bluuebunny/crossref_metadata_2025 huggingface dataset:
Tip Lesion Variant of Focal and Segmental Glomerulosclerosis in a COVID-19 Patient
Authors: Afonso Rita Serra , Calças Marques Roberto , Borges Henrique , Carias Eduarda , Domingos Ana Teresa , Cabrita Ana , Sampaio Sandra , Silva Ana Paula
Published: November 2022

Acute kidney injury is a common complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Several pathologic findings are continually being reported, showing a probably multifactorial etiology. The authors present a case of a patient diagnosed with a tip lesion variant of focal segmental glomerulosclerosis (FSGS) in the setting of COVID-19. A 43-year-old African American female with no known renal disease presented to the emergency department with a 6-day history of fatigue, headache, hypoageusia, myalgia, cough, nausea, and vomiting. Laboratory tests confirmed SARS-CoV-2 infection. During hospitalization, there was a progressive decline in kidney function and evidence of nephrotic-range proteinuria without nephrotic syndrome. Biopsy specimen showed a tip lesion variant of FSGS. Genetic test revealed a homozygous variant of uncertain clinical significance (c.397G>A [p.V133M]) in the epithelial membrane protein 2 (EMP2) gene. To our knowledge, this is the first case report of a tip lesion in a COVID-19 patient with no renal history. More studies are warranted to define susceptible groups and identify the detailed mechanisms of COVID-19-related kidney disease that would allow for specific management of this complication.
The role of international reserves on real exchange rate: a panel data analysis
Authors: Vieira Flavio Vilela , Silva Cleomar Gomes da
Published: November 2022

This article analyzes whether the accumulation of international reserves affects real exchange rates for a set of 57 economies. Panel ARDL estimations, for annual data from 1994 to 2017, show that higher (lower) levels of international reserves cause appreciation (depreciation) of exchange rate and reduce (increase) its volatility, in the long run. As for the error-correction related to deviations from the long run, short run adjustments in exchange rate volatility occur at a much faster rate than corrections in the exchange rate level. The Balassa-Samuelson effect, inflation and inflation differential also play significant roles, whereas monetary independence is partially important.
Effects of Carotid Artery Stiffness on Cerebral Small‐Vessel Disease and Cognition
Authors: Robert Caroline , Ling Lieng‐Hsi , Tan Eugene S. J. , Gyanwali Bibek , Venketasubramanian Narayanaswamy , Lim Shir Lynn , Gong Lingli , Berboso Josephine Lunaria , Richards Arthur Mark , Chen Christopher , Hilal Saima
Published: November 2022

Background

Carotid artery stiffness is associated with cognitive impairment and dementia, but the underlying mechanisms remain unknown. We examined the associations of carotid artery stiffness with cerebral small‐vessel disease markers, cognition, and dementia subtypes in a memory clinic cohort.

Methods and Results

A total of 272 participants underwent carotid ultrasonography, 3 Tesla brain magnetic resonance imaging, and neuropsychological assessment. Carotid ultrasonography was used to assess β‐index, pressure‐strain elastic modulus, and pulse‐wave velocity‐β. Brain magnetic resonance images were graded for cerebral small‐vessel disease markers, including white matter hyperintensities, lacunes, and cerebral microbleeds. Participants were classified as having no cognitive impairment, cognitive impairment and no dementia, or dementia subtyped as Alzheimer disease and vascular dementia. Cognition was assessed using National Institute of Neurological Disorders and Stroke–Canadian Stroke Network harmonization battery. After adjusting for age, sex, cardiovascular risk factors, and diseases, multivariable models showed that β‐index (
β
=0.69;
P
=0.002), elastic modulus (
β
=0.78;
P
<0.001), and pulse‐wave velocity‐β (
β
=0.80;
P
<0.001) were associated with white matter hyperintensities, and elastic modulus (odds ratio [OR], 1.39 [95% CI, 1.04–1.85]) and pulse‐wave velocity‐β (OR, 1.47 [95% CI, 1.10–1.98]) were independently associated with lacunes. Similarly, β‐index (OR, 2.04 [95% CI, 1.14–4.13]), elastic modulus (OR, 2.22 [95% CI, 1.25–4.42]), and pulse‐wave velocity‐β (OR, 2.50 [95% CI, 1.36–5.18]) were independently associated with vascular dementia. Carotid stiffness measures were independently associated with worse performance in global cognition, visuomotor speed, visuospatial function, and executive function. These associations became largely nonsignificant after further adjusting for cerebral small‐vessel disease markers.

Conclusions

In memory clinic patients, carotid artery stiffness was associated with white matter hyperintensities and lacunes, impairment in global and domain‐specific cognition, and causative subtypes of dementia, particularly vascular. The effects of carotid stiffness on cognition were not independent of, and were partially mediated by, cerebral small‐vessel disease.
A Decade of Improvement in Door‐to‐Puncture Times for Mechanical Thrombectomy But Ongoing Stagnation in Prehospital Care
Authors: Sun Chung‐Huan , Zaidat Osama O. , Castonguay Alicia C. , Veznedaroglu Erol , Budzik Ronald F. , English Joey , Baxter Blaise , Nogueira Raul G. , Krajina Antonín , Bartolini Bruno , Liebeskind David S. , Smith Wade , Koenig Matt , Jenkins Paul , Gupta Rishi
Published: November 2022

Background

Systems of care surrounding endovascular therapy for stroke have garnered much attention in recent years. In‐hospital metrics, such as “door‐to‐puncture” and procedure times have been areas for quality improvement. The temporal trend and clinical significance of prehospital “onset‐to‐door” time, however, remains unknown.

Methods

We performed a systematic review of time metric data from all published randomized controlled and investigational device exemption trials involving endovascular therapy for stroke between 2005 and 2019 (n=26). Second, we conducted a record‐level observational analysis on a total of 3512 patients from 3 real‐world registries (Mechanical Embolus Removal in Cerebral Ischemia [MERCI], Thrombectomy REvascularization of Large Vessel Occlusions in Acute Ischemic Stroke [TREVO], and TREVO Stent‐Retriever Acute Stroke [TRACK]), together with 4 prospective trials (MERCI trial, Multi‐MERCI, TREVO‐EU, and TREVO‐2). Only patients receiving mechanical thrombectomy within 9 hours from onset‐to‐puncture time were included. Predictors of good outcome were identified using generalized linear mixed modeling.

Results

Door‐to‐puncture times (slope=−5.83 min/y; R
2
=0.25;
P
=0.046), procedure times (slope=−3.78 min/y; R
2
=0.54;
P
<0.001), and onset‐to‐reperfusion times (slope=−11.82 min/y; R
2
=0.57;
P
<0.001) improved over the years among previously published randomized controlled trials/investigational device exemption trials from 2005 to 2019. The prehospital metric of onset‐to‐door time, however, remained statistically unchanged (slope=1.03 min/y; R
2
<0.01;
P
=0.806). Pooled analysis from record‐level data demonstrated a similar temporal trend where door‐to‐puncture, procedure, and onset‐to‐reperfusion times declined by an average of 12 minutes (R
2
=0.45;
P
<0.0001), 6 minutes (R
2
=0.27;
P
<0.0001), and 8 minutes per year (R
2
=0.18;
P
<0.0001), respectively, over a similar time period. Time from onset to door, however, did not improve (3.6 min/y; R
2
=0.34;
P
=0.005). In a backward‐selection regression model, onset‐to‐door time was found to be a significant predictor of patient outcomes, where every hour delay in hospital arrival correlated with a 14% reduction in the odds of a good outcome.

Conclusions

“Door‐to‐puncture” and procedure times have seen significant improvements over the past decade. The prehospital component of “onset‐to‐door” time, however, has remained stagnant. This presents an unrealized opportunity to enhance patient outcomes through improved systems of care in the prehospital setting.
Views on Thresholds by Transdisciplinary Partners: A Shared Journey Continues
Authors: Wolf Silvio , Rozentsvit Inna
Published: November 2022

This article is a reflection on a journey of transdisciplinary partners from two different and unusually paired “sets” of disciplines: photography art (Silvio Wolf, SW) and cross-pollinated research in the fields of applied clinical neuroscience and psychoanalysis (Inna Rozentsvit, IR). This relationship originated in examining the “beholder’s share” phenomenon and moved on to further collaboration on the topics of “thresholds” and “visible/invisible,” as they relate to these two individuals’ personal and professional beings.
Pattern forming mechanisms of color vision
Authors: Burstein Zily , Reid David D. , Thomas Peter J. , Cowan Jack D.
Published: November 2022

While our understanding of the way single neurons process chromatic stimuli in the early visual pathway has advanced significantly in recent years, we do not yet know how these cells interact to form stable representations of hue. Drawing on physiological studies, we offer a dynamical model of how the primary visual cortex tunes for color, hinged on intracortical interactions and emergent network effects. After detailing the evolution of network activity through analytical and numerical approaches, we discuss the effects of the model’s cortical parameters on the selectivity of the tuning curves. In particular, we explore the role of the model’s thresholding nonlinearity in enhancing hue selectivity by expanding the region of stability, allowing for the precise encoding of chromatic stimuli in early vision. Finally, in the absence of a stimulus, the model is capable of explaining hallucinatory color perception via a Turing-like mechanism of biological pattern formation.
Compositional Evaluation on Japanese Textual Entailment and Similarity
Authors: Yanaka Hitomi , Mineshima Koji
Published: November 2022

Natural Language Inference (NLI) and Semantic Textual Similarity (STS) are widely used benchmark tasks for compositional evaluation of pre-trained language models. Despite growing interest in linguistic universals, most NLI/STS studies have focused almost exclusively on English. In particular, there are no available multilingual NLI/STS datasets in Japanese, which is typologically different from English and can shed light on the currently controversial behavior of language models in matters such as sensitivity to word order and case particles. Against this background, we introduce JSICK, a Japanese NLI/STS dataset that was manually translated from the English dataset SICK. We also present a stress-test dataset for compositional inference, created by transforming syntactic structures of sentences in JSICK to investigate whether language models are sensitive to word order and case particles. We conduct baseline experiments on different pre-trained language models and compare the performance of multilingual models when applied to Japanese and other languages. The results of the stress-test experiments suggest that the current pre-trained language models are insensitive to word order and case marking.
Petro-States’ Shaping of International Law
Authors: Kulamadayil Lys
Published: November 2022

This article highlights the marks left on international law by Iran’s and Algeria’s early, and mid-20th century paths to re-claiming sovereignty over their petroleum reserves. It shows that Iran has significantly affected the contractual model of petroleum operations, whereas Algeria has championed the international law turn of third world internationalism. It thus hopes to shift attention from the frequently cited non-consequentialism of key moments in Third World Internationalism, such as Bandung and the NIEO to the significance of these domestic and transnational processes. While so doing, it is careful to point to the extraordinary bargaining power given to petro-states by the fossil-fuel dependent global economy, which elevated their influence in global affairs over that of other states in the Global South.
The Well-Tempered Career: Erasmus on the Emotional Health of Scholars
Authors: Haskell Yasmin
Published: November 2022

This lecture explores Erasmus’ beliefs about the life of the healthy Christian humanist, from boy student to mature scholar, through the prism of ‘history of emotions’. It appraises Erasmus’ place in the longer history of scholarly hygiene, a tradition of writing about the physical, psychological, and spiritual health of scholars. What for example does Erasmus have to say about those conditions with which early modern intellectuals were so frequently associated, viz. melancholy and ‘hypochondriac’ disease? Does he pathologize particular kinds of intellectual activity, and what preventatives or remedies does he prescribe for the occupational hazards, if not diseases, of learning? Finally, what was Erasmus’ view of the authority of contemporary learned medicine in relation to these matters?
Erasmus’ Edition of the Complete Works of Augustine
Authors: Tello Joan
Published: November 2022

This article offers a commented inventory of the complete works of Augustine that Erasmus published in 1528–1529. The inventory is preceded by an overview of Erasmus’ publications on the Fathers of the Church and previous editorial work on Augustine undertaken by other printers, which helps place the edition of Erasmus into context.
Missing the Forest for the Trees: Modular Search and Systemic Inertia as a Response to Environmental Change
Authors: Clement Julien
Published: November 2022

I develop and test a theory that explains why organizations may struggle to adapt in the face of change even when their members are aware of change, are motivated to adapt, and have the resources to do so. I build on complex-systems theory, which posits that organizations face a hierarchy of interdependent problems: they must choose how to fulfill different specialized tasks and choose processes to integrate the outputs of these tasks. Because these choices are interdependent, environmental change that directly affects only a few tasks in isolation can indirectly affect the viability of major organizational processes. Recognizing these ripple effects is difficult, however: understanding complex interdependencies is challenging for decision makers, and the division of labor within organizations can create an illusion of separability between tasks. As a result, organizations may respond to such change by engaging in “modular search” for new ways to fulfill specialized tasks, but they may fail to engage in “systemic search” for new processes integrating the outputs of specialized tasks unless they can rely on information-processing structures that help decision makers better understand interdependencies among choices. I test my theory by applying sequence analysis methods to micro-level behavioral data on competitive video gaming (esports) teams. Qualitative fieldwork and an online experiment provide additional evidence of my proposed mechanisms.
Income Support Policies for Single Parents in Europe and the United States: What Works Best?
Authors: Aerts Elise , Marx Ive , Parolin Zachary
Published: November 2022

Poverty rates among single parents vary considerably across countries, in part reflecting differences in the generosity and design of minimum income protections. We ask what the optimal ways are to target income support to single parents, if the prime objective of policy is to shelter those households from poverty. We map minimum income provisions for working and nonworking single-parent households across Europe and the United States, showing that three things matter for adequate minimum income protection. First, minimum wage levels matter, obviously for working single parents, but also for jobless ones since they effectively set the ‘glass ceiling’ for out-of-work benefits. Second, the overall generosity of the child benefit package is crucial to shelter both working and jobless single parents from poverty. Third, countries that employ a strategy of “targeting within universalism” (that is directing extra support to vulnerable groups such as single parents within the context of a universal benefit program) tend to do best.
Single Mothers’ Income in Twelve Rich Countries: Differences in Disadvantage across the Distribution
Authors: Harkness Susan
Published: November 2022

I examine how single motherhood affects income in different quantiles of the distribution in twelve rich countries. Using harmonized data from the Luxembourg Income Study, I show how the distribution of income for households headed by single mothers differs from households with children that are headed by couples. I show that there is a striking variation by country in the influence of single motherhood on income at different points of the distribution. In some countries, such as the United Kingdom, single motherhood has a greater effect on income at the top of the distribution than at the bottom. In others, such as the United States, effects are largest at the bottom of the distribution. I discuss the role of employment and social policies in driving differences between countries in the income penalties associated with single motherhood across the distribution.
Cross-National Variation in the Relationship between Welfare Generosity and Single Mother Employment
Authors: Biegert Thomas , Brady David , Hipp Lena
Published: November 2022

Reform of the U.S. welfare system in 1996 spurred claims that cuts to welfare programs effectively incentivized single mothers to find employment. It is difficult to assess the veracity of those claims, however, absent evidence of how the relationship between welfare benefits and single mother employment generalizes across countries. This study combines data from the European Union Labour Force Survey and the U.S. Current Population Survey (1992-2015) into one of the largest samples of single mothers ever, testing the relationships between welfare generosity and single mothers’ employment and work hours. We find no consistent evidence of a negative relationship between welfare generosity and single mother employment outcomes. Rather, we find tremendous cross-national heterogeneity, which does not clearly correspond to well-known institutional variations. Our findings demonstrate the limitations of single country studies and the pervasive, salient interactions between institutional contexts and social policies.
The Wealth (Disadvantage) of Single-Parent Households
Authors: Morelli Salvatore , Nolan Brian , Palomino Juan C. , Van Kerm Philippe
Published: November 2022

Wealth is a buffer against economic shocks and the intergenerational transmission of disadvantage. We investigate the wealth of single-parent households in six high-income countries that span a variety of institutional contexts and welfare regimes. Using household survey data, we show that single-parent households in all these countries are disadvantaged in the wealth they hold, compared to dual-parent households—more so in Great Britain, France, Germany, and the United States; and less so in Italy and, especially, Spain. We tease out major differences in types of wealth holdings in single- and dual-parent households. We find that the single-parent wealth deficit is not explained by differences in age or number of children but that it is influenced by education, income, homeownership, and receipt of intergenerational transfers. We discuss the policy implications of our findings, both in terms of how single parents are treated in social protection and taxation systems and, more broadly, in the supports they require if they are to overcome barriers to accumulating wealth.
Making Parental Leave Policies Work for Single Mothers: Lessons from Europe
Authors: Bartova Alzbeta , Otto Adeline , Van Lancker Wim
Published: November 2022

It is well documented that national parental leave policies encourage parents’ employment. Research on parental leave, though, has generally failed to draw lessons on how leave policy affects the employment and economic well-being of single parents. We examine the extent to which parental leave policies support the employment of single mothers with children under six years old across twenty-seven European countries, showing that single mothers are more likely to work and to work longer hours if they are eligible for parental leave. For single mothers who were not working before childbirth, eligibility for generous leave benefits and longer parental leave are associated with better employment outcomes after childbirth. We argue that while parental leave sustains employment for working single mothers, it might also facilitate entry into employment for nonworking mothers.
A Festschrift to John Elias Skandalakis, M.D., Ph.D., F.A.C.S.
Authors: Froman Carol R.
Published: November 2022

We hope that, one of these days, someone will collect enough pebbles from the “boundless ocean” to present to the medical profession the correct surgical anatomy … We as scientists are seeking the facts, the most consistent patterns of structure and function, with the hope that students, residents, and practicing physicians will be as well informed as possible and be able to perform without error in the operating room … It is the reader's challenge to decide if we have exacerbated or eased the controversy. John E. Skandalakis
A Review of Septic Shock
Authors: Hardaway Robert M.
Published: November 2022

The mortality of septic shock, both in percentage of septic shock cases and total number of septic shock cases, has been increasing over the past several decades. This is despite major advances in diagnosis and treatment. The basic cause of traumatic and septic shock has only partially been elucidated. This review presents information about the basic cause and mechanism of septic shock as well as a new treatment based on this information. Data sources include research papers on the subject of septic shock from 1875 until the present. These papers numbered more than 10,000, most of which are not included in the reference list because many are duplicative. The main result of the review of literature is that all of a wide variety of treatments of septic shock have not resulted in a lowering of mortality, but in fact have increased it. Another toxin (in addition to endotoxin and its secondarily induced host mediators) is proposed. This toxin causes disseminated intravascular coagulation, which may obstruct the microcirculation of any and all organs, producing multiple organ failure by microclots. These microclots may be lysed by plasminogen activator and circulation to the organs restored.
Laparoscopic Cholecystectomy for an Abnormal Hepato-lminodiacetic Acid Scan: A Worthwhile Procedure
Authors: Skipper Kent , Sligh Scott , Dunn Ernest , Schwartz Armond
Published: November 2022

Patients with symptoms similar to symptomatic cholelithiasis but with no sonographic evidence of gallstones can be difficult to manage. Cholecystokinin (CCK)-stimulated hepatobiliary scans can be helpful in determining whether the biliary tract is the potential source of the symptoms. We retrospectively reviewed the medical records of 69 patients at our institution who underwent CCK-stimulated hepatobiliary scans over a 2-year period. Twenty-nine of 69 patients had an abnormal gallbladder ejection fraction (defined as 35% or less). All 29 patients had no sonographic evidence of cholelithiasis. Seventeen of the 29 underwent cholecystectomy. There were no complications or deaths within the operative group. Fifteen of the pathologic specimens had evidence of chronic cholecystitis, one was cytomegalovirus cholecystitis, and one showed only cholesterolosis. There was no other intraperitoneal pathology to explain the abdominal symptoms. At an average follow-up of 11 months, eight patients (47%) in the operative group had complete resolution of their symptoms, six (35%) had significant improvement, two (12%) were unchanged, and one (6%) was worse. Twelve of 29 patients did not have a cholecystectomy. At an average follow-up of 11 months, four (33%) of these patients had improvement and eight (66%) reported no change or worsening of their symptoms. In the operative group, 53 per cent had reproduction of their symptoms with CCK stimulation, and in the nonoperative group, 33 per cent reported symptoms. Average gallbladder ejection fraction was 10 per cent (range, 0–32) in the operative group and 23 per cent (range, 0–35) in the nonoperative group. Liver function tests were similar in each group. CCK-stimulated hepatobiliary scans were helpful in defining biliary tract disease in patients without gallstones. These patients may benefit from cholecystectomy with minimal risk of morbidity and mortality.
Percutaneous Cholecystostomy is an Effective Treatment for High-Risk Patients with Acute Cholecystitis
Authors: Patel Mrunal , Miedema Brent W. , James Mark A. , Marshall John B.
Published: November 2022

We sought to determine the safety, efficacy, and outcome of percutaneous cholecystostomy (PC) in all patients undergoing the procedure at our institutions. We reviewed 53 consecutive cases of acute cholecystitis seen at our hospitals over 5.5 years in which PC was performed at the initial treatment. Follow-up was obtained by chart review and telephone questionnaire. Acute cholecystitis was the primary admitting diagnosis in 18 cases. In the remaining 35, cholecystitis developed during hospitalization. All patients were considered high surgical risks on the basis of the presence of comorbid conditions. The gallbladder was successfully catheterized under radiologic guidance in all patients and with no immediate procedure-related morbidity. Acute cholecystitis resolved in 44 of 53 patients (83%), whereas nine patients (17%) did not improve clinically after PC and died during the same hospitalization. A total of 33 (62%) eventually survived hospitalization. Elective cholecystectomy was done in 25 patients with no mortality. After cholecystectomy, three of these patients subsequently died of other causes, whereas 22 are alive. Eight patients did not undergo cholecystectomy because of underlying medical conditions or because they had acalculous cholecystitis. These patients remained free of biliary problems after removal of their cholecystostomy tube, but two have subsequently died of nonbiliary conditions. Percutaneous cholecystostomy is a safe, effective treatment for high-risk patients with acute cholecystitis. Cholecystostomy can be followed by elective cholecystectomy at a later time if the patient's condition permits or by expectant conservative management in patients who have had acalculous cholecystitis or have a very high mortality risk with surgery.
Schwannoma of the Cervical Sympathetic Chain: It's Not a Carotid Body Tumor
Authors: Souza John W. , Williams John T. , Dalton Martin L. , Solis Maurice M.
Published: November 2022

Schwannoma of the cervical sympathetic chain is a rare nerve tumor with fewer than 40 confirmed cases in the English literature. These lesions typically present as an asymptomatic neck mass and are easily mistaken for a carotid body tumor during the initial workup. We report a case of schwannoma of the cervical sympathetic chain in a 35-year-old man followed by a review of the current literature.
Intussusception after Roux-en-Y Gastric Bypass
Authors: Duane Therése M. , Wohlgemuth Stephen , Ruffin Kirk
Published: November 2022

Intussusception is a common pediatric surgical problem. Its occurrence in adults is rare and usually involves a specific lead point such as a small bowel tumor or other mass. We describe two adults who developed intussusception after Roux-en-Y gastric bypass. Signs and symptoms of small bowel obstruction were seen in both of these patients, but the responsible pathology was unusual. Because of the increasing frequency with which these gastric bypass procedures are being performed, a high index of suspicion must be employed when dealing with these postoperative patients who present with abdominal complaints.
Infections within the Peritoneal Cavity: A Historical Perspective
Authors: Steeb Glen , Wang Yi-Zarn , Siegrist Brett , O'Leary J. Patrick
Published: November 2022

Physicians in antiquity dreaded abdominal infections. Despite the fact that peritonitis was extremely common, reports of successful surgical interventions were only anecdotal before the past century. Medicine's comprehension of the pathophysiology of the peritoneal cavity is still evolving. The history of our understanding of the process could be considered to be as recent as the current literature. Despite this, the mortality rates for patients with secondary peritonitis have fallen in the last century from almost 100 per cent to less than 10 per cent.
Prophylactic Antibiotics in Surgery and Surgical Wound Infections
Authors: Polk Hiram C. , Christmas A. Britton
Published: November 2022

Wound infection remains a considerable cause of morbidity and mortality among surgical patients, despite the relative success of prophylactic antibiotics. In modern efforts to control healthcare costs while improving the quality of patient care, we must not overlook the basic principles of wound infections and their appropriate treatment. Predisposing factors for the development of surgical wound infection include the creation of a surgical wound, the presence of bacteria, and a susceptible host. The selection of an appropriate antimicrobial drug depends on the identification of the most likely pathogens associated with a given procedure, as well as the expected antibiotic susceptibility of those pathogens. Ideally, a prophylactic antibiotic should achieve high peak tissue concentration at the site of the wound before the first incision and should be maintained until the time of closure. Currently, the administration of prophylactic antibiotics is indicated for contaminated and clean-contaminated wounds. Despite the proven effectiveness of antibiotic prophylaxis, many researchers would argue that contemporary dosing regimens should be reevaluated. The debates concerning the dosage and timing of ideal prophylactic administration are likely to continue.
Surgical Treatment of Biliary Tract Infections
Authors: Lillemoe Keith D.
Published: November 2022

Despite major advances in surgical and nonsurgical therapy, biliary tract infections remain a significant cause of morbidity and mortality. The two classic biliary tract infections most commonly encountered are acute cholecystitis (either calculous or acalculous) and acute cholangitis. In addition, bile leakage associated with bile duct injuries during laparoscopic cholecystectomy has become a problem not infrequently encountered by surgeons. Acute calculous cholecystitis results from a combination of mechanical, biochemical, and infectious mechanisms, initiated by stone impaction in the cystic duct. After instituting empiric antibiotics, early laparoscopic cholecystectomy should be performed. Although conversion to open cholecystectomy is more common than in chronic cholecystitis, there appears to be no increased morbidity or mortality in that setting. Acute acalculous cholecystitis usually occurs in critically ill patients and may present both a diagnostic and therapeutic dilemma. Aggressive management, however, is warranted, both because of the critical nature of illness in these patients and the high incidence of perforation. Percutaneous cholecystostomy is indicated, particularly in high-risk patients both for diagnosis and treatment. Acute cholangitis results from a combination of bactibilia and biliary obstruction. The majority of patients can be successfully managed with intravenous antibiotics and fluid resuscitation. In those patients in whom initial management is not successful, biliary drainage, which is best accomplished nonoperatively, should be instituted. There is a very limited role for early surgical intervention in acute suppurative cholangitis. Biliary leaks resulting in bile “peritonitis” or bilomas are common sequelae of laparoscopic bile duct injury. Although surgeons may feel it is necessary to operate urgently, delineation of the proximal biliary anatomy via percutaneous transhepatic cholangiography and biliary stent placement is the appropriate first step in management. This procedure will usually control the bile leak and allow delineation of the anatomy and opportune timing of definitive reconstruction.
Acute Pancreatitis: Management of Complicating Infection
Authors: Laws Henry L. , Kent Raleigh B.
Published: November 2022

Acute pancreatitis develops precipitously, changing the patient's condition from apparent good health to a critically ill status. Of patients who succumb, 80 per cent die from secondary infection in the pancreas-peripancreatic area. Infection supervenes in the second week or later after onset. Prophylactic antibiotic(s) appear to be helpful in avoiding, delaying, and/or lessening secondary sepsis. Once infection develops, treatment requires open debridement of necrotic material, drainage, and appropriate antibiotic therapy; or mortality will approach 100 per cent. Infecting organisms are commonly Escherichia coli, Klebsiella, Staphylococcus, Enterococcus, Bacteroides, and/or fungi. Antibiotics felt to be preferable for prophylactic therapy include 1) imipenem-cilastatin, 2) a quinolone + metronidazole, and 3) possibly an extended-spectrum penicillin. Treatment should be continued for 2 weeks or until recovery. Because fungus infections are occurring more often, prophylaxis with fluconazole may be warranted.
Hepatitis: Risks for the Surgeon
Authors: Fry Donald E.
Published: November 2022

Six different hepatitis viruses have now been characterized. Hepatitis B and C are the two hepatitis infections that are of greatest concern for surgeons. Hepatitis B and C share several features that have led to this concern. Both are blood-borne infections. Both are associated with chronic infection ultimately leading to cirrhosis, portal hypertension, and hepatocellular carcinoma, and both can be occupational infections for the surgeon after percutaneous injury associated with infected blood. Chronic hepatitis B infection is seen in 1.25 million people in the U.S. It is associated with a transmission rate to healthcare workers of 25 to 30 per cent following a hollow needle stick injury. Five per cent of acute infections result in chronic disease. It can be effectively prevented as an occupational infection by vaccination with the highly effective hepatitis B vaccine. Chronic hepatitis C infection is present in nearly 4 million people in the U.S. It has a lower rate of transmission than hepatitis B following needle stick injury, but it has a 50 to 80 per cent rate of chronic disease after acute infections. There is no vaccine for hepatitis C, and only prevention of blood exposure will avoid the risks of this occupational infection. Other hepatitis viruses are likely to be identified. Prevention of blood exposure, by the better use of barriers in the operating room and modification of surgical techniques, is recommended to prevent occupational infection from both known and unknown blood-borne viruses from the surgical patient.
Experience with Pneumonia in Acutely Burned Patients Requiring Ventilator Support
Authors: Still Joseph , Newton Terry , Friedman Bruce , Furhman Steve , Law Edward , Dawson John
Published: November 2022

Acutely burned patients requiring ventilatory support who developed pneumonia while in the hospital were retrospectively reviewed. The Centers for Disease Control and Prevention (CDC) clinical criteria for pneumonia are based on clinical findings, radiographic findings, and culture data. During an 18-month period, 784 burn patients were admitted. Of these, 145 (18.5%) were placed on ventilators for at least 1 day. Fifty-three (36.6%) patients on ventilators developed acute pneumonia based on CDC criteria. Identification of causative organisms was based on positive cultures from blood or endotracheal aspiration within 3 days of the diagnosis of pneumonia. Thirty-nine patients were diagnosed as having inhalation injury. Forty-seven patients were placed on ventilatdrs before or on the day of admission. Ages ranged from 2 to 82 years (mean, 39). Burn size ranged from 2 to 85 per cent (mean, 29.7%) of total body surface area. The total number of ventilator days was 1310 for the 53 patients, with a mean of 27.7 days. Ten patients had positive blood cultures during the period in which pneumonia was present. Thirty-one different organisms were recovered from blood or tracheal aspirates. The most commonly recovered organism was Pseudomonas aeruginosa. In 30 incidences, polymicrobial cultures were encountered. Initiation of appropriate antimicrobial therapy was begun on the basis of clinical impression and current burn unit experience and revised on the basis of the culture data. Of the 53 patients, 13 (25.5%) died, all while still on ventilators. The other 40 patients survived. Thirty-four were weaned off their ventilators, and 6 were transferred while still on ventilator support.
Empyema and Restrictive Pleural Processes after Blunt Trauma: An Under-Recognized Cause of Respiratory Failure
Authors: Watkins James A. , Spain David A. , Richardson J. David , Polk Hiram C.
Published: November 2022

Respiratory failure is a common complication among patients sustaining major blunt trauma. This is usually due to the underlying pulmonary injury, pneumonia, or adult respiratory distress syndrome. However, we have frequently found these patients to actually have a pleural process as the cause of their respiratory failure. Our objective was to assess the frequency of empyema and restrictive pleural processes after blunt trauma and their contribution to respiratory failure. We retrospectively reviewed all blunt trauma patients over a 5-year period who required a thoracotomy and decortication for empyema. Twenty-eight patients with blunt trauma required a thoracotomy and decortication for empyema. The most common finding was infected, loculated hemothorax/effusion in 23 patients, whereas 5 had an associated pneumonia. Chest radiographs were nondiscriminating, whereas CT scans in 25 patients showed previously unrecognized fluid collections, air-fluid levels, or gas bubbles. Neither thoracentesis nor placement of additional chest tubes was helpful. Positive cultures were uncommon. Ventilator dependence was present preoperatively in 13 patients who were on the ventilator an average of 13 days preoperatively and only 5.8 days postoperatively. Several patients believed to have adult respiratory distress syndrome were weaned within 72 hours of operation. All patients were ultimately cured. Empyema is an under-recognized complication of blunt trauma and may contribute to respiratory failure and ventilator dependence. Although difficult to diagnose, empyema should be considered in blunt trauma patients with respiratory failure and an abnormal chest radiograph. CT aids in the diagnosis, and the results of surgical treatment are excellent.
The Use of Water-Soluble Contrast in Evaluating Clinically Equivocal Small Bowel Obstructions
Authors: Blackmon Shanda , Lucius Chris , Wilson John P. , Duncan Titus , Wilson Russell , Mason Edward M. , Ramshaw Bruce
Published: November 2022

This study seeks to determine whether a 6-hour abdominal radiograph after oral Gastrografin is a reliable indicator for nonoperative treatment in patients with a clinically equivocal small bowel obstruction. We collected retrospective data from medical records. Patients who received a Gastrografin transit time (GGTT) study between January 1995 and September 1998 were included in the study. Patients who did not appear to be obvious operative candidates, but had signs of intestinal obstruction, underwent a GGTT study. Serial plain abdominal radiographs were taken. If the contrast was in the colon within 6 hours, then the result was negative. A total of 418 GGTT studies were reviewed. Contrast reached the colon within 6 hours in 283 (68%) patients, and 247 (88%) of these patients were managed nonoperatively. The positive predictive value, negative predictive value, sensitivity, and specificity of Gastrografin reaching the colon within 6 hours were 48, 87, 64, and 78, respectively. False negatives included high-grade partial obstructions that ultimately required surgery. Recent operation preceded the GGTT in 128 (31%) cases. Of these 128 patients, only 17 (14%) received an operation. Although the decision to operate or not should never be based on a GGTT study alone, GGTT studies are of significant help in the clinical management of patients suspected to have a small bowel obstruction. GGTT allows for the judicious selection of the appropriate patient for nonoperative management. GGTT studies are cost effective, safe, and clinically useful when attempting to treat patients conservatively.
Choledocholithiasis: Evolving Intraoperative Strategies
Authors: Ponsky Jeffrey L. , Heniford B. Todd , Gersin Keith
Published: November 2022

In the era of open cholecystectomy, common bile duct stones were approached by traditional choledocholithotomy. Retained or recurrent stones discovered after cholecystectomy were approached by endoscopic extraction techniques or repeat surgery. With the advent of laparoscopic cholecystectomy, the approach to choledocholithiasis became more problematic as techniques for laparoscopic extraction were rudimentary. Preoperative endoscopic retrograde cholangiopancreatography rapidly became an adjunct to laparoscopic cholecystectomy when common duct stones were likely. Experience, however, revealed that many of these procedures were unnecessary. With developing sophistication of laparoscopic techniques, a variety of approaches to common duct stones developed. These included: transcystic extraction, direct laparoscopic choledocholithotomy, intraoperative endoscopic retrograde cholangiopancreatography, antegrade sphincterotomy, and transcystic placement of a common duct stent with subsequent endoscopic sphincterotomy and stone extraction. It is the purpose of this article to define the current role of each of these methods in the laparoscopic approach to choledocholithiasis.
Initial Neck Exploration for Untreated Hyperparathyroidism
Authors: Martin Robert C.G. , Greenwell Darren , Flynn Michael B.
Published: November 2022

This study represents the experience of the Department of Surgery at the University of Louisville over a 21-year interval. Many aspects of surgical management of hyperparathyroidism have changed over the last 2 decades; controversies regarding the extent of exploration and the value of preoperative localization studies remain unresolved. One hundred ninety-three patients underwent neck exploration for hyperparathyroidism from 1976 to 1997. Data were collected from four University of Louisville-affiliated hospitals by independent evaluators. One hundred sixty patients with untreated hyperparathyroidism underwent neck exploration. Preoperative localization was carried out in 52 per cent (83 of 160). The exact location of the abnormal gland was indicated in 55 per cent (46 of 83), and the correct side of the neck was identified in 74 per cent (61 of 83). Technetium sestamibi scan was most reliable and identified the abnormality in 83 per cent (24 of 29). The average operative time with preoperative localization was 118 minutes compared with 137 minutes without preoperative localization. Intraoperative methylene blue was used in 42 of 160 neck explorations. Average operative time with methylene blue was 102 minutes compared with 124 minutes without methylene blue. Thirty-seven per cent (59 of 160) of patients underwent unilateral neck exploration. Sixty-three per cent (101 of 160) underwent bilateral exploration. Successful exploration was conducted in 98 per cent of the unilateral group and 91 per cent of the bilateral group. Postoperative local complications were essentially the same in both groups (3%), whereas temporary hypocalcemia occurred in 24 per cent (24 of 101) of the bilateral group compared with 3 per cent (2 of 59) of the unilateral group. We conclude that neck exploration for hyperparathyroidism is a highly successful, safe treatment with no mortality and minimal morbidity. Preoperative localization studies modestly reduced the duration of surgery without improving outcome.
Clearing the Cervical Spine in Victims of Blunt Assault to the Head and Neck: What is Necessary?
Authors: Patton Joe H. , Kralovich Kurt A. , Cuschieri Joseph , Gasparri Mario
Published: November 2022

A number of guidelines have been proposed to aid in determining the need for radiologic evaluation of the cervical spine (c-spine) in victims of blunt trauma. Mechanism of injury has not been shown to be an independent predictor of injury or the lack thereof. The current study was undertaken to determine the incidence of clinically relevant c-spine injuries in patients who sustained a blunt assault to the head and neck. The trauma registry of an urban Level 1 trauma center was used to identify patients who suffered a blunt assult to the head and neck and were admitted to the hospital over a 30-month period. One hundred two patients were identified. Only 8 patients met criteria for clinical clearance of the c-spine. Eighty patients were unable to be evaluated because of head injury or intoxicants; 14 patients had neck pain on initial examination. These 94 patients underwent plain film examination of their c-spine. Twelve required CT scanning to supplement visualization. The possibility of ligamentous injury was investigated by MRI or flexion/extension radiographs in 26 patients. No clinically significant c-spine injuries were identified. Although many victims of a blunt assault to the head and neck region may have a decreased LOC or neck pain, the likelihood of a ligamentous injury is so low that plain-film X-ray evaluation of the c-spine is all that is necessary to rule out injury in this patient population.
Nonoperative Management of Blunt Liver Trauma: The Value of Follow-Up Abdominal Computed Tomography Scans
Authors: Cuff Robert F. , Cogbill Thomas H. , Lambert Pamela J.
Published: November 2022

Our hypothesis was that follow-up abdominal CT scans are not routinely necessary in patients with blunt liver injury treated nonoperatively. We conducted an 8-year retrospective review of hospital chart and outpatient clinic records. We reviewed all admission and follow-up CT scans. There were 42 adults and 12 children. There were 1 (2%) grade I, 15 (28%) grade II, 28 (52%) grade III, 8 (15%) grade IV, and 2 (4%) grade V liver injuries. Two patients died during the first 24 hours, both from associated injuries. Nonoperative management was successful in 51 (98%) of the remaining 52 patients. No follow-up abdominal CT scans were performed on 21 (40%) patients; none developed hepatic complications. An initial follow-up CT scan was obtained in 31 (60%) patients. Information from these scans directly affected management in 3 (9%) patients; in each case, the scans were prompted by a change in clinical status. One significant biloma with bile leak was managed by nasobiliary stenting and percutaneous drainage. One hepatic artery-to-portal vein fistula was obliterated by transarterial embolization. A single missed diaphragm rupture necessitated laparotomy. Additional late follow-up CT scans were obtained in 13 patients; no clinically useful information was evident on any of these examinations. We conclude that follow-up abdominal CT scans are not routinely necessary in patients with liver injuries treated nonoperatively. Selective criteria based on the severity of liver injury, presence of associated intraabdominal pathology, and clinical parameters should dictate the need for follow-up imaging studies.