Isolated Severe Traumatic Brain Injuries Sustained During Combat Operations: Demographics, Mortality Outcomes, and Lessons to be Learned From Contrasts to Civilian Counterparts

Telemedicine for Potential Application in Austere Military Environments: Neurosurgical Support for a Decompressive Craniectomy

INTRODUCTION

The main goal of this study was to assess the feasibility of a head-mounted display (HMD) providing telemedicine neurosurgical support during a decompressive craniectomy by a military surgeon who is isolated from readily available neurosurgical care. The secondary aim was to assess the usability perceived by the military surgeon and to evaluate technical aspects of the head-mounted display.

MATERIALS AND METHODS

After a standard concise lecture, 10 military surgeons performed a decompressive craniectomy on a AnubiFiX-embalmed post-mortem human head. Seven military surgeons used a HMD to receive telemedicine neurosurgical support. In the control group, three military surgeons performed a decompressive craniectomy without guidance. The performance of the decompressive craniectomy was evaluated qualitatively by the supervising neurosurgeon and quantified with the surgeons' operative performance tool. The military surgeons rated the usability of the HMD with the telehealth usability questionnaire.

RESULTS

All military surgeons performed a decompressive craniectomy adequately directly after a standard concise lecture. The HMD was used to discuss potential errors and reconfirmed essential steps. The military surgeons were very satisfied with the HMD providing telemedicine neurosurgical support. Military surgeons in the control group were faster. The HMD showed no hard technical errors.

CONCLUSIONS

It is feasible to provide telemedicine neurosurgical support with a HMD during a decompressive craniectomy performed by a non-neurosurgically trained military surgeon. All military surgeons showed competence in performing a decompressive craniectomy after receiving a standardized concise lecture. The use of a HMD clearly demonstrated the potential to improve the quality of these neurosurgical procedures performed by military surgeons.

[Current mortality from war injuries-A narrative review]

BACKGROUND

The war in Ukraine has led to a strategic reorientation of the German Armed Forces towards national and alliance defense. This has also raised the need for medical and surgical adaptation to scenarios of conventional warfare. In order to develop appropriate and effective concepts it is necessary to identify those war injuries that are associated with a relevant primary and secondary mortality and that can be influenced by medical measures (potentially survivable injuries).

OBJECTIVE

The aim of this selective literature review was to identify war injuries with high primary and secondary mortality.

METHODS

A selective literature review was performed in the PubMed® database with the search terms war OR combat AND injury AND mortality from 2001 to 2023. Studies including data of war injuries and associated mortality were included.

RESULTS

A total of 33 studies were included in the analysis. Severe traumatic brain injury and thoracoabdominal hemorrhage were the main contributors to primary mortality. Injuries to the trunk, neck, traumatic brain injury, and burns were associated with relevant secondary mortality. Among potentially survivable injuries, thoracoabdominal hemorrhage accounted for the largest proportion. Prehospital blood transfusions and short transport times significantly reduced war-associated mortality.

CONCLUSION

Control of thoracoabdominal hemorrhage has the highest potential to reduce mortality in modern warfare. Besides that, treatment of traumatic brain injury, burns and neck injuries has a high relevance in reducing mortality. Hospitals of the German Armed Forces need to focus on these requirements.

Association Between Admission Ionized Calcium Level and Neurological Outcome of Patients with Isolated Severe Traumatic Brain Injury: A Retrospective Cohort Study

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Pathophysiological processes following initial insult are complex and not fully understood. Ionized calcium (Ca++) is an essential cofactor in the coagulation cascade and platelet aggregation, and hypocalcemia may contribute to the progression of intracranial bleeding. On the other hand, Ca++ is an important mediator of cell damage after TBI and cellular hypocalcemia may have a neuroprotective effect after brain injury. We hypothesized that early hypocalcemia might have an adverse effect on the neurological outcome of patients suffering from isolated severe TBI. In this study, we aimed to evaluate the relationship between admission Ca++ level and the neurological outcome of these patients.

METHODS

This was a retrospective, single-center, cohort study of all patients admitted between January 2014 and December 2020 due to isolated severe TBI, which was defined as head abbreviated injury score ≥ 4 and an absence of severe (abbreviated injury score > 2) extracranial injuries. The primary outcome was a favorable neurological status at discharge, defined by a modified Rankin Scale of 0-2. Multivariable logistic regression was performed to determine whether admission hypocalcemia (Ca++  < 1.16 mmol L-1) is an independent predictor of neurological status at discharge.

RESULTS

The final analysis included 201 patients. Hypocalcemia was common among patients with isolated severe TBI (73.1%). Most of the patients had mild hypocalcemia (1 < Ca++  < 1.16 mmol L-1), and only 13 (6.5%) patients had Ca++  ≤ 1.00 mmol L-1. In the entire cohort, hypocalcemia was independently associated with higher rates of good neurological status at discharge (adjusted odds ratio of 3.03, 95% confidence interval 1.11-8.33, p = 0.03). In the subgroup of 81 patients with an admission Glasgow Coma Scale > 8, 52 (64.2%) had hypocalcemia. Good neurological status at discharge was recorded in 28 (53.8%) of hypocalcemic patients compared with 14 (17.2%) of those with normal Ca++ (p = 0.002). In multivariate analyses, hypocalcemia was independently associated with good neurological status at discharge (adjusted odds ratio of 6.67, 95% confidence interval 1.39-33.33, p = 0.02).

CONCLUSIONS

Our study demonstrates that among patients with isolated severe TBI, mild admission hypocalcemia is associated with better neurological status at hospital discharge. The prognostic value of Ca++ may be greater among patients with admission Glasgow Coma Scale > 8. Trials are needed to investigate the role of hypocalcemia in brain injury.

Neuro-psychiatric symptoms in directly and indirectly blast exposed civilian survivors of urban missile attacks

BACKGROUND

Blast-explosion may cause traumatic brain injury (TBI), leading to post-concussion syndrome (PCS). In studies on military personnel, PCS symptoms are highly similar to those occurring in post-traumatic stress disorder (PTSD), questioning the overlap between these syndromes. In the current study we assessed PCS and PTSD in civilians following exposure to rocket attacks. We hypothesized that PCS symptomatology and brain connectivity will be associated with the objective physical exposure, while PTSD symptomatology will be associated with the subjective mental experience.

METHODS

Two hundred eighty nine residents of explosion sites have participated in the current study. Participants completed self-report of PCS and PTSD. The association between objective and subjective factors of blast and clinical outcomes was assessed using multivariate analysis. White-matter (WM) alterations and cognitive abilities were assessed in a sub-group of participants (n = 46) and non-exposed controls (n = 16). Non-parametric analysis was used to compare connectivity and cognition between the groups.

RESULTS

Blast-exposed individuals reported higher PTSD and PCS symptomatology. Among exposed individuals, those who were directly exposed to blast, reported higher levels of subjective feeling of danger and presented WM hypoconnectivity. Cognitive abilities did not differ between groups. Several risk factors for the development of PCS and PTSD were identified.

CONCLUSIONS

Civilians exposed to blast present higher PCS/PTSD symptomatology as well as WM hypoconnectivity. Although symptoms are sub-clinical, they might lead to the future development of a full-blown syndrome and should be considered carefully. The similarities between PCS and PTSD suggest that despite the different etiology, namely, the physical trauma in PCS and the emotional trauma in PTSD, these are not distinct syndromes, but rather represent a combined biopsychological disorder with a wide spectrum of behavioral, emotional, cognitive and neurological symptoms.

Manchester Arena Attack: management of paediatric penetrating brain injuries

PURPOSE

The Manchester Arena bombing on 22 May 2017 resulted in 22 deaths and over 160 casualties requiring medical attention. Given the threat of modern- era terrorist attacks in civilian environments, it is important that we are able to anticipate and appropriately manage neurological injuries associated with these events. This article describes our experience of managing paediatric neurosurgical blast injuries, from initial triage and operative management to longer-term considerations.

MATERIALS AND METHODS

Case study and literature review.

RESULTS

Paediatric traumatic and penetrating brain injury patients often make a good neurological recovery despite low GCS at time of injury; this should be accounted for during triage and operative decision making in major trauma, mass casualty events. Conservative management of retained shrapnel is advocated in view of low long-term infection rates with retained shrapnel and worsened neurological outcome with shrapnel retrieval. All penetrating brain injuries should receive a prolonged course of broad-spectrum antibiotics and undergo long term follow-up imaging to monitor for the development of cerebral abscesses. MRI should never be utilised in penetrating brain injury cases, even in the absence of macroscopically visible fragments, due to the effect of MRI ferromagnetic field torque on shrapnel fragments. Anti-epileptic drugs should only be prescribed for the initial seven days after injury, as continuing beyond this does not incur any benefit in the reduction of long term post-traumatic epilepsy.

CONCLUSION

All receiving neurosurgical units should become familiar with optimum management of these thankfully rare, but complex injuries from their initial presentation to long term follow up considerations. All neurosurgical units should have well-rehearsed local plans to follow in the event of such incidents, ensuring timely deliverance of appropriate neurosurgical care in such extreme settings.

Decreased Intracranial Pressure Monitor Use at Level II Trauma Centers is Associated with Increased Mortality

Previous investigations suggest outcome differences at Level I and Level II trauma centers. We examined use of intracranial pressure (ICP) monitors at Level I and Level II trauma centers after traumatic brain injury (TBI) and its effect on mortality. The 2007 to 2008 National Trauma Databank was reviewed for patients with an indication for ICP monitoring based on Brain Trauma Foundation (BTF) guidelines. Demographic and clinical outcomes at Level I and Level II centers were compared by regression modeling. Overall, 15,921 patients met inclusion criteria; 11,017 were admitted to a Level I and 4,904 to a Level II trauma center. Patients with TBI admitted to a Level II trauma center had a lower rate of Injury Severity Score greater than 16 (80 vs 82%, P < 0.01) and lower frequency of head Abbreviated Injury Score greater than 3 (80 vs 82%, P < 0.01). After regression modeling, patients with TBI admitted to a Level II trauma center were 31 per cent less likely to receive an ICP monitor (adjusted odds ratio [AOR], 0.69; P < 0.01) and had a significantly higher mortality (AOR, 1.12; P < 0.01). Admission to a Level II trauma center after severe TBI is associated with a decreased use of ICP monitoring in patients who meet BTF criteria as well as an increased mortality. These differences should be validated prospectively to narrow these discrepancies in care and outcomes between Level I and Level II centers.

Mortality and Functional Outcome Predictors in Combat-Related Penetrating Brain Injury Treatment in a Specialty Civilian Medical Facility

INTRODUCTION

The combined use of new types of weapons and new types of personal protective equipment has led to changes in the occurrence, nature, and severity of penetrating brain wounds. The availability of modern equipment, methods of treatment, and trained medical personnel in a civilian hospital, as well as advanced specialty medical care, has improved treatment outcomes. There have been a limited number of publications regarding analysis and predictors of treatment outcomes in patients with combat-related penetrating brain injury in contemporary armed conflicts. The purpose of this study was to analyze the results of surgical treatment of patients with penetrating brain injury and to identify significant outcome predictors in these patients.

MATERIALS AND METHODS

This was a prospective analysis of penetrating brain injury in patients who were admitted to Mechnikov Dnipropetrovsk Regional Clinical Hospital, Ukraine, from May 9, 2014, to December 31, 2017. All wounds were sustained during local armed conflict in Eastern Ukraine. The primary outcomes of interest were mortality rate at 1 month and Glasgow Outcome Scale score at 12 months after the injury.

RESULTS

In total, 184 patients were identified with combat-related brain injury; of those, 121 patients with penetrating brain injury were included in our study. All patients were male soldiers with a mean age of 34.1 years (standard deviation [SD], 9.1 years). Mean admission Glasgow Coma Scale score was 10 (SD, 4), and mean admission Injury Severity Score was 27.7 (SD, 7.6). Mortality within 1 month was 20.7%, and intracranial purulent-septic complications were diagnosed in 11.6% of the patients. Overall, 65.3% of the patients had favorable outcome (good recovery or moderate disability) based on Glasgow Outcome Scale score at 12 months after the injury. The following were predictors of mortality or poor functional outcome at 1 year after the injury: low Glasgow Coma Scale score on admission, gunshot wound to the head, dural venous sinuses wound, presence of intracerebral hematomas, intraventricular and subarachnoid hemorrhage accompanied by lateral or axial dislocation, and presence of intracranial purulent-septic complications.

CONCLUSIONS

Generally, combat-related penetrating brain injuries had satisfactory treatment outcomes. Treatment outcomes in this study were comparable to those previously reported by other authors in military populations and significantly better than outcomes of peacetime penetrating brain injury treatment.

Outcomes of tranexamic acid administration in military trauma patients with intracranial hemorrhage: a cohort study

Background

Tranexamic acid (TXA) may be a useful adjunct for military patients with severe traumatic brain injury (TBI). These patients are often treated in austere settings without immediate access to neurosurgical intervention. The purpose of this study was to evaluate any association between TXA use and progression of intracranial hemorrhage (ICH), neurologic outcomes, and venous thromboembolism (VTE) in TBI.

Methods

This was a retrospective cohort study of military casualties from October 2010 to December 2015 who were transferred to a military treatment facility (MTF) in the United States. Data collected included: demographics, types of injuries, initial and interval head computerized tomography (CT) scans, Glasgow Coma Scores (GCS), and six-month Glasgow Outcome Scores (GOS). Results were stratified based on TXA administration, progression of ICH, and VTE.

Results

Of the 687 active duty service members reviewed, 71 patients had ICH (10.3%). Most casualties were injured in a blast (80.3%), with 36 patients (50.7%) sustaining a penetrating TBI. Mean ISS was 28.2 ± 12.3. Nine patients (12.7%) received a massive transfusion within 24 h of injury, and TXA was administered to 14 (19.7%) casualties. Patients that received TXA had lower initial reported GCS (9.2 ± 4.4 vs. 12.5 ± 3.4, p = 0.003), similar discharge GCS (13.3 ± 4.0 vs. 13.8 ± 3.2, p = 0.58), and a larger improvement between initial and discharge GCS (3.7 ± 3.9 vs. 1.3 ± 3.1, p = 0.02). However, there was no difference in mortality (7.1% vs. 7.0%, p = 1.00), progression of ICH (45.5% vs. 14.7%, p = 0.09), frequency of cranial decompression (50.0% vs. 42.1%, p = 0.76), or mean GOS (3.5 ± 0.9 vs. 3.8 ± 1.0, p = 0.13). Patients administered TXA had a higher rate of VTE (35.7% vs. 7.0%, p = 0.01). On multivariate analysis, however, TXA was not independently associated with VTE.

Conclusions

Patients that received TXA were associated with an improvement in GCS but not in progression of ICH or GOS. TXA was not independently associated with VTE, although this may be related to a paucity of patients receiving TXA. Decisions about TXA administration in military casualties with ICH should be considered in the context of the availability of neurosurgical intervention as well as severity of extracranial injuries and need for massive transfusion.

The Silver Lining: Advances in the Surgical Management of Brain Trauma Attributable to War

Within the text we elaborate on the relationship between war and medicine, particularly as it pertains to neurosurgery and the management of brain trauma, and emphasize neurosurgical advancements in the treatment of brain trauma gleaned from U.S.-involved conflicts of the 21st century.

Tactical Neurocritical Care

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

Analysis of Factors and Conditions Influencing Military Neurosurgery Recruitment and Retention

INTRODUCTION

The Defense Health Agency has shifted focus of military medicine to operational readiness. As such, neurosurgery remains a critical wartime specialty. We investigate the factors impacting recruitment and retention of military neurosurgeons.

METHODS

Survey of military neurosurgeons was performed via the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Committee of Military Neurosurgeons and the Council of State Neurosurgical Societies. Retention and recruitment were queried.

RESULTS

93/119 (78.2%) current or previously affiliated military neurosurgeons would recommend service as a military neurosurgeon to a colleague. Those who felt a sense of patriotism were 4.3 times more likely to recommend military service (P = 0.027, CI 1.19-16.82). Those who developed a sense of camaraderie showed a trend to recommending military neurosurgery (P = 0.058, CI 0.95-9.78). Those with a current military obligation were.28 times (P = 0.02, CI 0.09-0.85) as likely to recommend service. Military physicians who felt a need for reform to increase salary were 2.5 times less likely to be retained.

DISCUSSION

Service in the US military is a positive experience with camaraderie, patriotism, and unique military experiences predictive of recruitment. Meanwhile, focus on pay discrepancy can result in lost retention. These factors should be explored regarding recruitment and retention of military neurosurgeons.

Two-year mortality and functional outcomes in combat-related penetrating brain injury: battlefield through rehabilitation

OBJECTIVEThere are limited data concerning the long-term functional outcomes of patients with penetrating brain injury. Reports from civilian cohorts are small because of the high reported mortality rates (as high as 90%). Data from military populations suggest a better prognosis for penetrating brain injury, but previous reports are hampered by analyses that exclude the point of injury. The purpose of this study was to provide a description of the long-term functional outcomes of those who sustain a combat-related penetrating brain injury (from the initial point of injury to 24 months afterward).METHODSThis study is a retrospective review of cases of penetrating brain injury in patients who presented to the Role 3 Multinational Medical Unit at Kandahar Airfield, Afghanistan, from January 2010 to March 2013. The primary outcome of interest was Glasgow Outcome Scale (GOS) score at 6, 12, and 24 months from date of injury.RESULTSA total of 908 cases required neurosurgical consultation during the study period, and 80 of these cases involved US service members with penetrating brain injury. The mean admission Glasgow Coma Scale (GCS) score was 8.5 (SD 5.56), and the mean admission Injury Severity Score (ISS) was 26.6 (SD 10.2). The GOS score for the cohort trended toward improvement at each time point (3.6 at 6 months, 3.96 at 24 months, p > 0.05). In subgroup analysis, admission GCS score ≤ 5, gunshot wound as the injury mechanism, admission ISS ≥ 26, and brain herniation on admission CT head were all associated with worse GOS scores at all time points. Excluding those who died, functional improvement occurred regardless of admission GCS score (p < 0.05). The overall mortality rate for the cohort was 21%.CONCLUSIONSGood functional outcomes were achieved in this population of severe penetrating brain injury in those who survived their initial resuscitation. The mortality rate was lower than observed in civilian cohorts.

Association of time to craniectomy with survival in patients with severe combat-related brain injury

OBJECTIVEIn combat and austere environments, evacuation to a location with neurosurgery capability is challenging. A planning target in terms of time to neurosurgery is paramount to inform prepositioning of neurosurgical and transport resources to support a population at risk. This study sought to examine the association of wait time to craniectomy with mortality in patients with severe combat-related brain injury who received decompressive craniectomy.METHODSPatients with combat-related brain injury sustained between 2005 and 2015 who underwent craniectomy at deployed surgical facilities were identified from the Department of Defense Trauma Registry and Joint Trauma System Role 2 Registry. Eligible patients survived transport to a hospital capable of diagnosing the need for craniectomy and performing surgery. Statistical analyses included unadjusted comparisons of postoperative mortality by elapsed time from injury to start of craniectomy, and Cox proportional hazards modeling adjusting for potential confounders. Time from injury to craniectomy was divided into quintiles, and explored in Cox models as a binary variable comparing early versus delayed craniectomy with cutoffs determined by the maximum value of each quintile (quintile 1 vs 2-5, quintiles 1-2 vs 3-5, etc.). Covariates included location of the facility at which the craniectomy was performed (limited-resource role 2 facility vs neurosurgically capable role 3 facility), use of head CT scan, US military status, age, head Abbreviated Injury Scale score, Injury Severity Score, and injury year. To reduce immortal time bias, time from injury to hospital arrival was included as a covariate, entry into the survival analysis cohort was defined as hospital arrival time, and early versus delayed craniectomy was modeled as a time-dependent covariate. Follow-up for survival ended at death, hospital discharge, or hospital day 16, whichever occurred first.RESULTSOf 486 patients identified as having undergone craniectomy, 213 (44%) had complete date/time values. Unadjusted postoperative mortality was 23% for quintile 1 (n = 43, time from injury to start of craniectomy 30-152 minutes); 7% for quintile 2 (n = 42, 154-210 minutes); 7% for quintile 3 (n = 43, 212-320 minutes); 19% for quintile 4 (n = 42, 325-639 minutes); and 14% for quintile 5 (n = 43, 665-3885 minutes). In Cox models adjusted for potential confounders and immortal time bias, postoperative mortality was significantly lower when time to craniectomy was within 5.33 hours of injury (quintiles 1-3) relative to longer delays (quintiles 4-5), with an adjusted hazard ratio of 0.28, 95% CI 0.10-0.76 (p = 0.012).CONCLUSIONSPostoperative mortality was significantly lower when craniectomy was initiated within 5.33 hours of injury. Further research to optimize craniectomy timing and mitigate delays is needed. Functional outcomes should also be evaluated.

Inadequate Decompressive Craniectomy Following a Wartime Traumatic Brain Injury - An Illustrative Case of Why Size Matters

Traumatic brain injury has been called the "signature injury" of the wars in Iraq and Afghanistan, and the management of severe and penetrating brain injury has evolved considerably based on the experiences of military neurosurgeons. Current guidelines recommend that decompressive hemicraniectomy be performed with large, frontotemporoparietal bone flaps, but practice patterns vary markedly. The following case is illustrative of potential clinical courses, complications, and efforts to salvage inadequately-sized decompressive craniectomies performed for combat-related severe and penetrating brain injury. The authors follow this with a review of the current literature pertaining to decompressive craniectomy, and finally provide their recommendations for some of the technical nuances of performing decompressive hemicraniectomy after severe or penetrating brain injury.

Outcomes in patients with gunshot wounds to the brain

Introduction

Gunshot wounds to the brain (GSWB) confer high lethality and uncertain recovery. It is unclear which patients benefit from aggressive resuscitation, and furthermore whether patients with GSWB undergoing cardiopulmonary resuscitation (CPR) have potential for survival or organ donation. Therefore, we sought to determine the rates of survival and organ donation, as well as identify factors associated with both outcomes in patients with GSWB undergoing CPR.

Methods

We performed a retrospective, multicenter study at 25 US trauma centers including dates between June 1, 2011 and December 31, 2017. Patients were included if they suffered isolated GSWB and required CPR at a referring hospital, in the field, or in the trauma resuscitation room. Patients were excluded for significant torso or extremity injuries, or if pregnant. Binomial regression models were used to determine predictors of survival/organ donation.

Results

825 patients met study criteria; the majority were male (87.6%) with a mean age of 36.5 years. Most (67%) underwent CPR in the field and 2.1% (n=17) survived to discharge. Of the non-survivors, 17.5% (n=141) were considered eligible donors, with a donation rate of 58.9% (n=83) in this group. Regression models found several predictors of survival. Hormone replacement was predictive of both survival and organ donation.

Conclusion

We found that GSWB requiring CPR during trauma resuscitation was associated with a 2.1% survival rate and overall organ donation rate of 10.3%. Several factors appear to be favorably associated with survival, although predictions are uncertain due to the low number of survivors in this patient population. Hormone replacement was predictive of both survival and organ donation. These results are a starting point for determining appropriate treatment algorithms for this devastating clinical condition.

Level of evidence

Level II.

Outcomes Associated With Blast Versus Nonblast-Related Traumatic Brain Injury in US Military Service Members and Veterans: A Systematic Review

OBJECTIVES

To systematically review the literature on comparative clinical and functional outcomes following blast-related versus nonblast-related traumatic brain injury (TBI) among US service members and Veterans.

DESIGN

MEDLINE search (January 2001 to June 2016) supplemented with hand search of reference lists and input from peer reviewers.

RESULTS

Thirty-one studies (in 33 articles) reported on health outcomes; only 2 were rated low risk of bias. There was variation in outcomes reported and methods of assessment. Blast and nonblast TBI groups had similar rates of depression, sleep disorders, alcohol misuse, vision loss, vestibular dysfunction, and functional status. Comparative outcomes were inconsistent with regard to posttraumatic stress disorder diagnosis or symptoms, headache, hearing loss, and neurocognitive function. Mortality, burn, limb loss, and quality of life were each reported in few studies, most with small sample sizes. Only 4 studies reported outcomes by blast injury mechanism.

CONCLUSIONS

Most clinical and functional outcomes appeared comparable in military service members and Veterans with TBI, regardless of blast exposure. Inconsistent findings and limited outcomes reporting indicate that more research is needed to determine whether there is a distinct pattern of impairments and comorbidities associated with blast-related TBI.

Infection after penetrating brain injury-An Eastern Association for the Surgery of Trauma multicenter study oral presentation at the 32nd annual meeting of the Eastern Association for the Surgery of Trauma, January 15-19, 2019, in Austin, Texas

BACKGROUND

Fatality rates following penetrating traumatic brain injury (pTBI) are extremely high and survivors are often left with significant disability. Infection following pTBI is associated with worse morbidity. The modern rates of central nervous system infections (INF) in civilian survivors are unknown. This study sought to determine the rate of and risk factors for INF following pTBI and to determine the impact of antibiotic prophylaxis.

METHODS

Seventeen institutions submitted adult patients with pTBI and survival of more than 72 hours from 2006 to 2016. Patients were stratified by the presence or absence of infection and the use or omission of prophylactic antibiotics. Study was powered at 85% to detect a difference in infection rate of 5%. Primary endpoint was the impact of prophylactic antibiotics on INF. Mantel-Haenszel χ and Wilcoxon's rank-sum tests were used to compare categorical and nonparametric variables. Significance greater than p = 0.2 was included in a logistic regression adjusted for center.

RESULTS

Seven hundred sixty-three patients with pTBI were identified over 11 years. 7% (n = 51) of patients developed an INF. Sixty-six percent of INF patients received prophylactic antibiotics. Sixty-two percent of all patients received one dose or greater of prophylactic antibiotics and 50% of patients received extended antibiotics. Degree of dural penetration did not appear to impact the incidence of INF (p = 0.8) nor did trajectory through the oropharynx (p = 0.18). Controlling for other variables, there was no statistically significant difference in INF with the use of prophylactic antibiotics (p = 0.5). Infection was higher in patients with intracerebral pressure monitors (4% vs. 12%; p = <0.001) and in patients with surgical intervention (10% vs. 3%; p < 0.001).

CONCLUSION

There is no reduction in INF with prophylactic antibiotics in pTBI. Surgical intervention and invasive intracerebral pressure monitoring appear to be risk factors for INF regardless of prophylactic use.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Outcome and rational management of civilian gunshot injuries to the brain-retrospective analysis of patients treated at the Helsinki University Hospital from 2000 to 2012

Background

Treatment of gunshot wounds of the brain (GSWB) remains controversial and there is high variation in reported survival rates (from < 10 to > 90%) depending on the etiology and country. We retrospectively analyzed the outcome of a series of consecutive GSWB patients admitted alive to a level 1 trauma center in a safe high-income welfare country with a low rate of homicidal gun violence.

Methods

Patients admitted due to a GSWB to the HUS Helsinki University Hospital during 2000–2012 were identified from hospital discharge registry and log books of the emergency room and ICU. CT scans and medical records of these patients were reviewed. Univariate analysis and backward logistic regression were performed, and their results compared with that of a systematic literature review of factors related to the outcome of GSWB patients.

Results

Sixty-four patients admitted alive after GSWB were identified. Eighty percent had self-inflicted GSWB, 81% were contact shots, and 70% were caused by handguns. In-hospital mortality was 72%. Factors associated with mortality in our series were low GCS (≤ 8) at admission, transventricular bullet trajectory, and associated damage to deep brain structures, as reported before in the literature. Of the 64 patients admitted alive, 42% (27/64) were admitted to ICU, 34% (22/64) underwent surgery, and in 25% (16/64), craniotomy and hematoma evacuation was performed. Mortality in the surgically treated group was 32% but near 100% without surgery and ICU treatment. Median GOS in the surgically treated patients was 3 (range 1–5).

Conclusions

GSWB caused by contact shot from handguns has a high mortality rate, but can be survived with reasonable outcome if limited to lobar injury without significant damage to deep brain structures or brain stem. In such GSWB patients, initial aggressive resuscitation, ICU admission, and surgery seem indicated.

Electronic supplementary material

The online version of this article (10.1007/s00701-019-03952-y) contains supplementary material, which is available to authorized users.

Synergistic Role of Oxidative Stress and Blood-Brain Barrier Permeability as Injury Mechanisms in the Acute Pathophysiology of Blast-induced Neurotrauma

Blast-induced traumatic brain injury (bTBI) has been recognized as the common mode of neurotrauma amongst military and civilian personnel due to an increased insurgent activity domestically and abroad. Previous studies from our laboratory have identified enhanced blood-brain barrier (BBB) permeability as a significant, sub-acute (four hours post-blast) pathological change in bTBI. We also found that NADPH oxidase (NOX)-mediated oxidative stress occurs at the same time post-blast when the BBB permeability changes. We therefore hypothesized that oxidative stress is a major causative factor in the BBB breakdown in the sub-acute stages. This work therefore examined the role of NOX1 and its downstream effects on BBB permeability in the frontal cortex (a region previously shown to be the most vulnerable) immediately and four hours post-blast exposure. Rats were injured by primary blast waves in a compressed gas-driven shock tube at 180 kPa and the BBB integrity was assessed by extravasation of Evans blue and changes in tight junction proteins (TJPs) as well as translocation of macromolecules from blood to brain and vice versa. NOX1 abundance was also assessed in neurovascular endothelial cells. Blast injury resulted in increased extravasation and reduced levels of TJPs in tissues consistent with our previous observations. NOX1 levels were significantly increased in endothelial cells followed by increased superoxide production within 4 hours of blast. Blast injury also increased the levels/activation of matrix metalloproteinase 3 and 9. To test the role of oxidative stress, rats were administered apocynin, which is known to inhibit the assembly of NOX subunits and arrests its function. We found apocynin completely inhibited dye extravasation as well as restored TJP levels to that of controls and reduced matrix metalloproteinase activation in the sub-acute stages following blast. Together these data strongly suggest that NOX-mediated oxidative stress contributes to enhanced BBB permeability in bTBI through a pathway involving increased matrix metalloproteinase activation.

Neurosurgery and Medical Management of Severe Head Injury

Management of the patient with moderate to severe brain injury in any environment can be time consuming and resource intensive. In the austere or hostile environment, the challenges to deliver care to this patient population are magnified. These guidelines have been developed by acknowledging commonly recognized recommendations for neurosurgical and neuro-critical care patients and augmenting those evaluations and interventions based on the experience of neurosurgeons, trauma surgeons, and intensivists who have delivered care during recent coalition conflicts.

A Single Primary Blast-Induced Traumatic Brain Injury in a Rodent Model Causes Cell-Type Dependent Increase in Nicotinamide Adenine Dinucleotide Phosphate Oxidase Isoforms in Vulnerable Brain Regions

Blast-induced traumatic brain injury (bTBI) is a leading cause of morbidity in soldiers on the battlefield and in training sites with long-term neurological and psychological pathologies. Previous studies from our laboratory demonstrated activation of oxidative stress pathways after blast injury, but their distribution among different brain regions and their impact on the pathogenesis of bTBI have not been explored. The present study examined the protein expression of two isoforms: nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 and 2 (NOX1, NOX2), corresponding superoxide production, a downstream event of NOX activation, and the extent of lipid peroxidation adducts of 4-hydroxynonenal (4HNE) to a range of proteins. Brain injury was evaluated 4 h after the shock-wave exposure, and immunofluorescence signal quantification was performed in different brain regions. Expression of NOX isoforms displayed a differential increase in various brain regions: in hippocampus and thalamus, there was the highest increase of NOX1, whereas in the frontal cortex, there was the highest increase of NOX2 expression. Cell-specific analysis of changes in NOX expression with respect to corresponding controls revealed that blast resulted in a higher increase of NOX1 and NOX 2 levels in neurons compared with astrocytes and microglia. Blast exposure also resulted in increased superoxide levels in different brain regions, and such changes were reflected in 4HNE protein adduct formation. Collectively, this study demonstrates that primary blast TBI induces upregulation of NADPH oxidase isoforms in different regions of the brain parenchyma and that neurons appear to be at higher risk for oxidative damage compared with other neural cells.

Microwave technology for detecting traumatic intracranial bleedings: tests on phantom of subdural hematoma and numerical simulations

Traumatic brain injury is the leading cause of death and severe disability for young people and a major public health problem for elderly. Many patients with intracranial bleeding are treated too late, because they initially show no symptoms of severe injury and are not transported to a trauma center. There is a need for a method to detect intracranial bleedings in the prehospital setting. In this study, we investigate whether broadband microwave technology (MWT) in conjunction with a diagnostic algorithm can detect subdural hematoma (SDH). A human cranium phantom and numerical simulations of SDH are used. Four phantoms with SDH 0, 40, 70 and 110 mL are measured with a MWT instrument. The simulated dataset consists of 1500 observations. Classification accuracy is assessed using fivefold cross-validation, and a validation dataset never used for training. The total accuracy is 100 and 82-96 % for phantom measurements and simulated data, respectively. Sensitivity and specificity for bleeding detection were 100 and 96 %, respectively, for the simulated data. SDH of different sizes is differentiated. The classifier requires training dataset size in order of 150 observations per class to achieve high accuracy. We conclude that the results indicate that MWT can detect and estimate the size of SDH. This is promising for developing MWT to be used for prehospital diagnosis of intracranial bleedings.

[A new concept of organization and scope of neurosurgical care in the US army during armed conflicts in the early 2000s]

Military operations in various parts of the world in the early 2000s are becoming more regionalized; new warfare tactics emerge, which makes it necessary to review and modify the neurosurgical care system. The article reviews the results of original studies on this issue and summarizes the experience of the US Army medical service in Afghanistan and Iraq. The article discusses the structure of sanitary losses, organization and scope of medical and evacuation neurosurgical measures, types and techniques of surgical interventions, and the rate of complications. We describe five levels of neurosurgical care echelons and an implemented "injury control - neurosurgery" concept; particular attention is paid to the peculiarities of research and specialist training. We demonstrate that implementation of the new concept for organization and scope of neurosurgical care has improved treatment outcomes and reduced the mortality rate in the mentioned military conflicts of recent years compared to those in the Vietnam War. We may conclude that the described experience of the US Army can be used to improve the efficacy of neurosurgical care to the wounded and victims of armed conflicts.

Hypoxemia during aeromedical evacuation of the walking wounded

BACKGROUND

Hypobaric hypoxemia is a well-known risk of aeromedical evacuation (AE). Validating patients as safe to fly includes assessment of oxygenation status as well as oxygen-carrying capability (hemoglobin). The incidence and severity of hypoxemia during AE of noncritically injured casualties have not been studied.

METHODS

Subjects deemed safe to fly by the validating flight surgeon were monitored with pulse oximetry from the flight line until arrival at definitive care. All subjects were US military personnel or contractors following traumatic injuries. Noninvasive oxygen saturation (SpO2), pulse rate, and noninvasive hemoglobin were measured every 5 seconds and recorded to electronic memory. Patient demographics and physiologic data were collected by chart abstraction from the Air Force Form 3899, patient movement record. The incidence and duration of hypoxemic events (SpO2 < 90%) and critical hypoxemic events were determined (SpO2 < 85%).

RESULTS

Sixty-one casualties were evaluated during AE from Bagram Air Base to Landstuhl Regional Medical Center. The mean (SD) age was 26.2 (6) years, Injury Severity Score (ISS) was 8 (11), and mean SpO2 before AE was 96% (2%). The mean (SD) transport time was 9.3 (1.3) hours. Patients were monitored before AE for a brief period, yielding a total recording time of 10.28 hours. The mean (SD) hemoglobin at the time of enrollment was 13.2 (3.5) g/dL (9.4-18.0 g/dL). Hypoxemia (SpO2 < 90%) was seen in 55 (90%) of 61 subjects. The mean duration of SpO2 less than 90% was 44 minutes. The mean (SD) change in SpO2 from baseline to mean in-flight SpO2 was 4% (1.2%). Thirty-four patients (56%) exhibited an SpO2 less than 85% for 11.7 (15) minutes.

CONCLUSION

Hypoxemia is a common event during AE of casualties. In patients with infection and concussion or mild traumatic brain injury, this could have long-term consequences.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level V.

Early in-theater management of combat-related traumatic brain injury: A prospective, observational study to identify opportunities for performance improvement

BACKGROUND

Combat-related moderate-to-severe traumatic brain injury (CRTBI) is a significant cause of wartime morbidity and mortality. As of August 2014, moderate-to-severe traumatic brain injuries sustained by members of the Department of Defense worldwide since 2000 totaled 32,996 cases. Previously published epidemiologic reviews describe CRTBI management at a "strategic" level, but they lack "tactical" patient-specific data required for performance improvement. In addition, scarce data exist regarding prehospital CRTBI care.

METHODS

This is a prospective observational study of consecutive CRTBI casualties presenting to US Role 3 medical facilities. Admission variables including demographics, initial clinical findings, and laboratory results were collected. Head computed tomographic scan findings were noted. Interventions in the first 72 postinjury hours were recorded. Early in-theater mortality was noted, but longer-term outcomes were not.

RESULTS

Casualties were predominately injured by explosive blasts (78.6%). Penetrating injuries occurred in 42.9%. On arrival, Glasgow Coma Scale (GCS) score was less than 8 for 47.7%. Hypothermia (temperature < 95.0°F) was present in 4.5%, and hypotension (systolic blood pressure < 90 mm Hg) in 21.1%. Hypoxia (O2 saturation < 90%) was observed in 52.5%. Both hypercarbia (Paco2 > 45 mm Hg, 50%) and hypocarbia (Paco2 < 36 mm Hg, 20.3%) were common on presentation. Head computed tomographic scan most commonly found skull fracture (68.9%), subdural hematoma (54.1%), and cerebral contusion (51.4%). Hypertonic saline was administered to 69.7% and factor VIIa to 11.1%. Early in-theater mortality at Role 3 was 19.4%.

CONCLUSION

Avoidance of secondary brain injury by optimizing oxygenation, ventilation, and cerebral perfusion is the primary goal in the contemporary care of moderate-to-severe CRTBI. Ideally, this crucial care must begin as early as possible after injury. Given the frequency of hypotension, hypoxia, and both hypercarbia and hypocarbia upon Role 3 arrival, increased emphasis on prehospital management is indicated.

LEVEL OF EVIDENCE

Therapeutic study, level IV; epidemiologic study, level III.

Current concepts in penetrating and blast injury to the central nervous system

Aim

To review the current management, prognostic factors and outcomes of penetrating and blast injuries to the central nervous system and highlight the differences between gunshot wound, blast injury and stabbing.

Methods

A review of the current literature was performed.

Results

Of patients with craniocerebral GSW, 66–90 % die before reaching hospital. Of those who are admitted to hospital, up to 51 % survive. The patient age, GCS, pupil size and reaction, ballistics and CT features are important factors in the decision to operate and in prognostication. Blast injury to the brain is a component of multisystem polytrauma and has become a common injury encountered in war zones and following urban terrorist events. GSW to the spine account for 13–17 % of all gunshot injuries.

Conclusions

Urgent resuscitation, correction of coagulopathy and early surgery with wide cranial decompression may improve the outcome in selected patients with severe craniocerebral GSW. More limited surgery is undertaken for focal brain injury due to GSW. A non-operative approach may be taken if the clinical status is very poor (GCS 3, fixed dilated pupils) or GCS 4–5 with adverse CT findings or where there is a high likelihood of death or poor outcome. Civilian spinal GSWs are usually stable neurologically and biomechanically and do not require exploration. The indications for exploration are as follows: (1) compressive lesions with partial spinal cord or cauda equina injury, (2) mechanical instability and (3) complications. The principles of management of blast injury to the head and spine are the same as for GSW. Multidisciplinary specialist management is required for these complex injuries.

'Big data' approaches to trauma outcome prediction and autonomous resuscitation

Massive clinical digital data routinely collected by high throughput biomedical devices provide opportunities and challenges for optimal use. This article discusses how such data are used in learning prediction models at level 1 trauma centres to support decision making in trauma patients.

Traumatic brain injury and cognition

Traumatic brain injury (TBI) is a major cause of death and disability, and therefore an important health and socioeconomic problem for our society. Individuals surviving from a moderate to severe TBI frequently suffer from long-lasting cognitive deficits. Such deficits include different aspects of cognition such as memory, attention, executive functions, and awareness of their deficits. This chapter presents a review of the main neuropsychological and neuroimaging studies of patients with TBI. These studies found that patients evolve differently according to the severity of the injury, the mechanism causing the injury, and the lesion location. Further research is necessary to develop rehabilitation methods that enhance brain plasticity and recovery after TBI. In this chapter, we summarize current knowledge and controversies, focusing on cognitive sequelae after TBI. Recommendations from the Common Data Elements are provided, with an emphasis on diagnosis, outcome measures, and studies organization to make data more comparable across studies. Final considerations on neuroimaging advances, rehabilitation approaches, and genetics are described in the final section of the chapter.

Ethical and regulatory considerations in the design of traumatic brain injury clinical studies

Research is essential for improving outcomes after traumatic brain injury (TBI). However, the ubiquity, variability, and nature of TBI create many ethical issues and accompanying regulations for research. To capture the complexity and importance of designing and conducting TBI research within the framework of key ethical principles, a few highly relevant topics are highlighted. The selected topics are: (1) research conducted in emergency settings; (2) maintaining equipoise in TBI clinical trials; (3) TBI research on vulnerable populations; and (4) ethical considerations for sharing data. The topics aim to demonstrate the dynamic and multifaceted challenges of TBI research, and also to stress the value of addressing these challenges with the key ethical principles of respect, beneficence, and justice. Much has been accomplished to ensure that TBI research meets the highest ethical standards and has fair and enforceable regulations, but important challenges remain and continued efforts are needed by all members of the TBI research community.

Permutation entropy analysis of vital signs data for outcome prediction of patients with severe traumatic brain injury

Permutation entropy is computationally efficient, robust to outliers, and effective to measure complexity of time series. We used this technique to quantify the complexity of continuous vital signs recorded from patients with traumatic brain injury (TBI). Using permutation entropy calculated from early vital signs (initial 10-20% of patient hospital stay time), we built classifiers to predict in-hospital mortality and mobility, measured by 3-month Extended Glasgow Outcome Score (GOSE). Sixty patients with severe TBI produced a skewed dataset that we evaluated for accuracy, sensitivity and specificity. The overall prediction accuracy achieved 91.67% for mortality, and 76.67% for 3-month GOSE in testing datasets, using the leave-one-out cross validation. We also applied Receiver Operating Characteristic analysis to compare classifiers built from different learning methods. Those results support the applicability of permutation entropy in analyzing the dynamic behavior of TBI vital signs for early prediction of mortality and long-term patient outcomes.

Does the declining lethality of gunshot injuries mask a rising epidemic of gun violence in the United States?

Recent mass shootings in the U.S. have reignited the important public health debate concerning measures to decrease the epidemic of gun violence. Editorialists and gun lobbyists have criticized the recent focus on gun violence, arguing that gun-related homicide rates have been stable in the last decade. While true, data from the U.S. Centers for Disease Control and Prevention also demonstrate that although gun-related homicide rates were stable between 2002 and 2011, rates of violent gunshot injuries increased. These seemingly paradoxical trends may reflect the declining lethality of gunshot injuries brought about by surgical advances in the care of the patient with penetrating trauma. Focusing on gun-related homicide rates as a summary statistic of gun violence, rather than total violent gunshot injuries, can therefore misrepresent the rising epidemic of gun violence in the U.S.

Functional MRI and outcome in traumatic coma

Advances in task-based functional MRI (fMRI), resting-state fMRI (rs-fMRI), and arterial spin labeling (ASL) perfusion MRI have occurred at a rapid pace in recent years. These techniques for measuring brain function have great potential to improve the accuracy of prognostication for civilian and military patients with traumatic coma. In addition, fMRI, rs-fMRI, and ASL perfusion MRI have provided novel insights into the pathophysiology of traumatic disorders of consciousness, as well as the mechanisms of recovery from coma. However, functional neuroimaging techniques have yet to achieve widespread clinical use as prognostic tests for patients with traumatic coma. Rather, a broad spectrum of methodological hurdles currently limits the feasibility of clinical implementation. In this review, we discuss the basic principles of fMRI, rs-fMRI, and ASL perfusion MRI and their potential applications as prognostic tools for patients with traumatic coma. We also discuss future strategies for overcoming the current barriers to clinical implementation.

Blast-related traumatic brain injury

A bomb blast may cause the full severity range of traumatic brain injury (TBI), from mild concussion to severe, penetrating injury. The pathophysiology of blast-related TBI is distinctive, with injury magnitude dependent on several factors, including blast energy and distance from the blast epicentre. The prevalence of blast-related mild TBI in modern war zones has varied widely, but detection is optimised by battlefield assessment of concussion and follow-up screening of all personnel with potential concussive events. There is substantial overlap between post-concussive syndrome and post-traumatic stress disorder, and blast-related mild TBI seems to increase the risk of post-traumatic stress disorder. Post-concussive syndrome, post-traumatic stress disorder, and chronic pain are a clinical triad in this patient group. Persistent impairment after blast-related mild TBI might be largely attributable to psychological factors, although a causative link between repeated mild TBIs caused by blasts and chronic traumatic encephalopathy has not been established. The application of advanced neuroimaging and the identification of specific molecular biomarkers in serum for diagnosis and prognosis are rapidly advancing, and might help to further categorise these injuries.

Successful management of a severe combat penetrating brain injury

We report the case of successful management of a transcranial penetrating high-energy transfer injury in a 20-year-old soldier. The bullet traversed both cerebral hemispheres and lacerated the superior sagittal sinus rendering him unconscious. We detail the care received at all stages following injury from 'Buddy Aid' on the battlefield, resuscitation by a forward medical team through to prompt neurosurgery within 2 h of injury. Subsequent aeromedical evacuation and continuing aggressive critical care has allowed the patient to survive with acceptable neurological impairment after what is generally considered an unsurvivable injury.

Descriptive characteristics and rehabilitation outcomes in active duty military personnel and veterans with disorders of consciousness with combat- and noncombat-related brain injury

OBJECTIVE

To report the injury and demographic characteristics, medical course, and rehabilitation outcome for a consecutive series of veterans and active duty military personnel with combat- and noncombat-related brain injury and disorder of consciousness (DOC) at the time of rehabilitation admission.

DESIGN

Retrospective study.

SETTING

Rehabilitation center.

PARTICIPANTS

From January 2004 to October 2009, persons (N=1654) were admitted to the Polytrauma Rehabilitation System of Care. This study focused on the N=122 persons admitted with a DOC. Participants with a DOC were primarily men (96%), on active duty (82%), ≥12 years of education, and a median age of 25. Brain injury etiologies included mixed blast trauma (24%), penetrating (8%), other trauma (56%), and nontrauma (13%). Median initial Glasgow Coma Scale score was 3, and rehabilitation admission Glasgow Coma Scale score was 8. Individuals were admitted for acute neurorehabilitation approximately 51 days postinjury with a median rehabilitation length of stay of 132 days.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Recovery of consciousness and the FIM instrument.

RESULTS

Most participants emerged to regain consciousness during neurorehabilitation (64%). Average gains ± SD on the FIM cognitive and motor subscales were 19 ± 25 and 7 ± 8, respectively. Common medical complications included spasticity (70%), dysautonomia (34%), seizure occurrence (30%), and intracranial infection (22%). Differential outcomes were observed across etiologies, particularly for those with blast-related brain injury etiology.

CONCLUSIONS

Despite complex comorbidities, optimistic outcomes were observed. Individuals with severe head injury because of blast-related etiologies have different outcomes and comorbidities observed. Health-services research with a focus on prevention of comorbidities is needed to inform optimal models of care, particularly for combat injured soldiers with blast-related injuries.

The Human Connectome Project and beyond: initial applications of 300 mT/m gradients

The engineering of a 3 T human MRI scanner equipped with 300 mT/m gradients - the strongest gradients ever built for an in vivo human MRI scanner - was a major component of the NIH Blueprint Human Connectome Project (HCP). This effort was motivated by the HCP's goal of mapping, as completely as possible, the macroscopic structural connections of the in vivo healthy, adult human brain using diffusion tractography. Yet, the 300 mT/m gradient system is well suited to many additional types of diffusion measurements. Here, we present three initial applications of the 300 mT/m gradients that fall outside the immediate scope of the HCP. These include: 1) diffusion tractography to study the anatomy of consciousness and the mechanisms of brain recovery following traumatic coma; 2) q-space measurements of axon diameter distributions in the in vivo human brain and 3) postmortem diffusion tractography as an adjunct to standard histopathological analysis. We show that the improved sensitivity and diffusion-resolution provided by the gradients are rapidly enabling human applications of techniques that were previously possible only for in vitro and animal models on small-bore scanners, thereby creating novel opportunities to map the microstructure of the human brain in health and disease.

Placement of intracranial pressure monitors by non-neurosurgeons: excellent outcomes can be achieved

BACKGROUND

Traumatic brain injury remains one of the most prevalent and costly injuries encountered within the discipline of trauma and represents a leading cause of morbidity and mortality within our society. The purpose of this study was to compare the safety of intracranial pressure (ICP) monitor placement by general surgery residents and neurosurgeons.

METHODS

A retrospective chart review of all trauma patients requiring ICP monitor placement at an American College of Surgeons-verified Level 1 trauma center during a 10-year period was performed. Comparison of demographic variables, injury severity, intracranial injuries, incidence of ICP monitor-related complications, and outcomes were made between general surgery residents, trauma surgeons, and neurosurgeons.

RESULTS

There were 546 patients included in the study. The average age of the cohort was 37.6 years, with an average hospital length of stay being 16.0 days and an Injury Severity Score of 27.7. Mechanisms of injury varied, but 58.8% was a result of motor vehicle and motorcycle collisions, and an additional 19.2% was a result of falls. No significant difference was found in terms of procedure-related complications between subgroups, including intracranial hemorrhage, infection, malfunctions, dislodgment, or death.

CONCLUSION

Our results demonstrate that the placement of ICP monitors may be performed safely by both neurosurgeons and non-neurosurgeons. This procedure should thus be considered a core skill for trauma surgeons and surgical residents alike, thereby allowing initiation of prompt medical treatment in both rural areas and trauma centers with inadequate neurosurgeon or fellow coverage.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Impact of operative intervention delay on pediatric trauma outcomes

BACKGROUND

Establishing quality indicators is an essential step in improving mortality and disability among pediatric patients with trauma. We hypothesized that timing of craniotomy, intracranial pressure (ICP) monitoring for traumatic brain injury, and abdominal operation for solid organ injury correlates with a reduced risk of death, shorter stay, and reduced risk of requiring assistance at discharge.

METHODS

This was a retrospective cohort study of 99,513 pediatric patients with trauma, using the National Trauma Data Bank.

RESULTS

For patients who had an ICP monitor placed within 4 hours compared with those whose ICP monitor was delayed, there was no difference in mortality; however, there was a shorter stay in the hospital (relative risk [RR], 0.84; 95% confidence interval (CI), 0.72-0.97) and in the intensive care unit (ICU) (RR, 0.76; 95% CI, 0.66-0.86) in those that survived to discharge. Patients who had craniotomy within 4 hours had higher mortality (RR, 1.98; 95% CI, 1.11-3.51) compared with those that were delayed. After excluding those that died, there was a shorter overall stay (RR, 0.69; 95% CI, 0.59-0.81) and ICU stay (RR, 0.69; 95% CI, 0.57-0.83). Similar length of stay results were seen in pediatric patients with solid organ injuries. Excluding those that died, length of stay (RR, 0.58; 95% CI, 0.47-0.73) and ICU stay (RR, 0.52; 95% CI, 0.37-0.74) were shorter.

CONCLUSION

Early intervention in those who survive their initial operation is associated with shorter ICU and hospital stay for traumatic brain and solid organ injuries.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Pathophysiology of battlefield associated traumatic brain injury

As more data is accumulated from Operation Iraqi Freedom and Operation Enduring Freedom (OEF in Afghanistan), it is becoming increasing evident that traumatic brain injury (TBI) is a serious and highly prevalent battle related injury. Although traditional TBIs such as closed head and penetrating occur in the modern battle space, the most common cause of modern battle related TBI is exposure to explosive blast. Many believe that explosive blast TBI is unique from the other forms of TBI. This is because the physical forces responsible for explosive blast TBI are different than those for closed head TBI and penetrating TBI. The unique force associated with explosive blast is the blast shock pressure wave. This shock wave occurs over a very short period, milliseconds, and has a specific profile known as the Freidlander curve. This pressure-time curve is characterized by an initial very rapid up-rise followed by a longer decay that reaches a negative inflection point before returning to baseline. This is important as the effect of this shock pressure on brain parenchyma is distinct. The diffuse interaction of the pressure wave with the brain leads to a complex cascade of events that affects neurons, axons, glia cells, and vasculature. It is only by properly studying this disease will meaningful therapies be realized.