Risk Factors for Empyema Following Penetrating Diaphragmatic Injuries

Empyema resulting as a complication of penetrating diaphragmatic injuries is a subject that requires further investigation, and the aim of this study was to determine the risk factors associated with empyema in patients with penetrating trauma. Consecutive adult trauma patients from a level 1 trauma center were searched for penetrating diaphragm injuries. Data were collected on patient demographics, pre-existing conditions, injury type and severity, hospital interventions, in-hospital complications, and outcomes. Patients were stratified by empyema formation and univariant analyses were performed. 164 patients were identified, and 17 patients (10.4%) developed empyema. Empyema was associated with visible abdominal contamination (35.3% vs 15%, P = .04), thoracotomy (35.5% vs 13.6%, P = .03), pneumonia (41.2% vs 14.3%, P = .01), sepsis (35.3% vs 8.8%, P = .006), increased hospital length of stay (25.5 vs 10.1 days, p =<.001), increased intensive care unit length of stay (9.6 vs 4.3 days, P = .01), and decreased in-hospital mortality (0% vs 20.4%, P = .04).

Chest Tube Size Selection: Evaluating Provider Practices, Treatment Efficacy, and Complications in Management of Thoracic Trauma

BACKGROUND

The standard for managing traumatic pneumothorax (PTX), hemothorax (HTX), and hemopneumothorax (HPTX) has historically been large-bore (LB) chest tubes (>20-Fr). Previous studies have shown equal efficacy of small-bore (SB) chest tubes (≤19-Fr) in draining PTX and HTX/HPTX. This study aimed to evaluate provider practice patterns, treatment efficacy, and complications related to the selection of chest tube sizes for patients with thoracic trauma.

METHODS

A retrospective chart review was performed on adult patients who underwent tube thoracostomy for traumatic PTX, HTX, or HPTX at a Level 1 Trauma Center from January 2016 to December 2021. Comparison was made between SB and LB thoracostomy tubes. The primary outcome was indication for chest tube placement based on injury pattern. Secondary outcomes included retained hemothorax, insertion-related complications, and duration of chest tube placement. Univariate and multivariate analyses were performed.

RESULTS

Three hundred and forty-one patients were included and 297 (87.1%) received LB tubes. No significant differences were found between the groups concerning tube failure and insertion-related complications. LB tubes were more frequently placed in patients with penetrating MOI, higher average ISS, and higher average thoracic AIS. Patients who received LB chest tubes experienced a higher incidence of retained HTX.

DISCUSSION

In patients with thoracic trauma, both SB and LB chest tubes may be used for treatment. SB tubes are typically placed in nonemergent situations, and there is apparent provider bias for LB tubes. A future randomized clinical trial is needed to provide additional data on the usage of SB tubes in emergent situations.

Discrepancies in Mass Shootings and Access to Trauma Care Across the United States, 2014-2018

INTRODUCTION

The United States has one of the highest rates of gun violence and mass shootings. Timely medical attention in such events is critical. The objective of this study was to assess geographic disparities in mass shootings and access to trauma centers.

METHODS

Data for all Level I and II trauma centers were extracted from the American College of Surgeons and the Trauma Center Association of America registries. Mass shooting event data (4+ individuals shot at a single event) were taken from the Gun Violence Archive between 2014 and 2018.

RESULTS

A total of 564 trauma centers and 1672 mass shootings were included. Ratios of the number of mass shootings vs trauma centers per state ranged from 0 to 11.0 mass shootings per trauma center. States with the greatest disparity (highest ratio) included Louisiana and New Mexico.

CONCLUSION

States in the southern regions of the US experience the greatest disparity due to a high burden of mass shootings with less access to trauma centers. Interventions are needed to increase access to trauma care and reduce mass shootings in these medically underserved areas.

Venovenous Extracorporeal Membrane Oxygenation Usage Following Bullet Embolism to the Pulmonary Artery

Background: Pulmonary artery embolus is a rare complication following gunshot wounds that creates a unique and serious challenge for trauma surgeons. While the majority of bullets that embolize through the vascular system end in the peripheral circulation, approximately one-third enter the central venous circulation. Case Report: We present the case of a bullet embolus to the left pulmonary artery following gunshot wounds to the right chest and the abdomen, with the abdominal ballistic traversing the liver before entering the vena cava and embolizing. The patient's course was complicated by the development of severe acute respiratory distress syndrome that was successfully managed by venovenous extracorporeal membrane oxygenation. Conclusion: Venovenous extracorporeal membrane oxygenation support for severe acute respiratory distress syndrome after bullet embolization to the pulmonary tree and surgical embolectomy is a viable option in appropriately selected patients.

Comparison of rampage and non-rampage mass shootings in the U.S.: A 5-year demographic analysis

BACKGROUND

Rampage mass shootings (RMS) are a subset of mass shootings occurring in public involving random victims. Due to rarity, RMS are not well-characterized. We aimed to compare RMS and NRMS. We hypothesized that RMS and NRMS would be significantly different with respect to time/season, location, demographics, victim number/fatality rate, victims being law enforcement, and firearm characteristics.

STUDY DESIGN

Mass shootings (4 or more victims shot at a single event) from 2014-2018 were identified in the Gun Violence Archive (GVA). Data were collected from the public domain (e.g. news). Crude comparisons between NRMS and RMS were performed using Chi-squared or Fisher's exact tests. Parametric models of victim and perpetrator characteristics were conducted at the event level using negative binomial regression and logistic regression.

RESULTS

There were 46 RMS and 1626 NRMS. RMS occurred most in businesses (43.5%), whereas NRMS occurred most in streets (41.1%), homes (28.6%), and bars (17.9%). RMS were more likely to occur between 6AM-6PM (OR=9.0 (4.8-16.8)). RMS had more victims per incident (23.6 vs. 4.9, RR: 4.8 (4.3,5.4)). Casualties of RMS were more likely to die (29.7% vs. 19.9%, OR: 1.7 (1.5,2.0)). RMS were more likely to have at least one police casualty (30.4% versus 1.8%, OR: 24.1 (11.6,49.9)) or police death (10.9% versus 0.6%, OR: 19.7 (6.4,60.3)). RMS had significantly greater odds that casualties were adult (OR: 1.3 (1.0,1.6)) and female (OR: 1.7 (1.4,2.1)). Deaths in RMS were more likely to be female (OR: 2.0 (1.5,2.5)) and White (OR: 8.6 (6.2,12.0) and less likely to be children (OR: 0.4 (0.2,0.8)). Perpetrators of RMS were more likely to die by suicide (34.8%), be killed by police (28.3%), or be arrested at the scene (26.1%), while more than half of perpetrators from NRMS escaped without death or apprehension (55.8%). Parametric models of perpetrator demographics indicated significant increases in the odds that a RMS shooter was White (OR: 13.9 (7.3,26.6)) or Asian (OR: 16.9 (3.7,78.4)). There was no significant difference in weapon type used (p=0.35).

CONCLUSION

The demographics, temporality, and location differ between RMS and NRMS, suggesting that they are dissimilar and require different preventive approaches.

The COVID-19 pandemic and its impacts on mass shootings in six major US cities

BACKGROUND

The COVID-19 pandemic has significant impacts on the US socioeconomic structure. Gun violence is a major public health issue and the effects on this area have not been well-elucidated. The objective of this study was to determine the impacts of the pandemic on mass shootings in six major United States cities with historically high rates of gun violence.

METHODS

Mass shooting data were extracted from an open-source database, Gun Violence Archive. Mass shooting was defined as four or more people shot at a single event. Data from six cities with the highest incidence of mass shootings were analyzed in 2019 versus 2020 (Baltimore, Chicago, Detroit, New Orleans, Philadelphia, and St. Louis). Geographic data were examined to assess changes in each city's mass shooting geographic distribution over time. Quantitative changes were assessed using the Area Deprivation Index (ADI), and qualitative data were assessed using ArcGIS.

RESULTS

In 2020, the overall percentage of mass shootings increased by 46.7% though there was no change in the distribution of these events when assessed quantitatively (no change in average ADI) nor qualitatively (using ArcGIS). In the six cities analyzed, the total proportion of mass shooting events was unchanged during the pandemic (21.8% vs 20.6%, p = 0.64). Chicago, the US city with the highest incidence of mass shootings, did not experience a significant change in 2020 (n = 34/91, 37.3% vs. n = 53/126, 42.1%, p = 0.57). Baltimore had a significant decrease in mass shooting events (n = 18/91, 19.8% vs. 10/126, 7.9%, p = 0.01). The other four cities had no significant change in the number of mass shootings (p>0.05).

CONCLUSION

This study is the first to use ArcGIS technology to describe the patterns of mass shooting in six major US cities during the COVID-19 pandemic. The number of mass shootings in six US cities remained largely unchanged which suggests that changes in mass shootings is likely occurring in smaller cities. Future studies should focus on the changing patterns of homicides in at-risk communities and other possible social influences.

Does Vehicle Intrusion Alone Still Predict Injury: A Retrospective Analysis of Mechanism as Trauma Activation Criteria

Automobile collisions with driver side intrusion >12 inches or >18 elsewhere meet criteria for trauma activation. However, vehicle safety features have improved since this inception. We hypothesized vehicle intrusion (VI) alone as mechanism-of-injury (MOI) criteria inadequately predicts trauma center activation. A retrospective, single-center chart review of adult patients involved in motor vehicle collisions presenting to a level 1 trauma center from July 2016 to March 2022 was performed. Patients were divided by MOI criteria: VI vs. multiple MOI criteria. 2940 patients met inclusion criteria. The VI group reported lower injury severity scores (P = 0.004), higher incidence of ED discharge (P = 0.001), lower ICU admissions (P = 0.004), and fewer in-hospital procedures (P = 0.03). Vehicle intrusion was found to have a positive likelihood ratio of 0.889 for predicting trauma center need. According to current guidelines, these results suggest that VI criteria alone may not be an accurate predictor for trauma center transport and require further investigation.

Acute Kidney Injury in Hypotensive Trauma Patients Following Resuscitative Endovascular Balloon Occlusion of the Aorta Placement

BACKGROUND

ER-Resuscitative Endovascular Balloon Occlusion of the Aorta (ER-REBOA) is an adjunct tool to achieve hemostasis in trauma patients with non-compressible torso hemorrhage. The development of the partial REBOA (pREBOA) allows for distal perfusion of organs while maintaining occlusion of the aorta. The primary aim of this study was to compare rates of acute kidney injury (AKI) in trauma patients who had placement of either a pREBOA or ER-REBOA.

METHODS

A retrospective chart review of adult trauma patients who underwent REBOA placement between September 2017 and February 2022 was performed. Baseline demographics, information on REBOA placement, and post-procedure complications including AKI, amputations, and mortality were recorded. Chi-squared and T-test analyses were performed with P < .05 considered to be significant.

RESULTS

A total of 68 patients met study inclusion criteria with 53 patients (77.9%) having an ER-REBOA. 6.7% of patients treated with pREBOA had a resulting AKI, while 40% of patients treated with ER-REBOA had a resulting AKI, and this difference was significant (P < .05). The rates of rhabdomyolysis, amputations, and mortality were not significantly different between the two groups.

CONCLUSION

The results from this case series suggest that patients treated with pREBOA have a significantly lower incidence of developing an AKI compared to ER-REBOA. There were no significant differences in rates of mortality, and amputations. Future prospective studies are needed to further characterize the indications and optimal use for pREBOA.

Deterioration Index in Critically Injured Patients: A Feasibility Analysis

INTRODUCTION

Continuous prediction surveillance modeling is an emerging tool giving dynamic insight into conditions with potential mitigation of adverse events (AEs) and failure to rescue. The Epic electronic medical record contains a Deterioration Index (DI) algorithm that generates a prediction score every 15 min using objective data. Previous validation studies show rapid increases in DI score (≥14) predict a worse prognosis. The aim of this study was to demonstrate the utility of DI scores in the trauma intensive care unit (ICU) population.

METHODS

A prospective, single-center study of trauma ICU patients in a Level 1 trauma center was conducted during a 3-mo period. Charts were reviewed every 24 h for minimum and maximum DI score, largest score change (Δ), and AE. Patients were grouped as low risk (ΔDI <14) or high risk (ΔDI ≥14).

RESULTS

A total of 224 patients were evaluated. High-risk patients were more likely to experience AEs (69.0% versus 47.6%, P = 0.002). No patients with DI scores <30 were readmitted to the ICU after being stepped down to the floor. Patients that were readmitted and subsequently died all had DI scores of ≥60 when first stepped down from the ICU.

CONCLUSIONS

This study demonstrates DI scores predict decompensation risk in the surgical ICU population, which may otherwise go unnoticed in real time. This can identify patients at risk of AE when transferred to the floor. Using the DI model could alert providers to increase surveillance in high-risk patients to mitigate unplanned returns to the ICU and failure to rescue.

Perioperative Fluid Management in Surgical Patients: A Review

Intravenous (IV) fluids are one of the most widely prescribed medications. Despite their frequent usage, IV fluids are often not used appropriately. High-quality evidence to guide the surgeon in the perioperative period is sparse. A plethora of choices for IV fluids exists with limited evidence to help guide the surgeon in specific patient populations and situations. To address this, the authors have set out to provide a critical review of commonly used IV fluids to treat surgical patients. Gaps in the existing literature for the surgical population will also be discussed as potential target areas for future research.

Impact of Increased Enoxaparin Dosing on Anti-Xa Levels for Venous Thromboembolism Prophylaxis in Trauma Patients

INTRODUCTION

Venous thromboembolism (VTE) contributes to significant morbidity in trauma patients while increasing hospital costs and length of stay. Standard trauma prophylaxis dosing with enoxaparin 30 mg twice daily may be inadequate to prevent VTEs. The objective of this study was to compare standard dosing of enoxaparin to an increased dose of enoxaparin 40 mg twice daily for trauma patients. We hypothesized that increasing thromboprophylaxis dosing leads to an increase in therapeutic anti-Xa levels and reduced VTE rates.

METHODS

A retrospective study was performed from January 2020 to June 2021 at a Level I trauma center, following implementation of an increased enoxaparin dosing strategy. Patients with increased enoxaparin dosing were compared with those who received standard dosing. The primary outcome evaluated was the incidence of subtherapeutic anti-Xa levels. Secondary outcomes evaluated VTE rates and clinically significant bleed.

RESULTS

A total of 204 trauma patients were identified. Ninety-one patients received an increased enoxaparin dose compared to 113 who received standard dosing. The baseline demographics of both groups were similar (P > .05). Subtherapeutic levels were higher with standard dosing compared to the increased dose (50 vs 22%, P = .003). Higher VTE rates were observed with standard dosing compared to higher dosing (6.2 vs 3.3%) but with a lower incidence of major bleed (1.8 vs 4.4%). Overall annual VTE rates decreased from 1.6 to 1.3% after implementation of the increased dosing regimen.

CONCLUSIONS

This study demonstrated that an increased dosing strategy decreased rates of subtherapeutic anti-Xa levels and trended toward lower overall VTE rates in trauma.

Proposed Treatment Algorithm for Invasive Fungal Infections in Trauma Patients

Background: Invasive fungal infections, most commonly caused by Mucorales species, are an underrecognized sequalae of traumatic injury that can complicate management of patients. The injury mechanism can introduce environmental spores into areas of the body normally not exposed to pathogens and this inoculation can progress rapidly to severe disease. The objective of this study was to present a case series of four trauma patients with invasive fungal infections that was used to develop an algorithm for work-up and treatment of these complex patients in future admissions. Patients and Methods: Four trauma patients who developed mucormycosis from two different hospitals are presented. One patient succumbed to their injuries whereas three were able to clear their infection with medical and surgical intervention. The surviving patients all had an infection of their lower extremity whereas the deceased patient had more extensive disease involving the thorax. Conclusions: Mucormycosis is a rare but significant post-trauma complication with substantial morbidity and mortality. Surgeons should be aware of this complication and maintain a high clinical suspicion because afflicted patients may not match the traditional clinical picture of a mucormycosis-susceptible patient. Close coordination with a pathology service is required for confirmation of the diagnosis and timely intervention can prevent debilitating loss of tissue or death. Additionally, consideration should be given to newer treatment modalities for management such as local tissue irrigation with an antifungal agent.

Prehospital Tourniquets Placed on Limbs Without Major Vascular Injuries, has the Pendulum Swung Too far?

BACKGROUND

Combat applications of tourniquets for extremity trauma have led to increased civilian prehospital tourniquet use. Studies have demonstrated that appropriate prehospital tourniquet application can decrease the incidence of arrival in shock without increasing limb complications. The aim of this study was to examine outcomes of prehospital tourniquet placement without definitive vascular injury.

METHODS

Retrospective review was performed of a prospectively maintained database by the American Association for the Surgery of Trauma from 29 trauma centers. Patients in this subset analysis did not have a significant vascular injury as determined by imaging or intra-operatively. Patients who received prehospital tourniquets (PHTQ) were compared to patients without prehospital tourniquets (No-PHTQ). Outcomes were amputation rates, nerve palsy, compartment syndrome, and in-hospital mortality.

RESULTS

A total of 622 patients had no major vascular injury. The incidence of patients without major vascular injury was higher in the PHTQ group (n = 585/962, 60.8 vs n = 37/88, 42.0%, P < .001). Cohorts were similar in age, gender, penetrating mechanism, injury severity scores (ISS), abbreviated injury score (AIS), and mortality (P > .05). Amputation rates were 8.3% (n = 49/585) in the PHTQ group compared to 0% (n = 0/37) in the No-PHTQ group. Amputation rates were higher in PHTQ than No-PHTQ with similar ISS and AIS (P = .96, P = .59). The incidence of nerve palsy and compartment syndrome was not different (P > .05).

CONCLUSIONS

This study showed a significant amount of prehospital tourniquets are being placed on patients without vascular injuries. Further studies are needed to elucidate the appropriateness of prehospital tourniquets, including targeted education of tourniquet placement.

How Did the COVID-19 Pandemic Affect Trauma Volume at an Urban Level I Trauma Center?

Introduction

The COVID-19 pandemic changed the face of health care worldwide. While the impacts from this catastrophe are still being measured, it is important to understand how this pandemic impacted existing health care systems. As such, the objective of this study was to quantify its effects on trauma volume at an urban Level 1 trauma center in one of the earliest and most significantly affected US cities.

Methods

A retrospective chart review of consecutive trauma patients admitted to a Level 1 trauma center from January 1, 2017 to December 31, 2020 was completed. The total trauma volume in the years prior to the pandemic (2017-2019) was compared to the volume in 2020. These data were then further stratified to compare quarterly volume across all 4 years.

Results

A total of 4138 trauma patients were treated in the emergency room throughout 2020 with 4124 seen during 2019, 3774 during 2018, and 3505 during 2017 in the pre-COVID-19 time period. No significant difference in the volume of minor trauma or trauma transfers was observed (P < .05). However, there was a significant increase in the number of major traumas in 2020 as compared to prior years (38.5% vs 35.6%, P < .01) and in the volume of penetrating trauma (29.1% vs 24.0%, P < .01).

Discussion

During the COVID-19 outbreak, trauma remained a significant health care concern. This study found an increase in volume of penetrating trauma, specifically gunshot wounds throughout 2020. It remains important to continue to devote resources to trauma patients during the ongoing COVID-19 pandemic.

Does Time to Pelvic Fixation Influence Outcomes in Trauma Patients?

BACKGROUND

Pelvic fractures cause significant morbidity in the trauma population. Many factors influence time to fracture fixation. No previous study has determined the optimal time window for pelvic fixation.

METHODS

A retrospective review of trauma patients with pelvic fractures from 2016 to 2020 was performed. Patients were stratified into EARLY and LATE groups, by time to fixation within 3 days or greater than 3 days whether from admission or from completion of a life-saving procedure. Unpaired Student's t-test and Fisher's exact test were performed with multiple linear regression for variables with P < .2 on univariate analysis.

RESULTS

287 patients were identified with a median fixation time of 3 days. There was no significant difference in demographics, incidence of preceding life-saving procedure, angioembolization, or mechanism of injury in the 2 groups (P > .05). Length of stay in the EARLY group was significantly reduced at 11.9 +/- .7 days compared to 18.0 +/-1.2 days in the LATE group (P < .001). There was no significant difference in rates of ventilator-associated pneumonia, deep vein thrombosis, pulmonary embolism (PE), acute kidney injury (AKI), pressure ulcer, or acute respiratory distress syndrome (ARDS) (P > .05). There were significantly more SSIs (surgical site infections) in the LATE group. After multiple linear regression adjusting for covariates of age and ISS, the difference in hospital LOS was 5.5 days (95% CI -8.0 to -3.1, P < .001).

DISCUSSION

Fixation of traumatic pelvic fractures within 3 days reduced LOS. Prospective multi-center studies will help identify additional factors to decrease time to surgery and improve patient outcomes.

Compression of the Right Atrium and Inferior Vena Cava from an Extrahepatic Biloma Following Liver Trauma

A 26-year-old male presented to a Level 1 trauma center following a motorcycle crash. Workup of his injuries demonstrated a grade 5 liver laceration with active extravasation, grade 5 kidney laceration, right apical pneumothorax, and a sternal fracture. The patient underwent hepatic artery embolization with interventional radiology (IR) followed by an exploratory laparotomy, liver packing, and small bowel resection with primary anastomosis. Four days post-op, the patient developed dyspnea, tachycardia, and decreasing oxygen saturation. Computed tomography pulmonary angiography demonstrated perihepatic fluid compressing the right atrium and inferior vena cava. Percutaneous perihepatic drain placement with aspiration of 700 mL bilious fluid resulted in immediate resolution of the compression. He subsequently underwent endoscopic retrograde cholangiopancreatography (ERCP) with stenting of the ampulla nine days later. The patient was discharged ten days post-ERCP with oral amoxicillin/clavulanic acid for polymicrobial coverage and follow-up with gastroenterology and IR for stent removal and drain maintenance.

Maintaining trauma center operational readiness during a pandemic

The coronavirus disease 2019 (COVID-19) pandemic is a slow-moving global disaster with unique challenges for maintaining trauma center operations. University Medical Center New Orleans is the only level 1 trauma center in New Orleans, LA, which became an early hotspot for COVID-19. Intensive care unit surge capacity, addressing components including space, staff, stuff, and structure, is important in maintaining trauma center operability during a high resource-strain event like a pandemic. We report management of the trauma center's surge capacity to maintain trauma center operations while assisting in the care of critically ill COVID-19 patients. Lessons learned and recommendations are provided to assist trauma centers in planning for the influx of COVID-19 patients at their centers.

Predictors of Inappropriate Helicopter Transport

Background

Helicopter transport (HT) is an efficient, but costly, means for injured patients to receive life-saving, definitive trauma care. Identifying the characteristics of inappropriate HT presents an opportunity to improve the utilization of this finite medical resource.

Methods

Trauma registry records of all HT for a 3-year period (2016-2018) to an urban Level I trauma center were reviewed. HT was defined as inappropriate for patients who were discharged home from the emergency department or had a hospital length of stay <1 day, and who were discharged alive. Chi-square analysis and Student’s t-test were used for univariate analysis. Predictors with a P value of less than .15 were subject to binary logistic regression analysis. A P value ≤.05 was considered significant.

Results

There were 713 patients who received HT during the study period. One-hundred and forty-eight (20.8%) patients met the criteria as an inappropriate HT. In univariate analysis, Glasgow Coma Scale >8, Shock Index <0.9, and fall mechanism were found to be significantly associated with inappropriate HT. Age >55 was found to be associated with an appropriate HT. The average Injury Severity Score of the inappropriate HT group was 3.86 (±3.85) compared with 16.80 (±11.23) ( P = .0001, Student’s t-test).

Discussion

Our findings suggest that there are evidence-based predictors of patients receiving inappropriate HT. Triage of HT using these predictors has the potential to decrease unnecessary deployments and reduce health care costs.

Mechanism of Injury is not a Predictor of Trauma Center Admission

Most trauma systems use mechanism of injury (MOI) as an indicator for trauma center transport, often overburdening the system as a result of significant overtriage. Before 2005 our trauma center accepted all MOI. After 2005 we accepted only those patients meeting anatomic and physiologic (A&P) triage criteria. Patients entered into the trauma center database were divided into two groups: 2001 to 2005 (Group 1) and 2007 to 2010 (Group 2) and also categorized based on trauma team activation for either A&P or MOI criteria. Overtriage was defined as patient discharge from the emergency department within 6 hours of trauma activation. A total of 9899 patients were reviewed. Group 1 had 6584 patients with 3613 (55%) activated for A&P criteria and 2971 (45%) for MOI. Group 2 had 3315 patients with 3149 (95%) activated for A&P criteria and 166 (5%) for MOI. Accepting only those patients meeting A&P criteria resulted in a decrease in the overtriage rate from 66 to 9 per cent. By accepting only those patients meeting A&P criteria, we significantly reduced our overtriage rate. Patients meeting MOI criteria were transported to community hospitals and transferred to the trauma center if major injuries were identified. Trauma center transport for MOI results in significant overtriage and may not be justified.

Comparing human and mouse salivary glands: A practice guide for salivary researchers

Mice are a widely utilized in vivo model for translational salivary gland research but must be used with caution. Specifically, mouse salivary glands are similar in many ways to human salivary glands (i.e., in terms of their anatomy, histology, and physiology) and are both readily available and relatively easy and affordable to maintain. However, there are some significant differences between the two organisms, and by extension, the salivary glands derived from them must be taken into account for translational studies. The current review details pertinent similarities and differences between human and mouse salivary glands and offers practical guidelines for using both for research purposes.

Thinking it through: mental rehearsal and performance on 2 types of laparoscopic cholecystectomy simulators

OBJECTIVE

Simulation-based training (SBT) in laparoscopic cholecystectomy (LCCY) provides an opportunity for junior residents to learn the procedure in a safe, nonthreatening environment. Mental rehearsal (MR) has the potential of augmenting skill acquisition. This project investigated the correlation between MR of LCCY with performance on 2 different types of simulators: a procedural task (PT) training model and virtual reality (VR) machine.

DESIGN

Prospective, quasi-experimental design with purposeful sampling. Postgraduate years (PGYs) 1 through 3 general surgical residents underwent standardized, distributed SBT in LCCY on either a PT trainer or a VR machine with group-based MR undertaken before 2 SBT sessions. Participants completed a pre-MR and post-MR session mental imagery questionnaire (MIQ) containing 8-items using a 7-point Likert-type scale. Data related to VR objective measures and PT video-based performances were also collected. Total scale mean scores were calculated for the first MR session and the second MR session and were compared using the t test. Pearson correlation analysis of MIQ scores with performance scores was determined.

SETTING

Louisiana State University Health New Orleans Health Sciences Center in New Orleans, Louisiana. This health sciences center is a tertiary care, academic state institution located in the Southeastern United States.

PARTICIPANTS

A total of 21 PGYs 1 through 3 general surgery residents participated. They were purposefully divided into the PT and VR training groups to allow for even PGY distribution. Of the 21 participants, 19 completed both training sessions (n = 10 for PT [PGY1 = 4, PGY2 = 4, PGY3 = 2] and n = 9 for VR [PGY1 = 4, PGY2 = 3, PGY3 = 2]).

RESULTS

After the Bonferroni adjustment, significant gains in the MIQ items related to confidence, visual imagery, and knowledge of the procedure were found. VR performance data demonstrated some statistically significant improvements. A significant negative correlation was present between the two-handed clip-and-cut VR task and MIQ gains.

CONCLUSIONS

Group MR in LCCY before SBT on a VR machine is related to improved performance time for the VR two-handed clip-and-cut task. MR may be a useful adjunct to SBT LCCY. Future work will look at the translation of these skills to clinical practice.

Impact of infusion rates of fresh frozen plasma and platelets during the first 180 minutes of resuscitation

BACKGROUND

Whether high-ratio resuscitation (HRR) provides patients with survival advantage remains controversial. We hypothesized a direct correlation between HRR infusion rates in the first 180 minutes of resuscitation and survival.

STUDY DESIGN

This was a retrospective analysis of massively transfused trauma patients surviving more than 30 minutes and undergoing surgery at a level 1 trauma center. Mean infusion rates (MIR) of packed red blood cells (PRBC), fresh frozen plasma (FFP), and platelets (Plt) were calculated for length of intervention (emergency department [ED] time + operating room [OR] time). Patients were categorized as HRR (FFP:PRBC > 0.7, and/or Plts: PRBC > 0.7) vs low-ratio resuscitation (LRR). Student's t-tests and chi-square tests were used to compare survivors with nonsurvivors. Cox proportional hazards regression models and Kaplan-Meier curves were generated to evaluate the association between MIR for FFP:PRBC and Plt:PRBC and 180-minute survival.

RESULTS

There were 151 patients who met criteria: 121 (80.1%) patients survived 180 minutes (MIR:PRBC 71.9 mL/min, FFP 92.0 mL/min, Plt 3.5 mL/min) vs 30 (19.9%) who did not survive (MIR:PRBC 47.3 mL/min, FFP 33.7 mL/min, Plt 1.1 mL/min), p = 0.43, p < 0.0001 and p < 0.011, respectively. A Cox regression model evaluated PRBC rate, FFP rate, and Plt rate (mL/min) as mortality predictors within 180 minutes to assess if they significantly affected survival (hazard ratios 1.01 [p = 0.054], 0.97 [p < 0.0001], and 0.75 [p = 0.01], respectively). Another model used stepwise Cox regression including PRBC rate, FFP rate, and Plt rate (hazard ratios 1.00 [p = 0.85], 0.97 [p < 0.0001], and 0.88 [p = 0.24], respectively), as well as possible confounding variables.

CONCLUSIONS

This is the first study to examine effects of MIRs on survival. Further studies on the effects of narrow time-interval analysis for blood product resuscitation are warranted.

To TQIP or Not to TQIP? that is the Question

The Trauma Quality Improvement Program (TQIP) reports a feasible mortality prediction model. We hypothesize that our institutional characteristics differ from TQIP aggregate data, questioning its applicability. We conducted a 2-year (2008 to 2009) retrospective analysis of all trauma activations at a Level 1 trauma center. Data were analyzed using TQIP methodology (three groups: blunt single system, blunt multisystem, and penetrating) to develop a mortality prediction model using multiple logistic regression. These data were compared with TQIP data. Four hundred fifty-seven patients met TQIP inclusion criteria. Penetrating and blunt trauma differed significantly at our institution versus TQIP aggregates (61.9 vs 7.8%; 38.0 vs 92.2%, P < 0.01). There were more firearm mechanisms of injury and less falls compared with TQIP aggregates (28.9 vs 4.2%; 8.5 vs 34.8%, P < 0.01). All other mechanisms were not significantly different. Variables significant in the TQIP model but not found to be predictors of mortality included Glasgow Coma Score motor 2 to 5, systolic blood pressure greater than 90 mmHg, age, initial pulse rate in the emergency department, mechanism of injury, head Abbreviated Injury Score, and abdominal Abbreviated Injury Score. External benchmarking of trauma center performance using mortality prediction models is important in quality improvement for trauma patient care. From our results, TQIP methodology from the pilot study may not be applicable to all institutions.

To TQIP or not to TQIP? That is the question

The Trauma Quality Improvement Program (TQIP) reports a feasible mortality prediction model. We hypothesize that our institutional characteristics differ from TQIP aggregate data, questioning its applicability. We conducted a 2-year (2008 to 2009) retrospective analysis of all trauma activations at a Level 1 trauma center. Data were analyzed using TQIP methodology (three groups: blunt single system, blunt multisystem, and penetrating) to develop a mortality prediction model using multiple logistic regression. These data were compared with TQIP data. Four hundred fifty-seven patients met TQIP inclusion criteria. Penetrating and blunt trauma differed significantly at our institution versus TQIP aggregates (61.9 vs 7.8%; 38.0 vs 92.2%, P < 0.01). There were more firearm mechanisms of injury and less falls compared with TQIP aggregates (28.9 vs 4.2%; 8.5 vs 34.8%, P < 0.01). All other mechanisms were not significantly different. Variables significant in the TQIP model but not found to be predictors of mortality included Glasgow Coma Score motor 2 to 5, systolic blood pressure greater than 90 mmHg, age, initial pulse rate in the emergency department, mechanism of injury, head Abbreviated Injury Score, and abdominal Abbreviated Injury Score. External benchmarking of trauma center performance using mortality prediction models is important in quality improvement for trauma patient care. From our results, TQIP methodology from the pilot study may not be applicable to all institutions.

Mechanism of injury is not a predictor of trauma center admission

Most trauma systems use mechanism of injury (MOI) as an indicator for trauma center transport, often overburdening the system as a result of significant overtriage. Before 2005 our trauma center accepted all MOI. After 2005 we accepted only those patients meeting anatomic and physiologic (A&P) triage criteria. Patients entered into the trauma center database were divided into two groups: 2001 to 2005 (Group 1) and 2007 to 2010 (Group 2) and also categorized based on trauma team activation for either A&P or MOI criteria. Overtriage was defined as patient discharge from the emergency department within 6 hours of trauma activation. A total of 9899 patients were reviewed. Group 1 had 6584 patients with 3613 (55%) activated for A&P criteria and 2971 (45%) for MOI. Group 2 had 3315 patients with 3149 (95%) activated for A&P criteria and 166 (5%) for MOI. Accepting only those patients meeting A&P criteria resulted in a decrease in the overtriage rate from 66 to 9 per cent. By accepting only those patients meeting A&P criteria, we significantly reduced our overtriage rate. Patients meeting MOI criteria were transported to community hospitals and transferred to the trauma center if major injuries were identified. Trauma center transport for MOI results in significant overtriage and may not be justified.

Risk factors for cervical spine injury

INTRODUCTION

The early recognition of cervical spine injury remains a top priority of acute trauma care. Missed diagnoses can lead to exacerbation of an existing injury and potentially devastating consequences. We sought to identify predictors of cervical spine injury.

METHODS

Trauma registry records for blunt trauma patients cared for at a Level I Trauma Centre from 1997 to 2002 were examined. Cervical spine injury included all cervical dislocations, fractures, fractures with spinal cord injury, and isolated spinal cord injuries. Univariate and adjusted odds ratios (ORs) were calculated to identify potential risk factors. Variables and two-way interaction terms were subjected to multivariate analysis using backward conditional stepwise logistic regression.

RESULTS

Data from 18,644 patients, with 55,609 injuries, were examined. A total of 1255 individuals (6.7%) had cervical spine injuries. Motor Vehicle Collision (MVC) (odds ratio (OR) of 1.61 (1.26, 2.06)), fall (OR of 2.14 (1.63, 2.79)), age <40 (OR of 1.75 (1.38-2.17)), pelvic fracture (OR of 9.18 (6.96, 12.11)), Injury Severity Score (ISS) >15 (OR of 7.55 (6.16-9.25)), were all significant individual predictors of cervical spine injury. Neither facial fracture nor head injury alone were associated with an increased risk of cervical spine injury. Significant interactions between pelvic fracture and fall and pelvic fracture and head injury were associated with a markedly increased risk of cervical spine (OR 19.6 (13.1, 28.8)) and (OR 27.2 (10.0-51.3)).

CONCLUSIONS

MVC and falls were independently associated with cervical spine injury. Pelvic fracture and fall and pelvic fracture and head injury, had a greater than multiplicative interaction and high risk for cervical spine injury, warranting increased vigilance in the evaluation of patients with this combination of injuries.

Generation of tumor-initiating cells by exogenous delivery of OCT4 transcription factor

Introduction

Tumor-initiating cells (TIC) are being extensively studied for their role in tumor etiology, maintenance and resistance to treatment. The isolation of TICs has been limited by the scarcity of this population in the tissue of origin and because the molecular signatures that characterize these cells are not well understood. Herein, we describe the generation of TIC-like cell lines by ectopic expression of the OCT4 transcription factor (TF) in primary breast cell preparations.

Methods

OCT4 cDNA was over-expressed in four different primary human mammary epithelial (HMEC) breast cell preparations from reduction mammoplasty donors. OCT4-transduced breast cells (OTBCs) generated colonies (frequency ~0.01%) in self-renewal conditions (feeder cultures in human embryonic stem cell media). Differentiation assays, immunofluorescence, immunohistochemistry, and flow cytometry were performed to investigate the cell of origin of OTBCs. Serial dilutions of OTBCs were injected in nude mice to address their tumorigenic capabilities. Gene expression microarrays were performed in OTBCs, and the role of downstream targets of OCT4 in maintaining self-renewal was investigated by knock-down experiments.

Results

OTBCs overcame senescence, overexpressed telomerase, and down-regulated p16^INK4A. In differentiation conditions, OTBCs generated populations of both myoepithelial and luminal cells at low frequency, suggesting that the cell of origin of some OTBCs was a bi-potent stem cell. Injection of OTBCs in nude mice generated poorly differentiated breast carcinomas with colonization capabilities. Gene expression microarrays of OTBC lines revealed a gene signature that was over-represented in the claudin-low molecular subtype of breast cancer. Lastly, siRNA-mediated knockdown of OCT4 or downstream embryonic targets of OCT4, such as NANOG and ZIC1, suppressed the ability of OTBCs to self-renew.

Conclusions

Transduction of OCT4 in normal breast preparations led to the generation of cell lines possessing tumor-initiating and colonization capabilities. These cells developed high-grade, poorly differentiated breast carcinomas in nude mice. Genome-wide analysis of OTBCs outlined an embryonic TF circuitry that could be operative in TICs, resulting in up-regulation of oncogenes and loss of tumor suppressive functions. These OTBCs represent a patient-specific model system for the discovery of novel oncogenic targets in claudin-low tumors.

Fractal analysis for classification of breast carcinoma in optical coherence tomography

The accurate and rapid assessment of tumor margins during breast cancer resection using optical coherence tomography (OCT) has the potential to reduce patient risk. However, it is difficult to subjectively distinguish cancer from normal fibroglandular stromal tissues in OCT images, and an objective measure is needed. In this initial study, we investigate the potential of a one-dimensional fractal box-counting method for cancer classification in OCT. We computed the fractal dimension, a measure of the self-similarity of an object, along the depth axis of 44 ultrahigh-resolution OCT images of human breast tissues obtained from 4 cancer patients. Correlative histology was employed to identify distinct regions of adipose, stroma, and cancer in the OCT images. We report that the fractal dimension of stroma is significantly higher than that of cancer (P < 10(-5), t-test). Furthermore, by adjusting the cutoff values of fractal dimension between cancer, stroma, and adipose tissues, sensitivities and specificities of either 82.4% and 88.9%, or 88.2% and 81.5%, are obtained, respectively, for cancer classification. The use of fractal analysis with OCT could potentially provide automated identification of tumor margins during breast-sparing surgery.

The changing face of trauma: New Orleans before and after Hurricane Katrina

Charity Hospital (CH) was devastated by Hurricane Katrina and remains closed. Design and staffing of a new, temporary dedicated trauma hospital relied on data from prior experience at CH, updated census information, and a changed trauma demographic. The study objective was to analyze the new trauma program and evaluate changes in demographics, injury patterns, and outcomes between pre- (PK) and post-Katrina (POK) trauma populations. A retrospective review of trauma patients' demographics, anatomical variables, and physiological variables 6 months PK and POK was performed under an approved Institutional Review Board protocol. Trauma activation triage criteria between study periods were also analyzed. Continuous data comparisons between the two time periods were made with Student's t test. Dichotomous data were analyzed using chi2 test. The demographic of trauma patients is different in the POK interval, reflecting changes in the New Orleans population. Modification of triage criteria by the exclusion of mechanism as an activation criterion resulted in an increase of patients with higher acuity and Injury Severity Score, lower initial Glasgow Coma Score, and a higher proportion of penetrating mechanism. Outcome measures reflect longer length of stay (4.4 vs. 6.8 days, P < 0.0001) without a significant difference in mortality (6.0 vs 7.5, P = 0.227). Hospital data demonstrates that the POK trauma system was stressed by the increased acuity, penetrating injury, and number of procedures per patient (1.7 vs. 3.4). Resources should be directed toward patients requiring multidisciplinary care by increasing intensive care unit beds and operating room capacity. Future resource planning in the recovery phases of large-scale natural disasters should take into account these observations.

An unusual sinonasal tumor: soft tissue perineurioma

Soft tissue perineuriomas are an unusual type of peripheral nerve sheath tumors distinct from schwannomas and neurofibromas, with interesting histologic findings. They are not well characterized on radiographic examination. We report this case of a patient with sinonasal perineurioma to help define the imaging and pathologic features of this rare head and neck tumor.

Helicobacter pylori associated gastric Burkitt lymphoma

Chronic Helicobacter pylori (H. pylori) infection has been linked to lymphoma of gastric mucosa-associated lymphoid tissue (MALT), a tumor that is typically localized at presentation. Sporadic Burkitt lymphoma (BL) frequently presents as an abdominal mass. However, primary gastric BL is unusual and the role of H. pylori in its pathogenesis is unclear. We describe a 12 year old with localized gastric BL and concurrent H. pylori infection. In this report, we discuss the potential association between H. pylori and gastric BL and also highlight certain similarities between gastric MALT lymphomas and BL arising in the stomach.

Cholelithiasis of the ovary after laparoscopic cholecystectomy: a case report

BACKGROUND

Laparoscopic cholecystectomy may result in spilled bile and dropped gallstones. Although there are usually no consequences, occasionally this can lead to serious complications, including those requiring surgical procedures. Very few cases have been reported documenting the consequence of spilled biliary contents on or near the female genital tract.

CASE

A cholelith became embedded in the ovary of a 53-year-old woman and was detected >7 years after laparoscopic cholecystectomy.

CONCLUSION

The complications of cholelithiasis of the ovary may include chronic pelvic pain, dysmenorrhea, infection, adhesions, ectopic pregnancy and infertility. Ovarian choleliths may be an incidental finding or can mimic a primary ovarian tumor.

Factors affecting the diagnosis and prediction of PTSD symptomatology in children and adolescents

OBJECTIVE

In a cohort that spanned all of childhood and suffered equivalent types of traumas, the authors examined diagnostic validity and risk factors for posttraumatic stress disorder (PTSD). For older children, parent-child agreement was investigated.

METHOD

Sixty-two children ages 0-18 years who were hospitalized with injuries were assessed 2 months later for PTSD. Mothers were interviewed, and concurrent interviews were conducted with 24 adolescents.

RESULTS

Children did not attain the DSM-IV threshold of three criterion C items until age 7. The 0-6-year-old group had significantly fewer criterion C symptoms (mean=0.43) than the 12-18-year-olds (mean=1.17). The impact of altering thresholds for criteria C and D was examined. Older children reported symptoms meeting criterion B significantly more often (79.2%) than parents (45.8%). Combined parent-child reports yielded significantly more symptoms and higher rates for criteria B, C, and D (almost a twofold increase) and for the overall diagnosis (37.5%) than parent report alone (4.2%). This 8.9-fold increase in diagnosis from combined reports suggests that the diagnostic rates for children who cannot make self-reports may greatly underestimate the true numbers. The interaction between pretrauma externalizing behavior and witnessing a threat to a caregiver had a significant effect on the total number of PTSD symptoms.

CONCLUSIONS

These findings provide additional support for lowering the requirement of three criterion C symptoms for preschool children and raise questions about the appropriateness of this threshold for prepubertal children. The validity of studies that do not assess symptoms with combined parent and child reports is limited.

CT-angiography for the detection of a lower gastrointestinal bleeding source

The evaluation of lower gastrointestinal bleeding (LGIB) often involves the collaborative efforts of the gastroenterologist, radiologist, and surgeon. Efforts to localize the acute LGIB have traditionally involved colonoscopy, technetium-labeled red blood cell (RBC) scintigraphy, angiography, or a combination of these modalities. The sensitivity of each method of diagnosis is limited, with the most common cause of a negative study the spontaneous cessation of hemorrhage. Other technical factors include vasospasm, lack of adequate contrast volume or exposure time, a venous bleeding source, and a large surface bleeding area. We report the use of multidetector computed tomography (MDCT), or CT-angiography (CT-A), in the initial evaluation of LGIB, and speculate on the incorporation of this technique into a diagnostic algorithm to treat LGIB. MDCT may offer a very sensitive means to evaluate the source of acute LGIB, while avoiding some of the morbidity and intense resource use of contrast angiography, and may provide unique morphologic information regarding the type of pathology. Screening with the more rapid and available MDCT, followed by either directed therapeutic angiography or surgical management, may represent a reasonable algorithm for the early evaluation and management of acute LGIB in which an active bleeding source is strongly suspected.

Circumferential Adjustment of Ultrasound Probe Position to Determine the Optimal Approach to the Internal Jugular Vein: A Noninvasive Geometric Study in Adults

Circumferential adjustment of the position of a two-dimensional ultrasound (US) probe around the neck has been recommended as a strategy for reducing the potential for unintentional common carotid artery puncture during internal jugular venous (IJV) cannulation. We obtained multiple high-resolution US images bilaterally from the necks of 107 adult subjects and analyzed these to determine the degree to which this strategy permits identification of a pathway from the skin to the IJV that minimizes venoarterial overlap while maximizing venous target (angular) width. The method consistently permitted identification of an approach to the IJV superior to that obtainable with any one of four popular surface anatomy-based ("blind") approaches and was even more powerful if used in concert with a US-guided 1) adjustment of the degree of head rotation, 2) choice between a high and low approach, and 3) choice between the right and left IJV. Use of a high-resolution US imaging device also permitted identification of the precise boundaries of additional cervical anatomic structures (nontarget vessels, lymph nodes, and the thyroid gland) potentially relevant to selection of an optimal approach to the IJV.