Relationship of intracranial pressure and cerebral perfusion pressure with outcome in young children after severe traumatic brain injury

ICP, PRx, CPP, and ∆CPPopt in pediatric traumatic brain injury: the combined effect of insult intensity and duration on outcome

PURPOSE

The aim was to investigate the combined effect of insult intensity and duration, regarding intracranial pressure (ICP), pressure reactivity index (PRx), cerebral perfusion pressure (CPP), and optimal CPP (CPPopt), on clinical outcome in pediatric traumatic brain injury (TBI).

METHOD

This observational study included 61 pediatric patients with severe TBI, treated at the Uppsala University Hospital, between 2007 and 2018, with at least 12 h of ICP data the first 10 days post-injury. ICP, PRx, CPP, and ∆CPPopt (actual CPP-CPPopt) insults were visualized as 2-dimensional plots to illustrate the combined effect of insult intensity and duration on neurological recovery.

RESULTS

This cohort was mostly adolescent pediatric TBI patients with a median age at 15 (interquartile range 12-16) years. For ICP, brief episodes (minutes) above 25 mmHg and slightly longer episodes (20 min) of ICP 20-25 mmHg correlated with unfavorable outcome. For PRx, brief episodes above 0.25 as well as slightly lower values (around 0) for longer periods of time (30 min) were associated with unfavorable outcome. For CPP, there was a transition from favorable to unfavorable outcome for CPP below 50 mmHg. There was no association between high CPP and outcome. For ∆CPPopt, there was a transition from favorable to unfavorable outcome when ∆CPPopt went below -10 mmHg. No association was found for positive ∆CPPopt values and outcome.

CONCLUSIONS

This visualization method illustrated the combined effect of insult intensity and duration in relation to outcome in severe pediatric TBI, supporting previous notions to avoid high ICP and low CPP for longer episodes of time. In addition, higher PRx for longer episodes of time and CPP below CPPopt more than -10 mmHg were associated with worse outcome, indicating a potential role for autoregulatory-oriented management in pediatric TBI.

Monitoring cerebrovascular reactivity in pediatric traumatic brain injury: comparison of three methods

PURPOSE

To study three different methods of monitoring cerebral autoregulation in children with severe traumatic brain injury.

METHODS

Prospective cohort study of all children admitted to the pediatric intensive care unit at a university-affiliated hospital with severe TBI over a 4-year period to study three different methods of monitoring cerebral autoregulation: pressure-reactivity index (PRx), transcranial Doppler derived mean flow velocity index (Mx), and near-infrared spectroscopy derived cerebral oximetry index (COx).

RESULTS

Twelve patients were included in the study, aged 5 months to 17 years old. An empirical regression analyzing dependence of PRx on cerebral perfusion pressure (CPP) displayed the classic U-shaped distribution, with low PRx values (< 0.3) reflecting intact auto-regulation, within the CPP range of 50-100 mmHg. The optimal CPP was 75-80 mmHg for PRx and COx. The correlation coefficients between the three indices were as follows: PRx vs Mx, r = 0.56; p < 0.0001; PRx vs COx, r = 0.16; p < 0.0001; and COx vs Mx, r = 0.15; p = 0.022. The mean PRx with a cutoff value of 0.3 predicted correctly long-term outcome (p = 0.015).

CONCLUSIONS

PRx seems to be the most robust index to access cerebrovascular reactivity in children with TBI and has promising prognostic value. Optimal CPP calculation is feasible with PRx and COx.

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.

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.

Monitoring and Measurement of Intracranial Pressure in Pediatric Head Trauma

Purpose of Review: Monitoring of intracranial pressure (ICP) is an important and integrated part of the treatment algorithm for children with severe traumatic brain injury (TBI). Guidelines often recommend ICP monitoring with a treatment threshold of 20 mmHg. This focused review discusses; (1) different ICP technologies and how ICP should be monitored in pediatric patients with severe TBI, (2) existing evidence behind guideline recommendations, and (3) how we could move forward to increase knowledge about normal ICP in children to support treatment decisions.

Summary: Current reference values for normal ICP in adults lie between 7 and 15 mmHg. Recent studies conducted in “pseudonormal” adults, however, suggest a normal range below this level where ICP is highly dependent on body posture and decreases to negative values in sitting and standing position. Despite obvious physiological differences between children and adults, no age or body size related reference values exist for normal ICP in children. Recent guidelines for treatment of severe TBI in pediatric patients recommend ICP monitoring to guide treatment of intracranial hypertension. Decision on ICP monitoring modalities are based on local standards, the individual case, and the clinician's choice. The recommended treatment threshold is 20 mmHg for a duration of 5 min. Both prospective and retrospective observational studies applying different thresholds and treatment strategies for intracranial hypertension were included to support this recommendation. While some studies suggest improved outcome related to ICP monitoring (lower rate of mortality and severe disability), most studies identify high ICP as a marker of worse outcome. Only one study applied age-differentiated thresholds, but this study did not evaluate the effect of these different thresholds on outcome. The quality of evidence behind ICP monitoring and treatment thresholds in severe pediatric TBI is low and treatment can potentially be improved by knowledge about normal ICP from observational studies in healthy children and cohorts of pediatric “pseudonormal” patients expected to have normal ICP. Acceptable levels of ICP − and thus also treatment thresholds—probably vary with age, disease and whether the patient has intact cerebral autoregulation. Future treatment algorithms should reflect these differences and be more personalized and dynamic.

Syndromic Craniosynostosis

Management strategies for syndromic craniosynostosis patients require multidisciplinary subspecialty teams to provide optimal care for complex reconstructive approaches. The most common craniosynostosis syndromes include Apert (FGFR2), Crouzon (FGFR2), Muenke (FGFR3), Pfeiffer (FGFR1 and FGFR2), and Saethre-Chotzen (TWIST). Bicoronal craniosynostosis (turribrachycephaly) is most commonly associated with syndromic craniosynostosis. Disease presentation varies from mild sutural involvement to severe pansynostoses, with a spectrum of extracraniofacial dysmorphic manifestations. Understanding the multifaceted syndromic presentations while appreciating the panoply of variable presentations is central to delivering necessary individualized care. Cranial vault remodeling aims to relieve restriction of cranial development and elevated intracranial pressure and restore normal morphology.

Children With Severe Traumatic Brain Injury, Intracranial Pressure, Cerebral Perfusion Pressure, What Does it Mean? A Review of the Literature

Severe traumatic brain injury is a leading cause of morbidity and mortality in children. In 2003 the Brain Trauma Foundation released guidelines that have since been updated (2010) and have helped standardize and improve care. One area of care that remains controversial is whether the placement of an intracranial pressure monitor is advantageous in the management of traumatic brain injury. Another aspect of care that is widely debated is whether management after traumatic brain injury should be based on intracranial pressure-directed therapy, cerebral perfusion pressure-directed therapy, or a combination of the two. The aim of this article was to provide an overview and review the current evidence regarding these questions.

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.

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.

Management of severe traumatic brain injury (first 24hours)

The latest French Guidelines for the management in the first 24hours of patients with severe traumatic brain injury (TBI) were published in 1998. Due to recent changes (intracerebral monitoring, cerebral perfusion pressure management, treatment of raised intracranial pressure), an update was required. Our objective has been to specify the significant developments since 1998. These guidelines were conducted by a group of experts for the French Society of Anesthesia and Intensive Care Medicine (Société francaise d'anesthésie et de réanimation [SFAR]) in partnership with the Association de neuro-anesthésie-réanimation de langue française (ANARLF), The French Society of Emergency Medicine (Société française de médecine d'urgence (SFMU), the Société française de neurochirurgie (SFN), the Groupe francophone de réanimation et d'urgences pédiatriques (GFRUP) and the Association des anesthésistes-réanimateurs pédiatriques d'expression française (ADARPEF). The method used to elaborate these guidelines was the Grade^® method. After two Delphi rounds, 32 recommendations were formally developed by the experts focusing on the evaluation the initial severity of traumatic brain injury, the modalities of prehospital management, imaging strategies, indications for neurosurgical interventions, sedation and analgesia, indications and modalities of cerebral monitoring, medical management of raised intracranial pressure, management of multiple trauma with severe traumatic brain injury, detection and prevention of post-traumatic epilepsia, biological homeostasis (osmolarity, glycaemia, adrenal axis) and paediatric specificities.

Time spent with impaired autoregulation is linked with outcome in severe infant/paediatric traumatic brain injury

BACKGROUND

It could be shown in traumatic brain injury (TBI) in adults that the functional status of cerebrovascular autoregulation (AR), determined by the pressure reactivity index (PRx), correlates to and even predicts outcome. We investigated PRx, cerebral perfusion pressure (CPP) and intracranial pressure (ICP) and their correlation to outcome in severe infant and paediatric TBI.

METHODS

Seventeen patients (range, 1 day to 14 years) with severe TBI (median GCS at presentation, 4) underwent long-term computerised ICP and mean arterial pressure (MAP) monitoring using dedicated software to determine CPP and PRx and optimal CPP (CPP level where PRx shows best autoregulation) continuously. Outcome was determined at discharge and at follow-up using the Glasgow Outcome Scale.

RESULTS

Favourable outcome was reached in eight patients, unfavourable outcome in seven patients. Two patients died. Nine patients underwent decompressive craniectomy to control ICP during Intensive Care Unit treatment. When dichotomised to outcome, no significant difference was found for overall ICP, CPP and PRx. The time with severely impaired AR (PRx >0.2) was significantly longer for patients with unfavourable outcome (64 h vs 6 h, p = 0.001). Continuously impaired AR of ≥24 h and age <1 year was associated to unfavourable outcome. Children with favourable outcome spent the entire monitoring time at or above the optimal CPP.

CONCLUSIONS

Integrity of AR has a similar role for outcome after TBI in the paediatric population as in adults. The amount of time spent with deranged AR seems to be associated with outcome; a factor especially critical for infant patients. The results of this preliminary study need to be validated in the future.

Abusive Head Trauma and Mortality-An Analysis From an International Comparative Effectiveness Study of Children With Severe Traumatic Brain Injury

OBJECTIVES

Small series have suggested that outcomes after abusive head trauma are less favorable than after other injury mechanisms. We sought to determine the impact of abusive head trauma on mortality and identify factors that differentiate children with abusive head trauma from those with traumatic brain injury from other mechanisms.

DESIGN

First 200 subjects from the Approaches and Decisions in Acute Pediatric Traumatic Brain Injury Trial-a comparative effectiveness study using an observational, cohort study design.

SETTING

PICUs in tertiary children's hospitals in United States and abroad.

PATIENTS

Consecutive children (age < 18 yr) with severe traumatic brain injury (Glasgow Coma Scale ≤ 8; intracranial pressure monitoring).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographics, injury-related scores, prehospital, and resuscitation events were analyzed. Children were dichotomized based on likelihood of abusive head trauma. A total of 190 children were included (n = 35 with abusive head trauma). Abusive head trauma subjects were younger (1.87 ± 0.32 vs 9.23 ± 0.39 yr; p < 0.001) and a greater proportion were female (54.3% vs 34.8%; p = 0.032). Abusive head trauma were more likely to 1) be transported from home (60.0% vs 33.5%; p < 0.001), 2) have apnea (34.3% vs 12.3%; p = 0.002), and 3) have seizures (28.6% vs 7.7%; p < 0.001) during prehospital care. Abusive head trauma had a higher prevalence of seizures during resuscitation (31.4 vs 9.7%; p = 0.002). After adjusting for covariates, there was no difference in mortality (abusive head trauma, 25.7% vs nonabusive head trauma, 18.7%; hazard ratio, 1.758; p = 0.60). A similar proportion died due to refractory intracranial hypertension in each group (abusive head trauma, 66.7% vs nonabusive head trauma, 69.0%).

CONCLUSIONS

In this large, multicenter series, children with abusive head trauma had differences in prehospital and in-hospital secondary injuries which could have therapeutic implications. Unlike other traumatic brain injury populations in children, female predominance was seen in abusive head trauma in our cohort. Similar mortality rates and refractory intracranial pressure deaths suggest that children with severe abusive head trauma may benefit from therapies including invasive monitoring and adherence to evidence-based guidelines.

State of Cerebrovascular Autoregulation Correlates with Outcome in Severe Infant/Pediatric Traumatic Brain Injury

OBJECTIVE

It could be shown in adults with severe traumatic brain injury (TBI) that the functional status of cerebrovascular autoregulation (AR), determined by the pressure reactivity index (PRx), correlates with and even predicts outcome. We investigated PRx and its correlation with outcome in infant and pediatric TBI. Methods Ten patients (median age 2.8 years, range 1 day to 14 years) with severe TBI (Glasgow Coma Scale score <9 at presentation) underwent long-term computerized intracranial pressure (ICP) and mean arterial pressure (MAP) monitoring using dedicated software for continuous determination of cerebral perfusion pressure (CPP) and PRx. Outcome was determined at discharge and at follow-up at 6 months using the Glasgow Outcome Scale (GOS) score.

RESULTS

Median monitoring time was 182 h (range 22-355 h). Seven patients underwent decompressive craniectomy to control ICP during treatment in the intensive care unit. Favorable outcome (GOS 4 and 5) was reached in 4 patients, an unfavorable outcome (GOS 1-3) in 6 patients. When dichotomized to outcome, no correlation was found with ICP and CPP, but median PRx correlated well with outcome (r = -0.79, p = 0.006) and tended to be lower for GOS 4 and 5 (-0.04) than for GOS 1-3 (0.32; p = 0.067).

CONCLUSION

The integrity of AR seems to play the same fundamental role after TBI in the pediatric population as in adults and should be determined routinely. It carries an important prognostic value. PRx seems to be an ideal candidate parameter to guide treatment in the sense of optimizing CPP, aiming at improvement of cerebrovascular autoregulation (CPPopt concept).

The Anesthesiologist's Role in Treating Abusive Head Trauma

Abusive head trauma (AHT) is the most common cause of severe traumatic brain injury (TBI) in infants and the leading cause of child abuse-related deaths. For reasons that remain unclear, mortality rates after moderate AHT rival those of severe nonintentional TBI. The vulnerability of the developing brain to injury may be partially responsible for the poor outcomes observed after AHT. AHT is mechanistically more complex than nonintentional TBI. The acute-on-chronic nature of the trauma along with synergistic injury mechanisms that include rapid rotation of the brain, diffuse axonal injury, blunt force trauma, and hypoxia-ischemia make AHT challenging to treat. The anesthesiologist must understand the complex injury mechanisms inherent to AHT, as well as the pediatric TBI treatment guidelines, to decrease the risk of persistent neurologic disability and death. In this review, we discuss the epidemiology of AHT, differences between AHT and nonintentional TBI, the severe pediatric TBI treatment guidelines in the context of AHT, anesthetic considerations, and ethical and legal reporting requirements.

Past, Present, and Future of Traumatic Brain Injury Research

Traumatic brain injury (TBI) is the greatest cause of death and severe disability in young adults; its incidence is increasing in the elderly and in the developing world. Outcome from severe TBI has improved dramatically as a result of advancements in trauma systems and supportive critical care, however we remain without a therapeutic which acts directly to attenuate brain injury. Recognition of secondary injury and its molecular mediators has raised hopes for such targeted treatments. Unfortunately, over 30 late-phase clinical trials investigating promising agents have failed to translate a therapeutic for clinical use. Numerous explanations for this failure have been postulated and are reviewed here. With this historical context we review ongoing research and anticipated future trends which are armed with lessons from past trials, new scientific advances, as well as improved research infrastructure and funding. There is great hope that these new efforts will finally lead to an effective therapeutic for TBI as well as better clinical management strategies.

Intracranial Hypertension and Cerebral Hypoperfusion in Children With Severe Traumatic Brain Injury: Thresholds and Burden in Accidental and Abusive Insults

OBJECTIVES

The evidence to guide therapy in pediatric traumatic brain injury is lacking, including insight into the intracranial pressure/cerebral perfusion pressure thresholds in abusive head trauma. We examined intracranial pressure/cerebral perfusion pressure thresholds and indices of intracranial pressure and cerebral perfusion pressure burden in relationship with outcome in severe traumatic brain injury and in accidental and abusive head trauma cohorts.

DESIGN

A prospective observational study.

SETTING

PICU in a tertiary children's hospital.

PATIENTS

Children less than18 years old admitted to a PICU with severe traumatic brain injury and who had intracranial pressure monitoring.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A pediatric traumatic brain injury database was interrogated with 85 patients (18 abusive head trauma) enrolled. Hourly intracranial pressure and cerebral perfusion pressure (in mm Hg) were collated and compared with various thresholds. C-statistics for intracranial pressure and cerebral perfusion pressure data in the entire population were determined. Intracranial hypertension and cerebral hypoperfusion indices were formulated based on the number of hours with intracranial pressure more than 20 mm Hg and cerebral perfusion pressure less than 50 mm Hg, respectively. A secondary analysis was performed on accidental and abusive head trauma cohorts. All of these were compared with dichotomized 6-month Glasgow Outcome Scale scores. The models with the number of hours with intracranial pressure more than 20 mm Hg (C = 0.641; 95% CI, 0.523-0.762) and cerebral perfusion pressure less than 45 mm Hg (C = 0.702; 95% CI, 0.586-0.805) had the best fits to discriminate outcome. Two factors were independently associated with a poor outcome, the number of hours with intracranial pressure more than 20 mm Hg and abusive head trauma (odds ratio = 5.101; 95% CI, 1.571-16.563). As the number of hours with intracranial pressure more than 20 mm Hg increases by 1, the odds of a poor outcome increased by 4.6% (odds ratio = 1.046; 95% CI, 1.012-1.082). Thresholds did not differ between accidental versus abusive head trauma. The intracranial hypertension and cerebral hypoperfusion indices were both associated with outcomes.

CONCLUSIONS

The duration of hours of intracranial pressure more than 20 mm Hg and cerebral perfusion pressure less than 45 mm Hg best discriminated poor outcome. As the number of hours with intracranial pressure more than 20 mm Hg increases by 1, the odds of a poor outcome increased by 4.6%. Although abusive head trauma was strongly associated with unfavorable outcome, intracranial pressure/cerebral perfusion pressure thresholds did not differ between accidental and abusive head trauma.

Multimodality Neuromonitoring in Pediatric Neurocritical Care: Review of the Current Resources

Brain insults in children represent a daily challenge in neurocritical care. Having a constant grasp on various parameters in the pediatric injured brain may affect the patient's outcome. Currently, new advances provide clinicians with the ability to utilize several modalities to monitor brain function. This multi-modal approach allows real-time information, leading to faster responses in management and furthermore avoiding secondary insults in the injured brain.

Management of pediatric traumatic brain injury

OPINION STATEMENT

Pediatric severe traumatic brain injury continues to be a major cause of disability and death. Rapid initial airway and hemodynamic stabilization is critical, followed by the need for immediate recognition of intracranial pathology that requires neurosurgical intervention. Intracranial hypertension and cerebral hypoperfusion have been recognized as major insults after trauma and management should be directed at preventing both. Sedation with opioids, moderate hyperventilation to arterial carbon dioxide level of 35-40 mmHg, hyperosmolar therapy with 3 % saline or mannitol, normothermia, and cerebrospinal fluid drainage continue to be the cornerstones of initial management of intracranial hypertension (intracranial pressure >20 mmHg). Refractory intracranial hypertension is treated with high-dose barbiturate therapy to achieve medical burst suppression on electroencephalography and decompressive craniectomy. In addition, those children require antiepileptic medications for seizure prophylaxis, adequate nutritional management, and early physical therapy and rehabilitation referrals. Most of the evidence for care of children with brain injury comes from center-specific practice and experience rather than objective data. This lack of evidence provides the ground for ongoing research; nevertheless, outcomes after traumatic brain injury continue to show improvement.

Current concepts of optimal cerebral perfusion pressure in traumatic brain injury

Traumatic brain injury (TBI) consists of varied pathophysiological consequences and alteration of intracranial dynamics, reduction of the cerebral blood flow and oxygenation. In the past decade more emphasis has been directed towards optimizing cerebral perfusion pressure (CPP) in patients who have suffered TBI. Injured brain may show signs of ischemia if CPP remains below 50 mmHg and raising the CPP above 60 mmHg may avoid cerebral oxygen desaturation. Though CPP above 70 mmHg is influential in achieving an improved patient outcome, maintenance of CPP higher than 70 mmHg was associated with greater risk of acute respiratory distress syndrome (ARDS). The target CPP has been laid within 50-70 mmHg. Cerebral blood flow and metabolism are heterogeneous after TBI and with regional temporal differences in the requirement for CPP. Brain monitoring techniques such as jugular venous oximetry, monitoring of brain tissue oxygen tension (PbrO₂), and cerebral microdialysis provide complementary and specific information that permits the selection of the optimal CPP. This review highlights the rationale for use CPP directed therapies and neuromonitoring to identify optimal CPP of head injured patients. The article also reviews the evidence provided by various clinical trials regarding optimal CPP and their application in the management of head injured patients.

Intraoperative blood pressure and cerebral perfusion: strategies to clarify hemodynamic goals

Blood pressure can vary considerably during anesthesia. If blood pressure falls outside the limits of cerebrovascular autoregulation, children can become at risk of cerebral ischemic or hyperemic injury. However, the blood pressure limits of autoregulation are unclear in infants and children, and these limits can shift after brain injury. This article will review autoregulation, considerations for the hemodynamic management of children with brain injuries, and research on autoregulation monitoring techniques.

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.

The potential for bio-mediators and biomarkers in pediatric traumatic brain injury and neurocritical care

The use of biomarkers of brain injury in pediatric neurocritical care has been explored for at least 15 years. Two general lines of research on biomarkers in pediatric brain injury have been pursued: (1) studies of "bio-mediators" in cerebrospinal fluid (CSF) of children after traumatic brain injury (TBI) to explore the components of the secondary injury cascades in an attempt to identify potential therapeutic targets and (2) studies of the release of structural proteins into the CSF, serum, or urine in order to diagnose, monitor, and/or prognosticate in patients with TBI or other pediatric neurocritical care conditions. Unique age-related differences in brain biology, disease processes, and clinical applications mandate the development and testing of brain injury bio-mediators and biomarkers specifically in pediatric neurocritical care applications. Finally, although much of the early work on biomarkers of brain injury in pediatrics has focused on TBI, new applications are emerging across a wide range of conditions specifically for pediatric neurocritical care including abusive head trauma, cardiopulmonary arrest, septic shock, extracorporeal membrane oxygenation, hydrocephalus, and cardiac surgery. The potential scope of the utility of biomarkers in pediatric neurocritical care is thus also discussed.

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.