Accuracy of Pulse Oximetry for Long-Term Oxygen Therapy Assessment in Chronic Obstructive Pulmonary Disease.

Rationale: Landmark studies of long-term oxygen therapy (LTOT) in patients with chronic obstructive pulmonary disease (COPD) used arterial oxygen pressure (PaO2) to define severe hypoxemia; however, oxygen saturation as measured by pulse oximetry (SpO2) is commonly used instead. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines recommend evaluation with arterial blood gas (ABG) analysis if SpO2 is ⩽92%. This recommendation has not been evaluated in stable outpatients with COPD undergoing testing for LTOT. Objectives: To evaluate the performance of SpO2 compared with ABG analysis of PaO2 and arterial oxygen saturation (SaO2) to detect severe resting hypoxemia in patients with COPD. Methods: Retrospective analysis of paired SpO2 and ABG values from stable outpatients with COPD who underwent LTOT assessment in a single center. We calculated false negatives (FNs) as an SpO2 >88% or >89% in the presence of pulmonary hypertension with a PaO2 ⩽55 mm Hg or ⩽59 mm Hg in the presence of pulmonary hypertension. Test performance was assessed using receiver operating characteristic (ROC) analysis, intraclass correlation coefficient (ICC), test bias, precision, and accuracy root-mean-square (Arms). An adjusted multivariate analysis was used to evaluate factors affecting SpO2 bias. Results: Of 518 patients, the prevalence of severe resting hypoxemia was 74 (14.3%), with 52 missed by SpO2 (FN, 10%), including 13 (2.5%) with an SpO2 > 92% (occult hypoxemia). FNs and occult hypoxemia in Black patients were 9% and 1.5%, respectively, and were 13% and 5%, respectively, among active smokers. The correlation between SpO2 and SaO2 was acceptable (ICC = 0.78; 95% confidence interval, 0.74-0.81); and the bias of SpO2 was 0.45%, with a precision of 2.6 (-4.65 to +5.55%) and Arms of 2.59. These measurements were similar in Black patients, but in active smokers, correlation was lower and bias showed greater overestimation of SpO2. ROC analysis suggests that the optimal SpO2 cutoff to warrant LTOT evaluation by ABG analysis is ⩽94%. Conclusions: SpO2 as the only measure of oxygenation carries a high FN rate in detecting severe resting hypoxemia in patients with COPD undergoing evaluation for LTOT. Reflex measurement of PaO2 by ABG analysis should be used as recommended by GOLD, ideally at a cutoff higher than an SpO2 ⩽92%, especially in active smokers.

Clinical Spectrum and Outcomes of Cryptogenic Klebsiella pneumoniae Liver Abscess in the Americas: A Scoping Review.

(1) Background: Cryptogenic Klebsiella pneumoniae liver abscesses are an invasive infection with or without extra hepatic involvement in the absence of hepatobiliary disease or abdominal malignancy. Most of the evidence has emanated from reports from Asia, and previous studies in the Americas have limited clinical characterization. (2) Methods: To understand this syndrome's characteristics on our continent, we conducted a scoping review to identify adult cases of idiopathic, community-acquired monomicrobial K. pneumoniae liver abscess in the Americas. (3) Results: We identified 144 cases spanning 1978-2022. Most cases were reported in males that had traveled or migrated from Southeast or East Asia with diabetes mellitus. Extrahepatic involvement and bacteremia were common, including seeding to the lungs, ocular structures, and central nervous system. Although limited by sample size, the most commonly reported genes were magA or rmpA. Concomitant percutaneous drainage and third generation cephalosporins (alone or in combination with other antibiotics) were frequently used, yet pooled fatality occurred in 9% of the reported cases. (4) Conclusions: The features of cryptogenic K. pneumoniae liver abscess in the Americas mirror those described in Asia, confirming its global dissemination. This condition is increasingly being reported in our continent and carries significant clinical impact due to its systemic invasiveness.

NLRP3 inflammasome is a key driver of obesity-induced atrial arrhythmias.

AIMS: Obesity, an established risk factor of atrial fibrillation (AF), is frequently associated with enhanced inflammatory response. However, whether inflammatory signaling is causally linked to AF pathogenesis in obesity remains elusive. We recently demonstrated that the constitutive activation of the 'NACHT, LRR, and PYD Domains-containing Protein 3' (NLRP3) inflammasome promotes AF susceptibility. In this study, we hypothesized that the NLRP3 inflammasome is a key driver of obesity-induced AF. METHODS AND RESULTS: Western blotting was performed to determine the level of NLRP3 inflammasome activation in atrial tissues of obese patients, sheep, and diet-induced obese (DIO) mice. The increased body weight in patients, sheep, and mice was associated with enhanced NLRP3-inflammasome activation. To determine whether NLRP3 contributes to the obesity-induced atrial arrhythmogenesis, wild-type (WT) and NLRP3 homozygous knockout (NLRP3-/-) mice were subjected to high-fat-diet (HFD) or normal chow (NC) for 10 weeks. Relative to NC-fed WT mice, HFD-fed WT mice were more susceptible to pacing-induced AF with longer AF duration. In contrast, HFD-fed NLRP3-/- mice were resistant to pacing-induced AF. Optical mapping in DIO mice revealed an arrhythmogenic substrate characterized by abbreviated refractoriness and action potential duration (APD), two key determinants of reentry-promoting electrical remodeling. Upregulation of ultra-rapid delayed-rectifier K+-channel (Kv1.5) contributed to the shortening of atrial refractoriness. Increased profibrotic signaling and fibrosis along with abnormal Ca2+ release from sarcoplasmic reticulum (SR) accompanied atrial arrhythmogenesis in DIO mice. Conversely, genetic ablation of Nlrp3 (NLRP3-/-) in HFD-fed mice prevented the increases in Kv1.5 and the evolution of electrical remodeling, the upregulation of profibrotic genes, and abnormal SR Ca2+ release in DIO mice. CONCLUSION: These results demonstrate that the atrial NLRP3 inflammasome is a key driver of obesity-induced atrial arrhythmogenesis and establishes a mechanistic link between obesity-induced AF and NLRP3-inflammasome activation.

Treatment with a DC-SIGN ligand reduces macrophage polarization and diastolic dysfunction in the aging female but not male mouse hearts.

Cardiac diastolic dysfunction in aging arises from increased ventricular stiffness caused by inflammation and interstitial fibrosis. The diastolic dysfunction contributes to heart failure with preserved ejection fraction (HFpEF), which in the aging population is more common in women. This report examines its progression over 12 weeks in aging C57BL/6J mice and correlates its development with changes in macrophage polarization and collagen deposition.Aged C57BL/6J mice were injected with dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) ligand 1 (DCSL1, an anti-inflammatory agent) or saline for 12 weeks. Echo and Doppler measurements were performed before and after 4 and 12 weeks of treatment. DCSL1 prevented the worsening of diastolic dysfunction over time in females but not in males. Cardiac single cell suspensions analyzed by flow cytometry revealed changes in the inflammatory infiltrate: (1) in males, there was an increased total number of leukocytes with an increased pro-inflammatory profile compared with females and they did not respond to DCSL1; (2) by contrast, DCSL1 treatment resulted in a shift in macrophage polarization to an anti-inflammatory phenotype in females. Notably, DCSL1 preferentially targeted tumor necrosis factor-α (TNFα+) pro-inflammatory macrophages. The reduction in pro-inflammatory macrophage polarization was accompanied by a decrease in collagen content in the heart.Age-associated diastolic dysfunction in mice is more severe in females and is associated with unique changes in macrophage polarization in cardiac tissue. Treatment with DCSL1 mitigates the changes in inflammation, cardiac function, and fibrosis. The characteristics of diastolic dysfunction in aging female mice mimic similar changes in aging women.

En nuestra escuela esto no pasa: percepciones sobre la deshonestidad académica con estudiantes de medicina / This does not happen at our school: Perceptions about academic dishonesty with medical students

INTRODUCCIÓN: La deshonestidad académica se refiere a copiar en una prueba, plagiar, falsificar resultados de una investigación o conseguir anticipadamente resultados de actividades o exámenes; sin embargo, algunas conductas parecen no ser consideradas como deshonestas por los estudiantes. Se sabe que prevalecen dentro de muchos niveles y áreas del conocimiento, pero no se conocen las percepciones de estudiantes respecto al impacto en su aprendizaje. El objetivo del estudio fue evaluar la percepción que los estudiantes tienen sobre la deshonestidad académica observable cuando comparten el contenido de los casos y actividades de un curso con compañeros de generaciones posteriores. MATERIAL Y MÉTODO: El diseño fue cuantitativo y descriptivo, utilizando encuestas aplicadas a 3 generaciones (2014, 2016 y 2017) dentro de un curso de patología. Se incluyó ítems relacionados con deshonestidad académica y su impacto en la resolución de los casos. Para el análisis se utilizó una escala que determina las tendencias en las aseveraciones como honestos +1 y deshonestos como -1. RESULTADOS: La participación fue del 84%, 99% y 50%, respectivamente. A pesar de que la mayoría (40%) refirió no obtener beneficio en el aprendizaje al compartir el material, las generaciones más recientes demuestran una tendencia hacia el polo de conductas deshonestas (-0,124, -0,509 y -0,562). CONCLUSIONES: La intención de los alumnos al compartir las actividades fue disminuir el tiempo que sus compañeros invierten en buscar información del caso al comparar sus respuestas; sin embargo, refieren que el aprendizaje total del tema no aumenta como resultado de sus prácticas. Futuras intervenciones son necesarias para realizar difusión de ejemplos concretos relacionados con el concepto, para que interioricen los resultados sobre el beneficio en su aprendizaje y el significado de la integridad académica

INTRODUCTION: Academic dishonesty includes copying, plagiarising, or falsifying the results of an investigation, or obtaining the correct answers for activities or exams from peers that have already answered them. However, some of these behaviours do not appear to be considered as dishonest by students. Although it is known that this prevails within many levels and areas of knowledge, students' perceptions of the impact of this on their learning process are not known. The aim of this study was to evaluate the perception that students have about academic dishonesty when sharing course material with other students. MATERIAL AND METHOD: The design was quantitative and descriptive using questionnaires applied to students of 3 different years (2014, 2016 and 2017) during a pathology course. These included items related to academic dishonesty and its impact on the resolving of cases. A scale was used to classify the honest results as+1 and the dishonest ones as -1. RESULTS: Participation was 84%, 99% and 50%, respectively. Although the majority (40%) reported not benefiting from learning by sharing material, more recent generations show a greater tendency towards dishonesty (-0.124, -0.509, and -0.562). CONCLUSION: The intention of the students when sharing activities was to reduce the time that their classmates invest in looking for information by comparing their answers. However, they report that the total learning of the subject does not increase. Future interventions are necessary to transmit clear examples related to the concept so that they can internalise the results regarding the benefit to their learning, and the meaning of academic integrity

Primeros encuentros clínicos con pacientes: un estudio de la neurofobia y empatía en estudiantes de medicina / First clinical encounters with patients: A study of neurophobia and empathy in medical students

INTRODUCCIÓN: El temor hacia las neurociencias y a la neurología clínica por parte de los estudiantes, mejor conocido como neurofobia, dificulta la relación médico-paciente. La ansiedad creada en los encuentros clínicos obstaculiza el manejo efectivo y la creación de lazos como la empatía. El objetivo de este estudio fue evaluar los niveles de neurofobia y empatía que los estudiantes de medicina demuestran hacia los pacientes en el servicio de neurología. MATERIAL Y MÉTODOS: El diseño de la investigación fue cuantitativo, descriptivo y transeccional, con una muestra de 98 estudiantes del programa de medicina de una universidad privada. Se adaptó un instrumento y se utilizaron 19 ítems con posterioridad al encuentro clínico. RESULTADOS: Se encontró evidencia de neurofobia, siendo esta de mayor grado en mujeres. También se observaron altos niveles de empatía en los alumnos, los hombres presentaron un nivel de empatía significativamente menor. DISCUSIÓN: Los estudiantes presentaron evidente preocupación sobre su capacidad de manejar pacientes con enfermedad neurológica de forma autodirigida. Los resultados sobre empatía fueron más favorables que en otros estudios. Futuros trabajos pudieran adentrarse en el análisis de si estos niveles son sostenibles a largo plazo

INTRODUCTION: Fear of neurosciences and clinical neurology of students, best known as neurophobia, affects the doctor-patient relationship. The anxiety of clinical encounters interferes with effective management and the creation of inter-personal bonding, such as empathy towards patients. The objective of this study was to assess the levels of neurophobia and empathy that medical students show towards patients in the Neurology Department. MATERIAL AND METHODS: A quantitative, descriptive and cross-sectional study was conducted on a sample of 98 students of a private university. A clinical encounter evaluation tool was adapted and 19 items were then used to assess it afterwards. RESULTS: There was evidence of neurophobia, existing in a greater degree in female students. High levels of empathy were observed, although there were significantly lower levels shown by males. DISCUSSION: The students have an obvious concern as regards their ability to manage patients with neurological disease in a self-directed manner. The results regarding empathy were more favourable than previous studies. Future research must analyse these levels further, questioning if these could be preserved in the long-term