Intracranial Pressure Monitoring in Infants and Young Children With Traumatic Brain Injury

Development of a Randomized Trial Comparing ICP-Monitor-Based Management of Severe Pediatric Traumatic Brain Injury to Management Based on Imaging and Clinical Examination Without ICP Monitoring-Study Protocol

BACKGROUND AND OBJECTIVES

Traumatic brain injury (TBI) is a major global public health problem. It is a leading cause of death and disability in children and adolescents worldwide. Although increased intracranial pressure (ICP) is common and associated with death and poor outcome after pediatric TBI, the efficacy of current ICP-based management remains controversial. We intend to provide Class I evidence testing the efficacy of a protocol based on current ICP monitor-based management vs care based on imaging and clinical examination without ICP monitoring in pediatric severe TBI.

METHODS

A phase III, multicenter, parallel-group, randomized superiority trial performed in intensive care units in Central and South America to determine the impact on 6-month outcome of children aged 1-12 years with severe TBI (age-appropriate Glasgow Coma Scale score ≤8) randomized to ICP-based or non-ICP-based management.

EXPECTED OUTCOMES

Primary outcome is 6-month Pediatric Quality of Life. Secondary outcomes are 3-month Pediatric Quality of Life, mortality, 3-month and 6-month Pediatric extended Glasgow Outcome Score, intensive care unit length of stay, and number of interventions focused on treating measured or suspected intracranial hypertension.

DISCUSSION

This is not a study of the value of knowing the ICP in sTBI. This research question is protocol-based. We are investigating the added value of protocolized ICP management to treatment based on imaging and clinical examination in the global population of severe pediatric TBI. Demonstrating efficacy should standardize ICP monitoring in severe pediatric TBI. Alternate results should prompt reassessment of how and in which patients ICP data should be applied in neurotrauma care.

Wearable Intracranial Pressure Monitoring Sensor for Infants

Monitoring of intracranial pressure (ICP) is important for patients at risk of raised ICP, which may indicate developing diseases in brains that can lead to brain damage or even death. Monitoring ICP can be invaluable in the management of patients suffering from brain injury or hydrocephalus. To date, invasive measurements are still the standard method for monitoring ICP; however, these methods can not only cause bleeding or infection but are also very inconvenient to use, particularly for infants. Currently, none of the non-invasive methods can provide sufficient accuracy and ease of use while allowing continuous monitoring in routine clinical use at low cost. Here, we have developed a wearable, non-invasive ICP sensor that can be used like a band-aid. For the fabrication of the ICP sensor, a novel freeze casting method was developed to encapsulate the liquid metal microstructures within thin and flexible polymers. The final thickness of the ICP sensor demonstrated is 500 µm and can be further reduced. Three different designs of ICP sensors were tested under various pressure actuation conditions as well as different temperature environments, where the measured pressure changes were stable with the largest stability coefficient of variation being only CV = 0.0206. In addition, the sensor output values showed an extremely high linear correlation (R2 > 0.9990) with the applied pressures.

Ability of the PILOT score to predict 6-month functional outcome in pediatric patients with moderate-severe traumatic brain injury

PURPOSE

To assess the Pediatric Intensity Level of Therapy (PILOT) score alone and in combination with Emergency Department (ED) GCS and Rotterdam score of initial head CT to predict functional outcomes in children with traumatic brain injury (TBI).

METHODS

Children (n=108) aged 31months-15years with moderate to severe TBI were prospectively enrolled at two sites. The ability of PILOT, ED GCS, and Rotterdam scores to predict the 6-month Pediatric Injury Functional Outcome Scale (PIFOS) was evaluated using multivariable regression models with enrollment site, age, and sex as covariates.

RESULTS

PILOT total (sum) score was more predictive of PIFOS (R²=0.23) compared to mean (R² = 0.20) or peak daily PILOT scores (R²=0.11). PILOT total score predicted PIFOS better than ED GCS (R²=0.01) or Rotterdam score (R²=0.06) and was similar to PILOT, ED GCS, and Rotterdam score combined. PILOT total score performed better in patients with intracranial pressure monitors (n=30, R²=0.28, slope=0.30) than without (n=78, R²=0.09, slope=0.36).

CONCLUSIONS

The PILOT score correlated moderately with functional outcome following TBI and outperformed other common predictors. PILOT may be a useful predictor or moderator of functional outcomes.

LEVEL OF EVIDENCE

Prognosis study, Level II.

Intracranial pressure monitoring associated with increased mortality in pediatric brain injuries

BACKGROUND

Utilization of ICP monitors for pediatric patients is low and varies between centers. We hypothesized that in more severely injured patients (GCS 3-4), there would be a decreased mortality associated with invasive monitoring devices.

METHODS

The pediatric Trauma Quality Improvement Program (TQIP) was queried for patients aged ≤ 16 years meeting criteria for invasive monitors. Our primary outcome was mortality. Patients with ICP monitoring were compared to those without. A logistic regression was used to examine the risk of mortality.

RESULTS

Of 3,808 patients, 685 (18.0%) underwent ICP monitoring. ICP monitors were associated with increased risk of mortality (OR 1.82, CI 1.36-2.44, p < 0.001). A secondary analysis including type of invasive ICP monitor and dividing GCS into 3 categories revealed both intraventricular drain (OR 1.89, CI 1.3-2.7, p = 0.001) and intraparenchymal pressure monitor (OR 1.86, CI 1.32-2.6, p < 0.001) to be independently associated with an increased likelihood of mortality regardless of GCS, while intraparenchymal oxygen monitoring was not (OR 0.47, CI 0.11-2.05, p = 0.316). The strongest effect was seen in those patients with a GCS of 5-6.

CONCLUSION

ICP monitors are an independent risk factor for mortality, particularly with intraventricular drains and intraparenchymal monitors in patients with a GCS 5-6.

Non-invasive estimation of cerebral perfusion pressure using transcranial Doppler ultrasonography in children with severe traumatic brain injury

OBJECTIVE

To identify if cerebral perfusion pressure (CPP) can be non-invasively estimated by either of two methods calculated using transcranial Doppler ultrasound (TCD) parameters.

DESIGN

Retrospective review of previously prospectively gathered data.

SETTING

Pediatric intensive care unit in a tertiary care referral hospital.

PATIENTS

Twenty-three children with severe traumatic brain injury (TBI) and invasive intracranial pressure (ICP) monitoring in place.

INTERVENTIONS

TCD evaluation of the middle cerebral arteries was performed daily. CPP at the time of the TCD examination was recorded. For method 1, estimated cerebral perfusion pressure (CPPe) was calculated as: CPPe = MAP × (diastolic flow (Vd)/mean flow (Vm)) + 14. For method 2, critical closing pressure (CrCP) was identified as the intercept point on the x-axis of the linear regression line of blood pressure and flow velocity parameters. CrCP/CPPe was then calculated as MAP-CrCP.

MEASUREMENTS AND MAIN RESULTS

One hundred eight paired measurements were available. Using patient averaged data, correlation between CPP and CPPe was significant (r = 0.78, p = < 0.001). However, on Bland-Altman plots, bias was 3.7 mmHg with 95% limits of agreement of - 17 to + 25 for CPPe. Using patient averaged data, correlation between CPP and CrCP/CPPe was significant (r = 0.59, p = < 0.001), but again bias was high at 11 mmHg with wide 95% limits of agreement of - 15 to + 38 mmHg.

CONCLUSIONS

CPPe and CrCP/CPPe do not have clinical value to estimate the absolute CPP in pediatric patients with TBI.

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.

Anatomical and Physiological Differences between Children and Adults Relevant to Traumatic Brain Injury and the Implications for Clinical Assessment and Care

General and central nervous system anatomy and physiology in children is different to that of adults and this is relevant to traumatic brain injury (TBI) and spinal cord injury. The controversies and uncertainties in adult neurotrauma are magnified by these differences, the lack of normative data for children, the scarcity of pediatric studies, and inappropriate generalization from adult studies. Cerebral metabolism develops rapidly in the early years, driven by cortical development, synaptogenesis, and rapid myelination, followed by equally dramatic changes in baseline and stimulated cerebral blood flow. Therefore, adult values for cerebral hemodynamics do not apply to children, and children cannot be easily approached as a homogenous group, especially given the marked changes between birth and age 8. Their cranial and spinal anatomy undergoes many changes, from the presence and disappearance of the fontanels, the presence and closure of cranial sutures, the thickness and pliability of the cranium, anatomy of the vertebra, and the maturity of the cervical ligaments and muscles. Moreover, their systemic anatomy changes over time. The head is relatively large in young children, the airway is easily compromised, the chest is poorly protected, the abdominal organs are large. Physiology changes—blood volume is small by comparison, hypothermia develops easily, intracranial pressure (ICP) is lower, and blood pressure normograms are considerably different at different ages, with potentially important implications for cerebral perfusion pressure (CPP) thresholds. Mechanisms and pathologies also differ—diffuse injuries are common in accidental injury, and growing fractures, non-accidental injury and spinal cord injury without radiographic abnormality are unique to the pediatric population. Despite these clear differences and the vulnerability of children, the amount of pediatric-specific data in TBI is surprisingly weak. There are no robust guidelines for even basics aspects of care in children, such as ICP and CPP management. This is particularly alarming given that TBI is a leading cause of death in children. To address this, there is an urgent need for pediatric-specific clinical research. If this goal is to be achieved, any clinician or researcher interested in pediatric neurotrauma must be familiar with its unique pathophysiological characteristics.