clinical functional neuromonitoring to help clinicians understand the burden of exposure to physiological variables and response to therapies during intensive care in order to enhance the management of critically ill children with traumatic brain injury.

Variation in cerebral blood flow velocity with cerebral perfusion pressure >40 mm Hg in 42 children with severe traumatic brain injury

OBJECTIVE

: To determine the prevalence of low, normal, and high mean middle cerebral artery flow velocity when cerebral perfusion pressure is >40 mm Hg in children with severe traumatic brain injury. There is no information regarding the relationship between middle cerebral artery flow velocity and cerebral perfusion pressure in pediatric traumatic brain injury.

DESIGN

: Prospective, observational study.

SETTING

: Level I pediatric trauma center.

PATIENTS

: A total of 42 children <17 yrs of age with an admission diagnosis of severe traumatic brain injury (admission Glasgow Coma Scale score of <9), traumatic brain injury on computed tomography scan, tracheal intubation/mechanical ventilation, and intracranial pressure monitoring.

INTERVENTIONS

: None.

MEASUREMENTS AND MAIN RESULTS

: Bilateral middle cerebral arteries were insonated using transcranial Doppler ultrasonography to calculate mean middle cerebral artery flow velocity after traumatic brain injury. Low mean middle cerebral artery flow velocity was defined as middle cerebral artery flow velocity <2 standard deviation and high was defined as mean middle cerebral artery flow velocity >2 standard deviation. Patients were grouped by age (0.8-2.9, 3-5.9, 6-9.9, and 10-16.9 yrs) and gender to examine the relationship between cerebral perfusion pressure and low, high, or normal mean middle cerebral artery flow velocity. Potential confounders of the relationship between cerebral perfusion pressure and mean middle cerebral artery flow velocity (intracranial pressure, PaCO2, hematocrit, sedation, fever,and impaired autoregulation were examined). Most children (n = 33; 79%) had normal mean middle cerebral artery flow velocity but four patients (9%) had low mean middle cerebral artery flow velocity and five children (12%) had high mean middle cerebral artery flow velocity despite cerebral perfusion pressure >40 mm Hg. There was no difference in potential confounders of the relationship between cerebral perfusion pressure and mean middle cerebral artery flow velocity except for hematocrit, which was lower (25 +/- 4%; range = 21-30%) in children with high mean middle cerebral artery flow velocity. An inverse relationship between mean middle cerebral artery flow velocity and hematocrit was also found in boys aged 10 to 16.9 yrs.

CONCLUSIONS

: Both low and/or high mean middle cerebral artery flow velocity occur with cerebral perfusion pressure >40 mm Hg in severe pediatric traumatic brain injury. Of the potential confounders considered, only lower hematocrit was associated with high mean middle cerebral artery flow velocity.

Cerebral hemodynamic predictors of poor 6-month Glasgow Outcome Score in severe pediatric traumatic brain injury

Little is known regarding the cerebral autoregulation in pediatric traumatic brain injury (TBI). We examined the relationship between cerebral hemodynamic predictors, including cerebral autoregulation, and long-term outcome after severe pediatric TBI. After Institutional Review Board (IRB) approval, a retrospective analysis of prospectively collected data (May 2002 to October 2007) for children age < or =16 years with severe TBI (admission Glasgow Coma Scale [GCS] score <9) was performed. Cerebral autoregulation was assessed within 72 h after TBI. Cerebral hemodynamic predictors (intracranial pressure [ICP], systolic blood pressure [SBP], and cerebral perfusion pressure [CPP]) through the first 72 h after TBI were abstracted. Univariate and multivariate analyses examined the relationship between impaired cerebral autoregulation (autoregulatory index <0.4), intracranial hypertension (ICP >20 mm Hg), and hypotension (SBP <5th percentile and CPP <40 mm Hg). Six-month Glasgow Outcome Scale (GOS) score of <4 defined poor outcome. Ten (28%) of the 36 children examined (9.1 +/- 5.3 [0.8-16] years; 74% male) had poor outcome. Univariate factors associated with poor outcome were impaired cerebral autoregulation (p = 0.005), SBP <5(th) percentile for age and gender (p = 0.02), and low middle cerebral artery flow velocity (<2 SD for age and gender; p = 0.04). Independent risk factors for poor 6-month GOS were impaired cerebral autoregulation (adjusted odds ratio [aOR] 12.0; 95% confidence interval [CI] 1.4-99.4) and hypotension (SBP <5th percentile; aOR 8.8; 95% CI 1.1-70.5), respectively. Previous studies of TBI describing poor outcome with hemodynamics did not consider the status of cerebral autoregulation. In this study, both impaired cerebral autoregulation and SBP <5th percentile were independent risk factors for poor 6-month GOS.

Modern approaches to pediatric brain injury therapy

Each year, pediatric traumatic brain injury (TBI) accounts for 435,000 emergency department visits, 37,000 hospital admissions, and approximately 2,500 deaths in the United States. TBI results in immediate injury from direct mechanical force and shear. Secondary injury results from the release of biochemical or inflammatory factors that alter the loco-regional milieu in the acute, subacute, and delayed intervals after a mechanical insult. Preliminary preclinical and clinical research is underway to evaluate the benefit from progenitor cell therapeutics, hypertonic saline infusion, and controlled hypothermia. However, all phase III clinical trials investigating pharmacologic monotherapy for TBI have shown no benefit. A recent National Institutes of Health consensus statement recommends research into multimodality treatments for TBI. This article will review the complex pathophysiology of TBI as well as the possible therapeutic mechanisms of progenitor cell transplantation, hypertonic saline infusion, and controlled hypothermia for possible utilization in multimodality clinical trials.

Pediatric neurointensive care: 2008 update for the Rogers' Textbook of Pediatric Intensive Care

OBJECTIVE

To review important articles, in the field of pediatric neurointensive care, that were published subsequent to the fourth edition of the Rogers' Textbook of Pediatric Intensive Care.

DATA SOURCES

The U.S. National Library of Medicine (http://www.ncbi.nlm.nih.gov/sites/entrezPubMed) was searched for the term pediatric and the following individual terms, cardiac arrest, asphyxia, traumatic brain injury, status epilepticus, stroke, cerebral ischemia, and cerebral hemorrhage, to generate abstracts of additional citations that were then screened for potential inclusion. The authors were also aware of a number of key recent articles in both pediatric and adult neurointensive care and these were also screened.

STUDY SELECTION AND DATA EXTRACTION

Promising articles were reviewed and the decision as to whether they were included was made at the discretion of the section editors.

DATA SYNTHESIS

Articles in four categories were included based on selected chapters in the neurointensive care section of the textbook, using the specific chapter heading in the textbook, namely, head and spinal cord trauma, hypoxic-ischemic encephalopathy, status epilepticus, and cerebrovascular disease and stroke.

CONCLUSION

Developments in the field and practice of pediatric neurocritical care continue with significant additions to the literature and practice recommendations concerning care following traumatic brain injury, cardiac arrest, status epilepticus, and cerebrovascular events. Importantly, the continued progression in knowledge raises the health services issue of whether, in certain settings of high clinical volume, it is time for specialized pediatric neurointensive care services or units.

Delayed cerebral oxidative glucose metabolism after traumatic brain injury in young rats

Traumatic brain injury (TBI) results in a cerebral metabolic crisis that contributes to poor neurologic outcome. The aim of this study was to characterize changes in oxidative glucose metabolism in early periods after injury in the brains of immature animals. At 5 h after controlled cortical impact TBI or sham surgery to the left cortex, 21-22 day old rats were injected intraperitoneally with [1,6-13C]glucose and brains removed 15, 30 and 60 min later and studied by ex vivo 13C-NMR spectroscopy. Oxidative metabolism, determined by incorporation of 13C into glutamate, glutamine and GABA over 15-60 min, was significantly delayed in both hemispheres of brain from TBI rats. The most striking delay was in labeling of the C4 position of glutamate from neuronal metabolism of glucose in the injured, ipsilateral hemisphere which peaked at 60 min, compared with the contralateral and sham-operated brains, where metabolism peaked at 30 and 15 min, respectively. Our findings indicate that (i) neuronal-specific oxidative metabolism of glucose at 5-6 h after TBI is delayed in both injured and contralateral sides compared with sham brain; (ii) labeling from metabolism of glucose via the pyruvate carboxylase pathway in astrocytes was also initially delayed in both sides of TBI brain compared with sham brain; (iii) despite this delayed incorporation, at 6 h after TBI, both sides of the brain showed apparent increased neuronal and glial metabolism, reflecting accumulation of labeled metabolites, suggesting impaired malate aspartate shuttle activity. The presence of delayed metabolism, followed by accumulation of labeled compounds is evidence of severe alterations in homeostasis that could impair mitochondrial metabolism in both ipsilateral and contralateral sides of brain after TBI. However, ongoing oxidative metabolism in mitochondria in injured brain suggests that there is a window of opportunity for therapeutic intervention up to at least 6 h after injury.

Acute clinical grading in pediatric severe traumatic brain injury and its association with subsequent intracranial pressure, cerebral perfusion pressure, and brain oxygenation

Object

The goal of this paper was to examine the relationship between methods of acute clinical assessment and measures of secondary cerebral insults in severe traumatic brain injury in children.

Methods

Patients who underwent intracranial pressure (ICP), cerebral perfusion pressure (CPP), and brain oxygenation (PbtO2) monitoring and who had an initial Glasgow Coma Scale score, Pediatric Trauma Score, Pediatric Index of Mortality 2 score, and CT classification were evaluated. The relationship between these acute clinical scores and secondary cerebral insult measures, including ICP, CPP, PbtO2, and systemic hypoxia were evaluated using univariate and multivariate analysis.

Results

The authors found significant associations between individual acute clinical scores and select physiological markers of secondary injury. However, there was a large amount of variability in these results, and none of the scores evaluated predicted each and every insult. Furthermore, a number of physiological measures were not predicted by any of the scores.

Conclusions

Although they may guide initial treatment, grading systems used to classify initial injury severity appear to have a limited value in predicting who is at risk for secondary cerebral insults.