Role of Vena Cava Filter in the Prophylaxis and Treatment of Venous Thromboembolism in Injured Adult Patients: A Systematic Review, Meta-Analysis, and Practice Management Guideline from the Eastern Association for the Surgery of Trauma [RETRACTED]

BACKGROUND

Injured patients are at an increased risk of developing deep vein thrombosis (DVT) and pulmonary embolism (PE). Inferior vena cava (IVC) filters have been used in injured patients to prevent venous thromboembolism (VTE), but current evidence-based guidelines are lacking.

METHODS

Questions regarding IVC filter use in injured patients with clearly defined Population(s), Intervention(s), Comparison(s), and appropriately selected Outcomes (PICO) were formulated. The study sought to understand the evidence behind use of ultra short term IVC filters and use of IVC filters in injured patients with and without known VTE who are unable to receive therapeutic anticoagulation and chemoprophylaxis, respectively. A literature search and review was conducted, followed by meta-analysis. The quality of evidence was assessed per Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

There were twenty-one studies that were analyzed. Three studies were randomized controlled trials (RCTs), three were observational studies, and fifteen studies were retrospective studies. In injured patients without known acute VTE who cannot receive chemoprophylaxis, we recommend against placement of an IVC filter due to associated higher rate of mortality, DVT, PE, and length of stay. The quality of evidence was assessed to be low. In injured patients with known DVT who cannot receive chemoprophylaxis we conditionally recommend against placement of an IVC filter. The quality of evidence was assessed to be very low. No recommendations can be made with respect to placement of ultra short term IVC filters based upon available data.

CONCLUSION

IVC filters should not be placed routinely for prophylaxis in injured adult patients without known VTE who cannot receive chemoprophylaxis. The taskforce conditionally recommends against the placement of IVC filter in injured adult patients with known DVT who cannot receive chemoprophylaxis.

LEVEL OF EVIDENCE

Guideline; Systematic review/meta-analysis, level IV.

Progresses and perspectives on natural polysaccharide based hydrogels for repair of infarcted myocardium

Myocardial infarction (MI) is serious health threat and impairs the quality of life. It is a major causative factor of morbidity and mortality. MI leads to the necrosis of cardio-myocytes, cardiac remodelling and dysfunction, eventually leading to heart failure. The limitations of conventional therapeutic and surgical interventions and lack of heart donors have necessitated the evolution of alternate treatment approaches for MI. Polysaccharide hydrogel based repair of infarcted myocardium have surfaced as viable option for MI treatment. Polysaccharide hydrogels may be injectable hydrogels or cardiac patches. Injectable hydrogels can in situ deliver cells and bio-actives, facilitating in situ cardiac regeneration and repair. Polysaccharide hydrogel cardiac patches reduce cardiac wall stress, and inhibit ventricular expansion and promote angiogenesis. Herein, we discuss about MI pathophysiology and myocardial microenvironment and how polysaccharide hydrogels are designed to mimic and support the microenvironment for cardiac repair. We also put forward the versatility of the different polysaccharide hydrogels in mimicking diverse cardiac properties, and acting as a medium for delivery of cells, and therapeutics for promoting angiogenesis and cardiac repair. The objectives of this review is to summarize the factors leading to MI and to put forward how polysaccharide based hydrogels promote cardiac repair. This review is written to enable researchers understand the factors promoting MI so that they can undertake and design novel hydrogels for cardiac regeneration.

Research progresses on carboxymethyl xanthan gum: Review of synthesis, physicochemical properties, rheological characterization and applications in drug delivery

Xanthan gum is a nonionic polysaccharide widely explored in biomedical, nutraceutical, and pharmaceutical fields. XG suffers from several drawbacks like poor dissolution, lower bioavailability and an inability to form hydrogels. The carboxymethyl derivative of XG, CMX, has better solubility, dissolution, and bioavailability characteristics. Moreover, due to its anionic character, it forms water insoluble hydrogels upon crosslinking with metal cations. CMX hydrogels are used to prepare matrix tablets, microparticles, beads, and films. CMX hydrogels has been used in drug delivery and tissue engineering fields. CMX hydrogels are used for sustained gastrointestinal, colon targeted, and transdermal delivery of drugs. CMX nanoparticles have been used for targeted delivery of anticancer drugs to tumor cells. CMX hydrogels have already made significant strides in drug delivery and tissue engineering fields. Further understanding of the physicochemical properties and rheological characteristics of CMX would enable researchers to explore newer applications of CMX. This review article thus aims to discuss the synthesis, physicochemical properties, and rheological characteristics of CMX. The article also gives critical insights on the versatility of CMX as a drug delivery carrier and presents prospective trends on applications of CMX.

Assessment of bone ingrowth around beaded coated tibial implant for total ankle replacement using mechanoregulatory algorithm

The long-term performance of porous coated tibial implants for total ankle replacement (TAR) primarily depends on the extent of bone ingrowth at the bone-implant interface. Although attempts were made for primary fixation for immediate post-operative stability, no investigation was conducted on secondary fixation. The aim of this study is to assess bone ingrowth around the porous beaded coated tibial implant for TAR using a mechanoregulatory algorithm. A realistic macroscale finite element (FE) model of the implanted tibia was developed based on computer tomography (CT) data to assess implant-bone micromotions and coupled with microscale FE models of the implant-bone interface to predict bone ingrowth around tibial implant for TAR. The macroscale FE model was subjected to three near physiological loading conditions to evaluate the site-specific implant-bone micromotion, which were then incorporated into the corresponding microscale model to mimic the near physiological loading conditions. Results of the study demonstrated that the implant experienced tangential micromotion ranged from 0 to 71 μm with a mean of 3.871 μm. Tissue differentiation results revealed that bone ingrowth across the implant ranged from 44 to 96 %, with a mean of around 70 %. The average Young's modulus of the inter-bead tissue layer varied from 1444 to 4180 MPa around the different regions of the implant. The analysis postulates that when peak micromotion touches 30 μm around different regions of the implant, it leads to pronounced fibrous tissues on the implant surface. The highest amount of bone ingrowth was observed in the central regions, and poor bone ingrowth was seen in the anterior parts of the implant, which indicate improper osseointegration around this region. This macro-micro mechanical FE framework can be extended to improve the implant design to enhance the bone ingrowth and in future to develop porous lattice-structured implants to predict and enhance osseointegration around the implant.

Opportunity for a Community Health Fair Model of Bleeding Control Training

BACKGROUND

Traumatic hemorrhage is a prevalent cause of death nationally, with >50% of civilian deaths estimated to be preventable with more timely intervention. This study investigated the efficacy of training large and diverse audiences in bleeding control methods including tourniquets in community health fair settings.

METHODS

A booth was utilized for bleeding control training at community health fairs via direct demonstrations of pressure, wound packing, and commercial and improvised tourniquet application followed by hands-on practice. Participants self-rated their perceived abilities while instructors rated the participant competency.

RESULTS

117 community members participated during two fairs, though not every person completed every portion of the training. Average age was 33 (range 6-82) and the majority were female (65.0%). There was no difference in self-perceived skill compared to trainer grading of participant's ability to identify life-threatening bleeding (112 (97.4%) vs 106 (97.2%); P = 1), apply pressure (113 (98.3%) vs 106 (97.2%); P = .68), and pack a wound (102 (88.7%) vs 92 (84.4%); P = .43). No difference in difficulty was noted in placing commercial vs improvised tourniquets (16 (43%) vs 14 (45%); P = .87). However, participants were overconfident in their ability to place tourniquets compared to trainer grading, respectively (112 (98.2%) vs 100 (91.7%; P = .03)).

DISCUSSION

Community fair classes provide opportunities to train large and diverse audiences in bleeding control techniques. However, participants overestimated their ability to appropriately apply tourniquets. Further investigation is needed into best educational approaches to optimize the impact of bleeding control kits that have been distributed in multiple states.

Association of Early Rib Plating on Clinical and Financial Outcomes: A National Analysis

BACKGROUND

With reported improvements in patient outcomes, surgical stabilization of rib fractures (SSRF) has been increasingly adopted. While institutional series have sought to define the role of early SSRF, large scale analysis remains lacking. The present study evaluated clinical and financial outcomes of SSRF in a nationally representative cohort.

METHODS

Patients (≥16 years) admitted with multiple rib fractures were identified using the 2016-2020 National Inpatient Sample. Those who underwent rib plating >14 days following admission were omitted. Using restricted cubic spline analysis, patients who underwent SSRF within 2 days of hospitalization were classified as Expedited while fixation >2 days were deemed Routine. Multivariable regressions were used to evaluate the association of operative timing on outcomes of interest.

RESULTS

Of 8150 patients meeting final inclusion criteria, 4090 (50.2%) were Expedited. Compared to Routine, Expedited tended to be older but were of comparable race, primary payer, and income quartile. Traumatic mechanism was also similar but rates of concomitant sternal fracture as well as intra-abdominal and cardiac injuries were higher in Routine. After adjustment, Expedited was associated with lower odds of respiratory complications, which included need for mechanical ventilation, prolonged mechanical ventilation, and pneumonia, compared to Routine. Expedited was associated with similar hospitalization duration but had lower incremental costs (β: -$19.1 K, 95% CI: -24.1 to -14.2).

DISCUSSION

Early SSRF was associated with lower likelihood of a number of respiratory complications and in-hospital costs. While patient selection criteria may limit our findings, expeditious fixation may limit morbidity while enhancing value of care.

Medical Management of Traumatic Vertebral Artery Injury Is Safe Regardless of the Severity of Injury

BACKGROUND

Management of traumatic vertebral artery injury (VAI) remains under debate. Current consensus reserves surgical or endovascular management for high-grade injury in order to prevent stroke. We sought to evaluate the factors that influence posterior fossa stroke outcomes following traumatic VAI.

METHODS

A search of the prospectively maintained PROOVIT trauma registry of patients older than 18 years of age with a diagnosis of VAI was performed at a level 1 trauma center from 2013 to 2019. Patient demographics, type of injury, the timing of presentation, Biffl Classification of Cerebrovascular Injury Grade score, medical management, procedural interventions, and stroke outcomes were analyzed.

RESULTS

VAIs were identified in 66 trauma patients were identified out of 14,323 patients entered into the PROOVIT registry. The dominant mechanism was blunt injury (91.5% vs. 8.5%, blunt versus penetrating). Nine patients presented with symptomatic ipsilateral posterior circulation strokes visible on imaging. The average Biffl classification grade was similar between the stroke and nonstroke groups (2.0 vs. 1.5; P = 0.39). The average injury severity score (ISS) between stroke and nonstroke groups was also similar (9.0 vs. 14.0; P = 0.35). All 9 patients in the stroke group had magnetic resonance imaging verification of their infarct within an average of 21.2 hr from presentation. In the stroke group, 1 patient underwent diagnostic angiography but had no intervention. In the nonstroke group, all were treated with medical management alone and none underwent vertebral artery intervention. During a mean follow-up of 14.5 months, no patients experienced a new neurological deficit.

CONCLUSIONS

The severity of VAI by Biffl grading and ISS are not associated with ischemic stroke at presentation following VAI. Medical management of VAI appears safe regardless of Biffl and ISS staging in this trauma population. Neurological changes related to embolic stroke were generally appreciated on presentation. Conservative medical management was sufficient to protect from secondary neurological deficit regardless of index vertebral injury.

Stroke Prevention in Blunt Cerebrovascular Injury: Role of Aspirin 81 mg

BACKGROUND

The stroke rate in blunt cerebrovascular injury (BCVI) varies from 25% without treatment to less than 8% with antithrombotic therapy. There is no consensus on the optimal management to prevent stroke BCVI. We investigated the efficacy and safety of oral Aspirin (ASA) 81 mg to prevent BCVI-related stroke compared to historically reported stroke rates with ASA 325 mg and heparin.

METHODS

A single-center retrospective study included adult trauma patients who received oral ASA 81 mg for BCVI management between 2013 and 2022. Medical records were reviewed for demographic and injury characteristics, imaging findings, treatment-related complications, and outcomes.

RESULTS

Eighty-four patients treated with ASA 81 mg for BCVI were identified. The mean age was 41.50 years, and 61.9% were male. The mean Injury Severity Score and Glasgow Coma Scale were 19.82 and 12.12, respectively. A total of 101 vessel injuries were identified, including vertebral artery injuries in 56.4% and carotid artery injuries in 44.6%. Traumatic brain injury was found in 42.9%, and 16.7% of patients had a solid organ injur. Biffl grade I (52.4%) injury was the most common, followed by grade II (37.6%) and grade III (4.9%). ASA 81 mg was started in the first 24 hours in 67.9% of patients, including 20 patients with traumatic brain injury and 8 with solid organ injuries. BCVI-related stroke occurred in 3 (3.5%) patients with Biffl grade II (n = 2) and III (n = 1). ASA-related complications were not identified in any patient. The mean length of stay in the hospital was 10.94 days, and 8 patients died during hospitalization due to complications of polytrauma. Follow-up with computed tomography angiography was performed in 8 (9.5%) patients, which showed improvement in 5 and a stable lesion in 3 at a mean time of 58 days after discharge.

CONCLUSIONS

In the absence of clear guidelines regarding appropriate medication, BCVI management should be individualized case-by-case through a multidisciplinary approach. ASA 81 mg is a viable option for BCVI-related stroke prevention compared to the reported stroke rates (2%-8%) with commonly used antithrombotics like heparin and ASA 325 mg. Future prospective studies are needed to provide insight into the safety and efficacy of the current commonly used agent in managing BCVI.

Analysis of Extracranial Cerebrovascular Injuries: Clinical Predictors of Management and Outcomes

BACKGROUND

Optimal management of traumatic extracranial cerebrovascular injuries (ECVIs) remains undefined. We sought to evaluate the factors that influence management and neurologic outcomes (stroke and brain death) following traumatic ECVI.

METHODS

A retrospective review of a single level 1 trauma center's prospectively maintained data registry of patients older than 18 years of age with a diagnosis of ECVI was performed from 2013 to 2019. Injuries limited to the external carotid artery were excluded. Patient demographics, type of injury, timing of presentation, Biffl Classification of Cerebrovascular Injury Grade, Injury Severity Score (ISS), and Abbreviated Injury Scale were documented. Ultimate treatments (medical management and procedural interventions) and brain-related outcomes (stroke and brain death) were recorded.

RESULTS

ECVIs were identified in 96 patients. The primary mechanism of injury was blunt trauma (89.5% vs. 10.5%, blunt versus penetrating), with 70 cases (66%) of vertebral artery injury and 37 cases of carotid artery injury. Treatments included vascular intervention (6.5%) and medical management (93.5%). Overall outcomes included ipsilateral ischemic stroke (29%) and brain death (6.5%). In the carotid group, vascular intervention was associated with higher Biffl grades (mean Biffl 3.17 vs. 2.23; P = 0.087) and decreased incidence of brain death (0% vs. 19%, P = 0.006), with no difference seen in ISS scores. Brain death was associated with higher ISS scores (40.29 vs. 24.17, P = 0.01), lower glascow coma score on arrival (3.57 vs. 10.63, P < 0.001), and increased rates of ischemic stroke (71% vs. 30%, P = 0.025). In the vertebral group, neither Biffl grade nor ISS were associated with treatment or outcomes. Regarding the timing of stroke in ECVI, there was no significant difference in the time from presentation to cerebral infarction between the carotid and vertebral artery groups (24.7 hr vs. 21.20 hr, P = 0.739). After this window, 98% of the ECVI cases demonstrated no further aneurysmal degeneration or new neurological deficits beyond the early time period (mean follow-up 9.7 months).

CONCLUSIONS

Blunt cerebrovascular injuries should be viewed distinctly in the carotid and vertebral territories. In cases of injury to the carotid artery, Biffl grade and ISS score are associated with surgical intervention and neurologic events, respectively; vertebral artery injuries did not share this association. Neurologic deficits were detected in a similar time frame between the carotid artery and the vertebral artery injury groups and both groups had rare late neurologic events.

A Medium-Term Comparison of Quality of Life and Pain After Robotic or Laparoscopic Cholecystectomy

INTRODUCTION

We sought to compare medium-term outcomes between robotic-assisted cholecystectomy (RC) and laparoscopic cholecystectomy (LC) using validated quality of life (QoL) and pain assessments.

MATERIALS AND METHODS

Patients who underwent RC or LC between 2012 and 2017 at a single academic institution were examined. Cases converted to open were excluded. Patients were contacted by telephone in 2019 and completed two standardized surveys to rate their QoL and pain.

RESULTS

Of those screened, 122 (35.8%) completed both surveys. Ninety three (76.2%) underwent RC and 29 (23.8%) underwent LC. The groups (RC versus LC) were similar based on mean age (47.9 versus 45.5 y, P = 0.48), gender (66.7% versus 72.4% female, P = 0.56), race (86.0% White/5.4% Black versus 72.4% White/13.8% Black, P = 0.2), insurance status (98.9% versus 100.0% insured, P = 0.58), median body mass index (31.8 versus 31.3, P = 0.43), and median Charlson Comorbidity Index (1 versus 0, P = 0.14). Fewer RC patients had a history of steroid use compared to LC (16.1% versus 34.5%, P = 0.03). No overall significant difference in QoL was demonstrated. LC group had higher severity of "tiring-exhausting pain" (P = 0.04), "electric-shock pain" (P = 0.003), and "shooting pain" (P = 0.05). The "overall intensity" of pain in the "gallbladder region" between the groups was similar at the time of follow-up (P = 0.31).

CONCLUSIONS

QoL over 2-7 y following time of surgery is comparable for robotic-assisted versus conventional laparoscopic cholecystectomies. The laparoscopic approach may be associated with a higher severity of subset categories of pain, but overall pain between the two approaches is comparable.

Oxygen vacancy-enriched Zn2SnO4 for aliphatic alcohol sensing and enhanced selectivity towards n-butanol

The sensitive detection of toxic flammable volatile organics using low cost efficient sensors is important for ensuring both indoor and outdoor safety. It is essential for chemical sensors to exhibit a significantly stronger response to target analytes compared to equivalent amounts of analogous competing chemicals. In line with this importance, current work evaluated the performance of Zn2SnO4, a n-type semiconducting metal oxide, for sensing n-butanol in comparison to methanol, ethanol, and propanol vapours. These vapours fall within the category of aliphatic alcohols but vary in characteristics such as molecular weight, vapour pressure, volatility, and diffusivity. In this work we have explored the sensor's performance by adjusting the operating temperature over the range of 225-300 °C while detecting 1000 ppm of each of these vapours. Efforts were made to establish a correlation between the sensor's responses with the interactions of these vapours on the sensor's surface. Prior to assessing the sensing characteristics of the solid-state-route-derived Zn2SnO4, its structural characteristics, including phase purity, crystalline structure, bonding patterns, morphology, and defect characteristics, were studied. This comprehensive analysis sheds light on the potential of Zn2SnO4 as an effective sensor for detecting n-butanol.

Outcomes of Hospitalized Injured Suspects Sustaining Gunshot Wounds From Law Enforcement Action

BACKGROUND

Although firearms are implicated in the majority of law enforcement intervention (LEI)-related deaths, scientific research is lacking. The present study sought to characterize clinical and financial outcomes between injured suspects and other gunshot wound (GSW) patients.

STUDY DESIGN

The 2016-2020 National Inpatient Sample was queried for patients ≥16 years old admitted following GSW. Patients were categorized as injured suspects (ISs) if they were injured in LEI and non-IS otherwise. The primary outcome was in-hospital mortality with complications, hospitalization duration (LOS), and costs secondarily considered. Multivariable regression models were used to adjust for patient characteristics, injury burden using the Trauma Mortality Prediction Model (TMPM), and hospital factors.

RESULTS

Of 143,125 hospitalizations, 1575 (1.10%) were IS. Compared to non-IS, ISs were less frequently Black (24.4% vs 54.3%) but had a higher proportion of psychiatric conditions (19.4% vs 6.4%) (P < .05). Although having a similar requirement for major operations and TMPM score, ISs more frequently underwent thoracic (11.4% vs 4.1%) and gastrointestinal operations (33.0% vs 25.7%) (P < .05). After adjustment, IS was associated with similar odds of mortality but was associated with greater odds of cardiac complications, respiratory failure, and need for intensive care. While LOS was similar, IS was associated with greater costs (β: +$14,300, 95% CI: 6,200-22,400).

CONCLUSIONS

Suspects injured during law enforcement intervention have similar in-hospital mortality but greater complication rates and costs. Through the quantification of the clinical and financial burden of IS, our findings may help inform further policy discussions regarding use of potentially lethal force in law enforcement intervention.

PROPOSED REVISION OF THE AMERICAN ASSOCIATION FOR SURGERY OF TRAUMA RENAL TRAUMA ORGAN INJURY SCALE: SECONDARY ANALYSIS OF THE MULTI-INSTITUTIONAL GENITOURINARY TRAUMA STUDY

BACKGROUND

This study updates the American Association for Surgery of Trauma (AAST) Organ Injury Scale (OIS) for renal trauma using evidence-based criteria for bleeding control intervention.

METHODS

This was a secondary analysis of a multi-center retrospective study including patients with high grade renal trauma from 7 Level-1 trauma centers from 2013-2018. All eligible patients were assigned new renal trauma grades based on revised criteria. The primary outcome used to measure injury severity was intervention for renal bleeding. Secondary outcomes included intervention for urinary extravasation, units of packed red blood cells (PRBCs) transfused within 24 hours, and mortality. To test the revised grading system, we performed mixed effect logistic regression adjusted for multiple baseline demographic and trauma covariates. We determined the area under the receiver-operator curve (AUC) to assess accuracy of predicting bleeding interventions from the revised grading system and compared this to 2018 AAST organ injury scale.

RESULTS

based on the 2018 OIS grading system, we included 549 patients with AAST Grade III-V injuries and CT scans (III: 52% (n = 284), IV: 45% (n = 249), and V: 3% (n = 16)). Among these patients, 89% experienced blunt injury (n = 491) and 12% (n = 64) underwent intervention for bleeding. After applying the revised grading criteria, 60% (n = 329) of patients were downgraded and 4% (n = 23) were upgraded; 2.8% (n = 7) downgraded from grade V to IV, and 69.5% (n = 173) downgraded from IV to III. The revised renal trauma grading system demonstrated improved predictive ability for bleeding interventions (2018 AUC = 0.805, revised AUC = 0.883; p = 0.001) and number of units of PRBCs transfused. When we removed urinary injury from the revised system, there was no difference in its predictive ability for renal hemorrhage intervention.

CONCLUSIONS

A revised renal trauma grading system better delineates the need for hemostatic interventions than the current AAST OIS renal trauma grading system.

LEVEL OF EVIDENCE

II.

Probing the p-type Chemiresistive Response of NiFe2 O4 Nanoparticles for Potential Utilization as Ethanol Sensor

Detection of gas molecules and volatile organic compounds (VOCs) using efficient, low cost sensors has fetched significant attention in environmental monitoring, safety measures and medical diagnosis. In the present work, nickel ferrite (NFO) nanoparticles are explored as p-type semiconducting metal oxide (SMO) sensor for detection of five different organic vapors namely methanol, ethanol, n-propanol, iso-propanol and acetone which often cause severe damage to human body under prolonged exposure. The sensing studies in presence of the aforementioned five vapors are carried out by varying the sensor operating temperature (225-300 °C) and vapor concentrations (10-1000 ppm). Developed NFO sensor demonstrated best performance in terms of sensing (~10 ppm), response time (<10 s), excellent repeatability and selectivity towards ethanol among all other considered gas species. The repeatability of the sensor response is verified and the underlying reasons for the variation in the response of NFO sensor due to the change of operating temperature, analyte type and concentrations has been discussed. The synthesis of NFO through auto combustion method and study on their formation behaviour, oxygen vacancy evolution, band gap calculation, crystalline nature as well as microstructural features provides here the comprehensive information about the potential application of NFO nanoparticles as gas sensor.

ROBOtic Care Outcomes Project (ROBOCOP) for Acute Gallbladder Pathology

BACKGROUND

Robotic cholecystectomy is being increasingly used for patients with acute gallbladder disease who present to emergency department, but clinical evidence is limited. We aimed to compare the outcomes of emergent laparoscopic and robotic cholecystectomies in a large real-world database.

METHODS

Patients who received emergent laparoscopic or robotic cholecystectomies from 2020 to 2022 were identified from the Intuitive Custom Hospital Analytics database, based on de-identified extraction of electronic health record data from US hospitals. Conversion to open or subtotal cholecystectomy and complications were defined using ICD10 and/or CPT codes. Multivariate logistic regression with inverse probability treatment weighting (IPTW) was performed to compare clinical outcomes of laparoscopic versus robotic approach after balancing covariates. Cost analysis was performed with activity-based costing and adjustment for inflation.

RESULTS

Of 26,786 laparoscopic and 3,151 robotic emergent cholecystectomy patients being included, 64% were female, 60% were ≥ 45 years, and 24% were obese. Approximately 5.5% patients presented with pancreatitis, and 4% each presenting with sepsis and biliary obstruction. After IPTW, distributions of all baseline covariates were balanced. Robotic cholecystectomy decreased odds of conversion to open (OR 0.68 [95%CI 0.49, 0.93, p = 0.035]), but increased odds of subtotal cholecystectomy (OR 1.64 [95% CI 1.03, 2.60, p = 0.037]). Surgical site infection, readmission, length of stay, hospital acquired conditions, bile duct injury or leak, and hospital mortality were similar in both groups. There was no significant difference in hospital cost.

CONCLUSIONS

Robotic cholecystectomy has reduced odds of conversion to open and comparable complications, but increased odds of subtotal cholecystectomy compared to laparoscopic cholecystectomy for acute gallbladder diseases. Further work is required to assess the long-term implications of these differences.

LEVEL OF EVIDENCE

III, Therapeutic/Care Management Case-Control (Retrospective).

Effect of intragranular/extragranular tara gum on sustained gastrointestinal drug delivery from semi-IPN hydrogel matrices

The present research was undertaken to develop semi-IPN hydrogel matrix tablets of tara gum (TG) and carboxymethyl TG (CMTG) for sustained gastrointestinal delivery of highly water soluble tramadol hydrochloride (TH). The matrix tablets were developed by a hybrid process of wet granulation and direct compression technique. Carboxymethyl TG was crosslinked with dual cross-linking ions (Al3+/Ca2+). The uncross-linked component of the semi-IPN matrix was either incorporated within the granules (intragranular TG) or incorporated outside the granules (extragranular TG), prior to compression. The effect of intragranular/extragranular TG on the swelling, erosion and TH release characteristics from the semi-IPN hydrogel matrix tablets was investigated. The key finding of the investigation indicated that intragranular TG expedited TH release, while extragranular TG sustained TH release. Moreover, the effect of cross-linking ions on viscosity, rigidity, cross-link density and TH release behavior from hydrogel matrices was investigated. In-vivo pharmacokinetic performance of the optimized extragranular TG semi-IPN hydrogel matrix (F15) indicated sustained TH release in gastrointestinal milieu.

An Ounce of Prevention is the Only Cure: Nationwide Clinical and Financial Outcomes of Self-Inflicted Firearm Injuries

BACKGROUND

Self-inflicted gunshot wounds (SIGSWs) remain a leading, preventable cause of death in the United States. The present study evaluated patient demographics, operative characteristics, in-hospital outcomes, and resource utilization between patients with SIGSW and other GSW.

METHODS

The 2016-2020 National Inpatient Sample was queried for patients ≥16 years old admitted following gunshot wounds. Patients were categorized as SIGSW if they were injured through self-harm. Multivariable logistic regression was used to evaluate the association of SIGSW on outcomes. The primary endpoint was in-hospital mortality with complications, costs, and length of stay secondarily considered.

RESULTS

Of an estimated 157,795 surviving to hospital admission, 14,670 (9.30%) were SIGSW. Self-inflicted gunshot wounds were more commonly female (18.1 vs 11.3%), insured by Medicare (21.1 vs 5.0%), and white (70.8 vs 22.3%) (all P < .001) compared to non-SIGSW. Psychiatric illness was more prevalent in SIGSW (46.0 vs 6.6%, P < .001). Additionally, SIGSW more frequently underwent neurologic (10.7 vs 2.9%) and facial operations (12.5 vs 3.2%) (both P < .001). After adjustment, SIGSW was associated with greater odds of mortality (AOR: 12.4, 95% CI: 10.4-14.7). Length of stay (β: +1.5 days, 95% CI: .8-2.1) and costs (β: +$3.6 K, 95% CI: 1.4-5.7) were significantly greater in SIGSW.

CONCLUSIONS

Self-inflicted gunshot wounds are associated with increased mortality compared to other GSW, likely due to the increased proportion of injuries in the head and neck region. This lethality, coupled with the high prevalence of psychiatric illness in this population, indicates that efforts must be made to intervene through primary prevention, including enhanced screening and weapon safety considerations for those at risk.

Pediatric emergency resuscitative thoracotomy: A Western Trauma Association, Pediatric Trauma Society, and Eastern Association for the Surgery of Trauma collaborative critical decisions algorithm

LEVEL OF EVIDENCE

Literature synthesis and expert opinion, Level V.

3D mapping: has the mystery of proximal tibia fractures been solved?

PURPOSE

One of the major limitations of the 2D fracture evaluation (Schatzker classification) is its failure to adequately assess fracture lines in the frontal plane and fracture displacement in the antero-posterior direction. 3D fracture line mapping includes steric assessment which can aid decision making with regards to the surgical approach and fixation scheme. We hypothesized that there are consistent fracture patterns and zones of comminution for proximal tibial fractures.

METHODS

Radiographic data of 228 proximal tibia fractures were retrospectively included in this study. Fracture lines and zones of comminution were graphically superimposed onto a 3D template of an intact tibia after virtual reduction and normalization to identify major patterns of fracture and comminution.

RESULTS

Out of 206 male and 21 female patients, 89 had a fracture of the lateral condyle only (Schatzker I and II), 53 involved the medial plateau only (Schatzker IV) and 86 had a high-grade fracture involving both the condyles (Schatzker V and VI). 64.5% of the fracture lines involving the medial plateau alone were in the coronal plane, and this number was even lesser (44.2%) in medial plateau involvement of bicondylar fractures. In bicondylar fractures, lines were usually not seen to pass directly through the posteromedial region.

CONCLUSIONS

Medial tibial plateau fractures have a mix of coronal or sagittal fracture alignment. A clearer understanding of the 3D orientations of fractures based on CT scans can aid in diagnosing the pattern of fracture and adequate positioning of plates can be done to eventually improve operative outcomes.

Biomechanical influence of plate configurations on mandible subcondylar fracture fixation: a finite element study

Mandible subcondylar fractures have very high complication rate, yet there is no consensus on suitable plate design for optimal patient outcomes. Our study is aimed at comparing single mini, trapezoid, lambda, strut and double mini plates. A finite-element (FE) model of intact mandible was developed based on healthy CT-scan data, which was further virtually osteotomized and fixated with plates. The cortical and cancellous bones were assigned region-specific orthotropic and heterogenous isotropic material properties respectively. The models were subjected to six load cases representing the mastication cycle. Under opposite lateralities, the tensile and compressive mandibular strain distributions were found as the opposite, with tensile strains at the posterior border under ipsilateral molar clenching (RMOL) resulting in lesser mandibular strain in reconstructed mandible with single mini plate under RMOL but highest mandibular strain under the contralateral molar clenching (LMOL). Owing to the reduced mandibular strains under LMOL than RMOL, the contralateral chewing is preferred during the immediate post-surgery period for patients. Under LMOL, the peak von Mises stresses in the plate decreased with increase in the number of screws. Furthermore, the presence of two arms in double mini and trapezoid plates seems beneficial to neutralise the tensile and compressive strains across load cases.

Shattered Kidney After Renal Trauma: Should It Be Classified As an American Association for the Surgery of Trauma Grade V Injury?

OBJECTIVE

To study the prevalence and management of shattered kidney and to evaluate if the new description of "loss of identifiable renal anatomy" in the 2018 American Association for the Surgery of Trauma (AAST) organ injury scale (OIS) would improve the ability to predict bleeding control interventions.

METHODS

We used high-grade renal trauma data from 21 Level-1 trauma centers from 2013 to 2018. Initial CT scans were reviewed to identify shattered kidneys, defined as a kidney having ≥3 parenchymal fragments displaced by blood or fluid on cross-sectional imaging. We further categorized patients with shattered kidney in two models based on loss of identifiable renal parenchymal anatomy and presence or absence of vascular contrast extravasation (VCE). Bleeding interventions were compared between the groups.

RESULTS

From 861 high-grade renal trauma patients, 41 (4.8%) had shattered kidney injury. 25 (61%) underwent a bleeding control intervention including 18 (43.9%) nephrectomies and 11 (26.8%) angioembolizations. 18 (41%) had shattered kidney with "loss of identifiable parenchymal renal anatomy" per 2018 AAST OIS (model-1). 28 (68.3%) had concurrent VCE (model-2). Model-2 had a statistically significant improvement in area under the curve over model-1 in predicting bleeding interventions (0.75 vs 0.72; P = .01).

CONCLUSION

Shattered kidney is associated with high rates of active bleeding, urinary extravasation, and interventions including nephrectomy. The definition of shattered kidney is vague and subjective and our definition might be simpler and more reproducible. Loss of identifiable renal anatomy per the 2018 AAST OIS did not provide better distinction for bleeding control interventions over presence of VCE.

Emergency department thoracotomy in children: A Pediatric Trauma Society, Western Trauma Association, and Eastern Association for the Surgery of Trauma systematic review and practice management guideline

BACKGROUND

The role of emergency department resuscitative thoracotomy (EDT) in traumatically injured children has not been elucidated. We aimed to perform a systematic review and create evidence-based guidelines to answer the following PICO (population, intervention, comparator, and outcome) question: should pediatric patients who present to the emergency department pulseless (with or without signs of life [SOL]) after traumatic injuries (penetrating thoracic, penetrating abdominopelvic, or blunt) undergo EDT (vs. no EDT) to improve survival and neurologically intact survival?

METHODS

Using Grading of Recommendations Assessment, Development and Evaluation methodology, a group of 12 pediatric trauma experts from the Pediatric Trauma Society, Western Trauma Association, and Eastern Association for the Surgery of Trauma assembled to perform a systematic review. A consensus conference was conducted, a database was queried, abstracts and manuscripts were reviewed, data extraction was performed, and evidence quality was determined. Evidence tables were generated, and the committee voted on guideline recommendations.

RESULTS

Three hundred three articles were identified. Eleven studies met the inclusion criteria and were used for guideline creation, providing 319 pediatric patients who underwent EDT. No data were available on patients who did not undergo EDT. For each PICO, the quality of evidence was very low based on the serious risk of bias and serious or very serious imprecision.

CONCLUSION

Based on low-quality data, we make the following recommendations. We conditionally recommend EDT when a child presents pulseless with SOL to the emergency department following penetrating thoracic injury, penetrating abdominopelvic injury and after blunt injury if emergency adjuncts point to a thoracic source. We conditionally recommend against EDT when a pediatric patient presents pulseless without SOL after penetrating thoracic and penetrating abdominopelvic injury. We strongly recommend against EDT in the patient without SOL after blunt injury.

Alternating Layers of Morselized Allograft and Injectable Ceramic Bone Graft Substitute in Acetabular Reconstruction: A Novel 'Sandwich' Technique

Background

Impaction of morselized allograft is an appealing procedure for addressing the bone defects. However, concerns remain about its suitability for massive defects. We used a novel "sandwich" technique by impacting the morselized allograft in layers with an intervening layer of injectable bone graft substitute for restoring bone defects during acetabular reconstruction in total hip arthroplasties.

Methods

From August 2015 to June 2017, 17 revisions, 4 rerevisions, and 3 complex primary total hip arthroplasties were operated by this novel technique. Postoperatively, serial X-rays were evaluated at regular intervals. Clinical and functional outcomes were assessed by the Harris hip score. To examine if introducing an injectable bone substitute into allograft stock increased its load-bearing capability, simulated mechanical testing using Synbone samples was conducted in the laboratory.

Results

The mean Harris hip score significantly improved from 54.6 preoperatively to 86.8 at the latest follow-up. Graft incorporation was seen in all the cases. There was no evidence of component migration or loosening as compared to the X-rays at 3 weeks and 3 months in all the cases. With revision of component as end point, the survivorship was 100% at 82 months. The mechanical testing reported a higher capability of allograft samples when compared to those without bone substitutes.

Conclusions

Our data confirms that the use of the "sandwich" technique is a reliable option for major acetabular reconstruction. Early weight bearing is a significant value addition, and short-term results confirm good clinical and functional outcome. Longer follow-up is necessary to assess the status of the construct in the long term.

Grade V renal trauma management: results from the multi-institutional genito-urinary trauma study

PURPOSE

To investigate management trends for American Association for the Surgery of Trauma (AAST) grade V renal trauma with focus on non-operative management.

METHODS

We used prospectively collected data as part of the Multi-institutional Genito-Urinary Trauma Study (MiGUTS). We included patients with grade V renal trauma according to the AAST Injury Scoring Scale 2018 update. All cases submitted by participating centers with radiology images available were independently reviewed to confirm renal trauma grade. Management was classified as expectant, conservative (minimally invasive, endoscopic or percutaneous procedures), or operative (renal-related surgery).

RESULTS

Eighty patients were included, 25 of whom had complete imaging and had independent confirmation of AAST grade V renal trauma. Median age was 35 years (Interquartile range (IQR) 25-50) and 23 (92%) had blunt trauma. Ten patients (40%) were managed operatively with nephrectomy. Conservative management was used in nine patients (36%) of which six received angioembolization and three had a stent or drainage tube placed. Expectant management was followed in six (24%) patients. Transfusion requirements were progressively higher with groups requiring more aggressive treatment, and injury characteristics differed significantly across management groups in terms of hematoma size and laceration size. Vascular contrast extravasation was more likely in operatively managed patients though a statistically significant association was not found.

CONCLUSION

Successful use of nonoperative management for grade V injuries is used for a substantial subset of patients. Lower transfusion requirement and less severe injury radiologic phenotype appear to be important characteristics delineating this group.

Evidence of charge susceptibility and multiplef-chybridization configurations with the La doping in CeGe: a DFT + DMFT study

Kondo coupling has been extensively investigated in several Ce-based systems. However, the search for materials showing the interplay between the Kondo effect, spin-orbit interaction, and crystal-field effect along with the presence of local charge susceptibility; remains a challenge for the condensed matter community. Actually, in Ce-based systems, the strong coupling of the conduction electrons to the local magnetic moments usually hides these properties. Here, we present a detailed investigation of Ce_0.6La_0.4Ge through a combined density functional theory and dynamic mean-field theory study. Our investigations give evidence of the significant charge susceptibility and the multiple differentf-chybridization configurations. The weakening of the magnetization owing to the dilution of the Ce-site is the main cause for the appearance of such properties, which is believed to occur due to the presence of the relevant local moment andf-chybridization over the competition with the on-site Coulomb interaction.

Evidence of multi-band superconductivity in non-centrosymmetric full Heusler alloy LuPd2Sn

In this work, evidence of multi-band superconductivity and presence of mixed parity states in full Heusler alloy LuPd₂Sn is investigated using the x-ray diffraction, temperature and field dependent resistivity, temperature dependent magnetization, and heat capacity measurements. Our studies reveal that LuPd₂Sn is a type II superconductor and undergoes superconducting transition below 2.5 K. Above 2.5 K, the temperature and field dependence of resistivity indicate to the presence of multiple bands and inter-band phonon assisted scattering. The upper critical field,H_C2(T) exhibits linear behaviour and deviates from Werthamer, Helfand and Hohenberg model over the measured temperature range. Additionally, the Kadowaki-Woods ratio plot supports the unconventional superconductivity in this alloy. Moreover, a significant deviation from the s-wave behaviour is noted, which is studied using phases fluctuation analysis. It indicates the presence of spin triplet along with spin singlet component arising due to antisymmetric spin orbit coupling.

Al3+/Ca2+ cross-linked hydrogel matrix tablet of etherified tara gum for sustained delivery of tramadol hydrochloride in gastrointestinal milieu

Tara gum (TG) was derivatized to carboxymethyl TG (CMTG) and then cross-linked with Al³⁺/Ca²⁺ ions to prepare Al/Ca cross-linked CMTG matrices for sustained delivery of Tramadol Hydrochloride (TH), a highly water-soluble drug. The effect of Al³⁺/Ca²⁺ ions concentration on swelling, erosion, and drug release behavior from Al/Ca-CMTG matrices was investigated. Al-CMTG matrices had greater cross-linking density, produced a more rigid and denser hydrogel layer than Ca-CMTG matrices. The rate of swelling, erosion, and in vitro drug release from Al-CMTG matrices was slower than from Ca-CMTG matrices. The most important finding of our study indicated that at the same concentration of cross-linking ions, the release of TH from Al-CMTG matrices was slower compared to Ca-CMTG matrices. The optimized formulation containing 9 % w/w AlCl₃ in CMTG matrices released TH in a sustained manner up to 12 h in the gastrointestinal milieu. Moreover, it was observed that the prepared optimized formulation exhibited a more sustained release of TH compared to the marketed product.

Non-surgical management and analgesia strategies for older adults with multiple rib fractures: A systematic review, meta-analysis, and joint practice management guideline from the Eastern Association for the Surgery of Trauma and the Chest Wall Injury Society

BACKGROUND

Chest wall injury in older adults is a significant cause of morbidity and mortality. Optimal nonsurgical management strategies for these patients have not been fully defined regarding level of care, incentive spirometry (IS), noninvasive positive pressure ventilation (NIPPV), and the use of ketamine, epidural, and other locoregional approaches to analgesia.

METHODS

Relevant questions regarding older patients with significant chest wall injury with patient population(s), intervention(s), comparison(s), and appropriate selected outcomes were chosen. These focused on intensive care unit (ICU) admission, IS, NIPPV, and analgesia including ketamine, epidural analgesia, and locoregional nerve blocks. A systematic literature search and review were conducted, our data were analyzed qualitatively and quantitatively, and the quality of evidence was assessed per the Grading of Recommendations Assessment, Development, and Evaluation methodology. No funding was used.

RESULTS

Our literature review (PROSPERO 2020-CRD42020201241, MEDLINE, EMBASE, Cochrane, Web of Science, January 15, 2020) resulted in 151 studies. Intensive care unit admission was qualitatively not superior for any defined cohort other than by clinical assessment. Poor IS performance was associated with prolonged hospital length of stay, pulmonary complications, and unplanned ICU admission. Noninvasive positive pressure ventilation was associated with 85% reduction in odds of pneumonia ( p < 0.0001) and 81% reduction in odds of mortality ( p = 0.03) in suitable patients without risk of airway loss. Ketamine use demonstrated no significant reduction in pain score but a trend toward reduced opioid use. Epidural and other locoregional analgesia techniques did not affect pneumonia, length of mechanical ventilation, hospital length of stay, or mortality.

CONCLUSION

We do not recommend for or against routine ICU admission. We recommend use of IS to inform ICU status and conditionally recommend use of NIPPV in patients without risk of airway loss. We offer no recommendation for or against ketamine, epidural, or other locoregional analgesia.

LEVEL OF EVIDENCE

Systematic Review/Meta-analysis; Level IV.

A plausible investigation of low dimensional magnetism in a 3D spin system PrVO4

3D spin systems provide an important platform to investigate the novel magnetic behaviors, which arise due to the complex network of spins in such materials. In this context, we have studied a rare-earth orthovanadate PrVO₄, in which the distorted PrO₈ polyhedral results in complex spin geometries made by the near neighbor Pr atoms. The fourth near neighbor Pr atoms form linear chains, which are separated by non-magnetic VO₄ tetrahedra. DC magnetic susceptibility reveals a broad maximum and its position remains unaltered under applied magnetic field. The magnetic heat capacity shows a broad maximum with almost zero value at low temperatures. This indicates the presence of spin gap in the excitation spectra and hints toward the possibility of low dimensional magnetism. Our investigations reveal that PrVO₄ can be a potential candidate to study low dimensional magnetism in rare-earth-based systems.

Evolution of field induced magnetic phase attributed to higher order magnetic moments in TbVO4

Study of quantum magnetism in rare earth orthovanadates (RVO₄, R = rare earth) is a topic which is currently being investigated by the condensed matter physicists. In this work, through both experimental and theoretical tools, we report the presence of field induced magnetic phase, attributed to fifth order susceptibility, in TbVO₄, at low temperatures. The structural transition reported around 31 K, results in the formation of pseudospin-[Formula: see text] doublet ground state separated by an energy δ. Temperature dependent heat capacity indicates toward an increment in δ, on application of magnetic fields. Above 10 kOe, the Zeeman energy associated with magnetic anisotropy strengthens, resulting in an enhanced splitting of the pseudo-doublet ground state. This increased splitting stabilizes the magnetic phase associated with higher order moments. These observations are further supported by our theoretical model to evaluate δ, as a function of applied field. Our study provides a platform to study the possible presence of higher order moments in other Jahn-Teller systems.

Comparative evaluation of a patient-specific customised plate designs and screws for partial mandibular reconstruction

Mandibles with odontogenic tumors are often partially reconstructed with a metallic bone graft analogue with dental roots, crowns, along with a customized plate fixed with monocortical or bicortical screws, following resection of the tumor. In this study, two different designs of patient specific customized Ti reconstruction plates, solid and plate with holes, were considered. Fixation through both bicortical and monocortical screw types were investigated. FE models of the reconstructed mandibles were developed to analyse the influence of the plate-screw type combination on the load transfer across the mandibles under a mastication cycle. The effective homogenized orthotropic material properties of the lattice structures with 0.6 mm fibre diameter with 0.5 mm inter-fibre space were assigned to material properties for the bone graft analogue. The study shows that the combination of plate and screw types influences the state of stresses in the reconstructed mandible. Based on the results of this patient specific study, following resection of the tumor, either solid Ti plate with bicortical screws or Ti plate with holes along with monocortical screws may be used for partial mandibulectomy. It should also be noted that stresses in none of the plates or screws exceeded the yield limit for Ti under the mastication cycle indicating that the components are safe for mandibular reconstruction. However, the choice of this combination of reconstruction plates and screws is dependant on the condition and severity of the tumor in the diseased mandible.

ICD-10 based machine learning models outperform the Trauma and Injury Severity Score (TRISS) in survival prediction

Background

Precise models are necessary to estimate mortality risk following traumatic injury to inform clinical decision making or quantify hospital performance. The Trauma and Injury Severity Score (TRISS) has been the historical gold standard in survival prediction but its limitations are well-characterized. The present study used International Classification of Diseases 10^thRevision (ICD-10) injury codes with machine learning approaches to develop models whose performance was compared to that of TRISS.

Methods

The 2015–2017 National Trauma Data Bank was used to identify patients following trauma-related admission. Injury codes from ICD-10 were grouped by clinical relevance into 1,495 variables. The TRISS score, which comprises the Injury Severity Score, age, mechanism (blunt vs penetrating) as well as highest 24-hour values for systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Scale (GCS) was calculated for each patient. A base eXtreme gradient boosting model (XGBoost), a machine learning technique, was developed using injury variables as well as age, SBP, RR, mechanism and GCS. Prediction of in-hospital survival and other in-hospital complications were compared between both models using receiver operating characteristic (ROC) and reliability plots. A complete XGBoost model, containing injury variables, vitals, demographic information and comorbidities, was additionally developed.

Results

Of 1,380,740 patients, 1,338,417 (96.9%) survived to discharge. Compared to survivors, those who died were older and had a greater prevalence of penetrating injuries (18.0% vs 9.44%). The base XGBoost model demonstrated a greater receiver-operating characteristic (ROC) than TRISS (0.950 vs 0.907) which persisted across sub-populations and secondary endpoints. Furthermore, it exhibited high calibration across all risk levels (R² = 0.998 vs 0.816). The complete XGBoost model had an exceptional ROC of 0.960.

Conclusions

We report improved performance of machine learning models over TRISS. Our model may improve stratification of injury severity in clinical and quality improvement settings.

Interest in curves: when the radius of curvature matters in femur fractures. A CT based morphometric study

PURPOSE

In today's era, fractures of the femur are primarily managed with intramedullary devices. Keeping in mind the anatomical sagittal bow of the femur, intramedullary devices have been devised with an anterior bow, but this varies amongst various manufacturers - leading to complications such as anterior cortex impingement beyond the isthmus and posterior cortical opening at the fracture site. We intend to find the average radius of curvature (ROC) of the anatomical bow of the femur and the variation of the same.

METHODS

Radiographic data of 150 normal femur scans done in 81 patients were loaded in the Mimics 21.0 software (Materialise, Leuven, Belgium). A centerline (of the medullary cavity) was created using the software. A best-fit circle was created in the sagittal plane involving a major part of the centerline, and ROC was calculated.

RESULTS

We found the average ROC of our data was 1027.2, with a standard deviation of 241.55. ROC and length of the femur (an indirect measure of height) had a slight positive correlation (r = 0.36; p < 0.05); and a highly positive correlation in the ROC of the left and right femurs of the same individuals (r = 0.605; p < 0.05).

CONCLUSIONS

The usual ROC of intramedullary nails is commonly > 1300 mm, much higher than the average ROC we identified in our population. Thus, we conclude that implants with smaller ROC in the range of 1100 mm are needed, leading to better implant placement in the canal and avoiding complications of anterior cortex impingement and preventing fracture gap widening in our setting.

Possible realization of three-dimensional quantum spin liquid behavior in HoVO4

The study of geometrically frustrated magnetic systems with unusual crystal field ground states offers a possibility of realizing the new aspects of physics of disordered systems. In this study, we report our results of structural, magnetic susceptibility, heat capacity measurements, along with density functional theory (DFT) calculations on HoVO₄; a compound in which the presence of a distorted kind of HoO₈polyhedral leads to multiple magnetic interaction paths. The observed broad maximum below 10 K in the temperature response of DC susceptibility curves implies the presence of short-range correlations. AC susceptibility rules out the possibility of any kind of spin freezing. Temperature dependent heat capacity measurement at zero field indicate towards the absence of long-range ordering, along with the presence of a broad maximum centered around 14 K. The residual heat capacity exhibits a characteristic power-law (T^α) behavior with the exponentαnearly equal to 2, which is analogous to that observed for other three-dimensional (3D) quantum spin liquid (QSL) systems. The DFT calculations signify the presence of dominant second and third nearest neighbor interactions, which in turn lead to magnetic frustration in our system. Our investigations suggest that HoVO₄can be a candidate for realizing a 3D QSL state.

Emergence of low-temperature glassy dynamics in Ru substituted non-magnetic insulator CaHfO3

Non-magnetic insulators/semiconductors with induced magnetism introduced via transition metal substitution are one of the promising materials in the field of spintronics, magnetoelectronics and magneto-optical devices. In this context, here, we focus on magnetism induced in a non-magnetic insulator CaHfO₃, by the substitution of 4d element Ru, at Hf-site. Structural investigations indicate that substitution of Ru⁴⁺(up to 50%) does not affect the original crystal structure of the parent compound. Magnetic studies divulge a crossover from a diamagnetic to paramagnetic state with 20% Ru substitution. Further replacement of Hf results in a glassy magnetic state in CaHf_1-xRu_xO₃(0.3 ⩽x⩽ 0.5). The nature of the low temperature glassiness (below 20 K) in these compositions is confirmed through Vogel-Fulcher and Power law, along with, magnetic memory effect and relaxation dynamics. The observed glassiness is explained through the phenomenological 'hierarchical model'. Our studies indicate that the presence of competing short range interactions among randomly arranged Ru cations in non-magnetic insulator CaHfO₃are responsible for the observed low temperature magnetic state in this series with compositions >0.25.

Unravelling the signatures of effective spin1/2moments in CeVO4: magnetization and heat capacity study

The realization of an effective spin (J_eff) ½ state at low temperatures offers a platform to study the enthralling physics behind the disordered states in certain systems. Here, we report the signatures of magnetic ground state associated withJ_eff= ½ in CeVO₄. Our studies confirm the absence of any ordering or freezing down to 1.8 K. In the low temperature region, the Curie-Weiss fit of the inverse DC susceptibility indicate towards the presence of antiferromagnetic correlations among the Ce³⁺spins. The calculated value of effective moment (∼1.16μB) corresponds toJ= ½ withg_J∼ 1.20. Further, the field dependent magnetization curve at 2 K follows a behaviour corresponding toJ= ½ Brillouin function withg_J∼ 1.13. Magnetic field dependent heat capacity fits very well with two-level Schottky scheme. Our investigations suggest that CeVO₄can be a promising candidate to realiseJ_eff= ½ properties among 3D spin systems.

Large magnetodielectric coupling in the vicinity of metamagnetic transition in 6Hperovskite Ba3GdRu2O9

The 6H-perovskites Ba₃RRu₂O₉(R = rare earth element) demonstrate the magnetodielectric (MD) coupling as a manifestation of 4d-4fmagnetic interactions. Here, a detailed study of the structural, magnetic, heat capacity, and MD properties of the 6H-perovskite Ba₃GdRu₂O₉is reported. The signature of long-range antiferromagnetic (AFM) ordering ∼14.8 K (T_N) is evident from the magnetization and heat capacity studies. TheT_Nshifts towards the lower temperature side, apart from splitting in two with the application of the magnetic field. Field-dependent magnetization at 2 K shows three metamagnetic transitions with the opening of small hysteresis in different regions. A new transition atT₁emerges after the onset of the first metamagnetic transition. Complex magnetic behavior is observed in different magnetic field regions whereas these field regions themselves vary with the temperature. Dielectric response recorded at zero and 80 kOe field exhibits the development of MD coupling well aboveT_N. The MD coupling (∼4.5% at 10 K) is enhanced by 25% as compared to the Dy counterpart. Effect of complex magnetic behavior is also conveyed in the MD results where the maximum value of MD coupling is observed in the vicinity of 10 K (onset ofT₁) and near the second metamagnetic transition. Our investigation suggests that both Gd and Ru moments align simultaneously atT_N. Short-range magnetic ordering is possibly responsible for MD coupling aboveT_N.

Entropic topography associated with field-induced quantum criticality in a magnetic insulator DyVO4

Exploration of low temperature phase transitions associated with quantum critical point is one of the most mystifying fields of research which is under intensive focus in recent times. In this work, through comprehensive experimental evidences, we report the possibility of achieving quantum criticality in the neighborhood of a magnetic field-tuned tricritical point separating paramagnetic, antiferromagnetic and metamagnetic phases in a magnetic insulator, DyVO4. Magnetic susceptibility and heat capacity indicate to the presence of a long-range second order antiferromagnetic transition at TN ~ 3.2 K. Field variation of Magnetic susceptibility and heat capacity, along with differential magnetic susceptibility and DC field dependent AC susceptibility gives evidence of the modification of the antiferromagnetic structure below the tricritical point; implying the presence of a field-induced first order metamagnetic transition which persists down to 1.8 K. Further, the magnetic field dependence of the thermodynamic quantity - dM/dT, which is related to magnetic Gruneisen parameter, approaches a minimum, followed by a crossover near 5 kOe to a maximum; along with a hyperbolic divergence in temperature response of dM/dT in the critical field regime. Temperature response of heat capacity at 5 kOe also shows a deviation from the conventional behavior. Entropic topography phase diagram allows tracking of the variation of the entropy, which indicates towards the emergence of the peak at quantum critical point into a V-shaped region at high temperatures. Our studies yield an inimitable phase diagram describing a tricritical point at which the second-order antiferromagnetic phase line terminates followed by a first order line of metamagnetic transition, as the temperature is lowered, leading to metamagnetic quantum critical end point.

Eastern Association for the Surgery of Trauma Multicenter Trial: Comparison of pre-injury antithrombotic use and reversal strategies among severe traumatic brain injury patients

BACKGROUND

Trauma teams are often faced with patients on antithrombotic (AT) drugs, which is challenging when bleeding occurs. We sought to compare the effects of different AT medications on head injury severity and hypothesized that AT reversal would not improve mortality in severe traumatic brain injury (TBI) patients.

METHODS

An Eastern Association for the Surgery of Trauma-sponsored prospective, multicentered, observational study of 15 trauma centers was performed. Patient demographics, injury burden, comorbidities, AT agents, and reversal attempts were collected. Outcomes of interest were head injury severity and in-hospital mortality.

RESULTS

Analysis was performed on 2,793 patients. The majority of patients were on aspirin (acetylsalicylic acid [ASA], 46.1%). Patients on a platelet chemoreceptor blocker (P2Y12) had the highest mean Injury Severity Score (9.1 ± 8.1). Patients taking P2Y12 inhibitors ± ASA, and ASA-warfarin had the highest head Abbreviated Injury Scale (AIS) mean (1.2 ± 1.6). On risk-adjusted analysis, warfarin-ASA was associated with a higher head AIS (odds ratio [OR], 2.43; 95% confidence interval [CI], 1.34-4.42) after controlling for Injury Severity Score, Charlson Comorbidity Index, initial Glasgow Coma Scale score, and initial systolic blood pressure. Among patients with severe TBI (head AIS score, ≥3) on antiplatelet therapy, reversal with desmopressin (DDAVP) and/or platelet transfusion did not improve survival (82.9% reversal vs. 90.4% none, p = 0.30). In severe TBI patients taking Xa inhibitors who received prothrombin complex concentrate, survival was not improved (84.6% reversal vs. 84.6% none, p = 0.68). With risk adjustment as described previously, mortality was not improved with reversal attempts (antiplatelet agents: OR 0.83; 85% CI, 0.12-5.9 [p = 0.85]; Xa inhibitors: OR, 0.76; 95% CI, 0.12-4.64; p = 0.77).

CONCLUSION

Reversal attempts appear to confer no mortality benefit in severe TBI patients on antiplatelet agents or Xa inhibitors. Combination therapy was associated with severity of head injury among patients taking preinjury AT therapy, with ASA-warfarin possessing the greatest risk.

LEVEL OF EVIDENCE

Prognostic, level II.

Time is domain: factors affecting primary fascial closure after trauma and non-trauma damage control laparotomy (data from the EAST SLEEP-TIME multicenter registry)

PURPOSE

Damage control laparotomy (DCL) is used for both traumatic and non-traumatic indications. Failure to achieve primary fascial closure (PFC) in a timely fashion has been associated with complications including sepsis, fistula, and mortality. We sought to identify factors associated with time to PFC in a multicenter retrospective cohort.

METHODS

We reviewed retrospective data from 15 centers in the EAST SLEEP-TIME registry, including age, comorbidities (Charlson Comorbidity Index [CCI]), small and large bowel resection, bowel discontinuity, vascular procedures, retained packs, number of re-laparotomies, net fluid balance after 24 h, trauma, and time to first takeback in 12-h increments to identify key factors associated with time to PFC.

RESULTS

In total, 368 patients (71.2% trauma, of which 50.6% were penetrating, median ISS 25 [16, 34], with median Apache II score 15 [11, 22] in non-trauma) were in the cohort. Of these, 92.9% of patients achieved PFC at 60.8 ± 72.0 h after 1.6 ± 1.2 re-laparotomies. Each additional re-laparotomy reduced the odds of PFC by 91.5% (95%CI 88.2-93.9%, p < 0.001). Time to first re-laparotomy was highly significant (p < 0.001) in terms of odds of achieving PFC, with no difference between 12 and 24 h to first re-laparotomy (ref), and decreases in odds of PFC of 78.4% (65.8-86.4%, p < 0.001) for first re-laparotomy after 24.1-36 h, 90.8% (84.7-94.4%, p < 0.001) for 36.1-48 h, and 98.1% (96.4-99.0%, p < 0.001) for > 48 h. Trauma patients had increased likelihood of PFC in two separate analyses (p = 0.022 and 0.002).

CONCLUSION

Time to re-laparotomy ≤ 24 h and minimizing number of re-laparotomies are highly predictive of rapid achievement of PFC in patients after trauma- and non-trauma DCL.

LEVEL OF EVIDENCE

2B.

Unravelling the phonon scattering mechanism in half-Heusler alloys ZrCo1-xIrxSb (x0, 0.1 and 0.25)

Insight about the scattering mechanisms responsible for reduction in the lattice thermal conductivity (κ_L) in half-Heusler alloys (HHA) is imperative. In this context, we have thoroughly investigated the temperature response of thermal conductivity of ZrCo_1-xIr_xSb (x= 0, 0.1 and 0.25). For ZrCoSb,κ_Lis found to be ∼15.13 W m^-1 K^-1at 300 K, which is drastically reduced to ∼4.37 W m^-1 K^-1in ZrCo_0.9Ir_0.1Sb. This observed reduction is ascribed to softening of acoustic phonon modes and point defect scattering, on substitution of heavier mass. However, no further reduction inκ_Lis observed in ZrCo_0.75Ir_0.25Sb, because of identical scattering parameter. This has been elucidated based on the Klemen's Callaway model. Also, in the parent alloy, phonon-phonon scattering mechanism plays a significant role in heat conduction process, whereas in Ir substituted alloys, point defect scattering (below 500 K) and phonon-phonon scattering (above 750 K) are the dominant scattering mechanisms. The minimumκ_Lis found to be ∼1.73 W m^-1 K^-1(at 950 K) in ZrCo_0.9Ir_0.1Sb, which is the lowest reported value till now, for n-type Zr based HHA. Our studies indicate that partial substitution of heavier mass element Ir at Co-site effectively reduces theκ_Lof n-type ZrCoSb, without modifying the nature of charge carriers.

The small (14 Fr) percutaneous catheter (P-CAT) versus large (28-32 Fr) open chest tube for traumatic hemothorax: A multicenter randomized clinical trial

INTRODUCTION

The traditional treatment of traumatic hemothorax (HTX) has been an insertion of a large-bore 36- to 40-Fr chest tube. Our previous single-center randomized controlled trial (RCT) had shown that 14-Fr percutaneous catheters (PCs) (pigtail) were equally as effective as chest tube. We performed a multicenter RCT, hypothesizing that PCs are as equally effective as chest tubes in the management of patients with traumatic HTX (NCT03546764).

METHODS

We performed a multi-institution prospective RCT comparing 14-Fr PCs with 28- to 32-Fr chest tubes in the management of patients with traumatic HTX from July 2015 to September 2020. We excluded patients who were in extremis and required emergent tube placement and those who refused to participate. The primary outcome was failure rate, defined as a retained HTX requiring a second intervention. Secondary outcomes included daily drainage output, tube days, intensive care unit and hospital length of stay, and insertion perception experience (IPE) score on a scale of 1 to 5 (1, tolerable experience; 5, worst experience). Unpaired Student's t test, χ2, and Wilcoxon rank sum test were used with significance set at p < 0.05.

RESULTS

After exclusion, 119 patients participated in the trial, 56 randomized to PCs and 63 to chest tubes. Baseline characteristics between the two groups were similar. The primary outcome, failure rate, was similar between the two groups (11% PCs vs. 13% chest tubes, p = 0.74). All other secondary outcomes were also similar, except PC patients reported lower IPE scores (median, 1: "I can tolerate it"; interquartile range, 1-2) than chest tube patients (median, 3: "It was a bad experience"; interquartile range, 2-5; p < 0.001).

CONCLUSION

Small caliber 14-Fr PCs are equally as effective as 28- to 32-Fr chest tubes in their ability to drain traumatic HTX with no difference in complications. Patients reported better IPE scores with PCs over chest tubes, suggesting that PCs are better tolerated.

LEVEL OF EVIDENCE

Therapeutic, level II.

Analysis of Traumatic Axillo-Subclavian Vessel Injuries: Endovascular Management is a Viable Option to Open Surgical Reconstruction

BACKGROUND

In traumatic axillo-subclavian vessel injuries, endovascular repair has been increasingly described, despite ongoing questions regarding infection risk and long-term durability. We sought to compare the clinical and safety outcomes between endovascular and surgical treatment of traumatic axillo-subclavian vessel injuries.

METHOD

A search query of the prospectively maintained PROOVIT registry for patients older than 18 years of age with a diagnosis of axillary or subclavian vessel injury between 2014-2019 was performed at a Level 1 Trauma Center. Patient demographics, severity of injury, Mangled Extremity Severity Score (MESS), Injury Severity Score (ISS), procedural interventions, complications, and patency outcomes were collected and analyzed.

RESULTS

Twenty-three patients with traumatic axillo-subclavian vessel injuries were included. There were similar rates of penetrating and blunt injuries (48% vs. 52%, respectively). Eighteen patients (78%) underwent intervention: 11 underwent endovascular stenting or diagnostic angiography; 7 underwent open surgical repair. There was similar severity of arterial injuries between the endovascular and open surgical groups: transection (30% vs. 40%, respectively), occlusion (30% vs. 40%, respectively). The open surgical group had worse initial clinical comorbidities: higher ISS scores (17.0 vs 13.5, p = 0.034), higher median MESS scores (6 vs. 3.5, P = 0.001). The technical success for the endovascular group was 100%. The endovascular group had a lower estimated procedural blood loss (27.5 mL vs. 624 mL, P = 0.03). The endovascular arterial group trended toward a shorter length of hospital stay (5.6 days vs. 27.6 days, P = 0.09) and slightly reduced procedural time (191.0 min vs. 223.5 min, P = 0.165). Regarding imaging follow up (average of 60 days post-discharge), 7 patients (54%) underwent surveillance imaging (5 with duplex ultrasound, 2 with computed tomography angiography CTA) that demonstrated 100% patency. Regardless of ISS or MESS scores, at long term clinical follow up (average of 214 days), there were no limb losses, graft infections or vascular complications in either the endovascular or open surgical group.

CONCLUSIONS

Endovascular treatment is a viable option for axillo-subclavian vessel injuries. Preliminary results demonstrate that endovascular treatment, when compared to open surgical repair, can have similar rates of technical success and long-term outcomes in patency, infection and vascular complications.

Unconventional critical behaviour in weak ferromagnets Fe2-xMnxCrAl (0 ≤ x < 1)

Recent investigation on weak ferromagnets Fe2-xMnxCrAl (0 ≤ x < 1) reveal the existence of a cluster glass phase (CGP) and a Griffiths-like phase (GP) below and above the ferromagnetic transition temperature (TC), respectively [(2019) Sci. Rep. 9 15888]. In this work, the influence of these inhomogeneous phases on the critical behaviour (around TC) of the above-mentioned series of alloys has been investigated in detail. For the parent alloy Fe2CrAl, the critical exponent γ is estimated as ~ 1.34, which lies near to the ordered 3D Heisenberg class, whereas the obtained value of the critical exponent β ~ 0.273 does not belong to any universality class. With increment in Mn concentration, both exponents γ and β increase, where γ and β approach the disordered and ordered 3D Heisenberg class, respectively. The observed deviation of γ and unconventional value of δ can be ascribed to the increment of GP with Mn-concentration. The trend noted for β can be attributed to the increment in CGP regime with an increase in Mn-content. The estimated critical exponents are consistent and reliable as corroborated using the scaling law and equations of state. Our studies indicate that the critical phenomenon of Fe2-xMnxCrAl (0 ≤ x < 1) alloys possibly belong to a separate class, which is not described within the framework of any existing universal model.

Spontaneous Formation of Star-Shaped Surface Patterns in a Driven Bose-Einstein Condensate

We observe experimentally the spontaneous formation of star-shaped surface patterns in driven Bose-Einstein condensates. Two-dimensional star-shaped patterns with l-fold symmetry, ranging from quadrupole (l=2) to heptagon modes (l=7), are parametrically excited by modulating the scattering length near the Feshbach resonance. An effective Mathieu equation and Floquet analysis are utilized, relating the instability conditions to the dispersion of the surface modes in a trapped superfluid. Identifying the resonant frequencies of the patterns, we precisely measure the dispersion relation of the collective excitations. The oscillation amplitude of the surface excitations increases exponentially during the modulation. We find that only the l=6 mode is unstable due to its emergent coupling with the dipole motion of the cloud. Our experimental results are in excellent agreement with the mean-field framework. Our work opens a new pathway for generating higher-lying collective excitations with applications, such as the probing of exotic properties of quantum fluids and providing a generation mechanism of quantum turbulence.

When the balloon goes up, blood transfusion goes down: a pilot study of REBOA in placenta accreta spectrum disorders

Background

Patients with placenta accreta spectrum (PAS) disorders often suffer massive hemorrhage during cesarean hysterectomies (CHyst). A novel strategy to decrease blood loss and minimize perioperative morbidity associated with PAS is utilization of ER-REBOA Catheter intraoperatively. In this study, we explore the use of ER-REBOA Catheter during CHyst with the goal of minimizing perioperative morbidity and packed red blood cell (PRBC) transfusions.

Methods

We conducted a retrospective case-control study at a regional referral center of consecutive patients with PAS undergoing CHyst. The primary outcomes were PRBC transfusions of ≥4 units. Secondary outcomes included surgical intensive care unit admissions, postoperative length of stay (LOS), postoperative ileus, and vascular complication rate. We also explored utilization of manual palpation and omission of precesarean fluoroscopy for resuscitative endovascular balloon occlusion of the aorta (REBOA) placement verification in distal aortic zone 3.

Results

90 patients were included in the study. REBOA and non-REBOA cases were similar in clinicodemographic characteristics. 17.7% of REBOA cases received ≥4 units of PRBC compared with 49.3% of non-REBOA cases (p=0.03). Zero REBOA patients developed postoperative ileus, whereas 18 (25%) non-REBOA patients did (p=0.02). LOS was reduced in the REBOA group. Postplacement fluoroscopy was omitted in all REBOA cases. Two postoperative arterial thrombotic events (2 of 19, 11% of REBOA patients) were identified in the REBOA group, one requiring a thrombectomy (1 of 19, 5%).

Discussion

Decrease in blood transfusions of ≥4 units of PRBC is demonstrated when ER-REBOA Catheter is placed in distal aortic zone 3 during CHyst performed for severe PAS disorders. The incidence of postoperative ileus and LOS are reduced in the ER-REBOA Catheter group. Placement and utilization of ER-REBOA Catheter during CHyst may be feasible without fluoroscopy when manual placement verification is performed by an experienced operator. Protocol modifications focusing on reducing thrombotic rate are ongoing.

Level of evidence

IV.