Mixed reality surgical mentoring of combat casualty care related procedures in a perfused cadaver model: Initial results of a randomized feasibility study.

BACKGROUND: Most telemedicine modalities have limited ability to enhance procedural and operative care. We developed a novel system to provide synchronous bidirectional expert mixed reality-enabled virtual procedural mentoring. In this feasibility study, we evaluated mixed reality mentoring of combat casualty care related procedures in a re-perfused cadaver model. METHODS: Novices received real-time holographic mentoring from experts using augmented reality via Hololens (Microsoft Inc, Redmond, WA). The experts maintained real-time awareness of the novice's operative environment using virtual reality via HTC-Vive (HTC Corp, Xindian District, Taiwan). Additional cameras (both environments) and novel software created the immersive, shared, 3-dimensional mixed reality environment in which the novice and expert collaborated. The novices were prospectively randomized to either mixed reality or audio-only mentoring. Blinded experts independently evaluated novice procedural videos using a 5-point Likert scale-based questionnaire. Nonparametric variables were evaluated using the Wilcoxon rank-sum test and comparisons using the χ2 analysis; significance was defined at P < .05. RESULTS: Surgeon and nonsurgeon novices (14) performed 69 combat casualty care-related procedures (38 mixed reality, 31 audio), including various vascular exposures, 4-compartment lower leg fasciotomy, and emergency neurosurgical procedures; 85% were performed correctly with no difference in either group. Upon video review, mixed reality-mentored novices showed no difference in procedural flow and forward planning (3.67 vs 3.28, P = .21) or the likelihood of performing individual procedural steps correctly (4.12 vs 3.59, P = .06). CONCLUSION: In this initial feasibility study, our novel mixed reality-based mentoring system successfully facilitated the performance of a wide variety of combat casualty care relevant procedures using a high fidelity re-perfused cadaver model. The small sample size and limited variety of novice types likely impacted the ability of holographically mentored novices to demonstrate improvement over the audio-only control group. Despite this, using virtual, augmented, and mixed reality technologies for procedural mentoring demonstrated promise, and further study is needed.

Universal background checks for handgun purchases can reduce homicide rates of African Americans.

BACKGROUND: Federal law requires background checks for firearms purchased from licensed dealers, but states can extend requirements to private sales of handguns and purchases at gun shows (universal background checks for handguns [UBC-HG]). Although firearm homicide disproportionately affects African Americans, little is known about how UBG-HG impacts African Americans. We hypothesized that implementation of UBC-HG would reduce rates of firearm homicide of African Americans. METHODS: We collected Centers for Disease Control firearm homicide counts for African American and white populations in the 50 states, 1999 to 2017. Laws were drawn from the State Firearm Laws Database. The exposure and outcome of interest were UBC-HG adoption and firearm homicide. We included non-Hispanic African American and non-Hispanic white populations. We used Poisson regression to perform a differences-in-differences analysis. A categorical variable for state accounted for time-stable state characteristics. We controlled for year to account for trends over time unrelated to policy. We controlled for state-specific, time-variable factors, including median household income, population younger than 25 years or 65 years or older, alcohol consumption, and count of firearm laws (UBC-HG excluded). Standard errors were adjusted for clustering at the state level. RESULTS: The firearm homicide rate among whites was 1.8 per 100,000 (interquartile range, 1.2-2.7) ranging from 1.4 in 2011 to 1.8 in 2016. The firearm homicide rate was 15.6 per 100,000 (interquartile range, 11.6-21.0) among African Americans, ranging from 14.0 in 2009 to 19.6 in 2017. While no significant difference in firearm homicides among whites (incidence rate ratio, 0.93; 95% confidence interval, 0.73-1.20) was appreciated, the passage of UBC-HG was associated with an 19% decrease in African Americans firearm homicides (incidence rate ratio, 0.81; 95% confidence interval, 0.70-0.94; p = 0.006). CONCLUSION: Implementing UBC-HG was associated with decreased firearm homicides among African Americans-the population most at risk. Expanding UBC-HG may be an effective approach to reducing racial disparities in firearm homicides. LEVEL OF EVIDENCE: Epidemiological, level III.

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.

To end disease tomorrow, begin with trials today: Digital strategies for increased awareness of a clinical trials finder.

INTRODUCTION: Individuals experiencing different medical conditions, as well as healthy volunteers, may often be interested in trial participation, and researchers similarly need to find participants to advance medical knowledge. The ResearchMatch (RM) Trials Today clinical trial searching tool leverages clinicaltrials.gov data to enable potential participants to look for trial opportunities relevant to their situation. To facilitate expanded use of this tool, we undertook a national digital public awareness campaign to increase awareness of Trials Today among members of the general public. METHODS: The awareness campaign promoted Trials Today using Facebook and digital banner messages in 2017, encompassing nine cities across the USA. The digital strategy was complemented by print media in several outlets. We employed descriptive statistics to summarize campaign metrics and site usage data during the campaign. RESULTS: The campaign was successful in increasing visits to Trials Today, with 142,303 sessions logged during its run, as compared to pre-campaign data indicating 104,688 total sessions during the entire 2-year period since the site's inception. The city-specific click-through rate for all digital impressions, combining Facebook and banner messaging, ranged from 0.50% to 1.09%, resulting in a cost-per-click range of $0.69-$1.15. In addition, visitors conducted 29,697 searches and viewed individual trial records 173,512 times. CONCLUSION: The public awareness campaign was successful in increasing use of the RM Trials Today clinical trial searching tool. Our findings support the value of digital media messaging as a cost-effective vehicle for promoting clinical trial awareness, especially for chronic ailments.

American firearm homicides: The impact of your neighbors.

BACKGROUND: Restrictive firearm legislation has correlated with decreased overall firearm fatality rates, but not with firearm-related homicide or firearm mortality among Black Americans. We hypothesized that firearm trafficking from states with less restrictive firearm legislation to neighboring states with more restrictive firearm legislation increases firearm homicide rates in those restrictive states. METHODS: For years 2011-2015, state firearm legislation Brady Campaign to Prevent Gun Violence scorecards were analyzed in relation to firearms traced by the Bureau of Alcohol, Tobacco, and Firearms and Center for Disease Control and Prevention firearm mortality rates. States were ranked by Brady score and arranged by quintile to establish the Standardized Brady Score. The effect of less-restrictive neighboring states on the 10 most-restrictive firearm legislation states was modeled by averaging the 10 most-restrictive states with their bordering states to create a Border Adjustment Score. Firearm fatality rates were calculated for each quintile and Poisson regression models were created for each score and outcome. Model fit was compared using Akaike Information Criterion (AIC). RESULTS: There were 169,396 firearm fatalities including 57,885 firearm homicides. Comparing top and bottom quintile firearm legislation states, 65% vs. 44% of firearms traced by the Bureau of Alcohol, Tobacco, Firearms and Explosives originated in other states respectively. The Border Adjustment Score generated a more linear relationship than the Standardized Brady Score for all firearm fatality categories as firearm legislation scores decreased. The Border Adjustment Score minimized the AIC with respect to the Standardized Brady Score for black (AIC, 4443 vs. 4680) and white firearm homicide rates (3243 vs. 4319), indicating improved model fit after adjustment for neighboring state firearm legislation. CONCLUSION: Our results suggest that firearm movement across states plays an important role in firearm homicides. Accounting for firearm legislation in both individual and neighboring states may improve our understanding of the relationship between firearm legislation and homicide. LEVEL OF EVIDENCE: Prognostic and epidemiological study, level IV.

Connecting the public with clinical trial options: The ResearchMatch Trials Today tool.

Potential participants seek information about clinical trials for many reasons, but the process can be challenging. We analyzed 101,249 searches in ResearchMatch Trials Today, a free interface to recruiting trials from ClinicalTrials.gov. Searches from March 2015 to November 2016 included a broad range of conditions and healthy volunteer concepts, including 12,649 unique topics. Trials Today data indicate that it is being used to identify trials on a variety of topics.

Hereditary thrombophilia in trauma patients with venous thromboembolism: Is routine screening necessary?

BACKGROUND: Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), remains a common complication following trauma. The role of hereditary thrombophilia (HT) in posttraumatic VTE is unknown. In the general population with a first-time DVT, Factor V Leiden (FVL) and prothrombin G20210A mutation (PGM) are the most common types of HT with an incidence of 20% to 25% and 6% to 18%, respectively. The objective of this study was to identify the incidence of FVL and PGM in posttraumatic VTE to determine whether routine screening for HT in trauma should be performed. METHODS: We conducted a prospective observational study at our Level I trauma center from 2013 to 2016 when 70 patients with posttraumatic DVT and PE were screened for FVL and PGM. Demographics, injury characteristics, and established risk factors for VTE were collected for each patient. Statistical analysis was performed to compare patients with and without HT. RESULTS: The incidence of FVL and PGM in posttraumatic VTE was 1.4% and 5.7%, respectively. All HT-positive patients had a DVT and one had an associated PE. Both the individual risk factors and the total number of risk factors for VTE were similar between the HT-positive group and the HT-negative group. CONCLUSION: There was a lower incidence of FVL and PGM in patients with posttraumatic DVT than in patients with a first-time DVT in the general population. HT does not appear to significantly contribute to posttraumatic VTE in our trauma population. Further research is warranted to determine whether routine screening for HT in trauma should be performed. LEVEL OF EVIDENCE: Epidemiological study, level III; Care management/therapeutic study, level IV.

Risk factors for deep vein thrombosis and pulmonary embolism after traumatic injury: A competing risks analysis.

BACKGROUND: Venous thromboembolism, including deep vein thrombosis (DVT) and pulmonary embolism (PE), is typically reported as a composite measure of the quality of trauma center care. Given that recent data suggesting postinjury DVT and PE are distinct clinical processes, a better understanding may result from analyzing them as independent, competing events. Using competing risks analysis, we evaluated our hypothesis that the risk factors and timing of postinjury DVT and PE are different. METHODS: We examined all adult trauma patients admitted to our Level I trauma center from July 2006 to December 2011 who received at least one surveillance duplex ultrasound of the lower extremities and who were at high risk or greater for DVT. Outcomes included DVT and PE events, and time-to-event from admission. We used competing risks analysis to evaluate risk factors for DVT while accounting for PE as a competing event, and vice versa. RESULTS: Of 2,370 patients, 265 (11.2%) had at least one venous thromboembolism event, 235 DVT only, 19 PE only, 11 DVT and PE. Within 2 days of admission, 38% of DVT cases had occurred compared with 26% of PE. Competing risks modeling of DVT as primary event identified older age, severe injury (Injury Severity Score, ≥ 15), mechanical ventilation longer than 4 days, active cancer, history of DVT or PE, major venous repair, male sex, and prophylactic enoxaparin and prophylactic heparin as associated risk factors. Modeling of PE as the primary event showed younger age, nonsevere injury (Injury Severity Score, < 15), central line placement, and prophylactic heparin as relevant factors. CONCLUSION: The risk factors for PE and DVT after injury were different, suggesting that they are clinically distinct events that merit independent consideration. Many DVT events occurred early despite prophylaxis, bringing into question the preventability of postinjury DVT. We recommend trauma center quality reporting program measures be revised to account for DVT and PE as unique events. LEVEL OF EVIDENCE: Epidemiologic, level III.

Ureteral obstruction secondary to disseminated penicilliosis in a German shepherd dog.

Abdominal ultrasonographic evaluation of a 2-year-old male German shepherd dog evaluated for weight loss demonstrated a right ureteral mass with ipsilateral hydronephrosis, hypoechoic splenic nodules, and hypoechoic and rounded lymph nodes. A fungal mat extending from the renal pelvis into the ureter secondary to disseminated Penicillium was confirmed at necropsy.

Obstruction urétérale secondaire à une infection disséminée àPenicilliumchez un chien Berger allemand. L'évaluation abdominale par échographie d'un chien Berger allemand mâle âgé de 2 ans qui était évalué pour une perte de poids a révélé une masse urétrale droite avec de l'hydronéphrose ipsilatérale, des nodules spléniques hypoéchogènes et des ganglions lymphatiques arrondis et hypoéchogènes. Une masse fongique s'étendant du pelvis rénal jusqu'à l'urètre secondaire à une infection disséminée à Penicillium a été confirmée à la nécropsie.(Traduit par Isabelle Vallières).

Determining the magnitude of surveillance bias in the assessment of lower extremity deep venous thrombosis: A prospective observational study of two centers.

BACKGROUND: Venous thromboembolism (VTE) remains a significant cause of morbidity and mortality in trauma. Controversy exists regarding the use of lower extremity duplex ultrasound screening and surveillance (LEDUS). Advocates cite earlier diagnosis and treatment of deep venous thrombosis (DVT) to prevent clot propagation and pulmonary embolism (PE). Opponents argue that LEDUS identifies more DVT (surveillance bias) but does not reduce the incidence of PE. We sought to determine the magnitude of surveillance bias associated with LEDUS and test the hypothesis that LEDUS does not decrease the incidence of PE after injury. METHODS: We compared data from two Level 1 trauma centers: Scripps Mercy Hospital, which used serial LEDUS, and Christiana Care Health System, which used LEDUS only for symptomatic patients. Beginning in 2013, both centers prospectively collected data on demographics, injury severity, and VTE risk for patients admitted for more than 48 hours. Both centers used mechanical and pharmacologic prophylaxis based on VTE risk assessment. RESULTS: Scripps Mercy treated 772 patients and Christiana Care treated 454 patients with similar injury severity and VTE risk. The incidence of PE was 0.4% at both centers. The odds of a DVT diagnosis were 5.3 times higher (odds ratio, 5.3; 95% confidence interval, 2.5-12.9; p < 0.0001) for patients admitted to Scripps Mercy than for patients admitted to Christiana Care. Of the 80 patients who developed DVT, PE, or both, 99% received prophylaxis before the event. Among those who received pharmacologic prophylaxis, the VTE rates between the two centers were not statistically significantly different (Scripps Mercy, 11% vs. Christiana Care, 3%; p = 0.06). CONCLUSION: The odds of a diagnosis of DVT are increased significantly when a program of LEDUS is used in trauma patients. Neither pharmacologic prophylaxis nor mechanical prophylaxis is completely effective in preventing VTE in trauma patients. VTE should not be considered a "never event" in this cohort. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level III; therapeutic study, level III.

Heparin versus enoxaparin for prevention of venous thromboembolism after trauma: A randomized noninferiority trial.

BACKGROUND: Research comparing enoxaparin with unfractionated heparin (UFH) given every 12 hours for venous thromboembolism (VTE) prophylaxis after trauma overlooks original recommendations that UFH be given every 8 hours. We conducted a prospective, randomized, noninferiority trial comparing UFH every 8 hours and standard enoxaparin every 12 hours. We hypothesized that the incidence of VTE in trauma patients receiving UFH every 8 hours would be no more than 10% higher than that in patients receiving enoxaparin every 12 hours. METHODS: Trauma patients who met criteria for VTE prophylaxis at a Level I trauma center were randomly assigned to 5,000-U UFH every 8 hours or 30-mg enoxaparin every 12 hours between November 2012 and September 2014. Surveillance duplex ultrasound was performed twice weekly on intensive care unit patients and weekly on ward patients. Primary end points were deep vein thrombosis diagnosed by duplex ultrasound and pulmonary embolism diagnosed by computed tomography angiography. RESULTS: Of 495 randomized patients, 220 received UFH and 216 received enoxaparin for analysis. Overall, 105 in the UFH group and 103 in the enoxaparin group underwent VTE surveillance or diagnostic testing. In the analysis of randomized patients who received treatment, UFH was noninferior compared with enoxaparin (absolute VTE risk difference, 3.1%; 95% confidence interval, -1.6% to 7.7%; p = 0.196); however, in the screening ultrasound group, the noninferiority of UFH was inconclusive (absolute VTE risk difference, 6.5%; 95% confidence interval, -2.9% to 15.8%; p = 0.179). The two treatments did not differ with regard to adverse events. The pharmaceutical cost for the regimen of UFH ($2,809) was nearly 20-fold lower than that for enoxaparin ($54,138). CONCLUSION: A regimen of UFH every 8 hours may be noninferior to enoxaparin every 12 hours for the prevention of VTE following trauma. Given UFH's cost advantage, the use of UFH for VTE prophylaxis may offer greater value. LEVEL OF EVIDENCE: Therapeutic/care management study, level II.

Venous thromboembolic risk assessment models should not solely guide prophylaxis and surveillance in trauma patients.

BACKGROUND: Venous thromboembolism (VTE) risk assessment models exist to stratify patients at risk for VTE and guide surveillance and prophylaxis. We evaluated the only two models developed specifically for trauma patients: the Trauma Embolic Scoring System (TESS) and the Risk Assessment Profile (RAP). METHODS: Clinical and demographic data on patients admitted from July 2006 to December 2011 who underwent surveillance lower extremity duplex ultrasound were recorded. Patients were excluded if they were missing one or more of the variables required to calculate either TESS or RAP. Patients received prophylaxis according to American College of Chest Physicians guidelines. TESS and RAP scores were calculated retrospectively and compared between patients with VTE and patients without VTE. High risk was defined by the models as TESS score of 7 or greater and RAP score of 5 or greater. RESULTS: A total of 2,868 patients received surveillance lower extremity duplex ultrasound. TESS score was calculated for 2,140 patients; 215 developed VTE, 110 (51%) of whom had TESS score less than 7. The sensitivity and specificity at a cutoff point of 7 were 49% and 72%, respectively. RAP score was calculated for 1,505 patients; 152 developed VTE, 26 (17%) of whom had RAP score of less than 5. The sensitivity and specificity at a cutoff point of 5 were 83% and 37%, respectively. The area under the receiver operating characteristic curve for each model was 0.66. CONCLUSION: A clinically significant number of patients who developed VTE were classified as low risk by both TESS and RAP. The indications for VTE surveillance and chemoprophylaxis should not be based exclusively on these scores. These results suggest that additional variables should be sought to improve risk assessment for VTE following trauma. LEVEL OF EVIDENCE: Care management study, level III.

Parvoviral myocarditis in a 5-week-old Dachshund.

OBJECTIVE: To describe a case of myocarditis associated with naturally occurring canine parvovirus type 2 (CPV-2). CASE SUMMARY: A 5-week-old male intact Dachshund dog presented for acute respiratory distress. Limited diagnostic tests prior to the dog experiencing cardiopulmonary arrest included a lateral thoracic radiograph, which indicated cardiomegaly and diffuse unstructured pulmonary infiltrate. Necropsy was performed and results identified a lymphoplasmacytic myocarditis with positive CPV-2 immunohistochemistry within the myocardium. UNIQUE INFORMATION PROVIDED: This report describes the natural occurrence of CPV-2-associated myocarditis. In addition to highlighting this rare form of canine parvovirus, cardiomyopathy in survivors of the acute viral myocarditis phase is reviewed.

Does resuscitation with plasma increase the risk of venous thromboembolism?

BACKGROUND: Resuscitation with blood products improves survival in patients with traumatic hemorrhage. However, the risk of venous thromboembolic (VTE) complications associated with fresh frozen plasma (FFP) resuscitation is unknown. We hypothesized that a higher ratio of FFP to packed red blood cells (PRBCs) given during acute resuscitation increases the risk of VTE independent of severity of injury and shock. METHODS: The records of patients admitted from April 2007 to December 2011 who had surveillance lower extremity duplex ultrasounds were retrospectively reviewed. Patients who received at least 1 U of PRBCs within 24 hours of admission were included. Patients who died without VTE were excluded. The relationship between FFP and VTE was evaluated using logistic regression. RESULTS: A total of 381 patients met inclusion criteria, of whom 77 (20.2%) developed VTE. In patients who required less than 4 U of PRBCs, increasing units of FFP were associated with an increasing risk for VTE, with each unit of FFP having an adjusted odds ratio of 1.27 (95% confidence interval, 1.04-1.54, p = 0.015). Conversely, in patients who required four or greater units of PRBCs, FFP in equal or greater ratios than PRBCs was not associated with VTE. CONCLUSION: Each unit of FFP increased VTE risk by 25% in patients who required less than 4 U of PRBCs. In patients who required 4 U or greater PRBCs, FFP administration conferred no increased risk of VTE. This suggests that FFP should be used cautiously when early hemodynamic stability can be achieved with less than 4 U of PRBCs. LEVEL OF EVIDENCE: Care management study, level III.

Below-knee deep vein thrombosis: an opportunity to prevent pulmonary embolism?

BACKGROUND: The prevention of venous thromboembolic disease following trauma is a priority. In contrast to above-knee deep vein thrombosis (AKDVT), the management of below-knee deep vein thrombosis (BKDVT) is controversial because the risk of pulmonary embolism (PE) has not been firmly established. We hypothesized that BKDVT and AKDVT have an equivalent risk for PE in trauma patients. METHODS: We identified patients from July 2006 to December 2011 with BKDVT and/or AKDVT diagnosed by lower extremity duplex ultrasound (LEDU) and patients with PE diagnosed by computed tomography angiogram. Time of DVT onset, progression or regression, and time of PE were assessed. The BKDVT and AKDVT patient groups were defined by the location of DVT on initial LEDU. The use of therapeutic anticoagulation and inferior vena cava filter (IVCF) were compared between the BKDVT and AKDVT groups. RESULTS: Of 11,330 patients evaluated during the study period, 2,881 (25.4%) underwent surveillance LEDU, and 251 (8.7%) of these patients had DVT alone or associated with PE. BKDVT progressed to AKDVT and/or PE in 21 patients (12.9%). PE rates were 6.1% and 1.1% in the BKDVT and AKDVT groups, respectively (p = 0.1). There was a higher rate of therapeutic anticoagulation and/or IVCF in the AKDVT group than in the BKDVT group (86% vs. 24%, p < 0.0001). CONCLUSION: In our study population, BKDVT was associated with a higher rate of PE compared with AKDVT, which was likely secondary to the treatment of AKDVT. Because BKDVT progressed to AKDVT or PE in 1 of 8 patients, BKDVT should not be ignored in trauma patients. Aggressive chemical prophylaxis and perhaps therapeutic anticoagulation or IVCF should be considered in patients with BKDVT. Further investigation is warranted to confirm these conclusions. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Isolated traumatic brain injury and venous thromboembolism.

BACKGROUND: Traumatic brain injury (TBI) is considered an independent risk factor of venous thromboembolism (VTE). However, the role of TBI severity in VTE risk has not been determined. We hypothesized that increased severity of brain injury in patients with isolated TBI (iTBI) is associated with an increased incidence of VTE. METHODS: The records of patients admitted from June 2006 to December 2011 were reviewed for injury data, VTE risk factors, results of lower extremity surveillance ultrasound, and severity of TBI. Patients were identified by DRG International Classification of Diseases-9th Rev. codes for TBI, and only those with a nonhead Abbreviated Injury Scale (AIS) score of 1 or lower, indicating minimal associated injury, were included. The association of iTBI and VTE was determined using a case-control design. Among iTBI patients, those diagnosed with VTE (cases) were matched for age, sex, and admission year to those without VTE (controls). Data were analyzed using conditional logistic regression. RESULTS: There were 345 iTBI patients: 41 cases (12%) and 304 controls (88%). A total of 151 controls could not be matched to an appropriate case and were excluded. Of the remaining 153 controls, 1 to 16 controls were matched to each of the 41 VTE cases. Compared with the controls, the cases had a higher mean head-AIS score (4.4 vs. 3.9, p = 0.001) and overall Injury Severity Score (20.4 vs. 16.8, p = 0.001). Following adjustment for all factors found to be associated with VTE (ventilator days, central line placement, operative time > 2 hours, chemoprophylaxis, history of VTE, and history of cancer), the cases were significantly more likely to have a greater head injury severity (head-AIS score ≥ 5; odds ratio, 5.25; 95% confidence interval, 1.59-17.30; p = 0.006). CONCLUSION: The incidence of VTE in iTBI patients was significantly associated with the severity of TBI. VTE surveillance protocols may be warranted in these high-risk patients, as early detection of VTE could guide subsequent therapy. LEVEL OF EVIDENCE: Epidemiologic/prognostic study, level III.

Pulmonary embolism without deep venous thrombosis: De novo or missed deep venous thrombosis?

BACKGROUND: Pulmonary embolus (PE) is thought to arise from a deep venous thrombosis (DVT). Recent data suggest that PE can present without DVT, inferring that PE can originate de novo (DNPE). We examined the relationship between DVT and PE in trauma patients screened for DVT with duplex sonography (DS). We sought to validate the incidence of PE without evidence of DVT and to examine the clinical significance of this entity. METHODS: We reviewed the medical records of all trauma patients from July 2006 to December 2011 with PE who also had serial surveillance DS (groin to ankle). Demographics, severity of injury, interventions, signs and symptoms of PE, as well as chest computerized tomography findings were collected. Patients with no DS evidence of DVT either before or within 48 hours of PE diagnosis (DNPE) were compared with those with DVT (PE + DVT). RESULTS: Of 11,330 patients evaluated by the trauma service, 2,881 patients received at least one DS. PE occurred in 31 of these patients (1.08%): 19 (61%) were DNPE, and 12 (39%) were PE + DVT. Compared with patients with PE + DVT, patients with DNPE were significantly younger and had more rib fractures, pulmonary contusions, infections, pulmonary symptoms, and peripherally located PEs on computerized tomography. CONCLUSION: This is the first report of the clinical course of DNPE without embolic origin in a population with comprehensive duplex surveillance. In our series, DNPE seems to be more prevalent after trauma, to be clinically distinct from PE following DVT, and to likely represent a local response to injury or inflammation; however, further research is warranted to fully understand the pathophysiology of DNPE. LEVEL OF EVIDENCE: Care management study, level III.

Serum albumin and body weight as biomarkers for the antemortem identification of bone and gastrointestinal disease in the common marmoset.

The increasing use of the common marmoset (Callithrix jacchus) in research makes it important to diagnose spontaneous disease that may confound experimental studies. Bone disease and gastrointestinal disease are two major causes of morbidity and mortality in captive marmosets, but currently no effective antemortem tests are available to identify affected animals prior to the terminal stage of disease. In this study we propose that bone disease and gastrointestinal disease are associated disease entities in marmosets and aim to establish the efficacy of several economical antemortem tests in identifying and predicting disease. Tissues from marmosets were examined to define affected animals and unaffected controls. Complete blood count, serum chemistry values, body weight, quantitative radiographs, and tissue-specific biochemical markers were evaluated as candidate biomarkers for disease. Bone and gastrointestinal disease were associated, with marmosets being over seven times more likely to have either concurrent bone and gastrointestinal disease or neither disease as opposed to lesions in only one organ system. When used in tandem, serum albumin <3.5 g/dL and body weight <325 g identified 100% of the marmosets affected with concurrent bone and gastrointestinal disease. Progressive body weight loss of 0.05% of peak body weight per day predicted which marmosets would develop disease prior to the terminal stage. Bone tissue-specific tests, such as quantitative analysis of radiographs and serum parathyroid hormone levels, were effective for distinguishing between marmosets with bone disease and those without. These results provide an avenue for making informed decisions regarding the removal of affected marmosets from studies in a timely manner, preserving the integrity of research results.

Ovarian mixed germ cell tumor with yolk sac and teratomatous components in a dog.

Mixed germ cell tumors of the ovary have rarely been reported in veterinary species. A 3-year-old intact female Labrador Retriever dog was presented for lethargy, abdominal distention, and a midabdominal mass. An exploratory laparotomy revealed a large (23 cm in diameter) left ovarian tumor and multiple small (2-3 cm in diameter) pale tan masses on the peritoneum and abdominal surface of the diaphragm. Histological examination of the left ovary revealed a mixed germ cell tumor with a yolk sac component with rare Schiller-Duval bodies and a teratomatous component comprised primarily of neural differentiation. The abdominal metastases were solely comprised of the yolk sac component. The yolk sac component was diffusely immunopositive for cytokeratin with scattered cells reactive for α-fetoprotein and placental alkaline phosphatase. Within the teratomatous component, the neuropil was diffusely immunopositive for S100, neuron-specific enolase, and neurofilaments with a few glial fibrillary acidic protein immunopositive cells. Ovarian germ cell tumors may be pure and consist of only 1 germ cell element or may be mixed and include more than 1 germ cell element, such as teratoma and yolk sac tumor.