Prehospital hypertension is predictive of traumatic brain injury and is associated with higher mortality

Identification of clinically relevant patient endotypes in traumatic brain injury using latent class analysis

Traumatic brain injury (TBI) is a complex condition where heterogeneity impedes the advancement of care. Understanding the diverse presentations of TBI is crucial for personalized medicine. Our study aimed to identify clinically relevant patient endotypes in TBI using latent class analysis based on comorbidity data. We used the Medical Information Mart for Intensive Care III database, which includes 2,629 adult TBI patients. We identified five stable endotypes characterized by specific comorbidity profiles: Heart Failure and Arrhythmia, Healthy, Renal Failure with Hypertension, Alcohol Abuse, and Hypertension. Each endotype had distinct clinical characteristics and outcomes: The Heart Failure and Arrhythmia endotype had lower survival rates than the Renal Failure with Hypertension despite featuring fewer comorbidities overall. Patients in the Hypertension endotype had higher rates of neurosurgical intervention but shorter stays in contrast to the Alcohol Abuse endotype which had lower rates of neurosurgical intervention but significantly longer hospital stays. Both endotypes had high overall survival rates comparable to the Healthy endotype. Logistic regression models showed that endotypes improved the predictability of survival compared to individual comorbidities alone. This study validates clinical endotypes as an approach to addressing heterogeneity in TBI and demonstrates the potential of this methodology in other complex conditions.

Critical hypertension in trauma patients following prehospital emergency anaesthesia: a multi-centre retrospective observational study

BACKGROUND

Critical hypertension in major trauma patients is associated with increased mortality. Prehospital emergency anaesthesia (PHEA) is performed for 10% of the most seriously injured patients. Optimising oxygenation, ventilation, and cerebral perfusion, whilst avoiding extreme haemodynamic fluctuations are the cornerstones of reducing secondary brain injury. The aim of this study was to report the differential determinants of post-PHEA critical hypertension in a large regional dataset of trauma patients across three Helicopter Emergency Medical Service (HEMS) organisations.

METHODS

A multi-centre retrospective observational study of consecutive adult trauma patients undergoing PHEA across three HEMS in the United Kingdom; 2015-2022. Critical hypertension was defined as a new systolic blood pressure (SBP) > 180mmHg within 10 min of induction of anaesthesia, or > 10% increase if the baseline SBP was > 180mmHg prior to induction. Purposeful logistical regression was used to explore variables associated with post-PHEA critical hypertension in a multivariable model. Data are reported as number (percentage), and odds ratio (OR) with 95% confidence interval (95%CI).

RESULTS

30,744 patients were attended by HEMS during the study period; 2161 received PHEA and 1355 patients were included in the final analysis. 161 (11.9%) patients had one or more new episode(s) of critical hypertension ≤ 10 min post-PHEA. Increasing age (compared with 16-34 years): 35-54 years (OR 1.76, 95%CI 1.03-3.06); 55-74 years (OR 2.00, 95%CI 1.19-3.44); ≥75 years (OR 2.38, 95%CI 1.31-4.35), pre-PHEA Glasgow Coma Scale (GCS) motor score four (OR 2.17, 95%CI 1.19-4.01) and five (OR 2.82, 95%CI 1.60-7.09), patients with a pre-PHEA SBP > 140mmHg (OR 6.72, 95%CI 4.38-10.54), and more than one intubation attempt (OR 1.75, 95%CI 1.01-2.96) were associated with post-PHEA critical hypertension.

CONCLUSION

Delivery of PHEA to seriously injured trauma patients risks haemodynamic fluctuation. In adult trauma patients undergoing PHEA, 11.9% of patients experienced post-PHEA critical hypertension. Increasing age, pre-PHEA GCS motor score four and five, patients with a pre-PHEA SBP > 140mmHg, and more than intubation attempt were independently associated with post-PHEA critical hypertension.

Guidelines for Prehospital Management of Traumatic Brain Injury 3rd Edition: Executive Summary

Prehospital care markedly influences outcome from traumatic brain injury, yet it remains highly variable. The Brain Trauma Foundation's guidelines informing prehospital care, first published in 2002, have sought to identify and disseminate best practices. Many of its recommendations relate to the management of airway, breathing and circulation, and infrastructure for this care. Compliance with the second edition of these guidelines has been associated with significantly improved survival. A working group developed evidence-based recommendations informing assessment, treatment, and transport decision-making relevant to the prehospital care of brain injured patients. A literature search spanning May 2005 to January 2022 supplemented data contained in the 2nd edition. Identified studies were assessed for quality and used to inform evidence-based recommendations. A total of 122 published articles formed the evidentiary base for this guideline update including 5 providing Class I evidence, 35 providing Class II evidence, and 98 providing Class III evidence for the various topics. Forty evidence-based recommendations were generated, 30 of which were strong and 10 of which were weak. In many cases, new evidence allowed guidelines from the 2nd edition to be strengthened. Development of guidelines on some new topics was possible including the prehospital administration of tranexamic acid. A management algorithm is also presented. These guidelines help to identify best practices for prehospital traumatic brain injury care, and they also identify gaps in knowledge which we hope will be addressed before the next edition.

Cushing Index Based on Cushing Signs to Predict In-Hospital Death and Early Intervention for Minor Head Injury

A considerable number of patients with mild traumatic brain injury have been known to "talk and die." Serial neurological examinations, however, have been the only method of determining the necessity of repeat computed tomography (CT), and no validated method has been available to predict early deterioration of minor head injury. This study aimed to evaluate the association between hypertension and bradycardia, a classic sign of raised intracranial pressure (Cushing reflex) on hospital arrival and determine the clinical consequences of minor head injury after blunt trauma. We created a new Cushing Index (CI) by dividing the systolic blood pressure by the heart rate (equaling the inverse number of the Shock Index, a score for hemodynamic stability) and hypothesized that a high CI would predict surgical intervention for deterioration and in-hospital death among patients with minor head injury. To test our hypothesis, a retrospective observational study was conducted using a nationwide trauma database. Accordingly, adult blunt trauma with minor head injury (defined as a Glasgow Coma Scale of 13-15 and Abbreviated Injury Scale score of ≥2 in the head) who were transported directly from the scene by ambulances were included. Among the 338,744 trauma patients identified in the database, 38,844 were eligible for inclusion. A restricted cubic spline regression curve for risks of in-hospital death was created using the CI. Thereafter, the thresholds were determined based on inflection points of the curve, and patients were divided into low-, intermediate-, and high-CI groups. Patients with high CI showed significantly higher in-hospital mortality rates compared with those with intermediate CI (351 [3.0%] vs. 373 [2.3%]; odds ratio [OR] = 1.32 [1.14-1.53]; p < 0.001). Patients with high index also had a higher incidence of emergency cranial surgery within 24h after arrival than those with an intermediate CI (746 [6.4%] vs. 879 [5.4%]; OR = 1.20 [1.08-1.33]; p < 0.001). In addition, patients with low CI (equal to high Shock Index, meaning hemodynamically unstable) showed higher in-hospital death compared with those with intermediate CI (360 [3.3%] vs. 373 [2.3%]; p < 0.001). In conclusion, a high CI (high systolic blood pressure and low heart rate) on hospital arrival would be helpful in identifying patients with minor head injury who might experience deterioration and need close observation.

Prehospital Electroencephalography to Detect Traumatic Brain Injury during Helicopter Transport: A Pilot Observational Cohort Study

OBJECTIVE

Early recognition of traumatic brain injury (TBI) is important to facilitate time-sensitive care. Electroencephalography (EEG) can identify TBI, but feasibility of EEG has not been evaluated in prehospital settings. We tested the feasibility of obtaining single-channel EEG during air medical transport after trauma. We measured association between quantitative EEG features, early blood biomarkers, and abnormalities on head computerized tomography (CT).

METHODS

We performed a pilot prospective, observational study enrolling consecutive patients transported by critical care air ambulance from the scene of trauma to a Level I trauma center. During transport, prehospital clinicians placed a sensor on the patient's forehead to record EEG. We reviewed EEG waveforms and selected 90 seconds of recording for quantitative analysis. EEG data processing included fast Fourier transform to summarize component frequency power in the delta (0-4 Hz), theta (4-8 Hz), and alpha (8-13 Hz) ranges. We collected blood samples on day 1 and day 3 post-injury and measured plasma levels of two brain injury biomarkers (ubiquitin C-terminal hydrolase L1 [UCH-L1] and glial fibrillary acidic protein [GFAP]). We compared predictors between individuals with and without CT-positive TBI findings.

RESULTS

Forty subjects were enrolled, with EEG recordings successfully obtained in 34 (85%). Reasons for failure included uncharged battery (n = 5) and user error (n = 1). Data were lost in three cases. Of 31 subjects with data, interpretable EEG signal was recorded in 26 (84%). Mean age was 48 (SD 16) years, 79% were male, and 50% suffered motor vehicle crashes. Eight subjects (24%) had CT-positive TBI. Subjects with and without CT-positive TBI had similar median delta power, alpha power, and theta power. UCH-L1 and GFAP plasma levels did not differ across groups. Delta power inversely correlated with UCH-L1 day 1 plasma concentration (r = -0.60, p = 0.03).

CONCLUSIONS

Prehospital EEG acquisition is feasible during air transport after trauma.

Head Injury and Long-term Mortality Risk in Community-Dwelling Adults

Importance

Head injury is associated with significant short-term morbidity and mortality. Research regarding the implications of head injury for long-term survival in community-dwelling adults remains limited.

Objective

To evaluate the association of head injury with long-term all-cause mortality risk among community-dwelling adults, with consideration of head injury frequency and severity.

Design, Setting, and Participants

This cohort study included participants with and without head injury in the Atherosclerosis Risk in Communities (ARIC) study, an ongoing prospective cohort study with follow-up from 1987 through 2019 in 4 US communities in Minnesota, Maryland, North Carolina, and Mississippi. Of 15 792 ARIC participants initially enrolled, 1957 were ineligible due to self-reported head injury at baseline; 103 participants not of Black or White race and Black participants at the Minnesota and Maryland field centers were excluded due to race-site aliasing; and an additional 695 participants with missing head injury date or covariate data were excluded, resulting in 13 037 eligible participants.

Exposures

Head injury frequency and severity, as defined via self-report in response to interview questions and via hospital-based International Classification of Diseases diagnostic codes (with head injury severity defined in the subset of head injury cases identified using these codes). Head injury was analyzed as a time-varying exposure.

Main Outcomes and Measures

All-cause mortality was ascertained via linkage to the National Death Index. Data were analyzed between August 5, 2021, and October 23, 2022.

Results

More than one-half of participants were female (57.7%; 42.3% men), 27.9% were Black (72.1% White), and the median age at baseline was 54 years (IQR, 49-59 years). Median follow-up time was 27.0 years (IQR, 17.6-30.5 years). Head injuries occurred among 2402 participants (18.4%), most of which were classified as mild. The hazard ratio (HR) for all-cause mortality among individuals with head injury was 1.99 (95% CI, 1.88-2.11) compared with those with no head injury, with evidence of a dose-dependent association with head injury frequency (1 head injury: HR, 1.66 [95% CI, 1.56-1.77]; 2 or more head injuries: HR, 2.11 [95% CI, 1.89-2.37]) and severity (mild: HR, 2.16 [95% CI, 2.01-2.31]; moderate, severe, or penetrating: HR, 2.87 [95% CI, 2.55-3.22]). Estimates were similar by sex and race, with attenuated associations among individuals aged 54 years or older at baseline.

Conclusions and Relevance

In this community-based cohort with more than 3 decades of longitudinal follow-up, head injury was associated with decreased long-term survival time in a dose-dependent manner, underscoring the importance of measures aimed at prevention and clinical interventions to reduce morbidity and mortality due to head injury.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) may be superior to resuscitative thoracotomy (RT) in patients with traumatic brain injury (TBI)

Background

The effects of aortic occlusion (AO) on brain injury are not well defined. We examined the impact of AO by resuscitative endovascular balloon occlusion of the aorta (REBOA) and resuscitative thoracotomy (RT) on outcomes in the setting of traumatic brain injury (TBI).

Methods

Patients sustaining TBI who underwent RT or REBOA in zone 1 (thoracic aorta) from September 2013 to December 2018 were identified. The indication for REBOA or RT was hemodynamic collapse due to hemorrhage below the diaphragm. Primary outcomes included mortality and systemic complications.

Results

282 patients underwent REBOA or RT. Of these, 76 had mild TBI (40 REBOA, 36 RT) and 206 sustained severe TBI (107 REBOA, 99 RT). Overall, the mean (±SD) age was 42±17 years, with an Injury Severity Score (ISS) of 40±17 and mean systolic blood pressure (SBP) at the time of REBOA or RT of 81±34 mm Hg. REBOA patients had a mean SBP at the time of AO of 78.39±29.45 mm Hg, whereas RT patients had a mean SBP of 83.18±37.87 mm Hg at the time of AO (p=0.24). 55% had ongoing cardiopulmonary resuscitation (CPR) at the time of AO, and the in-hospital mortality was 86%. Binomial logistic regression controlling for TBI severity, age, ISS, SBP at the time of AO, crystalloid infusion, and CPR during AO demonstrated that the odds of mortality are 3.1 times higher for RT compared with REBOA. No significant differences were found in systemic complications between RT and REBOA.

Discussion

Patients with TBI who receive REBOA may have improved survival, but no difference in systemic complications, compared with patients who receive RT for the same indication. Although some patients are receiving RT prior to arrest for extrathoracic hemorrhagic shock, these results suggest that REBOA should be considered as an alternative to RT when RT is chosen for the sole purpose of resuscitation in the setting of TBI.

Level of evidence

4.

Brain-Derived Extracellular Vesicles Induce Vasoconstriction and Reduce Cerebral Blood Flow in Mice

Traumatic brain injury (TBI) impairs cerebrovascular autoregulation and reduces cerebral blood flow (CBF), leading to ischemic secondary injuries. We have shown that injured brains release brain-derived extracellular vesicles (BDEVs) into circulation, where they cause a systemic hypercoagulable state that rapidly turns into consumptive coagulopathy. BDEVs induce endothelial injury and permeability, leading to the hypothesis that they contribute to TBI-induced cerebrovascular dysregulation. In a study designed to test this hypothesis, we detected circulating BDEVs in C57BL/6J mice subjected to severe TBI, reaching peak levels of 3x104/µl at 3 hours post injury (71.2±21.5% of total annexin V-binding EVs). We further showed in an adaptive transfer model that 41.7±5.8% of non-injured mice died within 6 hours after being infused with 3x104/µl of BDEVs. BDEVs transmigrated through the vessel walls, induced rapid vasoconstriction by inducing calcium influx in vascular smooth muscle cells, and reduced CBF by 93.8±5.6% within 30 minutes after infusion. The CBF suppression was persistent in mice that eventually died but it recovered quickly in surviving mice. It was prevented by the calcium channel blocker nimodipine. When being separated, neither protein nor phospholipid components from the lethal number of BDEVs induced vasoconstriction, reduced CBF, and caused death. These results demonstrate a novel vasoconstrictive activity of BDEVs that depends on the structure of BDEVs and contributes to TBI-induced disseminated cerebral ischemia and sudden death.

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.

Hypertension in the Young Adult Trauma Population: Rethinking the Traditional "Incidentaloma"

BACKGROUND

Hypertension (HTN) is a treatable and preventable risk factor for cardiovascular disease that is often overlooked in young adults. As a result, young patients with HTN may enter the health care system as a trauma without a preexisting diagnosis. The potential impact of HTN (diagnosed and undiagnosed) on trauma outcomes is not known.

MATERIALS AND METHODS

Patients aged 18-39 y from the 2013-2017 North Carolina Trauma Registry were included. Patients were stratified as having no HTN, previously diagnosed HTN (PD-HTN), or newly diagnosed HTN (ND-HTN) during a trauma admission. Multivariable logistic and linear regression compared inpatient outcomes between patients with and without HTN, as well as ND-HTN and PD-HTN.

RESULTS

Six percent of trauma patients were diagnosed with HTN (n = 1906; 14% ND-HTN). Those with HTN were more likely to have an inpatient complication (odds ratio [OR]: 1.65, 95% confidence interval [CI]: 1.32-2.07) and intensive care unit stay (OR: 1.28, 95% CI: 1.12-1.46) compared with patients without HTN. Compared with PD-HTN, those with ND-HTN were more likely to present with extreme injury. In addition, patients with ND-HTN had higher odds of inpatient complications (OR: 1.95, 95% CI: 1.18-3.22) and 30-d readmission (OR: 2.00, 95% CI: 0.95-4.20) after accounting for demographics and injury severity.

CONCLUSIONS

More than 10% of young adult trauma patients with HTN are not diagnosed before admission. HTN appears to have a detrimental impact on patient outcomes, with newly diagnosed patients having the worst outcomes. Trauma may serve as an opportunity for the diagnosis and treatment of HTN in young adults. Future studies should assess the impact of intervention on trauma outcomes.

Does hypertension at initial presentation adversely affect outcomes in pediatric traumatic brain injury?

BACKGROUND

Adults with traumatic brain injury (TBI) who present hypertensive suffer worse outcomes and increased mortality compared to normotensive patients. The purpose of this study is to determine if age-adjusted hypertension on presentation is associated with worsened outcomes in pediatric TBI.

METHODS

A retrospective chart review was conducted on pediatric patients with severe TBI admitted to a single system pediatric tertiary care center. The primary outcome was mortality. Secondary outcomes included length of stay, need for neurosurgical intervention, duration of mechanical ventilation, and the need for inpatient rehabilitation.

RESULTS

Of 150 patients, 70% were hypertensive and 30% were normotensive on presentation. Comparing both groups, no statistically significant differences were noted in mortality (13.3% for both groups), need for neurosurgical intervention (51.4% vs 48.8%, p = 0.776), length of stay (6 vs 8 days, p = 0.732), duration of mechanical ventilation (2 vs 3 days, p = 0.912), or inpatient rehabilitation rates (48.6% vs 48.9%, p = 0.972). In comparing just the hypertensive patients, there was a trend toward increased mortality in the 95th and 99th percentile groups at 15.8% and 14.1%, versus the 90th percentile group at 6.7% but the difference was not statistically significant (p = 0.701).

CONCLUSIONS

Contrary to the adult literature, pediatric patients with severe TBI and hypertension on presentation do not appear to have worsened outcomes compared to those who are normotensive. However, a trend toward increased mortality did exist at extremes of age adjusted hypertension. Larger scale studies are needed to validate these findings.

STUDY TYPE

Retrospective cohort study LEVEL OF EVIDENCE: III.

Long Term Outcome in Survivors of Decompressive Craniectomy following Severe Traumatic Brain Injury

Background:

Decompressive craniectomy (DC) is done for the management of intracranial hypertension due to severe traumatic brain injury (sTBI). Despite DC, a number of patients die and others suffer from severe neurological disability. We conducted this observational study to assess functional outcome as measured by Glasgow outcome scale-extended (GOSE) in survivors of DC. The correlation between various factors at admission and hospital with functional outcome was also obtained.

Materials and Methods:

Patients (15–65 years) posted for cranioplasty following DC due to sTBI were prospectively enrolled. Demographic profile, clinical data, and GOSE were noted at the time of admission for cranioplasty from the patient or nearest relative or both. Retrospective data noted from hospital records included admission Marshalls grading, Glasgow coma score (GCS), motor response, mean arterial pressure (MAP), and timing of DC at the time of initial admission following sTBI.

Results:

A total of 85 patients (71 males and 14 females) were enrolled over a period of 2 years. The mean age of the patients was 33.42 ± 12.70 years. The median GCS at the time of admission due to head injury, at the time of discharge, and at the time of cranioplasty was 8 (interquartile range [IQR] 3–15), 10 (IQR 4–15), and 15 (IQR 7–15), respectively. Thirty-one patients (36%) had good functional outcome (GOSE 5–8) and 54 patients (64%) had poor functional outcome (GOSE 1–4). On univariate analysis tracheostomy (P = 0.00), duration of hospital stay (P = 0.002), MAP at admission (P = 0.01), and GCS at discharge (P = 0.01) correlated with outcome [Table 1]. On multivariate analysis MAP at admission (odds ratio [OR] [95% confidence interval {CI}]; 0.07 [0.01–0.40] and tracheostomy (OR [95% CI]; 15 [1.45–162.9]) were found to be the independent predictors of functional outcome.

Conclusion:

Significant disability is seen among the survivors of DC. Tracheostomy and MAP at admission were found to be independently associated with the patient outcome.

Cushing's sign and severe traumatic brain injury in children after blunt trauma: a nationwide retrospective cohort study in Japan

OBJECTIVE

We tested whether Cushing's sign could predict severe traumatic brain injury (TBI) requiring immediate neurosurgical intervention (BI-NSI) in children after blunt trauma.

DESIGN

Retrospective cohort study using Japan Trauma Data Bank.

SETTING

Emergency and critical care centres in secondary and tertiary hospitals in Japan.

PARTICIPANTS

Children between the ages of 2 and 15 years with Glasgow Coma Scale motor scores of 5 or less at presentation after blunt trauma from 2004 to 2015 were included. A total of 1480 paediatric patients were analysed.

PRIMARY OUTCOME MEASURES

Patients requiring neurosurgical intervention within 24 hours of hospital arrival and patients who died due to isolated severe TBI were defined as BI-NSI. The combination of systolic blood pressure (SBP) and heart rate (HR) on arrival, which were respectively divided into tertiles, and its correlation with BI-NSI were investigated using a multiple logistic regression model.

RESULTS

In the study cohort, 297 (20.1%) exhibited BI-NSI. After adjusting for sex, age category and with or without haemorrhage shock, groups with higher SBP and lower HR (SBP ≥135 mm Hg; HR ≤92 bpm) were significantly associated with BI-NSI (OR 2.84, 95% CI 1.68 to 4.80, P<0.001) compared with the patients with normal vital signs. In age-specific analysis, hypertension and bradycardia were significantly associated with BI-NSI in a group of 7-10 and 11-15 years of age; however, no significant association was observed in a group of 2-6 years of age.

CONCLUSIONS

Cushing's sign after blunt trauma was significantly associated with BI-NSI in school-age children and young adolescents.

Hypertension After Severe Traumatic Brain Injury: Friend or Foe?

Traumatic brain injury (TBI) is a major public health problem, with severe TBI contributing to a large number of deaths and disability worldwide. Early hypotension has been linked with poor outcomes following severe TBI, and guidelines suggest early and aggressive management of hypotension after TBI. Despite these recommendations, no guidelines exist for the management of hypertension after severe TBI, although observational data suggests that early hypertension is also associated with an increased risk of mortality after severe TBI. The purpose of this review is to discuss the underlying pathophysiology of hypertension after TBI, provide an overview of the current clinical data on early hypertension after TBI, and discuss future research that should test the benefits and harms of treating high blood pressure in TBI patients.

The accuracy of acuity scoring tools to predict 24-h mortality in traumatic brain injury patients: A guide to triage criteria

BACKGROUND AND AIM

Prompt identification of traumatic brain injury (TBI) is vital for patients in critical condition; however, it is not clear which acuity scoring tools are associated with short-term mortality. The aim of this study was to determine the accuracy of acuity scoring tools and 24-h mortality among TBI patients in both prehospital and hospital settings.

METHODS

This study was an observational, prospective cohort, in which patients with TBI were followed from the accident scene to the hospital. Vital signs and acuity scoring tools, including the Revised Trauma Score (RTS), Injury Severity Score (ISS), National Early Warning Score (NEWS), Shock Index (SI), Modified Shock Index (MSI) and Trauma and Injury Severity Score (TRISS), were collected both on the scene as well as at the hospital. A logistic regression was performed to ascertain the effects of clinical parameters on the likelihood of survival of patients with TBI regarding 24-h mortality.

RESULTS

A total of 185 patients were included in this study. The mortality rate was 14% (25/185). The logistic regression model was statistically significant at χ²=60.8, p=0.001. A hierarchical forward stepwise logistic regression analysis showed that age, hospital RTS and prehospital NEWS significantly improved mortality predictions. The model explained the 51.2% variance in survival of patients with TBI.

CONCLUSIONS

The NEWS and the RTS may be used to triage TBI patients for prehospital and hospital emergency care, respectively. Therefore, because traditional vital signs criteria may be of limited use for the triage of TBI patients, it is recommended that acuity scoring tools be used in such cases.

Presenting hypertension, burn injury, and mortality in combat casualties

INTRODUCTION

The effect of presenting hypertension is poorly studied in combat casualties. We hypothesized that elevated mean arterial pressure (MAP) on presentation to combat hospitals would be associated with poor outcomes.

METHODS

Data was obtained from the Department of Defense Trauma Registry and the Armed Forces Medical Examiner System. Variables analyzed included presenting vital signs to Role II-III military theater hospital, demographic variables, injury severity score (ISS), location and mechanism of injury, presence of traumatic brain injury (TBI), acute kidney injury (AKI), and mortality. Patients were stratified by decile of MAP and logistic regression analysis was employed to adjust for confounders.

RESULTS

A total of 4072 subjects injured from February 2002 to February 2011 were identified. Compared to patients in the middle deciles of presenting MAP, patients in the highest and lowest MAP deciles were the only groups that demonstrated a higher mortality on univariate analysis (OR 2.06, 95% CI 1.16-2.31 and OR 2.86, 95% CI 1.76-4.67, respectively), and this relationship persisted after adjustment for ISS, HR, temperature, presence of burn injury, TBI, and AKI. Burn injury was associated with mortality in the full multivariate analysis. However, further analysis limited to patients without burn injury did not demonstrate an association between high MAP and mortality (OR 0.84, 95% CI 0.36-1.99; p=0.70). Conversely, when limited to patients with burn injury, high MAP was associated with mortality (OR 3.78, 95% CI 1.74-8.20; p=0.001).

CONCLUSION

The relationship between mortality and presenting MAP appears to be U-shaped, demonstrating increased mortality in the lowest and highest deciles. However, mortality in the highest MAP decile appears to be limited to casualties with associated burn injury, even after adjustment for TBI, AKI, and ISS, which takes into account the severity of the burn injury. Physicians should recognize that burn patients presenting with an elevated MAP are at an increased risk for poor outcomes.

LEVEL OF EVIDENCE

III.

The effect of resuscitative endovascular balloon occlusion of the aorta, partial aortic occlusion and aggressive blood transfusion on traumatic brain injury in a swine multiple injuries model

BACKGROUND

Despite clinical reports of poor outcomes, the degree to which resuscitative endovascular balloon occlusion of the aorta (REBOA) exacerbates traumatic brain injury (TBI) is not known. We hypothesized that combined effects of increased proximal mean arterial pressure (pMAP), carotid blood flow (Qcarotid), and intracranial pressure (ICP) from REBOA would lead to TBI progression compared with partial aortic occlusion (PAO) or no intervention.

METHODS

Twenty-one swine underwent a standardized TBI via computer Controlled cortical impact followed by 25% total blood volume rapid hemorrhage. After 30 minutes of hypotension, animals were randomized to 60 minutes of continued hypotension (Control), REBOA, or PAO. REBOA and PAO animals were then weaned from occlusion. All animals were resuscitated with shed blood via a rapid blood infuser. Physiologic parameters were recorded continuously and brain computed tomography obtained at specified intervals.

RESULTS

There were no differences in baseline physiology or during the initial 30 minutes of hypotension. During the 60-minute intervention period, REBOA resulted in higher maximal pMAP (REBOA, 105.3 ± 8.8; PAO, 92.7 ± 9.2; Control, 48.9 ± 7.7; p = 0.02) and higher Qcarotid (REBOA, 673.1 ± 57.9; PAO, 464.2 ± 53.0; Control, 170.3 ± 29.4; p < 0.01). Increases in ICP were greatest during blood resuscitation, with Control animals demonstrating the largest peak ICP (Control, 12.8 ± 1.2; REBOA, 5.1 ± 0.6; PAO, 9.4 ± 1.1; p < 0.01). There were no differences in the percentage of animals with hemorrhage progression on CT (Control, 14.3%; 95% confidence interval [CI], 3.6-57.9; REBOA, 28.6%; 95% CI, 3.7-71.0; and PAO, 28.6%; 95% CI, 3.7-71.0).

CONCLUSION

In an animal model of TBI and shock, REBOA increased Qcarotid and pMAP, but did not exacerbate TBI progression. PAO resulted in physiology closer to baseline with smaller increases in ICP and pMAP. Rapid blood resuscitation, not REBOA, resulted in the largest increase in ICP after intervention, which occurred in Control animals. Continued studies of the cerebral hemodynamics of aortic occlusion and blood transfusion are required to determine optimal resuscitation strategies for multi-injured patients.

Impact of Cushing's sign in the prehospital setting on predicting the need for immediate neurosurgical intervention in trauma patients: a nationwide retrospective observational study

Background

Cushing’s reflex usually results from intracranial hypertension. Although Cushing’s sign can implicate severe traumatic brain injury (TBI) in injured patients, no major investigations have been made. The purpose of this study was to assess the predictability of life-threatening brain injury requiring immediate neurosurgical intervention (LT-BI) among trauma patients with Cushing’s sign in the prehospital setting.

Methods

This was a retrospective study using data from the Japan Trauma Data Bank from the period of 2010 to 2014. Patients 16 years old or older with blunt mechanisms of injury who were transported directly from the scene and Glasgow Coma Scale for eye opening of one in the prehospital setting were included. LT-BI was defined as patients requiring burr hole evacuation or craniotomy within 24 h of hospital arrival and patients who were non-survivors due to isolated severe TBI. Prehospital systolic blood pressure (pSBP) and heart rate (pHR) were assessed using area under the receiver operating characteristic curve (AUROC) and multiple logistic regression analysis to predict LT-BI.

Results

Of 6332 eligible patients, 1859 (29%) exhibited LT-BI. AUROC of LT-BI using pSBP and pHR was 0.666 (95% confidence interval (CI); 0.652–0.681, P < 0.001), and 0.578 (95% CI; 0.563–0.594, P < 0.001), respectively. AUROC of pSBP was the highest among the 60 ≤ pHR ≤ 99 subgroup, of which AUROC was 0.680 (95% CI; 0.662–0.699, P < 0.001).

Multiple logistic regression analysis showed that the higher the pSBP and the lower the pHR, the more likely that the patients had LT-BI. In a group with pSBP ≥ 180 mmHg and pHR ≤ 59 beats/min, the odds ratio and 95% CI of LT-BI after adjusting for age, sex, and severity of injuries to other body regions was 4.77 (2.85–7.97), P < 0.001 was compared with the reference group, which was defined as patients with normal vital signs.

Discussion

Our study has found that the combination of hypertension and bradycardia, which are the components of Cushing's sign without eye opening in the prehospital setting was a weak but a significant predictor of LT-BI, or death due to possible isolated severe TBI.

Conclusions

Prehospital Cushing’s sign with disturbed level of consciousness in trauma patients was a weak but significant predictor of the need for immediate neurosurgical intervention.

Extending the golden hour: Partial resuscitative endovascular balloon occlusion of the aorta in a highly lethal swine liver injury model

BACKGROUND

Combat-injured patients may require rapid and sustained support during transport; however, the prolonged aortic occlusion produced by conventional resuscitative endovascular balloon occlusion of the aorta (REBOA) may lead to substantial morbidity. Partial REBOA (P-REBOA) may permit longer periods of occlusion by allowing some degree of distal perfusion. However, the ability of this procedure to limit exsanguination is unclear. We evaluated the impact of P-REBOA on immediate survival and ongoing hemorrhage in a highly lethal swine liver injury model.

METHODS

Fifteen Yorkshire-cross swine were anesthetized, instrumented, splenectomized, and subjected to rapid 10% total blood loss followed by 30% liver amputation. Coagulopathy was created through colloid hemodilution. Randomized swine received no intervention (control), P-REBOA, or complete REBOA (C-REBOA). Central mean arterial pressure (cMAP), carotid blood flow, and blood loss were recorded. Balloons remained inflated in the P-REBOA and C-REBOA groups for 90 minutes followed by graded deflation. The study ended at 180 minutes from onset of hemorrhage or death of the animal. Survival analysis was performed, and data were analyzed using repeated-measures analysis of variance with post hoc pairwise comparisons.

RESULTS

Mean survival times in the control, P-REBOA, and C-REBOA groups were, 25 ± 21, 86 ± 40, and 163 ± 20 minutes, respectively (p < 0.001). Blood loss was greater in the P-REBOA group than the C-REBOA or control groups, but this difference was not significant (4,722 ± 224, 3,834 ± 319, 3,818 ± 37 mL, respectively, p = 0.10). P-REBOA resulted in maintenance of near-baseline carotid blood flow and cMAP, while C-REBOA generated extreme cMAP and prolonged supraphysiologic carotid blood flow. Both experimental groups experienced profound decreases in cMAP following balloon deflation.

CONCLUSION

In the setting of severe ongoing hemorrhage, P-REBOA increased survival time beyond the golden hour while maintaining cMAP and carotid flow at physiologic levels.

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.

Partial Resuscitative Endovascular Balloon Occlusion of the Aorta in Swine Model of Hemorrhagic Shock

BACKGROUND

Complete resuscitative endovascular balloon occlusion of the aorta (C-REBOA) increases proximal mean arterial pressure (MAP) at the cost of distal organ ischemia, limiting the duration of intervention. We hypothesized that partial aortic occlusion (P-REBOA) would maintain a more physiologic proximal MAP and reduce distal tissue ischemia. We investigated the hemodynamic and physiologic effects of P-REBOA vs C-REBOA.

STUDY DESIGN

Fifteen swine were anesthetized, instrumented, splenectomized, and subjected to rapid 25% blood volume loss. They were randomized to C-REBOA, P-REBOA, or no intervention (controls). Partial REBOA was created by partially inflating an aortic balloon catheter to generate a 50% blood pressure gradient across the balloon. Hemodynamics were recorded and serum makers of ischemia and inflammation were measured. After 90 minutes of treatment, balloons were deflated to evaluate the immediate effects of reperfusion. End organs were histologically examined.

RESULTS

Complete REBOA produced supraphysiologic increases in proximal MAP after hemorrhage compared with more modest augmentation in the P-REBOA group (p < 0.01), with both groups significantly greater than controls (p < 0.01). Less rebound hypotension after balloon deflation was seen in the P-REBOA compared with C-REBOA groups. Complete REBOA resulted in higher serum lactate than both P-REBOA and controls (p < 0.01). Histology revealed early necrosis and disruption of duodenal mucosa in all C-REBOA animals, but none in P-REBOA animals.

CONCLUSIONS

In a porcine hemorrhagic shock model, P-REBOA resulted in more physiologically tolerable hemodynamic and ischemic changes compared with C-REBOA. Additional work is needed to determine whether the benefits associated with P-REBOA can both extend the duration of intervention and increase survival.

Abdominal Injuries in the "Found Down": Is Imaging Indicated?

BACKGROUND

We sought to investigate the incidence of abdominal injuries in "found down" trauma patients to better understand the value of emergency department (ED) imaging. Found down patients are at high risk for injuries to the head or neck and low risk to the abdomen or pelvis, so imaging with CT of the abdomen/pelvis (AP) or Focused Assessment with Sonography for Trauma (FAST) is of questionable value.

STUDY DESIGN

The trauma registry was queried over a 10-year period ending December 2013 for found down patients. Demographics, CT AP, FAST scans, and injuries were abstracted from the trauma registry and then through a confirmatory chart review. The primary outcome was significant abdominal or pelvis injury, defined as abdomen/pelvis Abbreviated Injury Scale (AIS) ≥ 3 or an abdominal injury that required operative intervention. The secondary outcome was mortality due to abdominal injury.

RESULTS

Of the 342 patients who met inclusion criteria, mean Glasgow Coma Scale (GCS) was 11.0, and 189 (60%) of those tested for alcohol were intoxicated. Abdominal imaging included: CT AP only, 88 (57%); FAST only, 37 (24%); and CT AP and FAST, 29 (19%). Neither CT AP nor FAST scan led to a change in treatment and no patient had abdomen/pelvis AIS ≥ 3. Overall mortality was 33 (10%).The 24 trauma deaths were attributed to serious head trauma (n = 16) or traumatic arrest in the ED (n = 8); the 9 medical deaths were due to cerebral vascular accident (n = 5) or sepsis (n = 4).

CONCLUSIONS

Although patients found down have a high mortality, abdominal injuries identified by imaging are highly unlikely. Efforts should focus on rapidly identifying and treating other causes of mortality, especially trauma to the head and neck, or medical diagnoses such as cerebral vascular accident or sepsis.