Head injury in children

Variation in therapy and outcome for pediatric head trauma patients

OBJECTIVE

This study was undertaken to examine variation in therapies and outcome for pediatric head trauma patients by patient characteristics and by pediatric intensive care unit. Specifically, the study was designed to examine severity of illness on admission to the pediatric intensive care unit, the therapies used during the pediatric intensive care unit stay, and patient outcomes.

DATA SOURCES AND SETTING

Consecutive admissions from three pediatric intensive care units were recorded prospectively (n = 5,749). For this study, all patients with an admitting diagnosis of head trauma were included (n = 477). Data collection occurred during an 18-month period beginning in June 1996. All of the pediatric intensive care units were located in children's hospitals, had residency and fellowship training programs, and were headed by a pediatric intensivist.

METHODS

Admission severity was measured as the worst recorded physiological derangement during the period <or=6 hrs before pediatric intensive care unit admission. Therapies and resource use were based on the Therapeutic Intervention Scoring System with adaptations for pediatrics. The use of intracranial pressure monitoring was recorded on admission to the unit (within 1 hr) and at any time during the pediatric intensive care unit stay. Outcomes were measured at the time of pediatric intensive care unit discharge by the Pediatric Overall Performance Category scale. Risk factors for mortality were examined by using bivariate analyses with significant predictors as candidate variables in a logistic regression to predict expected mortality. Intracranial pressure monitoring and other therapies were added to the mortality prediction model to test for protective effects. Finally, race and insurance status were added to the model to test for differences in the quality of care.

RESULTS

The overall mortality rate for the entire sample was 7.8%. Mortality rates for children <or=1 yr old were significantly higher than for children >1 yr old (16.1% vs. 6.1%; p = .002). Comparisons by insurance status indicated that observed mortality rates were highest for self-paying patients. However, patient characteristics were not associated with use of therapies or standardized mortality rates after adjustment for patient severity. There was significant variation in the use of paralytic agents, seizure medications, induced hypothermia, and intracranial pressure monitoring on admission across the three pediatric intensive care units. In multivariate models, only the use of seizure medications was associated significantly with reduced mortality risk (odds ratio = 0.17; 95% confidence interval = 0.04-0.70; p = .014).

CONCLUSIONS

Therapies and outcomes vary across pediatric intensive care units that care for children with head injuries. Increased use of seizure medications may be warranted based on data from this observational study. Large randomized controlled trials of seizure prophylaxis in children with head injury have not been conducted and are needed to confirm the findings presented here.

Application of technology in the treatment of traumatic brain injury

The goal of care of the traumatic brain-injured patient is to prevent secondary injury. Technology gives the caregivers information as to the cause and severity of injury and can guide appropriate management of the patient. Use of multimodality monitoring increases the complexity of care but may allow for better targeted therapy. This article will discuss the current state of technology, the physiology and pathophysiology that it assesses, the normal and abnormal values obtained, and how care will be impacted.

Mechanisms of neurodegeneration after paediatric brain injury

Trauma to the developing brain constitutes an unexplored field. The few studies attempting to model and study paediatric head trauma, the leading cause of death and disability in the paediatric population, have revealed interesting aspects and potential targets for future research. One feature unique to the developing brain is overactivation by trauma of ongoing physiological programmed neuronal death (apoptosis). Understanding the underlying biochemical and molecular pathomechanisms may help set new pharmacotherapeutic targets for neuroprotection at an early age.

[Effect of a lung contusion on the prognosis of severe head injury in the child]

OBJECTIVES

To assess the effects of a pulmonary contusion (PC) on the outcome of a severe head trauma (SHT) in children less than 15-year-old.

STUDY DESIGN

Retrospective study.

PATIENTS

The study included 30 severely head injured children with a Glasgow Coma Scale score (GCS) < or = 8, associated with a PC (PC+) diagnosed on a thoracic CT-scan and 30 severely head injured children without PC (PC-).

METHODS

Outcome was assessed using the Glasgow Outcome Scale (GOS), on discharge and six months later. Age, body weight, gender, GCS, PTS, ISS, hypoxaemia, arterial hypotension, the results of the cerebral CT-scan, the main treatment administered, complications, the duration of tracheal intubation as well as the duration of stay in the intensive care unit (ICU) and in the hospital were compared between groups.

RESULTS

GCS median was lower (6 vs 8, P = 0.001) and ISS median higher (25 vs 23, P = 0.0004) in the PC+ group. Hypoxaemia was more frequent in the PC+ group (n = 12 vs n = 0, P = 0.0001). There was no difference between groups regarding the results of cerebral CT scan. Blood transfusion was more frequently used in the PC+ group (n = 14 vs n = 5, P = 0.03). Median duration of tracheal intubation, and of stay in the ICU and in the hospital were shorter in the PC- group (respectively 8 vs 6 days, P = 0.03; 10 vs 7.5 days, P = 0.008; 13.5 vs 10.5 days, P = 0.01). No difference was observed regarding complications between groups. GOS on discharge was higher in the PC+ group (3 vs 2, P = 0.01). There was an increase in GOS at six months in the two groups, however GOS remained significantly higher in the PC+ group (median values 2 vs 1, P = 0.002). A favourable outcome occurred less frequently in the PC+ group on discharge and at six months (respectively n = 14 vs 25, P = 0.006; n = 20 vs 28, P = 0.02).

CONCLUSION

The association of a PC to a severe head trauma is responsible for a poorer outcome in children, probably because, at least in part, a higher incidence of hypoxaemia.

Minor head injury in the pediatric patient

Minor head injury is a common occurrence in children of all ages; however, controversy exists regarding the management of these children. Reports of neurologically intact children with intracranial injuries have caused many to recommend cautious management, while the infrequency of serious intracranial injuries after minor head trauma have prompted others to be less conservative. Based on recent literature reports, strategies for the management of children with minor head trauma are presented.

Noninvasive continuous monitoring of cerebral oxygenation periictally using near-infrared spectroscopy: a preliminary report

PURPOSE

To report on the use of near-infrared spectroscopy (NIRS) to examine the changes in cerebral oxygenation in the periictal period in patients with seizures.

METHODS

Cerebral hemoglobin oxygen availability was monitored continuously and noninvasively with NIRS in three patients (one in the pediatric intensive care unit (ICU) and two in epilepsy-monitoring units) in conjunction with continuous EEG monitoring. Ictal events were recorded and compared with the pre-, intra-, and postictal periods for cerebral oxygen availability, as defined by oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (Hb), and the redox state of cytochrome oxidase (cytox).

RESULTS

Several important preliminary observations were made by using this technology. First, a preictal increase in cerebral oxygenation began between 1 and 2 h and >10 h before the ictal event. Second, despite adequate perfusion, based on an observed increased HbO2, reduction in cytox indicates a perfusion-metabolism mismatch during seizure activity. Third, continued seizure activity and even isolated ictal events were associated with decreased cerebral oxygen availability. Fourth, differences in cerebral oxygen availability were noted between different types of seizures (e.g., electrographic seizures were accompanied by rapid reductions in HbO2 and cerebral blood volume without reduction of cytox, whereas electroclinical seizures were characterized by marked increases in HbO2 with or without reduction of cytox).

CONCLUSIONS

In this preliminary report on the use of NIRS for patients with seizures, we believe that NIRS allows continuous and noninvasive monitoring of changes in cerebral oxygenation periictally, thereby permitting investigations into the pathophysiology of seizures and the exploration of the potential of cerebral oximetry as a tool for seizure localization.

Monitoring and management of the paediatric neurosurgical patient

Head injury remains the most common cause of death in children, and tumours of the central nervous system are the most common solid tumour encountered. There is little class 1 evidence on which to base the monitoring and management of the paediatric patient with these conditions, management strategies commonly being extrapolated from those in use for adults. However, the clinical outcome for these conditions appears to be improving, with evidence suggesting that this improvement is being achieved by the management of these children in specialist centres.

Neuroimaging in pediatric traumatic head injury: diagnostic considerations and relationships to neurobehavioral outcome

Contemporary neuorimaging techniques in child traumatic brain injury are reviewed, with an emphasis on computerized tomography (CT) and magnetic resonance (MR) imaging. A brief overview of MR spectroscopy (MRS), functional MR imaging (fMRI), single-photon emission computed tomography (SPECT), and magnetoencephalography (MEG) is also provided because these techniques will likely constitute important neuroimaging techniques of the future. Numerous figures are provided to illustrate the multifaceted manner in which traumatic deficits can be imaged and the role of neuroimaging information as it relates to TBI outcome.

Apoptotic neurodegeneration following trauma is markedly enhanced in the immature brain

Age dependency of apoptotic neurodegeneration was studied in the developing rat brain after percussion head trauma. In 7-day-old rats, mechanical trauma, applied by means of a weight drop device, was shown to trigger widespread cell death in the hemisphere ipsilateral to the trauma site, which first appeared at 6 hours, peaked at 24 hours, and subsided by 5 days after trauma. Ultrastructurally, degenerating neurons displayed features consistent with apoptosis. A decrease of bcl-2 in conjunction with an increase of c-jun mRNA levels, which were evident at 1 hour after trauma and were accompanied by elevation of CPP 32-like proteolytic activity and oligonucleosomes in vulnerable brain regions, confirmed the apoptotic nature of this process. Severity of trauma-triggered apoptosis in the brains of 3- to 30-day-old rats was age dependent, was highest in 3- and 7-day-old animals, and demonstrated a subsequent rapid decline. Adjusting the mechanical force in accordance with age-specific brain weights revealed a similar vulnerability profile. Thus, apoptotic neurodegeneration contributes in an age-dependent fashion to neuropathological outcome after head trauma, with the immature brain being exceedingly vulnerable. These results help explain unfavorable outcomes of very young pediatric head trauma patients and imply that, in this group, an antiapoptotic regimen may constitute a successful neuroprotective approach.

Ontogenetic aspects of traumatic brain edema--facts and suggestions

Diffuse brain swelling (DBS) after severe traumatic brain injury (TBI) occurs more commonly in children than adults. Most of the recent clinical studies suggest that young children are more negatively affected by DBS. Until now studies in young animals in which the pathophysiology of DBS was evaluated remained seldom. However, pathogenetic mechanisms of edema formation after TBI in the immature brain appeared to be different in comparison to adult brains. There are evidences that vasogenic as well as cytotoxic edema components may be responsible for the development of DBS. Besides mechanical disturbance, the blood-brain barrier seems to be strongly endangered by oxidative stress after TBI because regional antioxidative capacity is obviously diminished. In addition, cytotoxic components of DBS may be caused by at least two different mechanisms. First, it was shown that a sustained posttraumatic cerebral hypoperfusion occurs in the immature brain. Moreover, a transient increase of NMDA receptor expression at this period of life may be responsible for an increased threat of intracellular sodium ion accumulation in brain cells. Obviously, brain swelling can be detrimental because it can elevate intracranial pressure, impair CBF, and may represent ongoing secondary brain injury.