Implementation strategies in pediatric neurocritical care

PURPOSE OF REVIEW

Brain-directed critical care for children is a relatively new area of subspecialization in pediatric critical care. Pediatric neurocritical care teams combine the expertise of neurology, neurosurgery, and critical care medicine. The positive impact of delivering specialized care to pediatric patients with acute neurological illness is becoming more apparent, but the optimum way to implement and sustain the delivery of this is complicated and poorly understood. We aim to provide emerging evidence supporting that effective implementation of pediatric neurocritical care pathways can improve patient survival and outcomes. We also provide an overview of the most effective strategies across the field of implementation science that can facilitate deployment of neurocritical care pathways in the pediatric ICU.

RECENT FINDINGS

Implementation strategies can broadly be grouped according to six categories: planning, educating, restructuring, financing, managing quality, and attending to the policy context. Using a combination of these strategies in the last decade, several institutions have improved patient morbidity and mortality. Although much work remains to be done, emerging evidence supports that implementation of evidence-based care pathways for critically ill children with two common neurological diagnoses - status epilepticus and traumatic brain injury - improves outcomes.

SUMMARY

Pediatric and neonatal neurocritical care programs that support evidence-based care can be effectively structured using appropriately sequenced implementation strategies to improve outcomes across a variety of patient populations and in a variety of healthcare settings.

Tripartite Stratification of the Glasgow Coma Scale in Children with Severe Traumatic Brain Injury and Mortality: An Analysis from a Multi-Center Comparative Effectiveness Study

The Glasgow Coma Scale (GCS) score has not been validated in children younger than 5 years and the clinical circumstances at the time of assignment can limit its applicability. This study describes the distribution of GCS scores in the population, the relationship between injury characteristics with the GCS score, and the association between the tripartite stratification of the GCS on mortality in children with severe traumatic brain injury (TBI). The first 200 children from a multi-center comparative effectiveness study in severe TBI (inclusion criteria: age 0-18 years, GCS ≤8 at the time of intracranial pressure [ICP] monitoring) were analyzed. After tripartite stratification of GCS scores (Group A, GCS 3; Group B, GCS 4 - 5; and Group C, GCS 6 - 8), analyses of variance and chi-square testing were performed. Mean age was 7.61 years ±5.33 and mortality was 19.1%. There was no difference in etiology or type/mechanism of injury between groups. However, groups demonstrated differences in neuromuscular blockade, endotracheal intubation, pre-hospital events (cardiac arrest and apnea), coagulopathy, and pupil response. Mortality between groups was different (42.2% Group A, 22.6% Group B, and 3.8% Group C; p < 0.001), and adding pupil response improved mortality associations. In children younger than 5 years of age, a similar relationship between GCS and mortality was observed. Overall, GCS score at the time of ICP monitor placement is strongly associated with mortality across the pediatric age range. Development of models with GCS and other factors may allow identification of subtypes of children after severe TBI for future studies.

Variation in Anticonvulsant Selection and Electroencephalographic Monitoring Following Severe Traumatic Brain Injury in Children-Understanding Resource Availability in Sites Participating in a Comparative Effectiveness Study

OBJECTIVES

Early posttraumatic seizures may contribute to worsened outcomes after traumatic brain injury. Evidence to guide the evaluation and management of early posttraumatic seizures in children is limited. We undertook a survey of current practices of continuous electroencephalographic monitoring, seizure prophylaxis, and the management of early posttraumatic seizures to provide essential information for trial design and the development of posttraumatic seizure management pathways.

DESIGN

Surveys were sent to site principal investigators at all 43 sites participating in the Approaches and Decisions in Acute Pediatric TBI trial at the time of the survey. Surveys consisted of 12 questions addressing strategies to 1) implement continuous electroencephalographic monitoring, 2) posttraumatic seizure prophylaxis, 3) treat acute posttraumatic seizures, 4) treat status epilepticus and refractory status epilepticus, and 5) monitor antiseizure drug levels.

SETTING

Institutions comprised a mixture of free-standing children's hospitals and university medical centers across the United States and Europe.

SUBJECTS

Site principal investigators of the Approaches and Decisions in Acute Pediatric TBI trial.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Continuous electroencephalographic monitoring was available in the PICU in the overwhelming majority of clinical sites (98%); however, the plans to operationalize such monitoring for children varied considerably. A similar majority of sites report that administration of prophylactic antiseizure medications is anticipated in children (93%); yet, a minority reports that a specified protocol for treatment of posttraumatic seizures is in place (43%). Reported medication choices varied substantially between sites, but the majority of sites reported pentobarbital for refractory status epilepticus (81%). The presence of treatment protocols for seizure prophylaxis, early posttraumatic seizures, posttraumatic status epilepticus, and refractory status epilepticus was associated with decreased reported medications (all p < 0.05).

CONCLUSIONS

This study reports the current management practices for early posttraumatic seizures in select academic centers after pediatric severe traumatic brain injury. The substantial variation in continuous electroencephalographic monitoring implementation, choice of seizure prophylaxis medications, and management of early posttraumatic seizures across institutions was reported, signifying the areas of clinical uncertainty that will help provide focused design of clinical trials. Although sites with treatment protocols reported a decreased number of medications for the scenarios described, completion of the Approaches and Decisions in Acute Pediatric TBI trial will be able to determine if these protocols lead to decreased variability in medication administration in children at the clinical sites.

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.

Pathophysiology and Management of Moderate and Severe Traumatic Brain Injury in Children

Traumatic brain injury remains a leading cause of morbidity and mortality in children. Key pathophysiologic processes of traumatic brain injury are initiated by mechanical forces at the time of trauma, followed by complex excitotoxic cascades associated with compromised cerebral autoregulation and progressive edema. Acute care focuses on avoiding secondary insults, including hypoxia, hypotension, and hyperthermia. Children with moderate or severe traumatic brain injury often require intensive monitoring and treatment of multiple parameters, including intracranial pressure, blood pressure, metabolism, and seizures, to minimize secondary brain injury. Child neurologists can play an important role in acute and long-term care. Acutely, as members of a multidisciplinary team in the intensive care unit, child neurologists monitor for early signs of neurological change, guide neuroprotective therapies, and transition patients to long-term recovery. In the longer term, neurologists are uniquely positioned to treat complications of moderate and severe traumatic brain injury, including epilepsy and cognitive and behavioral issues.

Effect of administration of neuromuscular blocking agents in children with severe traumatic brain injury on acute complication rates and outcomes: a secondary analysis from a randomized, controlled trial of therapeutic hypothermia

OBJECTIVE

To evaluate the association between neuromuscular blocking agents and outcome, intracranial pressure, and medical complications in children with severe traumatic brain injury.

DESIGN

A secondary analysis of a randomized, controlled trial of therapeutic hypothermia.

SETTING

Seventeen hospitals in the United States, Australia, and New Zealand.

PATIENTS

Children (< 18 yr) with severe traumatic brain injury.

INTERVENTIONS

None for this secondary analysis.

MEASUREMENTS AND MAIN RESULTS

Children received neuromuscular blocking agent on the majority of days of the study (69.6%), and the modified Pediatric Intensity Level of Therapy scores (modified by removing neuromuscular blocking agent administration from the score) were increased on days when neuromuscular blocking agents were used (9.67 ± 0.21 vs 5.48 ± 0.26; p < 0.001). Children were stratified into groups based on exposure to neuromuscular blocking agents (group 1 received neuromuscular blocking agents each study day; group 2 did not). Group 1 had increased number of daily intracranial pressure readings more than 20 mm Hg (4.4 ± 1.1 vs 2.4 ± 0.5;p = 0.015) and longer ICU and hospital length of stay (p = 0.003 and 0.07, respectively, Kaplan-Meier). The Glasgow Outcome Score-Extended for Pediatrics at hospital discharge and 3, 6, and 12 months after traumatic brain injury and medical complications observed during the acute hospitalization were similar between groups.

CONCLUSIONS

Administration of neuromuscular blocking agents was ubiquitous and daily administration of neuromuscular blocking agents was associated with intracranial hypertension but not outcomes-likely indicating that increased injury severity prompted their use. Despite this, neuromuscular blocking agent use was not associated with complications. A different study design-perhaps using randomization or methodologies-of a larger cohort will be required to determine if neuromuscular blocking agent use is helpful after severe traumatic brain injury in children.

Energy expenditure in children after severe traumatic brain injury

OBJECTIVE

To evaluate energy expenditure in a cohort of children with severe traumatic brain injury.

DESIGN

A prospective observational study.

SETTING

A pediatric neurotrauma center within a tertiary care institution.

PATIENTS

Mechanically ventilated children admitted with severe traumatic brain injury (Glasgow Coma Scale < 9) with a weight more than 10 kg were eligible for study. A subset of children was co-enrolled in a phase 3 study of early therapeutic hypothermia. All children were treated with a comprehensive neurotrauma protocol that included sedation, neuromuscular blockade, temperature control, antiseizure prophylaxis, and a tiered-based system for treating intracranial hypertension.

INTERVENTIONS

Within the first week after injury, indirect calorimetry measurements were performed daily when the patient's condition permitted.

MEASUREMENTS AND MAIN RESULTS

Data from 13 children were analyzed (with a total of 32 assessments). Measured energy expenditure obtained from indirect calorimetry was compared with predicted resting energy expenditure calculated from Harris-Benedict equation. Overall, measured energy expenditure/predicted resting energy expenditure averaged 70.2% ± 3.8%. Seven measurements obtained while children were hypothermic did not differ from normothermic values (75% ± 4.5% vs 68.9% ± 4.7%, respectively, p = 0.273). Furthermore, children with favorable neurologic outcome at 6 months did not differ from children with unfavorable outcome (76.4% ± 6% vs 64.7% ± 4.7% for the unfavorable outcome, p = 0.13).

CONCLUSIONS

Contrary to previous work from several decades ago that suggested severe pediatric traumatic brain injury is associated with a hypermetabolic response (measured energy expenditure/predicted resting energy expenditure > 110%), our data suggest that contemporary neurocritical care practices may blunt such a response. Understanding the metabolic requirements of children with severe traumatic brain injury is the first step in development of rational nutritional support goals that might lead to improvements in outcome.

Hospitalizations of children with neurologic disorders in the United States

OBJECTIVES

Although neurologic disorders are among the most serious acute pediatric illnesses, epidemiologic data are scarce. We sought to determine the scope and outcomes of children with these disorders in the United States.

DESIGN

Retrospective cohort study.

SETTING

All nonfederal hospitals in 11 states encompassing 38% of the U.S. pediatric population.

PATIENTS

Children 29 days to 19 years old hospitalized in 2005.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Using International Classification of Diseases, 9th Revision, Clinical Modification, codes, we identified admissions with neurologic diagnoses, analyzed patient and hospitalization characteristics, and generated age- and sex-adjusted national estimates. Of 960,020 admissions in the 11 states, 10.7% (103,140) included a neurologic diagnosis, which yields a national estimate of 273,900 admissions of children with neurologic diagnoses. The most common were seizures (53.9%) and traumatic brain injury (17.3%). Children with neurologic diagnoses had nearly three times greater ICU use than other hospitalized children (30.6% vs 10.6%, p < 0.001). Neurologic diagnoses were associated with nearly half of deaths (46.2%, n = 1,790). Among ICU patients, children with neurologic diagnoses had more than three times the mortality of other patients (4.8% vs1.5%, p < 0.001). Children with neurologic diagnoses had a significantly longer median hospital length of stay than other children (3 d [1, 5] vs 2 d [2, 4], p < 0.001) and greater median hospital costs ($4,630 [$2,380, $9,730] vs $2,840 [$1,520, $5,550], p < 0.001).

CONCLUSIONS

Children with neurologic diagnoses account for a disproportionate amount of ICU stays and deaths compared with children hospitalized for other reasons.

Differences in medical therapy goals for children with severe traumatic brain injury-an international study

OBJECTIVES

To describe the differences in goals for their usual practice for various medical therapies from a number of international centers for children with severe traumatic brain injury.

DESIGN

A survey of the goals from representatives of the international centers.

SETTING

Thirty-two pediatric traumatic brain injury centers in the United States, United Kingdom, France, and Spain.

PATIENTS

None.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A survey instrument was developed that required free-form responses from the centers regarding their usual practice goals for topics of intracranial hypertension therapies, hypoxia/ischemia prevention and detection, and metabolic support. Cerebrospinal fluid diversion strategies varied both across centers and within centers, with roughly equal proportion of centers adopting a strategy of continuous cerebrospinal fluid diversion and a strategy of no cerebrospinal fluid diversion. Use of mannitol and hypertonic saline for hyperosmolar therapies was widespread among centers (90.1% and 96.9%, respectively). Of centers using hypertonic saline, 3% saline preparations were the most common but many other concentrations were in common use. Routine hyperventilation was not reported as a standard goal and 31.3% of centers currently use PbO(2) monitoring for cerebral hypoxia. The time to start nutritional support and glucose administration varied widely, with nutritional support beginning before 96 hours and glucose administration being started earlier in most centers.

CONCLUSIONS

There were marked differences in medical goals for children with severe traumatic brain injury across our international consortium, and these differences seemed to be greatest in areas with the weakest evidence in the literature. Future studies that determine the superiority of the various medical therapies outlined within our survey would be a significant advance for the pediatric neurotrauma field and may lead to new standards of care and improved study designs for clinical trials.

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.

Brain injuries and neurological system failure are the most common proximate causes of death in children admitted to a pediatric intensive care unit

OBJECTIVE

Mortality rates from critical illness in children have declined over the past several decades, now averaging between 2% and 5% in most pediatric intensive care units. Although these rates, and mortality rates from specific disorders, are widely understood, the impact of acute neurologic injuries in such children who die and the role of these injuries in the cause of death are not well understood. We hypothesized that neurologic injuries are an important cause of death in children.

DESIGN

Retrospective review.

SETTING

Pediatric intensive care unit at Children's Hospital of Pittsburgh, an academic tertiary care center.

PATIENTS

Seventy-eight children who died within the pediatric intensive care unit from April 2006 to February 2008.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data regarding admission diagnosis, presence of chronic illness, diagnosis of brain injury, and cause of death were collected. Mortality was attributed to brain injury in 65.4% (51 of 78) of deaths. Ninety-six percent (28 of 29) of previously healthy children died with brain injuries compared with 46.9% (23 of 49) of chronically ill children (p < .05). The diagnosed brain injury was the proximate cause of death in 89.3% of previously healthy children and 91.3% with chronic illnesses. Pediatric intensive care unit and hospital length of stay was longer in those with chronic illnesses (38.8 ± 7.0 days vs. 8.9 ± 3.7 days and 49.2 ± 8.3 days vs. 9.0 ± 3.8 days, p < .05 and p < .001, respectively).

CONCLUSION

Brain injury was exceedingly common in children who died in our pediatric intensive care unit and was the proximate cause of death in a large majority of cases. Neuroprotective measures for a wide variety of admission diagnoses and initiatives directed to prevention or treatment of brain injury are likely to attain further improvements in mortality in previously healthy children in the modern pediatric intensive care unit.