Prehospital management of traumatic brain injury

Interobserver reliability and diagnostic accuracy of prehospital triage for identifying traumatic brain injury in paediatric patients: a systematic review

PURPOSE

The consistency and accuracy of paediatric TBI triage tools can be affected by different factors, such as patients' characteristics and the level of knowledge and skill of the caregiver. This systematic review included all the available data on the level of agreement between paramedics and ED physicians about the reliability of tools to identify paediatric TBI and the diagnostic accuracy of several such tools in prehospital settings when used by paramedics.

METHODS

MEDLINE (OVID), EMBASE (OVID), Cochrane Library (OVID), and CINAHL Plus (EBSCO) databases were searched from inception to 27 October 2022. Quality, bias, and applicability were assessed using COSMIN for interobserver reliability studies and QUADAS-2 tool for diagnostic accuracy studies. Narrative synthesis was employed because data were unsuitable for meta-analysis.

RESULTS

Initial searches identified 660 papers in total. Five met the inclusion criteria. Two studies showed moderate agreement between paramedics and ED physicians for GCS assessment. The PTS overtriage rate was 10% and the undertriage rate was 62%, while the triage tape had an overtriage rate of 18% and an undertriage rate of 68%. Pre-hospital GCS had 86.67% sensitivity and 71.43% specificity [95% CI]: 0.74-0.96 for neurosurgically significant TBI.

CONCLUSION

Low level of GCS agreement and poor diagnostic accuracy may cause further harm to the patient; thus, further studies are recommended to improve the prehospital management of children with head injuries.

Increased distance or time from a major trauma centre in South Australia is not associated with worse outcomes after moderate to severe traumatic brain injury

OBJECTIVE

Considerations in traumatic brain injury (TBI) management include time to critical interventions and neurosurgical care, which can be influenced by the geographical location of injury. In Australia, these distances can be vast with varying degrees of first-responder experience. The present study aimed to evaluate the association that distance and/or time to a major trauma centre (MTC) had on patient outcomes with moderate to severe TBI.

METHODS

A retrospective cohort study was conducted using data from the Royal Adelaide Hospital's (RAH) Trauma Registry over a 3-year period (1 January 2018 to 31 December 2020). All patients with a moderate to severe TBI (Glasgow Coma Scale [GCS] ≤13 and abbreviated injury score head of ≥2) were included. The association of distance and time to the RAH and patient outcomes were compared by calculating the odds ratio utilising a logistic regression model.

RESULTS

A total of 378 patients were identified; of these, 226 met inclusion criteria and comprised our study cohort. Most patients were male (79%), injured in a major city (55%), with median age of 38 years old and median injury severity score (ISS) of 25. After controlling for age, ISS, ED GCS on arrival and pre-MTC intubation, increasing distance or time from injury site to the RAH was not shown to be associated with mortality or discharge destination in any of the models investigated.

CONCLUSION

Our analysis revealed that increasing distance or time from injury site to a MTC for patients with moderate to severe TBI was not significantly associated with adverse patient outcomes.

[Prehospital care of pediatric traumatic brain injury]

BACKGROUND

Traumatic brain injury (TBI) in children and adolescents is associated with significant morbidity and, in severe TBI, mortality. The aim of this article is to provide an overview of the spectrum of TBI, its pathophysiology, and current treatment recommendations for prehospital management of children and adolescents with TBI.

MATERIALS AND METHODS

The current literature was reviewed for studies on the management of TBI in children and adolescents.

RESULTS

In recent years, a large number of scientific studies have been published that have resulted in evidence-based guidelines for primary care of children with TBI. The primary aim is to minimize secondary brain damage following TBI, for which immediate assessment of the severity of TBI at the scene based on clinical findings and the accident mechanism and initiation of specific treatment measures to prevent hypoxia, hypotension, and hypothermia are critical. Not only prehospital management, but also the rapid transfer of children with severe TBI to centers with high neurosurgical, pediatric surgical, and pediatric intensive care expertise is of particular importance to improve survival and neurological outcome after severe TBI.

CONCLUSION

Structured prehospital management may help reduce secondary brain injury after TBI and lead to improved clinical outcomes.

Early Onset of Rapid Lesion Growth in an Acute Subdural Hematoma Model in Rats

OBJECTIVE

Acute subdural hematoma (ASDH) leads to the highest mortality rates of all head injuries with secondary brain damage playing a pivotal role in terms of morbidity and mortality. In patients with ASDH, a delay in surgery leads to disproportional mortality. The benefit of (very) early therapy is therefore, a target of ongoing research. As the process of delayed brain damage in ASDH has not yet been described, this study therefore aimed to examine secondary lesion growth in an experimental rat model of ASDH to define the ideal timing for testing potential neuroprotective therapies.

METHODS

Cerebral blood flow was monitored during ASDH induction with 300 μl of autologous blood. Lesion growth was characterized using Hematoxylin-Eosin- , Cresyl-Violet-, and Fluoro-Jade B-staining for early signs of neuronal degeneration. Histological evaluations were performed between 15 minutes and 24 hours after ASDH.

RESULTS

There was a significant reduction of cerebral blood flow after ASDH. Fluoro-Jade B-positive cells were visible 15 minutes after ASDH in the lesioned hemisphere. Nonlinear growth of lesion volume from 3.7 ± 0.4 mm3 to 17.5 ± 0.6 mm3 was observed at 24 hours in Hematoxylin-Eosin-staining.

CONCLUSIONS

The most damage develops between 15 minutes and 1 hour and again between 2 and 6 hours after ASDH. The time course of lesion growth supports the approach of early surgery for patients. It furthermore constitutes a basis for further ASDH research with more clearly defined time windows for therapy in animal models.

Mobile Smartphone-Based Digital Pupillometry Curves in the Diagnosis of Traumatic Brain Injury

Objective

The pupillary light reflex (PLR) and the pupillary diameter over time (the PLR curve) is an important biomarker of neurological disease, especially in the diagnosis of traumatic brain injury (TBI). We investigated whether PLR curves generated by a novel smartphone pupillometer application could be easily and accurately interpreted to aid in the diagnosis of TBI.

Methods

A total of 120 PLR curves from 42 healthy subjects and six patients with TBI were generated by PupilScreen. Eleven clinician raters, including one group of physicians and one group of neurocritical care nurses, classified 48 randomly selected normal and abnormal PLR curves without prior training or instruction. Rater accuracy, sensitivity, specificity, and interrater reliability were calculated.

Results

Clinician raters demonstrated 93% accuracy, 94% sensitivity, 92% specificity, 92% positive predictive value, and 93% negative predictive value in identifying normal and abnormal PLR curves. There was high within-group reliability (k = 0.85) and high interrater reliability (K = 0.75).

Conclusion

The PupilScreen smartphone application-based pupillometer produced PLR curves for clinical provider interpretation that led to accurate classification of normal and abnormal PLR data. Interrater reliability was greater than previous studies of manual pupillometry. This technology may be a good alternative to the use of subjective manual penlight pupillometry or digital pupillometry.

Pediatric traumatic brain injury prehospital guidelines: a systematic review and appraisal

BACKGROUND

Traumatic brain injury (TBI) disproportionately affects children within low- and middle-income countries (LMICs). Prehospital emergency care can mitigate secondary brain injury and improve outcomes. Here, we systematically review clinical practice guidelines (CPGs) for pediatric TBI with the goal to inform LMICs prehospital care.

METHODS

A systematic search was conducted in PubMed/Medline, Embase, and Web of Science databases. We appraised evidence-based CPGs addressing prehospital management of pediatric TBI using the Appraisal of Guidelines for Research & Evaluation (AGREE) tool. CPGs were rated as high-quality if ≥ 5 (out of 6) AGREE domains scored > 60%.

RESULTS

Of the 326 articles identified, 10 CPGs were included in analysis. All 10 were developed in HICs, and 4 were rated as high-quality. A total of 154 pediatric prehospital recommendations were grouped into three subcategories, initial assessment (35.7%), prehospital treatment (38.3%), and triage (26.0%). Of these, 79 (51.3%) were evidence-based with grading, and 31 (20.1%) were consensus-based without direct evidence.

CONCLUSION

Currently available CPGs for prehospital pediatric TBI management were all developed in HICs. Four CPGs have high-quality, and recommendations from these can serve as frameworks for LMICs or resource-limited settings. Context-specific evaluation and implementation of evidence-based recommendations allow LMIC settings to respond to the public health crisis of pediatric TBI and address gaps in trauma care systems.

The Impact of a Cervical Collar on Intracranial Pressure in Traumatic Brain Injury Patients: A Systematic Review and Meta-Analysis

Purpose: Although the use of a cervical collar in the prehospital setting is recommended to prevent secondary spinal cord injuries and ensure spinal immobilization, it is not known what effects this has on raising intracranial pressure (ICP) in traumatic brain injury (TBI) patients. In the absence of studies measuring ICP in the prehospital setting, the aim of this study was to systematically review the data related to ICP changes measured after presentation at the hospital in patients who had arrived wearing cervical collars. Methods: We searched Medline (PubMed), Embase, CINAHL, and Google Scholar for studies that investigated in-hospital ICP changes in TBI patients arriving at the hospital wearing collars. Titles, abstracts, and full texts were then searched for inclusion in the study. A narrative synthesis, as well as a meta-analysis, was performed. Results: Of the 1006 studies identified, only three met the inclusion/exclusion criteria. The quality of the three included studies was moderate and the risk of bias was low. All three studies used the Laerdal Stifneck collar, but all studies showed an increase in ICP after application of the collar. A further three studies that measured ICP but did not fit the systematic search were also included due to low patient numbers. A meta-analysis of the pooled data confirmed a significant increase in ICP, although between the four studies, only 77 patients were included. The meta-analysis also confirmed that after removal of the collar, there was a significant decrease in ICP. Conclusions: Our study suggests that the use of a cervical collar increases ICP in TBI and head injury patients, which may have detrimental effects. However, due to the extremely low sample size from all six studies, caution must be exercised when interpreting these data. Thus, further high-quality research is necessary to unequivocally clarify whether cervical collars should be used in patients with TBI.

Measuring the effects of institutional pediatric traumatic brain injury volume on outcomes for rural-dwelling children

OBJECTIVE

Rural-dwelling children may suffer worse pediatric traumatic brain injury (TBI) outcomes due to distance from and accessibility to high-volume trauma centers. This study aimed to compare the impacts of institutional TBI volume and sociodemographics on outcomes between rural- and urban-dwelling children.

METHODS

This retrospective study identified patients 0-19 years of age with ICD-9 codes for TBI in the 2012-2015 National Inpatient Sample database. Patients were characterized as rural- or urban-dwelling using United States Census classification. Logistic and linear (in log scale) regressions were performed to measure the effects of institutional characteristics, patient sociodemographics, and mechanism/severity of injury on occurrence of medical complications, mortality, length of stay (LOS), and costs. Separate models were built for rural- and urban-dwelling patients.

RESULTS

A total of 19,736 patients were identified (median age 11 years, interquartile range [IQR] 2-16 years, 66% male, 55% Caucasian). Overall, rural-dwelling patients had higher All Patient Refined Diagnosis Related Groups injury severity (median 2 [IQR 1-3] vs 1 [IQR 1-2], p < 0.001) and more intracranial monitoring (6% vs 4%, p < 0.001). Univariate analysis showed that overall, rural-dwelling patients suffered increased medical complications (6% vs 4%, p < 0.001), mortality (6% vs 4%, p < 0.001), and LOS (median 2 days [IQR 1-4 days ] vs 2 days [IQR 1-3 days], p < 0.001), but multivariate analysis showed rural-dwelling status was not associated with these outcomes after adjusting for injury severity, mechanism, and hospital characteristics. Institutional TBI volume was not associated with medical complications, disposition, or mortality for either population but was associated with LOS for urban-dwelling patients (nonlinear beta, p = 0.008) and cost for both rural-dwelling (nonlinear beta, p < 0.001) and urban-dwelling (nonlinear beta, p < 0.001) patients.

CONCLUSIONS

Overall, rural-dwelling pediatric patients with TBI have worsened injury severity, mortality, and in-hospital complications, but these disparities disappear after adjusting for injury severity and mechanism. Institutional TBI volume does not impact clinical outcomes for rural- or urban-dwelling children after adjusting for these covariates. Addressing the root causes of the increased injury severity at hospital arrival may be a useful path to improve TBI outcomes for rural-dwelling children.

Emergency medical services protocols for traumatic brain injury in the United States: A call for standardization

BACKGROUND

Traumatic brain injury (TBI) with acute elevation in intracranial pressure (ICP) is a neurologic emergency associated with significant morbidity and mortality. In addition to indicated trauma resuscitation, emergency department (ED) management includes empiric administration of hyperosmolar agents, rapid diagnostic imaging, anticoagulation reversal, and early neurosurgical consultation. Despite optimization of in-hospital care, patient outcomes may be worsened by variation in prehospital management. In this study, we evaluate geographic variation between emergency medical services (EMS) protocols for patients with suspected TBI.

METHODS

We performed a cross-sectional analysis of statewide EMS protocols in the United States in December 2020 and included all complete protocols published on government websites. Outcome measures were defined to include protocols or orders for the following interventions, given TBI: (1) hyperventilation and end-tidal capnography (EtCO2) goals, (2) administration of hyperosmolar agents, (3) tranexamic acid (TXA) administration for isolated head injury, (4) non-invasive management including head-of-bed elevation, and (5) hemodynamic goals.

RESULTS

We identified 32 statewide protocols including Washington, D.C., 4 of which did not include specific guidance for TBI. Of 28 states providing ventilatory guidance, 22/28 (78.6%) recommend hyperventilation, with 17/22 (77.3%) restricting hyperventilation to signs of acute herniation. The remaining 6 states prohibited hyperventilation. Regarding EtCO2 goals among states permitting hyperventilation, 17/22 (77.3%) targeted an EtCO2 of < 35 mmHg, while 5/22 (22.7%) provided no guide EtCO2 for hyperventilation. Rhode Island was the only state identified that included hypertonic saline (3%), and Delaware was the only state that allowed TXA in the setting of isolated TBI with GCS ≤ 12. Only 15/32 (46.9%) identified states recommend head-of-bed elevation. For blood pressure goals, 12/28 (42.9%) of states set minimum systolic blood pressure at 90 mmHg, while 10/28 (35.7%) set other SBP goals. The remaining 6/28 (21.4%) did not provide TBI-specific SBP goals.

CONCLUSIONS

There is wide variation among civilian prehospital protocols for traumatic brain injury. Prehospital care within the first "golden hour" may dramatically affect patient outcomes. Neurocritical care providers should be mindful of geographic variation in local protocols when designing and evaluating quality improvement interventions and should aim to standardize prehospital care protocols.

Timely Access to Neurosurgical Care in the Caribbean Using Geospatial Analysis

BACKGROUND

Access to timely neurosurgical care in particular remains limited worldwide, and is associated with increased morbidity and mortality, a decrease in overall life expectancy, and catastrophic economic costs. To date, access to neurosurgical care has not been completely studied and reported in the Caribbean neurosurgical literature. In this study, we aim to understand the geographic distribution of hospital facilities with neurosurgical capacity among the CARICOM member states to determine timely access to neurosurgical care.

METHODS

We assessed geographical access to facilities capable of providing neurosurgical care in the Caribbean. The GPS coordinates of the hospitals that provide neurosurgical care were identified using street addresses and satellite imaging from Google Maps. Facilities with neurosurgical care were mapped in ArcGIS Pro (Version 2.6.0). using Manhattan distance. We identified the area around each facility and stratified by 30- minute, 1-hour, 2-hour, and 4-hour geographic driving intervals.

RESULTS

A total of 16 hospitals were identified as providing neurosurgical care in the Caribbean. Our results suggest that 14 million people (76% of the population) had 4-hour geographic access to a facility capable of providing neurosurgical care. In addition, 7 million people (40% of the population) had 2-hour geographical access to neurosurgical care.

CONCLUSIONS

Timely access to care is an important tenet of global neurosurgery. We found that 3.5 million Caribbean residents are outside of the access zone to neurosurgical capacity. Public health advocates, governments, providers, and patients should be aware of the inequity in access to neurosurgical care and should collectively work to close the gap.

Effects of Preinjury and Postinjury Exposure to Caffeine in a Rat Model of Traumatic Brain Injury

Background: Lethal apnea is a significant cause of acute mortality following a severe traumatic brain injury (TBI). TBI is associated with a surge of adenosine, which also suppresses respiratory function in the brainstem. Methods and Materials: This study examined the acute and chronic effects of caffeine, an adenosine receptor antagonist, on acute mortality and morbidity after fluid percussion injury. Results: We demonstrate that, regardless of preinjury caffeine exposure, an acute bolus of caffeine given immediately following the injury dosedependently prevented lethal apnea and has no detrimental effects on motor performance following sublethal injuries. Finally, we demonstrate that chronic caffeine treatment after injury, but not caffeine withdrawal, impairs recovery of motor function. Conclusions: Preexposure of the injured brain to caffeine does not have a major impact on acute and delayed outcome parameters; more importantly, a single acute dose of caffeine after the injury can prevent lethal apnea regardless of chronic caffeine preexposure.

Tactical Neurocritical Care

Neurocritical care is usually practiced in the comfort of an intensive care unit within a tertiary care medical center. Physicians deployed to the frontline with the US military or allied military are required to use their critical care skills and their neurocritical skills in austere environments with limited resources. Due to these factors, tactical critical care and tactical neurocritical care differ significantly from traditional critical care. Operational constraints, the tactical environment, and resource availability dictate that tactical neurocritical care be practiced within a well-defined, mission-constrained framework. Although limited interventions can be performed in austere conditions, they can significantly impact patient outcome. This review focuses on the US Army approach to the patient requiring tactical neurocritical care specifically point of injury care and care during transportation to a higher level of care.

Management of moderate and severe traumatic brain injury

Traumatic brain injury (TBI) is a common disorder with high morbidity and mortality, accounting for one in every three deaths due to injury. Older adults are especially vulnerable. They have the highest rates of TBI-related hospitalization and death. There are about 2.5 to 6.5 million US citizens living with TBI-related disabilities. The cost of care is very high. Aside from prevention, little can be done for the initial primary injury of neurotrauma. The tissue damage incurred directly from the inciting event, for example, a blow to the head or bullet penetration, is largely complete by the time medical care can be instituted. However, this event will give rise to secondary injury, which consists of a cascade of changes on a cellular and molecular level, including cellular swelling, loss of membrane gradients, influx of immune and inflammatory mediators, excitotoxic transmitter release, and changes in calcium dynamics. Clinicians can intercede with interventions to improve outcome in the mitigating secondary injury. The fundamental concepts in critical care management of moderate and severe TBI focus on alleviating intracranial pressure and avoiding hypotension and hypoxia. In addition to these important considerations, mechanical ventilation, appropriate transfusion of blood products, management of paroxysmal sympathetic hyperactivity, using nutrition as a therapy, and, of course, venous thromboembolism and seizure prevention are all essential in the management of moderate to severe TBI patients. These concepts will be reviewed using the recent 2016 Brain Trauma Foundation Guidelines to discuss best practices and identify future research priorities.

Neurologic injuries following road traffic accidents in the Dominican Republic: Examining causes and potential solutions

Objective: Road traffic accidents (RTAs) are the number one cause of traumatic brain injuries (TBIs) worldwide. This study examines RTA-related TBIs in the Dominican Republic, a country in the Caribbean with the highest RTA fatality rate in the Western Hemisphere. Methods: We interviewed 117 adult patients or medical guardians of patients admitted to Hospital Traumatológico Dr. Ney Arias Lora in Santo Domingo following an RTA. Information regarding the type of accident, patient demographics, and injuries sustained was collected for each patient. Results: Most study participants were males (79.5%), and the most common method of transportation was motorized 2-wheeled vehicle (MTW; 74.4%). Of the 69 patients who suffered a TBI, 66.7% were classified as moderate-severe TBIs and 30.3% were classified as mild TBIs. The most common types of intracranial hemorrhage were subdural hemorrhage (12%) and subarachnoid hemorrhage (9.4%). Helmet use among admitted MTW riders was reported at 22.4%, and none of the 9 MTW riders who died in the hospital were wearing a helmet. Only 58.1% of patients lived in an area that offered 911 emergency response services at the time of the study. At 66.2%, the majority of people living within the 911 service area utilized emergency response services following an RTA. Multiple logistic regression determined that the utilization of 911 emergency response services was associated with a decrease in the likelihood of presenting with a moderate/severe TBI by a factor of 0.78 (adjusted odds ratio [OR]; P < .008; 95% confidence interval [CI], 0.65, 0.93). Nonuse of a helmet was associated with a 1.22 times increased risk of presenting with a moderate/severe TBI (adjusted OR; P < .04; 95% CI, 1.01, 1.61). Age and gender were not statistically significant in this model. Conclusions: The results of this study support 2 important avenues for reducing the burden of RTA-associated neurologic disease in the Dominican Republic. As with many other middle-income countries, MTWs represent an economical and efficient mode of transportation. Therefore, increasing helmet use may be the most effective way to reduce RTA-associated TBIs. In addition, continuing the expansion of postcrash emergency response services may mitigate the severity of RTA-associated neurologic disease.

Injury-to-Admission Delay Beyond 4 Hours Is Associated with Worsening Outcomes for Traumatic Brain Injury in Cambodia

BACKGROUND

In Cambodia, the most common victims of traumatic brain injury (TBI) are men 20-30 years of age involved in motor vehicle collision. Secondary injury sustained by these patients occurs during the time period between initial insult and hospital admission. Strengthening prehospital systems for TBI in low- and middle-income countries (LMICs) such as Cambodia is therefore a key element of the development agenda for universal health equity. We report a retrospective analysis of the relationship between prehospital delays and TBI outcomes among patients from a large government hospital in Cambodia.

METHODS

Data were collected from 3476 patients with TBI admitted to a major government hospital in Phnom Penh, Cambodia, from June 2013 to June 2018. Patients with missing data or those admitted >8 hours postinjury were excluded. Statistical analyses examined associations between injury-to-admission delay (IAD) and outcomes such as Glasgow Outcome Scale (GOS) score and length of stay (LOS).

RESULTS

A total of 2125 patients with TBI (76.85% men) were included. The median age was 27 years (interquartile range, 22-37 years). Injury severity at presentation included 1406 mild (66%), 464 moderate (22%), and 240 severe cases (11%). No Glasgow Coma Scale (GCS) data were available for 15 patients (1%). We found an inverse relationship between IAD and GOS score, most evidently for mild and moderate TBI (n = 1870; 88%). Regression analysis revealed a marked decrease in GOS score at the IAD >4-hour threshold. Each 30-minute delay in IAD was correlated with >2-hour increase in LOS for mild (P < 0.001) and moderate TBI (P < 0.001).

CONCLUSIONS

In a retrospective cohort of >2000 patients with TBI from Cambodia, we found that increasing IAD was associated with worsening outcome, especially beyond the 4-hour threshold. These data should inform development of prehospital guidelines for TBI care in LMICs.

Prehospital Factors Associated with Discharge Outcomes: Baseline Data from the Andhra Pradesh Traumatic Brain Injury Project

Objective

Strategies to improve traumatic brain injury (TBI) outcomes in India are ill defined. The objective of this study was to examine baseline prehospital (PH) factors associated with outcomes from the Andhra Pradesh Traumatic Brain Injury Project.

Methods

We conducted a prospective observational cohort study of adult patients with TBI admitted to the primary referral hospital. Modes of injury, prehospital care and transport, and factors associated with increased in-hospital mortality were evaluated. Poisson regression with robust error variance and adjusted attributable risk percent estimates determined factors associated with outcomes.

Results

A total of 447 adults (38% with mild TBI, 30% with moderate TBI, and 32% with severe TBI; 81% men) with isolated TBI (89%) from road traffic accidents (48.1%) or falls (46.5%) were enrolled. Of the patients, 45.7% were transported by ambulance, 61% had scalp/facial bleeding, 11% had respiratory distress, and 7% had cervical spine stabilization. Of these, 25.3% died and 34% had unfavorable outcomes. Among 335 direct admits, 45% traveled more than 50 km and nearly 20% traveled more than 100 km. Bleeding was associated with higher mortality (adjusted relative risk [aRR], 1.56; 95% confidence interval [CI], 1.05–2.31) and unfavorable outcome (aRR, 1.60; 95% CI, 1.18–2.17). Of the patients, 45 (31%) with severe TBI received PH airway management prior to definitive treatment, and respiratory distress was associated with unfavorable discharge outcomes (aRR, 1.23; 95% CI, 1.00–1.51).

Conclusions

Patients with TBI often received treatment far away from injury, bypassing closer hospitals. Scalp/facial bleeding was common and associated with unfavorable outcomes. Ambulance use was infrequent, and few patients received PH airway management, hemorrhage control, or cervical spine stabilization when needed.

Prevalence of a definitive airway in patients with severe traumatic brain injury received at four urban public university hospitals in India: a cohort study

AIM

To estimate the proportion of patients arriving with a Glasgow Coma Scale (GCS) less than 9 who had a definitive airway placed prior to arrival.

METHODS

We conducted a retrospective analysis of the data from a multicentre, prospective observational research project entitled Towards Improved Trauma Care Outcomes in India. Adults aged ≥18 years with an isolated traumatic brain injury (TBI) who were transferred from another hospital to the emergency department of the participating hospital with a GCS less than 9 were included. Our outcome was a definitive airway, defined as either intubation or surgical airway, placed prior to arrival at a participating centre.

RESULTS

The total number of patients eligible for this study was 1499. The median age was 40 years and 84% were male. Road traffic injuries and falls comprised 88% of the causes of isolated TBI. The number of patients with GCS<9 who had a definitive airway placed before reaching the participating centres was 229. Thus, the proportion was 0.15 (95% CI 0.13 to 0.17). The proportions of patients with a definitive airway who arrived after 24 hours (19%) were approximately double the proportion of patients who arrived within 6 hours (10%) after injury to the definitive care centre.

CONCLUSION

The rates of definitive airway placement are poor in adults with an isolated TBI who have been transferred from another health facility to tertiary care centres in India.

Prehospital Assessment of Trauma

The organization of prehospital care for trauma patients began in the military arena. At the urging of multiple stakeholders and providers, these lessons were applied to the civilian setting and emergency medical services were created across the nation. Advances have taken place in the triage, transport, and management of severely injured patients. Many issues remain in the care of trauma patients in the prehospital environment. Collaboration between stakeholders and providers, regionalization of trauma care, and protocol-driven care may be solutions to some of these issues. Further research is necessary to dictate standard of care in this early phase after injury.

Traumatic brain injury: physiological targets for clinical practice in the prehospital setting and on the Neuro-ICU

PURPOSE OF REVIEW

Over many years, understanding of the pathophysiology in traumatic brain injury (TBI) has resulted in the development of core physiological targets and therapies to preserve cerebral oxygenation, and in doing so prevent secondary insult. The present review revisits the evidence for these targets and therapies.

RECENT FINDINGS

Achieving oxygen, carbon dioxide, blood pressure, temperature and glucose targets remain a key goal of therapy in TBI, as does the role of effective prehospital care. Physician led air ambulance teams reduce mortality. Normobaric hyperoxia is dangerous to the injured brain; as are both high and low carbon dioxide levels. Hypotension is life threatening and higher targets have now been suggested in TBI. Both therapeutic normothermia and hypothermia have a role in specific groups of patients with TBI. Although consensus has not been reached on the optimal intravenous fluid for resuscitation in TBI, vigilant goal-directed fluid administration may improve outcome. Osmotherapeutic agents such as hypertonic sodium lactate solutions may also have a role alongside conventional agents.

SUMMARY

Maintaining physiological targets in several areas remains part of protocol led care in the acute phase of TBI management. As evidence accumulates however, the target values and therefore therapies may be set to change.

Real-Time Detection and Monitoring of Acute Brain Injury Utilizing Evoked Electroencephalographic Potentials

Rapid detection and diagnosis of a traumatic brain injury (TBI) can significantly improve the prognosis for recovery. Helmet-mounted sensors that detect impact severity based on measurements of acceleration or pressure show promise for aiding triage and transport decisions in active, field environments such as professional sports or military combat. The detected signals, however, report on the mechanics of an impact rather than directly indicating the presence and severity of an injury. We explored the use of cortical somatosensory evoked electroencephalographic potentials (SSEPs) to detect and track, in real-time, neural electrophysiological abnormalities within the first hour following head injury in an animal model. To study the immediate electrophysiological effects of injury in vivo, we developed an experimental paradigm involving focused ultrasound that permits continuous, real-time measurements and minimizes mechanical artifact. Injury was associated with a dramatic reduction of amplitude over the damaged hemisphere directly after the injury. The amplitude systematically improved over time but remained significantly decreased at one hour, compared with baseline. In contrast, at one hour there was a concomitant enhancement of the cortical SSEP amplitude evoked from the uninjured hemisphere. Analysis of the inter-trial electroencephalogram (EEG) also revealed significant changes in low-frequency components and an increase in EEG entropy up to 30 minutes after injury, likely reflecting altered EEG reactivity to somatosensory stimuli. Injury-induced alterations in SSEPs were also observed using noninvasive epidermal electrodes, demonstrating viability of practical implementation. These results suggest cortical SSEPs recorded at just a few locations by head-mounted sensors and associated multiparametric analyses could potentially be used to rapidly detect and monitor brain injury in settings that normally present significant levels of mechanical and electrical noise.

Factors correlating with delayed trauma center admission following traumatic brain injury

BACKGROUND

Delayed admission to appropriate care has been shown increase mortality following traumatic brain injury (TBI). We investigated factors associated with delayed admission to a hospital with neurosurgical expertise in a cohort of TBI patients in the intensive care unit (ICU).

METHODS

A retrospective analysis of all TBI patients treated in the ICUs of Helsinki University Central Hospital was carried out from 1.1.2009 to 31.12.2010. Patients were categorized into two groups: direct admission and delayed admission. Patients in the delayed admission group were initially transported to a local hospital without neurosurgical expertise before inter-transfer to the designated hospital. Multivariate logistic regression was utilized to identify pre-hospital factors associated with delayed admission.

RESULTS

Of 431 included patients 65% of patients were in the direct admission groups and 35% in the delayed admission groups (median time to admission 1:07h, IQR 0:52-1:28 vs. 4:06h, IQR 2:53-5:43, p <0.001). In multivariate analysis factors increasing the likelihood of delayed admission were (OR, 95% CI): male gender (3.82, 1.60-9.13), incident at public place compared to home (0.26, 0.11-0.61), high energy trauma (0.05, 0.01-0.28), pre-hospital physician consultation (0.15, 0.06-0.39) or presence (0.08, 0.03-0.22), hypotension (0.09, 0.01-0.93), major extra cranial injury (0.17, 0.05-0.55), abnormal pupillary light reflex (0.26, 0.09-0.73) and severe alcohol intoxication (12.44, 2.14-72.38). A significant larger proportion of patients in the delayed admission group required acute craniotomy for mass lesion when admitted to the neurosurgical hospital (57%, 21%, p< 0.001). No significant difference in 6-month mortality was noted between the groups (p= 0.814).

CONCLUSION

Delayed trauma center admission following TBI is common. Factors increasing likelihood of this were: male gender, incident at public place compared to home, low energy trauma, absence of pre-hospital physician involvement, stable blood pressure, no major extra cranial injuries, normal pupillary light reflex and severe alcohol intoxication. Focused educational efforts and access to physician consultation may help expedite access to appropriate care in TBI patients.

A review of traumatic brain injury trauma center visits meeting physiologic criteria from The American College of Surgeons Committee on Trauma/Centers for Disease Control and Prevention Field Triage Guidelines

BACKGROUND

Traumatic brain injury (TBI) represents a serious subset of injuries among persons in the United States, and prehospital care of these injuries can mitigate both the morbidity and the mortality in patients who suffer from these injuries. Guidelines for triage of injured patients have been set forth by the American College of Surgeons Committee on Trauma (ACS-COT) in cooperation with the Centers for Disease Control and Prevention (CDC). These guidelines include physiologic criteria, such as the Glasgow Coma Scale (GCS) score, systolic blood pressure, and respiratory rate, which should be used in determining triage of an injured patient.

OBJECTIVES

This study examined the numbers of visits at level I and II trauma centers by patients with a diagnosed TBI to determine the prevalence of those meeting physiologic criteria from the ACS-COT/CDC guidelines and to determine the extent of mortality among this patient population.

METHODS

The data for this study were taken from the 2007 National Trauma Data Bank (NTDB) National Sample Program (NSP). This data set is a nationally representative sample of visits to level I and II trauma centers across the United States and is funded by the American College of Surgeons. Estimates of demographic characteristics, physiologic measures, and death were made for this study population using both chi-square analyses and adjusted logistic regression modeling.

RESULTS

The analyses demonstrated that although many people who sustain a TBI and were taken to a level I or II trauma center did not meet the physiologic criteria, those who did meet the physiologic criteria had significantly higher odds of death than those who did not meet the criteria. After controlling for age, gender, race, Injury Severity Score (ISS), and length of stay in the hospital, persons who had a GCS score ≤13 were 17 times more likely to die than TBI patients who had a higher GCS score (odds ratio [OR] 17.4; 95% confidence interval [CI] 10.7-28.3). Other physiologic criteria also demonstrated significant odds of death.

CONCLUSIONS

These findings support the validity of the ACS-COT/CDC physiologic criteria in this population and stress the importance of prehospital triage of patients with TBI in the hopes of reducing both the morbidity and the mortality resulting from this injury.

In vivo monitoring of neuronal loss in traumatic brain injury: a microdialysis study

Traumatic brain injury causes diffuse axonal injury and loss of cortical neurons. These features are well recognized histologically, but their in vivo monitoring remains challenging. In vivo cortical microdialysis samples the extracellular fluid adjacent to neurons and axons. Here, we describe a novel neuronal proteolytic pathway and demonstrate the exclusive neuro-axonal expression of Pavlov’s enterokinase. Enterokinase is membrane bound and cleaves the neurofilament heavy chain at positions 476 and 986. Using a 100 kDa microdialysis cut-off membrane the two proteolytic breakdown products, extracellular fluid neurofilament heavy chains NfH_476−986 and NfH_476−1026, can be quantified with a relative recovery of 20%. In a prospective clinical in vivo study, we included 10 patients with traumatic brain injury with a median Glasgow Coma Score of 9, providing 640 cortical extracellular fluid samples for longitudinal data analysis. Following high-velocity impact traumatic brain injury, microdialysate extracellular fluid neurofilament heavy chain levels were significantly higher (6.18 ± 2.94 ng/ml) and detectable for longer (>4 days) compared with traumatic brain injury secondary to falls (0.84 ± 1.77 ng/ml, <2 days). During the initial 16 h following traumatic brain injury, strong correlations were found between extracellular fluid neurofilament heavy chain levels and physiological parameters (systemic blood pressure, anaerobic cerebral metabolism, excessive brain tissue oxygenation, elevated brain temperature). Finally, extracellular fluid neurofilament heavy chain levels were of prognostic value, predicting mortality with an odds ratio of 7.68 (confidence interval 2.15–27.46, P = 0.001). In conclusion, this study describes the discovery of Pavlov’s enterokinase in the human brain, a novel neuronal proteolytic pathway that gives rise to specific protein biomarkers (NfH_476−986 and Nf_H476−1026) applicable to in vivo monitoring of diffuse axonal injury and neuronal loss in traumatic brain injury.

Head trauma

Worldwide, an estimated 10 million people are affected annually by traumatic brain injury (TBI). More than 5 million Americans currently live with long-term disability as a result of TBI and more than 1.5 million individuals sustain a new TBI each year. It has been predicted that TBI will become the third leading cause of death and disability in the world by the year 2020. This article outlines the classification of TBI, details the types of lesions encountered, and discusses the various imaging modalities available for the evaluation of TBI.

Lymphocytic choriomeningitis virus-induced mortality in mice is triggered by edema and brain herniation

Although much is known about lymphocytic choriomeningitis virus (LCMV) infection and the subsequent immune response in its natural murine host, some crucial aspects of LCMV-mediated pathogenesis remain undefined, including the underlying basis of the characteristic central nervous system disease that occurs following intracerebral (i.c.) challenge. We show that the classic seizures and paresis that occur following i.c. infection of adult, immunocompetent mice with LCMV are accompanied by anatomical and histological changes that are consistent with brain herniation, likely of the uncal subtype, as a causative basis for disease and precipitous death. Both by water weight determinations and by magnetic resonance imaging of infected brain tissues, edema was detected only at the terminal stages of disease, likely caused by the leakage of cerebrospinal fluid from the ventricles into the parenchyma. Furthermore, death was accompanied by unilateral pupillary dilation, which is indicative of uncal herniation. While immunohistochemical analysis revealed periventricular inflammation and a loss of integrity of the blood-brain barrier (BBB), these events preceded seizures by 2 to 3 days. Moreover, surviving perforin knockout mice showed barrier permeability equivalent to that of moribund, immunocompetent mice; thus, BBB damage does not appear to be the basis of LCMV-induced neuropathogenesis. Importantly, brain herniation can occur in humans as a consequence of injuries that would be predicted to increase intracranial pressure, including inflammation, head trauma, and brain tumors. Thus, a mechanistic dissection of the basis of LCMV neuropathogenesis may be informative for the development of interventive therapies to prevent this typically fatal human condition.