bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional relationship between woody plants and insect communities in response to Bursaphelenchus xylophilus infestation in the Three Gorges Reservoir region
Authors: Wang Zhuang , Zhao Lijuan , Liu Jiaqi , Yang Yajie , Shi Juan , Wen Junbao , Gao Ruihe
Published: January 2021

To study the effect of the invasion of Bursaphelenchus xylophilus on the
functional relationship between woody plants and insect communities, the
populations of tree species and insect communities were investigative in
the Masson pine forests with different infestation durations of B.
xylophilus. In this study, the number of Pinus massoniana began to
decrease sharply, whereas the total number of other tree species in the
arboreal layer increased gradually with the infestation duration of B.
xylophilus. The principal component analysis ordination biplot shows
that there was a significant change in the spatial distribution of woody
plant species in different Masson pine forest stands. Additionally, a
total of 7,188 insect specimens was obtained. The insect population
showed an upward trend in stand types with the increase of pine wilt
disease infection periods, which demonstrated that the insect community
had been significantly affected by the invasion of B. xylophilus. The
structure of insect functional groups changed from herbivorous (He)
> omnivorous (Om) > predatory (Pr)
> parasitic (Pa) > detritivorous (De) in the
control stand to He > Pa > Om, De
> Pr after B. xylophilus infestation in the forests. The
results showed that the populations of He, Pa, and De increased after
the invasion of B. xylophilus, but the populations of Pr decreased.
Moreover, the redundancy analysis ordination bi-plots reflected the
complicated functional relationship between woody plant communities and
insects after the invasion of B. xylophilus. The present study provides
insights into the changes in the community structure of woody plants and
insects, as well as the functional relationship between woody plant
communities and insect communities after invasion of B. xylophilus.
Numerical Solution of Schrodinger Equation for Rotating Morse Potential using Matrix Methods with Fourier Sine Basis
Authors: sharma Aditi , Sastri O S K
Published: January 2021

In this paper, an elegant and easy to implement numerical method using
matrix mechanics approach is proposed, to solve the time independent
Schrodinger equation (TISE) for Morse potential. It is specifically
applied to non-homogeneous diatomic molecule HCl to obtain its
rotating-vibrator spectrum. While matrix diagonalization technique is
utilised for solving TISE, model parameters for Morse potential are
optimized using variational Monte-Carlo (VMC) approach by minimizing χ 2
− value. Thus, validation with experimental vibrational frequencies is
completely numerical based with no recourse to analytical solutions. The
ro-vibrational spectra of HCl molecule obtained using the optimized
parameters through VMC have resulted in least χ 2 − value as compared to
those determined using best parameters from multiple regression analysis
of analytical expressions. Numerical algorithm for solving the
Hamiltonian matrix has been implemented utilizing Free Open Source
Software (FOSS) Scilab and simulation results are matching well with
those obtained using analytical solutions from Nikiforov-Uvarov (NU)
method and asymptotic iteration method (AIM).
Indoor exposure to airborne PAHs: A comparison of stir bar sorptive extraction and pump sampling
Authors: Becker Roland , Heyn Lisa , Jung Christian
Published: January 2021

Stir bar sorptive extraction (SBSE) was compared with standardized pump
sampling regarding the prospects to assess airborne levels of polycyclic
aromatic hydrocarbons (PAHs) in indoor environments. A historic railway
water tower, which will be preserved aa technical monument for museum
purposes, was sampled with both approaches because built-in insulation
material was suspected to release PAHs to the indoor air. The 16 PAH on
the US EPA list were quantified using gas chromatography with mass
selection detection in filters from pump sampling after solvent
extraction and on SBSE devices after thermal desorption. SBSE was seen
to sample detectable PAH masses with excellent repeatability and a
congener pattern largely similar to that observed with pump sampling.
Congener patterns were however significantly different from that in the
PAH source because release from the insulation material is largely
triggered by the respective congener vapor pressures. Absolute masses in
the ng range sampled by SBSE corresponded to airborne concentrations in
the ng L -1 range determined by pump sampling. Principle differences
between SBSE and pump sampling as well as prospects of SBSE as
cost-effective and versatile complement of pump sampling are discussed.
The Relationship Between Secondary Schools Students' Perceptions of School Climate, Their School Belonging And Their Academic Achievement
Authors: Demiroz Seva
Published: January 2021

The aim of this study is to examine the relationship between secondary school students' perceptions of school climate, their school belonging and their academic achievement. This descriptive study uses the correlational survey model. The participants were 340 sixth and seventh graders at a secondary school in the 2007-2008 academic year. To this end, the students were administered the School Climate Scale and the School Belonging Scale, and the average of their first term grades was used as a measure of academic achievement. This study found no significant difference between the students' perceptions of school climate and their school belonging by gender and grade. However, a significant differences were found between the students' perceptions of school climate and their school belonging, and their perceptions of school climate, school belonging and their academic success.
Signature reliability evaluation of renewable energy system
Authors: Tyagi Subhi , Kumar Akshay , Bhandari Ashok , Ram Mangey
Published: January 2021

In this paper, a real-life renewable energy-based system is considered and the reliability function of this system is evaluated with the help of Universal Generating Function technique.The renewable energy-based system is considered from the project in Germany where the wind turbine and hydro power plant are combined. In this project the wind turbines are the world?s tallest wind turbines of about 584 feet and one reservoir have the capacity of 1.6 million gallons of water. The wind turbines are set at the top of the hills and the reservoirs are allowed to be filled with river water. This paper presents a renewable energy-based system where the wind turbine and hydro power plant are combined together to produce electricity in bulk. Universal generating function technique is used to obtain the reliability function of the proposed system. Also tail signature, signature, expected cost rate, expected lifetime, and Barlow-Proschan Index are estimated.
Depictions of St. Mark of Ephesus in post-Byzantine art
Authors: Zivkovic Milos
Published: January 2021

The paper discusses the visual representations of St. Mark of Ephesus,
under-researched in previous scholarship, which have survived in several
monuments of post-Byzantine wall painting in the Balkans. These depictions
are analyzed as visual testimonies of the veneration of Mark of Ephesus in
the period under consideration, i.e. as important indicators of the
presence, continuity and dissemination of his cult a long time before his
official canonization in the 18th century. The paper also offers an overview
of the different iconographic versions of the images of St. Mark of Ephesus.
Finally, it examines the possible reasons for the emergence of images
representing this famed anti-Unionist metropolitan in the discussed
monuments. In this context, the images of Mark of Ephesus are considered
through the prism of their placement in a given iconographic program;
wherever possible, the role of the ktetor and artist in their creation is
examined.
Time to Get It Right: An Examination of Post-Acquisition Fair Value Adjustments
Authors: Kubic Matthew
Published: January 2021

I examine the role of preparer information gathering and processing constraints in fair value measurement. Using two business combination samples, I investigate whether acquirers adjust the initial fair value measurements of identifiable assets and liabilities during the one-year measurement period permitted by FASB Statement 141(R). Empirical proxies for preparers' information gathering and processing costs explain variation in the incidence and magnitude of measurement period adjustments (MPAs). I classify abnormally large MPAs that allow firms to exceed the consensus analyst forecast as suspect adjustments. Suspect adjustments exhibit little association with earnings management incentives and no association with future goodwill impairment. Overall, the results suggest that acquirers use the measurement period when there are concerns about the quality or availability of information, consistent with the FASB's intentions.
Surgical Treatment for Hepatocellular Carcinoma in the Era of Multiple Staging and Algorithm
Authors: Yamashita Suguru , Joechle Katharina , Vauthey Jean-Nicolas
Published: January 2021

A plethora of staging systems for hepatocellular carcinoma (HCC) has existed, as the management for HCC is made complex by the interplay of tumor characteristics and the health and underlying functions of both the patient and the liver. The majority of patients with HCC have nonsurgical HCC. The Barcelona Clinic Liver Cancer (BCLC) classification has been regarded as the optimal staging system and treatment algorithm for HCC. However, even in patients with intermediate or advanced stage in BCLC classification, who had not been originally recommended to undergo surgery, some could benefit in terms of long-term survival by surgical treatments. An expert panel on HCC has stated that the American Joint Committee on Cancer staging system, whose predictive power on the outcome have been improved by continuous amendments, should be applied for patients undergoing surgery. Herein, we review the recent staging system focusing on patients with HCC undergoing surgery.
 
This review contains 5 figures, 3 tables and 34 references
Key Words: American Joint Committee on Cancer, Barcelona Clinic Liver Cancer, hepatic resection, hepatocellular carcinoma, orthotopic liver transplantation
Understanding the Genetics of Pancreatic Adenocarcinoma
Authors: Nayyar Apoorve , Yeh Jen Jen
Published: January 2021

The underlying molecular basis of pancreatic ductal adenocarcinoma (PDAC) is complex, with multiple genetic, epigenetic, and transcriptomic changes. Five to 10% of PDAC cases have a hereditary basis, with multiple risk-conferring genetic mutations running in the family. All PDAC tumors develop from noninvasive precursor lesions that reflect the temporal accumulation of mutations. Recent advances in high-throughput sequencing technologies have facilitated a better understanding of the diverse mutational landscape of PDAC, reaffirming the role of genes previously known to be mutated (K-ras, CDKN2A, TP53, SMAD4, SLIT/ROBO, SWI/SNF) and revealing novel insights into the differential gene expression patterns and structural variations involved. K-ras mutation, an early event in disease pathogenesis, plays a pivotal role in the initiation, progression, and maintenance of PDAC, with the mutation type impacting disease pathophysiology and prognosis. The subsequent loss of tumor suppressors (CDKN2A, TP53, SMAD4) promotes genetic instability and uncontrolled cellular proliferation. Molecular subtypes with potential prognostic and therapeutic relevance have been identified. The challenge now is to translate this wealth of knowledge to the clinic.

This review contains 3 figures, 3 tables and 50 references
Key words: familial pancreatic cancer, heterogeneity, molecular subtypes, pancreatic ductal adenocarcinoma, whole genome/exome sequencing
Squamous Cell Carcinoma: Epidemiology, Risk Factors, and Treatment Options
Authors: Farma Jeffrey M , Lamb Elena P
Published: January 2021

Ultraviolent (UV) solar radiation is considered to be the dominant risk factor for development of squamous cell carcinoma (SCC). The development of SCC appears to be linked to the cumulative dose of UV radiation over time. Identifying patients with high-risk factors for developing SCC includes chronic immunosuppression, exposure to ionizing radiation, and certain genetic syndromes. Primary treatment goals of cutaneous SCC include cure of tumor with maximal preservation of function. Treatment options should be stratified for low- and high-risk SCC. Primary treatment options for low-risk SCC include (1) curettage and electrodesiccation, (2) excision with postoperative margin assessment (POMA) with 4 to 6 mm margins, and (3) radiation therapy (RT) for nonsurgical candidates. Options for high-risk SCC lesions include (1) Mohs surgery or resection with complete circumferential peripheral and deep margin assessment, (2) excision with POMA with wider surgical margins and primary or delayed repair, and (3) RT for nonsurgical candidates.    
This review contains 4 figures, 5 tables, and 32 references.
Key words: cutaneous squamous cell carcinoma, Mohs micrographic surgery, pathologic risk factors, radiation therapy, surgical margins
Dermatofibrosarcoma Protuberans
Authors: Deschner Benjamin , Wayne Jeffrey
Published: January 2021

Dermatofibrosarcoma protuberans (DFSP) is a rare malignant cutaneous tumor with an annual incidence of 4.2 per million. The tumor typically grows slowly and has a proclivity toward local invasiveness and away from distant metastasis. The mainstay of treatment is complete surgical resection, which is curative in almost all cases. The tumor’s characteristics make this difficult, however, and reexcision to negative margins can be challenging. DFSP can also present with or develop fibrosarcomatous change (DFSP-FS), a more aggressive variant. Thus, these tumors require thoughtful management. In this review, we discuss the biologic background of DFSP, describe the tumor’s behavior and presentation, and discuss current concepts in management.
 
This review contains 5 figures, 4 tables and 28 references
Key words: dermatofibrosarcoma protuberans, fibrosarcomatous change, imatinib, local recurrence, micrographic surgery, nonmelanoma, radiation, sarcoma, skin cancer, surgical excision
Supraventricular Tachycardia
Authors: Epstein Laurence M.
Published: January 2021

Supraventricular tachycardias (SVTs) comprise a group of arrhythmias for which the atria and/or atrioventricular (AV) node are integral to sustaining the rhythm. These arrhythmias typically have a benign natural history but account for a considerable proportion of patients presenting with symptoms including palpitations, shortness of breath, chest discomfort, dizziness, and, on occasion, syncope. They affect a broad range of patients, from young, otherwise healthy adults and children to elderly patients with multiple comorbidities. Although medical management with AV nodal blocking medications or antiarrhythmic medications is a reasonable first-line approach, catheter ablation is a definitive, most often curable option that has minimal risk and offers the chance of avoiding long-term medications. This chapter covers the epidemiology, diagnosis, and management of SVTs, which include atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reentrant tachycardia (AVRT), atrial tachycardia (AT), and others (atrial flutter, inappropriate sinus tachycardia, and junctional tachycardia). Atrial fibrillation, which is more prevalent than all other SVTs combined, are discussed elsewhere. Figures describe the differential diagnosis of tachycardia with narrow and wide QRS complexes, the relationship between the response to intravenous adenosine and the cause of tachycardia, the mechanism of tachycardia induction in patients with dual AV node conduction pathways, and the management of atrial flutter. Electrocardiograms illustrate features of various forms of SVT.
This review contains 11 highly rendered figures (included 6 twelve-lead ECGs), 1 table, and 69 references.
Cardiac Catheterization and Intervention
Authors: Kumbhani Dharam J. , Januzzi Jr James L
Published: January 2021

Cardiac catheterization involves the insertion of a catheter (hollow polymer-coated tubing) into a blood vessel of the heart or into one of its chambers. Cardiac catheterization procedures are one of the most commonly performed cardiac procedures today. This review outlines the basics of angiography and coronary anatomy, the technical details of cardiac catheterizations, preferred access sites, and hemodynamic measurements. The basic steps in coronary intervention are listed. Common indications and contraindications for cardiac catheterization and intervention are described, as are appropriate use criteria for diagnostic catheterization and coronary intervention, fractional flow reserve (FFR) and intravascular ultrasonography, and complications of cardiac catheterization and percutaneous coronary intervention. Future directions in the field are discussed. Tables describe normal hemodynamic measurements, derived measurements during right heart catheterization, coronary artery disease prognostic index for medically managed patients, American College of Cardiology (ACC)/American Heart Association (AHA) guidelines regarding indications for coronary angiography, ACC/AHA appropriate use criteria for diagnostic catheterization, common indications for FFR, and risk of cardiac catheterization and coronary angiography. Figures include an overview of coronary anatomy, angiograms of the coronary arteries, images of a normal cardiac cycle and hemodynamic waveforms, the design of a stent, FFR evaluation, basic intravascular ultrasonography measurements, and coronary imaging with an optical coherence tomography system.
This review contains 7 highly rendered figures, 8 tables, and 62 references.
Minimizing Vulnerability to Malpractice Claims
Authors: Berry William R
Published: January 2021

This review provides strategies for avoiding lawsuits and advice for dealing with a lawsuit if one is ever filed. Medical malpractice is explained as are the personal issues for the defendant physician. Strategies for preventing malpractice suits are presented, including those relative to communication and interpersonal skills, the informed consent process, and documentation. Advice is provided for what surgeons should do if sued or if threatened with a lawsuit, including measures for assisting in the defense and settling claims versus trying a case. Preparing for a deposition is discussed. How a surgeon should act when a defendants or witness in a courtroom trial is presented. This review contains 13 references.
Postoperative Complications of Thyroid and Parathyroid Disease
Authors: Imbus Joseph R , Schneider David F
Published: January 2021

Although thyroid and parathyroid surgery is considered very safe, with rare morbidity and mortality, serious complications can occur. These include bilateral recurrent laryngeal nerve injury, life-threatening hematoma, and severe hypoparathyroidism. Although infrequent, these complications require timely identification and intensive care. Critical care physicians should understand the clinical presentations and management of affected patients. This review provides a critical care–focused review of endocrine surgery complications, including relevant background information, definitions, risk factors, identification, and management. Special clinical situations and treatment considerations are included. Figures show the vocal fold anatomy in recurrent laryngeal nerve paralysis, the regulation of calcium homeostasis, and electrocardiogram changes seen in the setting of severe hypocalcemia.
This review contains 3 figures, and 58 references.
Key words: hypocalcemia, hypoparathyroidism, neck hematoma, parathyroid, recurrent laryngeal nerve injury, thyroid
Brain Death and Resuscitation of the Organ Donor
Authors: Khatibi Kasra , Venkatasubramanian Chitra
Published: January 2021

When is a patient brain dead? Under what scenarios in the surgical intensive care unit is brain death a possibility? Who can declare brain death and how? What are the steps after brain death declaration? You will find answers to all of these and more in this review. We will walk you through the principles, prerequisites, and techniques of clinical brain death evaluation using checklists and videos. The role and interpretation of ancillary testing and pitfalls are also discussed. New in this section is a description of the techniques that can be adapted when a patient is on extracorporeal membrane oxygenation. In addition, we have included a section on how to communicate effectively (i.e., what phrases to use) with families while discussing brain death and thereby avoid conflicts. We conclude with a detailed section on the physiology and critical care of the potential organ donor after brain death.

This review contains 2 videos, 8 figures, 3 tables and 21 references
Key words: Brain death, Apnea testing, ECMO, Organ donation
Immunosuppression for the Transplant Surgical Patient
Authors: Ravichandran Bharath R. , Sparkes Tracy M. , Casale Jillian P. , Hammad Sara , Clark Jacqueline E. , Freedman Sari R. , Masters Brian M.
Published: January 2021

Immunosuppression brings with it many additional challenges in the management of the surgical patient already fraught with complexity. Given advances in surgery and medicine, transplantation has become a therapeutic option for patients once considered too ill. In the medical management of these patients, it is always most important to take into account the clinical status of the patient to balance the risk of infection and rejection. The management of immunosuppression in the surgical patient is challenging depending on the clinical scenario. In addition to patient-specific factors, there are many medication-related factors to consider, including toxicity, interactions, and pharmacokinetics. It is always important to consult a transplant specialist prior to initiating or reinitiating immunosuppression in these patients as the therapeutic goals are likely to be modified. Additionally, consideration of the patient’s history as it pertains to infection, rejection, and malignancy is highly pertinent in their immunosuppression management. Appropriate management and augmentation of immunosuppression are critical to the success of these patients, both at the time of transplantation and in the years that follow. The goal of this review is to provide a basis for the understanding of the complexities of immunosuppression in the surgical transplant patient.
This review contains 5 figures, 7 tables, and 54 references. 
Key Words: immunosuppression; infection; rejection; solid-organ transplantation
Acute Liver Failure
Authors: DellaVolpe Jeffrey , Al Khafaji Ali
Published: January 2021

Acute liver failure (ALF) can be challenging to manage due to the effect of liver failure on other organs and the severity of illness that ensues. Both the practicing surgeon and the intensivist should be aware of the manifestations, workup, and management implications as ALF is not uncommon to many intensive care settings. ALF precipitates a severe multiorgan dysfunction syndrome in a majority of cases, with high rates of complications and an elevated risk of death. Management requires a systemic approach in addition to the collaboration of a multidisciplinary team with an emphasis on early recognition, prompt management of complications, and timely transfer to a transplant center. In the absence of spontaneous recovery, transplantation is the only definitive management option and may not always be feasible or immediately available. The continuing search to develop alternatives is essential.
This review contains 2 figures, 9 tables and 70 references
Keywords: acetaminophen, acute liver failure, cerebral edema, coagulopathy, hepatitis, jaundice, N-acetylcysteine, transplantation
Pathologic Evaluation of Soft Tissue Sarcoma
Authors: Agaram Narasimhan P.
Published: January 2021

Soft tissue sarcomas are rare tumors and are mostly managed in tertiary care centers. They are broadly classified based on their differentiation into multiple different types. They affect patients of all ages and mostly occur in the extremities. Pathologic examination of the biopsy or resection of the tumor is an extremely important aspect in the diagnosis of these tumors and appropriately guiding the clinical team in the management of these rare tumors. This review focuses on the aspects of pathologic evaluation of these tumors and discusses the morphologic aspects of the predominant soft tissue sarcomas based on differentiation. The review also highlights the latest molecular diagnostic studies that are used in the accurate subtyping of these tumors. 
This review contains 12 figures, 2 tables, and 28 references.
Key words: angiosarcoma, fibromatosis, fibrous, liposarcoma, myxoid, nerve sheath tumor, sarcoma, synovial sarcoma
Rare Fibroblastic and Myofibroblastic Tumors
Authors: Zheleva Vasilena , Liang Yu , Melstrom Laleh
Published: January 2021

This review discusses the clinical presentation, histopathologic characteristics, and diagnostic and treatment algorithms for several distinct fibroblastic and myofibroblastic tumor subtypes. Low-grade fibromyxoid sarcomas typically arise in the deep soft tissues of the proximal extremities or trunk in young adults. They tend to have a high local recurrence rate, although some may have distant metastases. Histologically, they consist of bland fibroblasts with a whorled or linear arrangement alternating with hypocellular myxoid stroma. Sclerosing epithelioid fibrosarcomas typically arise in the deep soft tissues of the lower extremities of middle-aged adults. They tend to be slow growing but clinically aggressive, with a high propensity for local recurrence and distant metastases. Classic histologic features include the presence of small, uniform, ovoid epithelioid cells with sparse cytoplasm, arranged in cords within a sclerotic fibrous stroma. Myxoinflammatory fibroblastic sarcomas mainly affect the hands and feet. They are prone to local recurrence, with a very low likelihood of distant metastasis. Histologically, they have nodular architecture and highly cellular areas with an abundance of inflammatory cells, among which characteristic large Reed-Sternberg–like and lipoblast-like cells and hypocellular areas rich in myxoid stroma can be seen. Inflammatory myofibroblastic tumors typically occur in children and young adults, with common anatomic locations being the omentum, mesentery, retroperitoneum, and lung. Histologically, they are composed of myofibroblastic spindle cells accompanied by a lymphoplasmacytic inflammatory infiltrate. Surgical resection is the mainstay of treatment for all of the above tumor types. Radiation therapy may be used as adjuvant therapy for tumors with a high risk of local recurrence, in the setting of positive margins, or for unresectable primary or metastatic disease. There is no definite role for standard chemotherapy, but in certain cases, targeted therapy may be of use, such as ALK inhibitors in ALK-positive inflammatory myofibroblastic tumors. 
Key words: inflammatory myofibroblastic sarcoma, low-grade fibromyxoid sarcoma, myxoinflammatory fibroblastic sarcoma, sclerosing epithelioid fibrosarcoma
Hernias in the Emergency Department
Authors: Berhanu Daniel , Barclay-Buchanan Ciara J. , Westergaard Mary C.
Published: January 2021

Hernia is defined as an abnormal protrusion of an organ or tissue through a pathologic defect in its surrounding wall. Overall, hernia is common and is generally believed to be a benign condition associated with some morbidity, although it is not thought to be associated with significant mortality. Between 2001 and 2010, 2.3 million inpatient abdominal hernia repairs were performed in the United States, of which 567,000 were performed emergently. In some cases, a hernia can be a deadly condition. In 2002, hernia was listed as the cause of death for 1,595 US citizens. This review covers the pathophysiology, stabilization and assessment, diagnosis and treatment, and disposition and outcomes of hernia. Figures show anatomic locations of the various abdominal wall, groin, lumbar, and pelvic floor hernias; a direct inguinal hernia; an indirect inguinal hernia; point-of-care sonograms showing a ventral wall hernia and an abdominal wall hernia; and the differential diagnosis of an abdominal mass based on anatomic location. Tables list risk factors for the development of inguinal hernia, sex-based differences in inguinal hernia development, risk factors for the development of incisional hernia, factors to consider when assessing the patient for a hernia, and factors associated with the highest rates of incarceration in patients with groin hernia. 
Key words: emergent hernia, hernia incarceration, incisional hernia, inguinal hernia, strangulated hernia
This review contains 6 highly rendered figures, 5 tables, and 66 references.
Coagulopathies
Authors: Levine Michael
Published: January 2021

Coagulopathy can be caused by numerous hereditary or acquired etiologies. Although some of these conditions are known and the patient is aware of the bleeding disorder, other bleeding disorders are diagnosed only after the onset of excessive hemorrhage. This review discusses both hereditary and acquired disorders of coagulopathy. Platelet disorders are discussed elsewhere.
This review contains 2 figures, 7 tables, and 72 references.
Key words: Coagulopathies; Coagulopathy; Bleeding disorder; Hereditary bleeding disorder; Acquired bleeding disorder; von Willebrand disease; Hemophilia; Coagulation cascade; Hemorrhage; Anticoagulant-associated hemorrhage
Hydrocarbons
Authors: Burns Jarrett M.
Published: January 2021

Hydrocarbons (HCs) are organic compounds that contain primarily hydrogen and carbon atoms. Although most HC exposures occur in occupational settings dealing with various solvents, they can be found in products in every household. Therefore, the risk of exposure in everyday life is high. This review discusses the toxicokinetics, pathophysiology, common clinical presentation, and management of HCs. The three major classes of HCs (aliphatic, aromatic, and halogenated) are closely examined. An in-depth look is taken at commonly encountered HCs with unique toxicologic characteristics. The principles of toxicity, immediate stabilization, diagnosis, definitive management, disposition, and outcomes of these specific HCs are defined. Tables describe HCs commonly found in the household, toxic metabolites and viscosities of common HCs, and target organs of the toxic effects of common alihepatic, halogenated, and aromatic HCs both early and late after exposure. Figures show the structure of the various HCs described in the review.
This review contains 13 highly rendered figures, 6 tables, and 116 references.
Heavy Metals
Authors: Carey Jennifer L. , Boyer Edward W.
Published: January 2021

Heavy metal poisoning may be acute, subacute, or chronic, and it is important for the emergency physician to recognize poisonings that are acutely life threatening. Nearly all parts of the human body are affected by heavy metals, including the cardiovascular, gastrointestinal, renal, hematologic and nervous systems. In many heavy metal poisonings, chelation therapy is the standard of care. This review details the principles of toxicity, immediate stabilization, diagnosis and definitive therapy, and disposition and outcomes for patients who have been exposed to arsenic, chromium, cobalt, lead, mercury, and thallium. Figures show the skin manifestations of chronic arsenic toxicity and treatment algorithms for lead exposure and thallium poisoning. Tables list the clinical manifestations of arsenic poisoning, the side effects of common chelators, systemic manifestations of lead toxicity in adults, routes of exposure and clinical manifestations of mercury poisoning, and symptoms following acute thallium overdose.
This review contains 3 highly rendered figures, 5 tables, and 92 references.
Shock: Pathophysiology and Management
Authors: Shokoohi Hamid , Armstrong Paige
Published: January 2021

Shock is a serious clinical condition in which tissue perfusion is inadequate to meet oxygen demand, resulting in tissue hypoxia. Shock is categorized based on the primary process leading to hemodynamic instability. There are five main classifications: cardiogenic, distributive, hypovolemic, obstructive, and dissociative. Regardless of etiology, the diagnosis and initial care of patients with shock must be prompt and directed towards reversing the tissue ischemia and preventing its consequences. Often initial evaluation, diagnosis, and resuscitation occur simultaneously. The first goal is to accurately identify the etiologic cause and initiate therapy before there is irreversible damage to end vital organs.
This review focuses on the pathophysiology and management of shock and addresses a number of new developments that have profoundly altered the treatment paradigms.  A number of protocols have been developed in the arena of shock resuscitation. Focused ultrasonography is recommended for the prompt recognition of complicating physiology in patients with hypotension and shock, especially in unstable patients. Tables outline classification systems for different types of shock as well as appropriate first and second line vasopressors indicated in each.
Key words:  Hypovolemic shock, cardiogenic shock, obstructive shock, distributive shock, dissociative shock, point-of-care ultrasonography, cardiac ultrasonography, vasopressors
This review contains 5 highly rendered figures, 8 tables, and 64 references.
Pediatric Trauma
Authors: Bryant Kathleen , Smith Jeremiah , Gibbs Michael
Published: January 2021

Children have unique anatomy and physiologic responses to trauma that create different challenges for their management. It is important to follow the Advanced Trauma Life Support (ATLS) algorithm for assessing and treating a pediatric trauma patient, paying close attention to the primary survey. Once the primary survey is accomplished with adequate stabilization, the secondary survey proceeds with a focus on specific injuries. Head trauma is the leading cause of morbidity and mortality (M+M) in children. Early identification and prevention of secondary injury are important to optimize outcomes. The head and neck anatomic differences in a child cause a higher fulcrum of their cervical spine, leading to higher cervical spine injuries (CSIs). CSI is rare but carries a higher M+M due to higher spinal cord injuries. The National Emergency X-radiography Utilization Study (NEXUS) and Canadian C-spine Rule (CCR) are useful decision rules to clear cervical spines in adults but have limited strength in young children. PECARN has derived a pediatric cervical spine clearance rule, but this has yet to be prospectively validated. Similar to CSIs, thoracic injuries in children are rare but carry a higher M+M due to anatomic differences in children. A child’s chest anatomy and increased compliance cause more difficulty in injury identification. Abdominal trauma is common in children and can also be difficult to identify. Unlike adults, children can compensate for blood loss much longer while maintaining their blood pressure. Serial abdominal examinations are useful when imaging is negative and a patient has persistent symptoms.
This review contains 5 highly rendered figures, 18 tables, and 92 references.
Key words: abdominal trauma, Advanced Trauma Life Support (ATLS), cervical spine injury, head trauma, National Emergency X-radiography Utilization Study (NEXUS),  Pediatric Emergency Care Applied Research Network (PECARN), thoracic trauma, traumatic brain injury
Congenital Heart Disease
Authors: Pittsenbarger Zachary , Roben Emily
Published: January 2021

Congenital heart disease (CHD) is common, affecting approximately 8 in 1000 live-born children, and encompasses a broad range of diagnoses and presentations.  CHDs can include inborn derangements in almost any aspect of the hearts structure of function, but the most common type of congenital heart disease are structural lesions of the heart that affect the normal pattern of blood flow.  These structural lesions can present with varied symptoms and physical exam signs that are rooted in their underlying blood flow patterns often lead to one of four groups of diseases based on blood flow patterns.  Overcirculation, systemic outflow obstruction, systolic failure, and cyanosis are the four groups used as descriptive classifications of structural CHD.  CHD findings can be present prenatally, in the newborn nursery, and well child office visits, but very often present to the EDs without any cardiac history when the lesion progresses to a point of crisis when the cardiac output is no longer meeting the body’s perfusion demands.  Early presentations of CHD frequently are related to closure of the ductus arteriosus and may benefit from early treatment with prostaglandin E.  Lab tests, radiology studies, and exam findings may be suggestive of certain types of lesions, but the gold standard to determine the type of CHD is an echocardiogram.  Once the diagnosis of CHD is suspected, consultation with a pediatric cardiologist is highly recommended to arrange the timely evaluation of the child and prompt initiation of therapies if needed to mitigate the disease progression.
                       
Key words: Congenital heart disease, overcirculation, systemic outflow obstruction, systolic failure, and cyanosis, ductus arteriosus
Nondiabetic Endocrine Emergencies 2: Hypoparathyroidism, Hyperparathyroidism, Myxedema Coma, And Thyroid Storm
Authors: Lewis Jason J , Wolfe Richard E
Published: January 2021

Acute emergent presentations of the thyroid and parathyroids are rarer occurrences in the emergency department but essential to diagnose and treat early in the course of illness. Disorders of the parathyroids are typically related to circulating calcium levels and the metabolic effects thereof, whereas thyroid deficiency or excess can lead to profound shock, coma, hypothermia, hyperthermia, and death. The diagnosis of parathyroid disease should be considered in patients presenting with signs and symptoms consistent with hyper- or hypocalcemia. Myxedema coma should be considered in any patient presenting with evidence of severe sepsis or shock, particularly when there is a history of hypothyroidism. Thyroid storm should be suspected in any patient with unexplained increased adrenergic activity, hyperpyrexia, or multiorgan failure. Empirical treatment must begin prior to definitive diagnosis in all cases. This review demonstrates how to recognize and manage acute presentations of hypo- and hyperparathyroidism, myxedema coma, and thyroid storm in the emergency setting. Patients with nondiabetic endocrine emergencies may present in extremis, and immediate stabilization, typically without confirmatory testing, is necessary. Early intervention is key in treating such presentations.

This review contains 3 figures, 8 tables and 28 references
Key words: disorders of the parathyroids, hyperparathyroidism, hypoparathyroidism, hypothyroidism, myxedema coma, thyroid storm, thyrotoxicosis
Bradyarrhythmias
Authors: Leybell Inna , Abrukin Liliya
Published: January 2021

Bradyarrhythmias can present as an incidental electrocardiographic (ECG) finding or a life-threatening condition requiring immediate intervention. They are caused by sinus node disease or atrioventricular block. This review covers pathophysiology, stabilization and assessment, diagnosis and treatment options, and disposition and outcomes for patients with bradycardia. Figures in the review demonstrate characteristic ECG tracings. Tables list classifications of sinus node dysfunction as well as of sinoatrial and atrioventricular blocks, presenting symptoms, important information to elicit on history taking, various causes of bradycardia, and specific interventions for toxicologic etiologies.
Key words: atrioventricular block, atropine, bradyarrhythmia, bradycardia, first-degree atrioventricular block, second-degree atrioventricular block, sinoatrial block, sinus bradycardia, sinus node disease, tachycardia-bradycardia syndrome, third-degree atrioventricular block
This review contains 9 highly rendered figures, 7 tables, and 92 references.
Wide Complex Tachycardia
Authors: Green Gary , Graglia Sally
Published: January 2021

Wide-complex tachycardias (WCTs) should always alert the emergency physician to a potentially immediate or rapidly developing, life-threatening scenario. The approach to these patients should follow general emergency medicine principles. The review covers the pathophysiology, stabilization and assessment, diagnosis and treatment, and disposition and outcomes of WCT. Figures show a basic electrocardiogram (ECG) tracing, an ambulatory monitoring strip of a patient with recurrent presyncope showing repetitive monomorphic ventricular tachycardia, a 12-lead ECG of a rapid wide QRS tachycardia due to an antidromic atrioventricular reciprocating tachycardia in a patient with Wolff-Parkinson-White (WPW) syndrome, an example of pacemaker-mediated tachycardia, ventricular tachycardia occurring in the context of QT prolongation consistent with torsades de pointes, a 12-lead ECG in a patient with WPW syndrome showing a rapid, irregular ventricular rate and wide QRS complexes of atrial fibrillation with a short refractory period, an ECG representative of tricyclic antidepressant overdose, and an algorithm for identifying patients with systolic heart failure and left ventricular ejection fraction less than or equal to 35% who are candidates for an implantable cardioverter-defibrillator. Tables list causes of regular WCT, causes of prolonged QT interval, common medications with potential QT prolongation activity, pharmacologic treatment options for stable patients with WCT, Kindwall and colleagues’ criteria for ventricular tachycardia, Brugada and colleagues’ criteria for ventricular tachycardia, Vereckei and colleagues’ aVr algorithm for the diagnosis of ventricular tachycardia, and a comparison of self-reported sensitivities, specificities, and test accuracies of the algorithms presented by Kindwall, Brugada, and Vereckei and their colleagues.
 
Key words: prolonged QT interval, supraventricular tachycardia, ventricular tachycardia, wide-complex tachycardias
 
This review contains 8 highly rendered figures, 8 tables, and 59 references.
Penetrating Neck Trauma
Authors: Kellogg Adam R. , Davis B. Witkind
Published: January 2021

Penetrating neck injuries are approximately 1% of all traumatic injuries in the US, yet the case fatality rate approaches 10%. All emergency physicians need to be able to expediently differentiate those requiring emergent interventions from those with less serious injuries. Initial management of penetrating neck injuries focuses on identification of patients requiring early airway management or emergent surgical evaluation. Due to bleeding, anatomic distortion, hemodynamic instability, or potential airway violation patients with penetrating neck trauma should be presumed to have difficult to manage airways. The emergency physician must be prepared to perform cricothyrotomy, and even tracheostomy, should orotracheal intubation attempts fail. Diagnosis of injury in the stable patient with evidence of violation of the platysma has moved away from the traditional zone based approach and now focuses on structured physical exam and the use of MDCTA. Further diagnostic testing may be required dependent on the results of the MDCTA and should be at the direction of a surgeon.
 
Keywords:
Penetrating Neck Trauma, Laryngotracheal Trauma, Carotid Artery Injury, Airway Management, Cricothyrotomy, Surgical Airway, CT Angiography
Hepatic Disorders
Authors: Goldsmith Andrew
Published: January 2021

Hepatic disorders are characterized by a variety of etiologies that can present to the emergency department (ED) as acute, chronic, or acute on chronic liver disease. Unfortunately, a large number of these complex disorders can progress to cirrhosis, a progressive and severe clinical condition associated with high morbidity and mortality. Primary prevention, measures include vaccine prophylaxis and abstaining from alcohol. Unfortunately, liver disease can lead to a wide spectrum of clinical manifestations that are in need of urgent and/or emergent therapy mainly attributable to hepatic insufficiency and portal hypertension. Major complications of portal hypertension include ascites, gastrointestinal variceal bleeding, hepatic encephalopathy, renal failure, and bacterial infections. This review covers the epidemiology, pathophysiology, diagnosis, treatment, and disposition of patients who present to the ED with liver disease.
This review contains 3 figures, 4 tables, and 59 references.
Key words: abdominal pain, ascites, cirrhosis, encephalopathy, hepatic abscess, hepatic liver transplant, hepatitis, hepatorenal syndrome, spontaneous bacterial peritonitis
Practicing Evidence-Based Medicine (SAGHE)
Authors: Barnett Michael , Choudhry Niteesh
Published: January 2021

Today, a plethora of resources for evidence-based medicine (EBM) are available via alert services, compendia, and more. In theory, a clinician researching a topic or looking for information regarding a clinical decision should easily find the literature or synopses needed. However, the real challenge lies in recognizing which resources (out of hundreds or possibly thousands) present the best and most reliable evidence. As well, evidence from research is only part of the decision calculus, and the clinician, not the evidence, makes the final decisions. Medical decision analysis attempts to formalize the process and reduce it to algebra, but it is difficult or impossible to represent all the components of a decision mathematically and validly let alone do so in “real time” for individual patients. This review discusses these challenges and more, including how to ask answerable questions, understand the hierarchy for evidence-based information resources, critically appraise evidence, and apply research results to patient care. Figures show the total number of new articles in Medline from 1965 to 2012, a “4S” hierarchy of preappraised medicine, percentage of physician and medical student respondents with a correct or incorrect answer to a question about calculating the positive predictive value of a hypothetical screening test, a nomogram for Bayes’s rule, an example of nomogram use for pulmonary embolism, and a model for evidence-informed clinical decisions. Tables list selected barriers to the implementation of EBM; Patient, Intervention, Comparison, and Outcome (PICO) framework for formulating clinical questions; guides for assessing medical texts for evidence-based features; clinically useful measures of disease frequency and statistical significance and precision; definitions of clinically useful measures of diagnostic test performance and interpretation; definitions of clinically useful measures of treatment effects from clinical trials; summary of results and derived calculations from the North American Symptomatic Carotid Endarterectomy Trial (NASCET); and selected number needed to treat values for common therapies.
This review contains 6 highly rendered figures, 9 tables, and 28 references.
Clinical Features and Differential Diagnosis of Ulcerative Colitis and Crohn Disease
Authors: Barnes Edward L. , Levine Jonathan S.
Published: January 2021

Inflammatory bowel disease (IBD) is composed of two major subtypes, ulcerative colitis (UC) and Crohn disease (CD). These chronic disorders, characterized by inflammation of the gastrointestinal tract, demonstrate a variety of clinical features, including intestinal and extraintestinal manifestations during periods of relapse and remission over many years. This review examines the clinical features of IBD, including the extraintestinal manifestations and diagnosis. Figures include examples of images conducted via computed tomography (CT), magnetic resonance imaging, and position emission tomography (PET)/CT. Tables list the location frequencies of UC and CD at the time of diagnosis, extraintestinal manifestations of IBD, differential diagnosis of UC and CD, and clinical utility of fecal calprotectin in the evaluation and management of IBD.
This review contains 4 highly rendered figures, 5 tables, and 48 references.