Survival Rates and Biomarkers in a Large Animal Model of Traumatic Brain Injury Combined With Two Different Levels of Blood Loss

INTRODUCTION

The pathology resulting from concurrent traumatic brain injury (TBI) and hemorrhagic shock (HS; TBI+HS) are leading causes of mortality and morbidity worldwide following trauma. However, the majority of large animal models of TBI+HS have utilized focal/contusional injuries rather than incorporating the types of brain trauma (closed-head injury caused by dynamic acceleration) that typify human injury.

OBJECTIVE

To examine survival rates and effects on biomarkers from rotational TBI with two levels of HS.

METHODS

Twenty-two sexually mature Yucatan swine (30.39 ± 2.25 kg; 11 females) therefore underwent either Sham trauma procedures (n = 6) or a dynamic acceleration TBI combined with either 55% (n = 8) or 40% (n = 8) blood loss in this serial study.

RESULTS

Survival rates were significantly higher for the TBI+40% (87.5%) relative to TBI+55% (12.5%) cohort, with the majority of TBI+55% animals expiring within 2 h post-trauma from apnea. Blood-based neural biomarkers and immunohistochemistry indicated evidence of diffuse axonal injury (increased NFL/Aβ42), blood-brain barrier breach (increased immunoglobulin G) and inflammation (increased glial fibrillary acidic protein/ionized calcium-binding adaptor molecule 1) in the injured cohorts relative to Shams. Invasive hemodynamic measurements indicated increased shock index and decreased pulse pressure in both injury cohorts, with evidence of partial recovery for invasive hemodynamic measurements in the TBI+40% cohort. Similarly, although both injury groups demonstrated ionic and blood gas abnormalities immediately postinjury, metabolic acidosis continued to increase in the TBI+55% group ∼85 min postinjury. Somewhat surprisingly, both neural and physiological biomarkers showed significant changes within the Sham cohort across the multi-hour experimental procedure, most likely associated with prolonged anesthesia.

CONCLUSION

Current results suggest the TBI+55% model may be more appropriate for severe trauma requiring immediate medical attention/standard fluid resuscitation protocols whereas the TBI+40% model may be useful for studies of prolonged field care.

Computer-Assisted Measurement of Traumatic Brain Hemorrhage Volume Is More Predictive of Functional Outcome and Mortality than Standard ABC/2 Method: An Analysis of Computed Tomography Imaging Data from the Progesterone for Traumatic Brain Injury Experimental Clinical Treatment Phase-III Trial

Hemorrhage volume is an important variable in emergently assessing traumatic brain injury (TBI). The most widely used method for rapid volume estimation is ABC/2, a simple algorithm that approximates lesion geometry as perfectly ellipsoid. The relative prognostic value of volume measurement based on more precise hematoma topology remains unknown. In this study, we compare volume measurements obtained using ABC/2 versus computer-assisted volumetry (CAV) for both intra- and extra-axial traumatic hemorrhages, and then quantify the association of measurements using both methods with patient outcome following moderate to severe TBI. A total of 517 computer tomography (CT) scans acquired during the Progesterone for Traumatic Brain Injury Experimental Clinical Treatment Phase-III (ProTECTIII) multi-center trial were retrospectively reviewed. Lesion volumes were measured using ABC/2 and CAV. Agreement between methods was tested using Bland-Altman analysis. Relationship of volume measurements with 6-month mortality, Extended Glasgow Outcome Scale (GOS-E), and Disability Rating Scale (DRS) were assessed using linear regression and area under the curve (AUC) analysis. In subdural hematoma (SDH) >50cm3, ABC/2 and CAV produce significantly different volume measurements (p < 0.0001), although the difference was not significant for smaller SDH or intra-axial lesions. The disparity between ABC/2 and CAV measurements varied significantly with hematoma size for both intra- and extra-axial lesions (p < 0.0001). Across all lesions, volume was significantly associated with outcome using either method (p < 0.001), but CAV measurement was a significantly better predictor of outcome than ABC/2 estimation for SDH. Among large traumatic SDH, ABC/2 significantly overestimates lesion volume compared with measurement based on precise bleed topology. CAV also offers significantly better prediction of patient functional outcofme and mortality.

Early CT in dogs following traumatic brain injury has limited value in predicting short-term prognosis

Traumatic brain injury is associated with a high risk of mortality in veterinary patients, however publications describing valid prognostic indicators are currently lacking. The objective of this retrospective observational study was to determine whether early CT findings are associated with short-term prognosis following traumatic brain injury (TBI) in dogs. An electronic database was searched for dogs with TBI that underwent CT within 72 h of injury; 40 dogs met the inclusion criteria. CT findings were graded based on a Modified Advanced Imaging System (MAIS) from grade I (normal brain parenchyma) to VI (bilateral lesions affecting the brainstem with or without any foregoing lesions of lesser grades). Other imaging features recorded included presence of midline shift, intracranial hemorrhage, brain herniation, skull fractures, and percentage of total brain parenchyma affected. Outcome measures included survival to discharge and occurrence of immediate onset posttraumatic seizures. Thirty dogs (75%) survived to discharge. Seven dogs (17.5%) suffered posttraumatic seizures. There was no association between survival to discharge and posttraumatic seizures. No imaging features evaluated were associated with the study outcome measures. Therefore, the current study failed to identify any early CT imaging features with prognostic significance in canine TBI patients. Limitations associated with CT may preclude its use for prognostication; however, modifications to the current MAIS and evaluation in a larger study population may yield more useful results. Despite this, CT is a valuable tool in the detection of structural abnormalities following TBI in dogs that warrants further investigation.

Cross-sectional study of major procedure codes among hospitalized patients with traumatic brain injury by level of injury severity in the 2004 to 2014 Nationwide Inpatient Sample

Despite its public health significance, TBI management across US healthcare institutions and patient characteristics with an emphasis on utilization and outcomes of TBI-specific procedures have not been evaluated at the national level.We aimed to characterize top 10 procedure codes among hospitalized adults with TBI as primary diagnosis by injury severity.A Cross-sectional study was conducted using 546, 548 hospitalization records from the 2004 to 2014 Nationwide Inpatient Sample were analyzed.Data elements of interest included injury, patient, hospital characteristics, procedures, in-hospital death and length of stay.Ten top procedure codes were "Closure of skin and subcutaneous tissue of other sites", "Insertion of endotracheal tube", "Continuous invasive mechanical ventilation for less than 96 consecutive hours", "Venous catheterization (not elsewhere classified)", "Continuous invasive mechanical ventilation for 96 consecutive hours or more", "Transfusion of packed cells", "Incision of cerebral meninges", "Serum transfusion (not elsewhere classified)", "Temporary tracheostomy", and "Arterial catherization". Prevalence rates ranged between 3.1% and 15.5%, with variations according to injury severity and over time. Whereas "Closure of skin and subcutaneous tissue of other sites" was associated with fewer in-hospital deaths and shorter hospitalizations, "Temporary tracheostomy" was associated with fewer in-hospital deaths among moderate-to-severe TBI patients, and "Continuous invasive mechanical ventilation for less than 96 consecutive hours" was associated with shorter hospitalizations among severe TBI patients. Other procedures were associated with worse outcomes.Nationwide, the most frequently reported hospitalization procedure codes among TBI patients aimed at homeostatic stabilization and differed in prevalence, trends, and outcomes according to injury severity.

Prognostic value of variables derived from heart rate variability in patients with traumatic brain injury after decompressive surgery

Measurement of heart rate variability can reveal autonomic nervous system function. Changes in heart rate variability can be associated with disease severity, risk of complications, and prognosis. We aimed to investigate the prognostic value of heart rate variability measurements in patients with moderate-to-severe traumatic brain injury after decompression surgery. We conducted a prospective study of 80 patients with traumatic brain injury after decompression surgery using a noninvasive electrocardiography device for data collection. Assessment of heart rate variability parameters included the time and frequency domains. The correlations between heart rate variability parameters and one-year mortality and functional outcomes were analyzed. Time domain measures of heart rate variability, using the standard deviation of the RR intervals and the square root of the mean squared differences of successive RR intervals, were statistically significantly lower in the group of patients with unfavorable outcomes and those that died. In frequency domain analysis, very low-frequency and total power were significantly higher in patients with favorable functional outcomes. High-frequency, low-frequency, and total power were statistically significantly higher in patients who survived for more than one year. Multivariate analysis using a model combining age and the Glasgow Coma Scale score with variables derived from heart rate variability substantially improved the prognostic value for predicting long-term outcome. These findings reinforced the concept that traumatic brain injury impacts the brain-heart axis and cardiac autonomic modulation even after decompression surgery, and variables derived from heart rate variability may be useful predictors of outcome.

Effect of Implementing the Out-of-Hospital Traumatic Brain Injury Treatment Guidelines: The Excellence in Prehospital Injury Care for Children Study (EPIC4Kids)

STUDY OBJECTIVE

We evaluate the effect of implementing the out-of-hospital pediatric traumatic brain injury guidelines on outcomes in children with major traumatic brain injury.

METHODS

The Excellence in Prehospital Injury Care for Children study is the preplanned secondary analysis of the Excellence in Prehospital Injury Care study, a multisystem, intention-to-treat study using a before-after controlled design. This subanalysis included children younger than 18 years who were transported to Level I trauma centers by participating out-of-hospital agencies between January 1, 2007, and June 30, 2015, throughout Arizona. The primary and secondary outcomes were survival to hospital discharge or admission for children with major traumatic brain injury and in 3 subgroups, defined a priori as those with moderate, severe, and critical traumatic brain injury. Outcomes in the preimplementation and postimplementation cohorts were compared with logistic regression, adjusting for risk factors and confounders.

RESULTS

There were 2,801 subjects, 2,041 in preimplementation and 760 in postimplementation. The primary analysis (postimplementation versus preimplementation) yielded an adjusted odds ratio of 1.16 (95% confidence interval 0.70 to 1.92) for survival to hospital discharge and 2.41 (95% confidence interval 1.17 to 5.21) for survival to hospital admission. In the severe traumatic brain injury cohort (Regional Severity Score-Head 3 or 4), but not the moderate or critical subgroups, survival to discharge significantly improved after guideline implementation (adjusted odds ratio = 8.42; 95% confidence interval 1.01 to 100+). The improvement in survival to discharge among patients with severe traumatic brain injury who received positive-pressure ventilation did not reach significance (adjusted odds ratio = 9.13; 95% confidence interval 0.79 to 100+).

CONCLUSION

Implementation of the pediatric out-of-hospital traumatic brain injury guidelines was not associated with improved survival when the entire spectrum of severity was analyzed as a whole (moderate, severe, and critical). However, both adjusted survival to hospital admission and discharge improved in children with severe traumatic brain injury, indicating a potential severity-based interventional opportunity for guideline effectiveness. These findings support the widespread implementation of the out-of-hospital pediatric traumatic brain injury guidelines.

Antiplatelet and anticoagulant agents have minimal impact on traumatic brain injury incidence, surgery, and mortality in geriatric ground level falls: A multi-institutional analysis of 33,710 patients

BACKGROUND

Falls are the leading cause of traumatic brain injury (TBI) and TBI-related deaths for older persons (age, ≥65 years). Antiplatelet and/or anticoagulant therapy (antithrombotics [ATs]) is generally felt to increase this risk, but the literature is inconsistent. The purpose of this study was to determine the impact of AT use on the rate, severity, and outcomes of TBI in older patients following ground level falls.

METHODS

Ground level fall patients from 90 hospitals' trauma registries were selected. Patients were excluded if younger than 65 years or had an Abbreviated Injury Scale score of >2 in a region other than head. Electronic medical record data for preinjury AT therapy were obtained. Patients were grouped by regimen for no AT, single, or multiple agents. Groups were compared on rates of diagnosed TBI, TBI surgery, and mortality.

RESULTS

There were 33,710 patients (35% male; mean age, 80.5 years; mean Glasgow Coma Scale, 14.6), with 47.6% on single or combination AT therapy. The proportion of patients with TBI diagnoses did not differ between those on no AT (21.25%) versus AT (21.61%; p = 0.418). Apixaban (15.7%; p < 0.001) and rivaroxaban (13.19%; p = 0.011) were associated with lower rates of TBI, and acetylsalicylic acid-clopidogrel was associated with a higher TBI rate (24.34%; p = 0.002) versus no AT. acetylsalicylic acid-clopidogrel was associated with a higher cranial surgery rate (2.9%; p = 0.006) versus no AT (1.96%), but surgery rates were similar for all other regimens. No regimen was associated with higher mortality.

CONCLUSION

In this large multicenter study, the intake of ATs in older patients with ground level falls was associated with inconsistent effects on risk of TBI and no significant increases in mortality, indicating that AT use may have negligible impact on patient clinical management. A large, confirmatory, prospective study is needed because the commonly held belief that ATs uniformly increase the risk of traumatic intracranial bleeding and mortality is not supported.

LEVEL OF EVIDENCE

Therapeutic/care management, level II.

Random Forest-Based Prediction of Outcome and Mortality in Patients with Traumatic Brain Injury Undergoing Primary Decompressive Craniectomy

BACKGROUND

Various prognostic models are used to predict mortality and functional outcome in patients after traumatic brain injury with a trend to incorporate machine learning protocols. None of these models is focused exactly on the subgroup of patients indicated for decompressive craniectomy. Evidence regarding efficiency of this surgery is still incomplete, especially in patients undergoing primary decompressive craniectomy with evacuation of traumatic mass lesions.

METHODS

In a prospective study with a 6-month follow-up period, we assessed postoperative outcome and mortality of 40 patients who underwent primary decompressive craniectomy for traumatic brain injuries during 2018-2019. The results were analyzed in relation to a wide spectrum of preoperatively available demographic, clinical, radiographic, and laboratory data. Random forest algorithms were trained for prediction of both mortality and unfavorable outcome, with their accuracy quantified by area under the receiver operating curves (AUCs) for out-of-bag samples.

RESULTS

At the end of the follow-up period, we observed mortality of 57.5%. Favorable outcome (Glasgow Outcome Scale [GOS] score 4-5) was achieved by 30% of our patients. Random forest-based prediction models constructed for 6-month mortality and outcome reached a moderate predictive ability, with AUC = 0.811 and AUC = 0.873, respectively. Random forest models trained on handpicked variables showed slightly decreased AUC = 0.787 for 6-month mortality and AUC = 0.846 for 6-month outcome and increased out-of-bag error rates.

CONCLUSIONS

Random forest algorithms show promising results in prediction of postoperative outcome and mortality in patients undergoing primary decompressive craniectomy. The best performance was achieved by Classification Random forest for 6-month outcome.

Prognostic significance of preinjury anticoagulation in patients with traumatic brain injury: A systematic review and meta-analysis

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of injury-related deaths and neurological disability globally. Considering the widespread anticoagulant use among the aging population, we aimed to perform a systematic review and meta-analysis to evaluate the prognostic significance of preinjury anticoagulation in TBI patients.

METHODS

This systematic review was conducted according to a predefined protocol (International Prospective Register of Systematic Reviews CRD42020192323). In compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-Analysis of Observational Studies in Epidemiology standards, a structured electronic database search was undertaken to identify all observational studies comparing preinjury anticoagulation with no preinjury anticoagulation in TBI patients. The primary outcome measure was overall mortality. The secondary outcome measures comprised in-hospital mortality, length of hospital stay, length of intensive care unit stay, need for neurosurgical procedure, and number of patients discharged home. All outcome data were analyzed using random effects modeling.

RESULTS

Twelve comparative studies enrolling a total of 4,417 patients were included. Preinjury anticoagulation was associated with higher risk of overall mortality (odds ratio [OR], 2.39; 95% confidence interval [CI], 1.63-3.50, p < 0.00001), in-hospital mortality (OR, 2.47; 95% CI, 1.56-3.93, p = 0.0001), and longer length of intensive care unit stay (mean difference, 1.06; 95% CI, 0.54-1.57; p < 0.0001) compared with no preinjury anticoagulation. No statistical difference was observed in length of hospital stay (mean difference, -2.15; 95% CI, -5.36 to 1.05, p = 0.19), need for neurosurgical procedure (OR, 1.30; 95% CI, 0.70-2.44; p = 0.41), and discharged home (OR, 0.76; 95% CI, 0.55-1.04; p = 0.09) between the two groups.

CONCLUSION

Preinjury anticoagulation is a powerful prognosticator of mortality in TBI patients. This highlights the need for dedicated triage and trauma team activation protocols considering earlier intervention and more aggressive imaging in all anticoagulated patients. Future studies should focus on strategies that can potentially reduce the risk of mortality in this population. The prognostic significance of direct oral anticoagulants versus warfarin remains unanswered.

LEVEL OF EVIDENCE

Systematic review and meta-analysis of observational studies, level III.

Intensive care of traumatic brain injury and aneurysmal subarachnoid hemorrhage in Helsinki during the Covid-19 pandemic

Background

To ensure adequate intensive care unit (ICU) capacity for SARS-CoV-2 patients, elective neurosurgery and neurosurgical ICU capacity were reduced. Further, the Finnish government enforced strict restrictions to reduce the spread. Our objective was to assess changes in ICU admissions and prognosis of traumatic brain injury (TBI) and aneurysmal subarachnoid hemorrhage (SAH) during the Covid-19 pandemic.

Methods

Retrospective review of all consecutive patients with TBI and aneurysmal SAH admitted to the neurosurgical ICU in Helsinki from January to May of 2019 and the same months of 2020. The pre-pandemic time was defined as weeks 1–11, and the pandemic time was defined as weeks 12–22. The number of admissions and standardized mortality rates (SMRs) were compared to assess the effect of the Covid-19 pandemic on these. Standardized mortality rates were adjusted for case mix.

Results

Two hundred twenty-four patients were included (TBI n = 123, SAH n = 101). There were no notable differences in case mix between TBI and SAH patients admitted during the Covid-19 pandemic compared with before the pandemic. No notable difference in TBI or SAH ICU admissions during the pandemic was noted in comparison with early 2020 or 2019. SMRs were no higher during the pandemic than before.

Conclusion

In the area of Helsinki, Finland, there were no changes in the number of ICU admissions or in prognosis of patients with TBI or SAH during the Covid-19 pandemic.

Interventions to reduce body temperature to 35 ⁰C to 37 ⁰C in adults and children with traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a major cause of death and disability, with an estimated 5.5 million people experiencing severe TBI worldwide every year. Observational clinical studies of people with TBI suggest an association between raised body temperature and unfavourable outcome, although this relationship is inconsistent. Additionally, preclinical models suggest that reducing temperature to 35 °C to 37.5 °C improves biochemical and histopathological outcomes compared to reducing temperature to a lower threshold of 33 °C to 35 °C. It is unknown whether reducing body temperature to 35 °C to 37.5 °C in people admitted to hospital with TBI is beneficial, has no effect, or causes harm. This is an update of a review last published in 2014.

OBJECTIVES

To assess the effects of pharmacological interventions or physical interventions given with the intention of reducing body temperature to 35 °C to 37.5 °C in adults and children admitted to hospital after TBI.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Web of Science, and PubMed on 28 November 2019. We searched clinical trials registers, grey literature and references lists of reviews, and we carried out forward citation searches of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with participants of any age admitted to hospital following TBI. We included interventions that aimed to reduce body temperature to 35 °C to 37.5 °C: these included pharmacological interventions (such as paracetamol, or non-steroidal anti-inflammatory drugs), or physical interventions (such as surface cooling devices, bedside fans, or cooled intravenous fluids). Eligible comparators were placebo or usual care.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We assessed the certainty of the evidence with GRADE.

MAIN RESULTS

We included one RCT with 41 participants. This study recruited adult participants admitted to two intensive care units in Australia, and evaluated a pharmacological intervention. Researchers gave participants 1 g paracetamol or a placebo intravenously at four-hourly intervals for 72 hours. We could not be certain whether intravenous paracetamol influenced mortality at 28 days (risk ratio 2.86, 95% confidence interval 0.32 to 25.24). We judged the evidence for this outcome to be very low certainty, meaning we have very little confidence in this effect estimate, and the true result may be substantially different to this effect. We downgraded the certainty for imprecision (because the evidence was from a single study with very few participants), and study limitations (because we noted a high risk of selective reporting bias). This study was otherwise at low risk of bias. The included study did not report the primary outcome for this review, which was the number of people with a poor outcome at the end of follow-up (defined as death or dependency, as measured on a scale such as the Glasgow Outcome Score), or any of our secondary outcomes, which included the number of people with further intracranial haemorrhage, extracranial haemorrhage, abnormal intracranial pressure, or pneumonia or other serious infections. The only other completed trial that we found was of a physical intervention that compared advanced fever control (using a surface cooling device) versus conventional fever control in 12 participants. The trial was published as an abstract only, with insufficient details to allow inclusion, so we have added this to the 'studies awaiting classification' section, pending further information from the study authors or publication of the full study report. We identified four ongoing studies that will contribute evidence to future updates of the review if they measure relevant outcomes and, in studies with a mixed population, report data separately for participants with TBI.

AUTHORS' CONCLUSIONS

One small study contributed very low-certainty evidence for mortality to this review. The uncertainty is largely driven by limited research into reduction of body temperature to 35 °C to 37.5 °C in people with TBI. Further research that evaluates pharmacological or physical interventions, or both, may increase certainty in this field. We propose that future updates of the review, and ongoing and future research in this field, incorporate outcomes that are important to the people receiving the interventions, including side effects of any pharmacological agent (e.g. nausea or vomiting), and discomfort caused by physical therapies.

Geographical Variation in Traumatic Brain Injury Mortality by Proximity to the Nearest Neurosurgeon

BACKGROUND

Trauma mortality disproportionately affects populations farther from potentially lifesaving trauma care, and traumatic brain injury (TBI) is no exception. Previous examinations have examined proximity to trauma centers as an explanation for trauma mortality, but little is known about the relationship between proximity to neurosurgeons specifically in TBI mortality.

MATERIALS AND METHODS

In this cross-sectional study, county-level TBI mortality rates from 2008 to 2014 were examined in relation to the distance to the nearest neurosurgeon and trauma facility. The locations of practicing neurosurgeons and trauma facilities in the United States were determined by geocoding data from the 2017 Medicare Physician and Other Supplier and Provider of Services files (respectively). The association between TBI mortality and the distance from the population-weighted centroid of the county to a closest neurosurgeon and trauma facility was examined using multivariate negative binomial regression.

RESULTS

A total of 761 of the 3108 counties (24.5%) in the continental United States were excluded from the analysis because they had 20 or fewer TBI deaths during this time, producing unstable estimates. Excluded counties accounted for 1.67% of the US population. Multivariate analysis revealed a county's mortality increased 10% for every 25 miles from the nearest neurosurgeon (adjusted incident rate ratio: 1.10 [95% confidence interval: 1.08-1.12]; P < 0.001). The distance to the nearest trauma facility was not found to be significantly associated with mortality (adjusted incident rate ratio: 1.01 [95% confidence interval: 0.99-1.03]; P = 0.36).

CONCLUSIONS

These findings suggest that proximity to neurosurgeons may influence county-level TBI mortality. Further research into this topic with more granular data may help to allocate scarce public health resources.

Association of Prehospital Plasma With Survival in Patients With Traumatic Brain Injury: A Secondary Analysis of the PAMPer Cluster Randomized Clinical Trial

IMPORTANCE

Prehospital plasma administration improves survival in injured patients at risk for hemorrhagic shock and transported by air ambulance. Traumatic brain injury (TBI) is a leading cause of death following trauma, but few early interventions improve outcomes.

OBJECTIVE

To assess the association between prehospital plasma and survival in patients with TBI.

DESIGN, SETTING, AND PARTICIPANTS

The Prehospital Air Medical Plasma (PAMPer) trial was a pragmatic, multicenter, phase 3, cluster randomized clinical trial involving injured patients who were at risk for hemorrhagic shock during air medical transport to a trauma center. The trial was conducted at 6 US sites with 9 level-I trauma centers (comprising 27 helicopter emergency services bases). The original trial analyzed 501 patients, including 230 patients who were randomized to receive plasma and 271 randomized to standard care resuscitation. This secondary analysis of a predefined subgroup included patients with TBI. Data analysis was performed from October 2019 to February 2020.

INTERVENTIONS

Patients were randomized to receive standard care fluid resuscitation or 2 units of thawed plasma.

MAIN OUTCOMES AND MEASURES

The primary outcome was mortality at 30 days. Patients with TBI were prespecified as a subgroup for secondary analysis and for measurement of markers of brain injury. The 30-day survival benefit of prehospital plasma in subgroups with and without TBI as diagnosed by computed tomography was characterized using Kaplan-Meier survival analysis and Cox proportional hazard regression.

RESULTS

In total, 166 patients had TBI (median [interquartile range] age, 43.00 [25.00-59.75] years; 125 men [75.3%]). When compared with the 92 patients who received standard care, the 74 patients with TBI who received prehospital plasma had improved 30-day survival even after adjustment for multiple confounders and assessment of the degree of brain injury with clinical variables and biomarkers (hazard ratio [HR], 0.55; 95% CI, 0.33-0.94; P = .03). Receipt of prehospital plasma was associated with improved survival among patients with TBI with a prehospital Glasgow Coma Scale score of less than 8 (HR, 0.56; 95% CI, 0.35-0.91) and those with polytrauma (HR, 0.50; 95% CI, 0.28-0.89). Patients with TBI transported from the scene of injury had improved survival following prehospital plasma administration (HR, 0.45; 95% CI, 0.26-0.80; P = .005), whereas patients who were transferred from an outside hospital showed no difference in survival for the plasma intervention (HR, 1.00; 95% CI, 0.33-3.00; P = .99).

CONCLUSIONS AND RELEVANCE

These findings are exploratory, but they suggest that receipt of prehospital plasma is associated with improved survival in patients with computed tomography-positive TBI. The prehospital setting may be a critical period to intervene in the care of patients with TBI. Future studies are needed to confirm the clinical benefits of early plasma resuscitation following TBI and concomitant polytrauma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01818427.

The Emergency Department Systolic Blood Pressure Relationship After Traumatic Brain Injury

BACKGROUND

Blood pressure alterations in patients with traumatic brain injury (TBI) have been shown to be associated with increased mortality. However, there is paucity of data describing the optimal emergency department (ED) systolic blood pressure (SBP) target during the initial evaluation. The aim of our study was to assess the association between SBP on presentation and mortality in patients with TBI.

METHODS

We performed a retrospective (2015-2016) review of the American College of Surgeons Trauma Quality Improvement Program database and included all adult (age ≥18y) trauma patients who had TBI on presentation. The outcome measure was in-hospital mortality at different ED-SBP values. A subanalysis by age and TBI severity in accordance with the Glasgow Coma Scale (GCS) was performed (mild (GCS ≥13), moderate (GCS 9-12), and severe (≤8)). Multivariate logistic regression analysis was performed.

RESULTS

A total of 94,411 adult trauma patients with TBI were included. Mean age was 59 ± 21y, 62% were male, and median GCS was 15 [14-15]. Mean SBP was 147 ± 28 mmHg, and overall mortality was 8.6%. The lowest rate of mortality was noticed at ED SBP between 110 and 149 mmHg, whereas the highest mortality was at admission SBP <90 mmHg and SBP >190 mmHg. On regression analysis, SBP between 130 and 149 mmHg (odds ratio = 0.92; P = 0.68) was not associated with increased odds of mortality relative to SBP between 110 and 129 mmHg. On subanalysis based on severity of TBI (mild 80.9%, moderate 5.3%, and severe 13.8%), patients with SBP between 110 and 149 mmHg were less likely to die across all TBI groups.

CONCLUSIONS

The optimal ED-SBP range for patients with TBI seems to be age and severity dependent. The optimum range might guide clinicians in developing resuscitation protocols for managing patients with TBI.

LEVEL OF EVIDENCE

Level III Prognostic.

Effect of Out-of-Hospital Tranexamic Acid vs Placebo on 6-Month Functional Neurologic Outcomes in Patients With Moderate or Severe Traumatic Brain Injury

IMPORTANCE

Traumatic brain injury (TBI) is the leading cause of death and disability due to trauma. Early administration of tranexamic acid may benefit patients with TBI.

OBJECTIVE

To determine whether tranexamic acid treatment initiated in the out-of-hospital setting within 2 hours of injury improves neurologic outcome in patients with moderate or severe TBI.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, double-blinded, randomized clinical trial at 20 trauma centers and 39 emergency medical services agencies in the US and Canada from May 2015 to November 2017. Eligible participants (N = 1280) included out-of-hospital patients with TBI aged 15 years or older with Glasgow Coma Scale score of 12 or less and systolic blood pressure of 90 mm Hg or higher.

INTERVENTIONS

Three interventions were evaluated, with treatment initiated within 2 hours of TBI: out-of-hospital tranexamic acid (1 g) bolus and in-hospital tranexamic acid (1 g) 8-hour infusion (bolus maintenance group; n = 312), out-of-hospital tranexamic acid (2 g) bolus and in-hospital placebo 8-hour infusion (bolus only group; n = 345), and out-of-hospital placebo bolus and in-hospital placebo 8-hour infusion (placebo group; n = 309).

MAIN OUTCOMES AND MEASURES

The primary outcome was favorable neurologic function at 6 months (Glasgow Outcome Scale-Extended score >4 [moderate disability or good recovery]) in the combined tranexamic acid group vs the placebo group. Asymmetric significance thresholds were set at 0.1 for benefit and 0.025 for harm. There were 18 secondary end points, of which 5 are reported in this article: 28-day mortality, 6-month Disability Rating Scale score (range, 0 [no disability] to 30 [death]), progression of intracranial hemorrhage, incidence of seizures, and incidence of thromboembolic events.

RESULTS

Among 1063 participants, a study drug was not administered to 96 randomized participants and 1 participant was excluded, resulting in 966 participants in the analysis population (mean age, 42 years; 255 [74%] male participants; mean Glasgow Coma Scale score, 8). Of these participants, 819 (84.8%) were available for primary outcome analysis at 6-month follow-up. The primary outcome occurred in 65% of patients in the tranexamic acid groups vs 62% in the placebo group (difference, 3.5%; [90% 1-sided confidence limit for benefit, -0.9%]; P = .16; [97.5% 1-sided confidence limit for harm, 10.2%]; P = .84). There was no statistically significant difference in 28-day mortality between the tranexamic acid groups vs the placebo group (14% vs 17%; difference, -2.9% [95% CI, -7.9% to 2.1%]; P = .26), 6-month Disability Rating Scale score (6.8 vs 7.6; difference, -0.9 [95% CI, -2.5 to 0.7]; P = .29), or progression of intracranial hemorrhage (16% vs 20%; difference, -5.4% [95% CI, -12.8% to 2.1%]; P = .16).

CONCLUSIONS AND RELEVANCE

Among patients with moderate to severe TBI, out-of-hospital tranexamic acid administration within 2 hours of injury compared with placebo did not significantly improve 6-month neurologic outcome as measured by the Glasgow Outcome Scale-Extended.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01990768.

Clinical characteristics and outcomes in patients with traumatic brain injury in China: a prospective, multicentre, longitudinal, observational study

BACKGROUND

Large-scale studies are required to better characterise traumatic brain injury (TBI) and to identify the most effective treatment approaches for TBI. However, evidence is scarce and mostly originates from high-income countries. We aimed to describe the existing care for patients with TBI and the outcomes in China.

METHODS

The Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) China registry is a prospective, multicentre, longitudinal, observational study done in 56 neurosurgical centres across China. We collected data of patients who were admitted to hospital with a clinical diagnosis of TBI and an indication for CT. Patients who were discharged directly from the emergency room were excluded. The primary endpoint was survival on discharge. Prognostic analyses were applied to identify predictors of mortality. Variations in mortality were compared between centres and provinces within China. Mortality was compared with expected mortality, estimated using the CRASH basic model. This study was registered with ClinicalTrials.gov, NCT02210221.

FINDINGS

From Dec 22, 2014, to Aug 1, 2017, 13 627 patients with TBI from 56 centres were enrolled in the registry. Data from 13 138 patients from 52 hospitals in 22 provinces of China were analysed. Most patients were male (9782 [74%]), with a median age of 48 years (IQR 33-61). The median Glasgow Coma Scale (GCS) score was 13 (IQR 9-15), and the leading cause of injury was road-traffic incident (6548 [50%]). Overall, 637 (5%) patients died, including 552 (20%) patients with severe TBI. Age, GCS score, injury severity score, pupillary light reflex, CT findings (compressed basal cistern and midline shift ≥5 mm), presence of hypoxia, systemic hypotension, altitude higher than >500 m, and GDP per capita were significantly associated with survival in all patients with TBI. Variation in mortality existed between centres and regions. The expected 14-day mortality was 1116 (13%), but 544 (7%) deaths within 14 days were observed (observed to expected ratio 0·49 [95% CI 0·45-0·53]).

INTERPRETATION

The results show differences in mortality between centres and regions across China, which indicates potential for identifying best practices through comparative effectiveness research. The risk factors identified in prognostic analyses might contribute to developing benchmarks for assessing quality of care.

FUNDING

None.

Serum bilirubin level correlates with mortality in patients with traumatic brain injury

As a catabolic product of hemoglobin, bilirubin has been confirmed playing an important role in the development of various central nervous system disease. The aim of this study is to explore the correlation between serum bilirubin level and mortality in patients with traumatic brain injury (TBI).Patients admitted with traumatic brain injury (TBI) in our hospital between January 2015 and January 2018 were enrolled in this study. Clinical and laboratory data of 361 patients were retrospectively collected to explore the independent risk factors of mortality.The comparison of baseline characteristics showed that non-survivors had lower Glasgow Coma Scale (GCS) (P < .001) and higher level of serum total bilirubin (TBIL) (P < .001) and direct bilirubin (DBIL) (P < .001). We found that only GCS (P < .001), glucose (P < .001), lactate dehydrogenase (LDH) (P = .042) and DBIL (P = .005) were significant risk factors in multivariate logistic regression analysis. GCS and DBIL had comparable AUC value (0.778 vs 0.750, P > .05) on predicting mortality in TBI patients. The AUC value of the combination of GCS and DBIL is higher than the single value of these two factors (P < .05). Moreover, predictive model 1 consisted of GCS, glucose, LDH and DBIL had the highest AUC value of 0.894.DBIL is a significant risk factor of mortality in TBI patients. Assessing the level of DBIL is beneficial for physicians to evaluate severity and predict outcome for TBI patients.

Functional outcome, in-hospital healthcare consumption and in-hospital costs for hospitalised traumatic brain injury patients: a Dutch prospective multicentre study

BACKGROUND

The high occurrence and acute and chronic sequelae of traumatic brain injury (TBI) cause major healthcare and socioeconomic challenges. This study aimed to describe outcome, in-hospital healthcare consumption and in-hospital costs of patients with TBI.

METHODS

We used data from hospitalised TBI patients that were included in the prospective observational CENTER-TBI study in three Dutch Level I Trauma Centres from 2015 to 2017. Clinical data was completed with data on in-hospital healthcare consumption and costs. TBI severity was classified using the Glasgow Coma Score (GCS). Patient outcome was measured by in-hospital mortality and Glasgow Outcome Score-Extended (GOSE) at 6 months. In-hospital costs were calculated following the Dutch guidelines for cost calculation.

RESULTS

A total of 486 TBI patients were included. Mean age was 56.1 ± 22.4 years and mean GCS was 12.7 ± 3.8. Six-month mortality (4.2%-66.7%), unfavourable outcome (GOSE ≤ 4) (14.6%-80.4%) and full recovery (GOSE = 8) (32.5%-5.9%) rates varied from patients with mild TBI (GCS13-15) to very severe TBI (GCS3-5). Length of stay (8 ± 13 days) and in-hospital costs (€11,920) were substantial and increased with higher TBI severity, presence of intracranial abnormalities, extracranial injury and surgical intervention. Costs were primarily driven by admission (66%) and surgery (13%).

CONCLUSION

In-hospital mortality and unfavourable outcome rates were rather high, but many patients also achieved full recovery. Hospitalised TBI patients show substantial in-hospital healthcare consumption and costs, even in patients with mild TBI. Because these costs are likely to be an underestimation of the actual total costs, more research is required to investigate the actual costs-effectiveness of TBI care.

Apoptosis in cerebrospinal fluid as outcome predictors in severe traumatic brain injury: An observational study

Traumatic brain injury (TBI), due to its high mortality and morbidity, is an important research topic. Apoptosis plays a pathogenic role in a series of neurological disorders, from neurodegenerative diseases to acute neurological lesions.In this study, we analyzed the association between apoptosis and the Glasgow Outcome Scale (GOS), to examine the potential of apoptosis as a biomarker for a TBI outcome. Patients with severe TBI were recruited at the Department of Neurosurgery, Wujin Hospital Affiliated with Jiangsu University, between January 2018 and December 2019. As a control group, healthy subjects were recruited. The concentrations of caspase-3, cytochrome c, sFas, and caspase-9 in the cerebrospinal fluid (CSF) were analyzed by enzyme-linked immunosorbent assay (ELISA). The association between the GOS and the clinical variables age, sex, initial Glasgow Coma Scale (GCS) score, intracranial pressure (ICP), cerebral perfusion pressure (CPP), initial computed tomography (CT) findings, and apoptotic factors was determined using logistic regression. The area under the receiver operator characteristic (ROC) curve (AUC), and thus the sensitivity and specificity of each risk factor, were obtained.The levels of caspase-3, cytochrome c, sFas, and caspase-9 in the TBI group were significantly higher than those in the control group (P < .05). The logistic regression results showed that ICP and caspase-3 were significant predictors of outcome at 6 months post-TBI (P < .05). The AUC was 0.925 and 0.888 for ICP and caspase-3, respectively. However, the AUC for their combined prediction was 0.978, with a specificity and sensitivity of 96.0% and 95.2%, respectively, showing that the combined prediction was more reliable than that of the 2 separate factors.We demonstrated that caspase-3, cytochrome C, sFas, and caspase-9 were significantly increased in the CSF of patients following severe TBI. Furthermore, we found that ICP and caspase-3 were more reliable for outcome prediction in combination, rather than separately.

Case-mix, care pathways, and outcomes in patients with traumatic brain injury in CENTER-TBI: a European prospective, multicentre, longitudinal, cohort study

BACKGROUND

The burden of traumatic brain injury (TBI) poses a large public health and societal problem, but the characteristics of patients and their care pathways in Europe are poorly understood. We aimed to characterise patient case-mix, care pathways, and outcomes of TBI.

METHODS

CENTER-TBI is a Europe-based, observational cohort study, consisting of a core study and a registry. Inclusion criteria for the core study were a clinical diagnosis of TBI, presentation fewer than 24 h after injury, and an indication for CT. Patients were differentiated by care pathway and assigned to the emergency room (ER) stratum (patients who were discharged from an emergency room), admission stratum (patients who were admitted to a hospital ward), or intensive care unit (ICU) stratum (patients who were admitted to the ICU). Neuroimages and biospecimens were stored in repositories and outcome was assessed at 6 months after injury. We used the IMPACT core model for estimating the expected mortality and proportion with unfavourable Glasgow Outcome Scale Extended (GOSE) outcomes in patients with moderate or severe TBI (Glasgow Coma Scale [GCS] score ≤12). The core study was registered with ClinicalTrials.gov, number NCT02210221, and with Resource Identification Portal (RRID: SCR_015582).

FINDINGS

Data from 4509 patients from 18 countries, collected between Dec 9, 2014, and Dec 17, 2017, were analysed in the core study and from 22 782 patients in the registry. In the core study, 848 (19%) patients were in the ER stratum, 1523 (34%) in the admission stratum, and 2138 (47%) in the ICU stratum. In the ICU stratum, 720 (36%) patients had mild TBI (GCS score 13-15). Compared with the core cohort, the registry had a higher proportion of patients in the ER (9839 [43%]) and admission (8571 [38%]) strata, with more than 95% of patients classified as having mild TBI. Patients in the core study were older than those in previous studies (median age 50 years [IQR 30-66], 1254 [28%] aged >65 years), 462 (11%) had serious comorbidities, 772 (18%) were taking anticoagulant or antiplatelet medication, and alcohol was contributory in 1054 (25%) TBIs. MRI and blood biomarker measurement enhanced characterisation of injury severity and type. Substantial inter-country differences existed in care pathways and practice. Incomplete recovery at 6 months (GOSE <8) was found in 207 (30%) patients in the ER stratum, 665 (53%) in the admission stratum, and 1547 (84%) in the ICU stratum. Among patients with moderate-to-severe TBI in the ICU stratum, 623 (55%) patients had unfavourable outcome at 6 months (GOSE <5), similar to the proportion predicted by the IMPACT prognostic model (observed to expected ratio 1·06 [95% CI 0·97-1·14]), but mortality was lower than expected (0·70 [0·62-0·76]).

INTERPRETATION

Patients with TBI who presented to European centres in the core study were older than were those in previous observational studies and often had comorbidities. Overall, most patients presented with mild TBI. The incomplete recovery of many patients should motivate precision medicine research and the identification of best practices to improve these outcomes.

FUNDING

European Union 7th Framework Programme, the Hannelore Kohl Stiftung, OneMind, and Integra LifeSciences Corporation.

Survival and Functional Outcomes at Discharge After Traumatic Brain Injury in Children versus Adults in Resource-Poor Setting

BACKGROUND

More than 90% of trauma mortality occurs in low- and middle-income countries, especially in sub-Saharan Africa. Head injury is the primary driver of trauma mortality in the prehospital and in-hospital setting.

METHODS

An observational study was performed on patients presenting with traumatic brain injury (TBI) from October 2016 through May 2017 at Kamuzu Central Hospital, Malawi. Bivariate analysis and logistic regression were performed to determine the odds of favorable functional outcomes and mortality after controlling for significant covariates.

RESULTS

Of the 356 patients with TBI, 72 (20.2%) were children <18 years of age. Males comprised 202 (87.1%) and 46 (63.9%) of the adult and pediatric cohorts, respectively. Motor vehicle crash was the leading etiology in adults and children. There was no significant difference between adult and pediatric Glasgow Coma Scale score on admission, 10.8 ± 3.9 versus 10.9 ± 3.5, respectively (P = 0.8). More adult (n = 76, 32.3%) than pediatric (n = 13, 18.1%) patients died. On multivariable analysis, pediatric patients were more likely to have a favorable outcome defined by a Glasgow Outcome Scale of good recovery or moderate disability (odds ratio 3.70, 95% confidence interval 1.22-11.17, P = 0.02) and were less likely to die after TBI (odds ratio 0.29, 95% confidence interval 0.09-0.93, P = 0.04).

CONCLUSIONS

We show a survival advantage and better functional outcomes in children following TBI. This may be attributable to increased resiliency to TBI in children or the prioritization of children in a resource-poor environment. Investments in neurosurgical care following TBI are needed to improve outcomes.

Circulating Brain Injury Exosomal Proteins following Moderate-To-Severe Traumatic Brain Injury: Temporal Profile, Outcome Prediction and Therapy Implications

Brain injury exosomal proteins are promising blood biomarker candidates in traumatic brain injury (TBI). A better understanding of their role in the diagnosis, characterization, and management of TBI is essential for upcoming clinical implementation. In the current investigation, we aimed to explore longitudinal trajectories of brain injury exosomal proteins in blood of patients with moderate-to-severe TBI, and to evaluate the relation with the free-circulating counterpart and patient imaging and clinical parameters. Exosomal levels of glial (glial fibrillary acidic protein (GFAP)) and neuronal/axonal (ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), neurofilament light chain (NFL), and total-tau (t-tau)) proteins were measured in serum of 21 patients for up 5 days after injury using single molecule array (Simoa) technology. Group-based trajectory analysis was used to generate distinct temporal exosomal biomarker profiles. We found altered profiles of serum brain injury exosomal proteins following injury. The dynamics and levels of exosomal and related free-circulating markers, although correlated, showed differences. Patients with diffuse injury displayed higher acute exosomal NFL and GFAP concentrations in serum than those with focal lesions. Exosomal UCH-L1 profile characterized by acutely elevated values and a secondary steep rise was associated with early mortality (n = 2) with a sensitivity and specificity of 100%. Serum brain injury exosomal proteins yielded important diagnostic and prognostic information and represent a novel means to unveil underlying pathophysiology in patients with moderate-to-severe TBI. Our findings support their utility as potential tools to improve patient phenotyping in clinical practice and therapeutic trials.

10 Years of Implementation of the "Glasgow 7" Quality Guarantee Program in the Mendoza Central Hospital: Epidemiology and Evolution of Neurocrytic Patients

INTRODUCTION

In 2003, the Glasgow 7 Quality Guarantee Program was put into effect in Argentina with the objective of standardizing the donation and transplant process throughout the country, establishing the observation and registration of all neurocritical patients with a score on the Glasgow Coma Scale of 7 of 15 or less admitted to critical beds of selected establishments.

MATERIALS AND METHODS

The following study is retrospective, observational, and cohort-based. It was developed in the Central Hospital of Mendoza, in the critical units, including guard, coronary, cardiovascular surgery recovery, and intensive care therapy. The inclusion criteria were admission to the institution with a score on the Glasgow Coma Scale of 7 or less with a structural cause of coma. Data collection was carried out in the national online database SINTRA.

RESULTS

From January 1, 2008, to December 31, 2018, 1757 patients were enrolled at the Central Hospital of Mendoza, Argentina with Glasgow scores of 7 or less. The most frequent cause of coma was brain trauma (934 patients; 53%), followed by stroke (614 patients; 35%). Of those who scored 3 of 15 in the GCS upon admission, 65% progressed to brain death, whereas 72% of those who scored 7 were discharged. Of all these patients, 270 became donors, accounting for 43% of all brain deaths, whereas 187 had refused to become organ donors (30.6%). Of the total real donors, 55% were multiorganic (150 donors).

Signal Information Prediction of Mortality Identifies Unique Patient Subsets after Severe Traumatic Brain Injury: A Decision-Tree Analysis Approach

Nonlinear physiological signal features that reveal information content and causal flow have recently been shown to be predictors of mortality after severe traumatic brain injury (TBI). The extent to which these features interact together, and with traditional measures to describe patients in a clinically meaningful way remains unclear. In this study, we incorporated basic demographics (age and initial Glasgow Coma Scale [GCS]) with linear and non-linear signal information based features (approximate entropy [ApEn], and multivariate conditional Granger causality [GC]) to evaluate their relative contributions to mortality using cardio-cerebral monitoring data from 171 severe TBI patients admitted to a single neurocritical care center over a 10 year period. Beyond linear modelling, we employed a decision tree analysis approach to define a predictive hierarchy of features. We found ApEn (p = 0.009) and GC (p = 0.004) based features to be independent predictors of mortality at a time when mean intracranial pressure (ICP) was not. Our combined model with both signal information-based features performed the strongest (area under curve = 0.86 vs. 0.77 for linear features only). Although low "intracranial" complexity (ApEn-ICP) outranked both age and GCS as crucial drivers of mortality (fivefold increase in mortality where ApEn-ICP <1.56, 36.2% vs. 7.8%), decision tree analysis revealed clear subsets of patient populations using all three predictors. Patients with lower ApEn-ICP who were >60 years of age died, whereas those with higher ApEn-ICP and GCS ≥5 all survived. Yet, even with low initial intracranial complexity, as long as patients maintained robust GC and "extracranial" complexity (ApEn of mean arterial pressure), they all survived. Incorporating traditional linear and novel, non-linear signal information features, particularly in a framework such as decision trees, may provide better insight into "health" status. However, caution is required when interpreting these results in a clinical setting prior to external validation.