[Predictive value of C-reactive protein on hospital admission and mechanical ventilation requirement in adults hospitalized for COVID-19] / Valor predictivo de proteína C reactiva al ingreso sanatorial y requerimiento de asistencia respiratoria mecánica en adultos internados por COVID-19.

Introduction: During the COVID-19 pandemic, patients with worse evolution presented clinical deterioration 7-10 days after the onset of symptoms, which suggests that the inflammatory response could participate in the pathophysiology of the disease. The objective of this study was to evaluate the association between plasma C-reactive protein (PCr) on hospital admission and mechanical ventilation requirement during hospitalization in adults with COVID-19. Methods: Retrospective, observational cohort at a private center in the province of Buenos Aires. Hospitalized adults diagnosed with COVID-19 by nasal swab using real time transcription polymerase chain reaction or antigen were included. The primary outcome was the association between high plasma PCr values on hospital admission (≥8 mg/L) and mechanical ventilation requirement during hospitalization. Results: Of the 1,242 patients enrolled, 19.4% required mechanical ventilation and 11.7% died during the hospitalization. The PCr of the patients who required mechanical ventilation was higher than that of those who did not require mechanical ventilation (9.45 [5.20-18.70] mg/L vs 4.95 [1.80-10.70] mg/L; p < 0.01). PCr analyzed as a continuous variable (OR = 1.39; 95%CI 1.21-1.60; p < 0.001) and as a categorical variable (≥8 mg/L) (OR = 2.66; 95%CI 2.19 -3.78, p < 0.001) presented a significant association with the requirement of mechanical ventilation during hospitalization. Additionally, a significant association was found between PCr and in-hospital mortality. Conclusion: Plasma PCr on hospital admission could predict clinical evolution in adult patients hospitalized for COVID-19.

Introducción: Durante la pandemia por COVID-19, los pacientes con peor evolución presentaron deterioro clínico a los 7-10 días del inicio de síntomas, lo cual sugiere que la respuesta inflamatoria podría participar de la fisiopatogenia de la enfermedad. Objetivo: El objetivo de este estudio fue evaluar la asociación entre los valores de proteína C reactiva (PCr) en plasma al ingreso sanatorial en adultos con COVID-19 y el requerimiento de asistencia respiratoria mecánica (ARM) durante la internación. Métodos: Cohorte retrospectiva, observacional, en un centro privado de la provincia de Buenos Aires. Se incluyeron a adultos internados con diagnóstico de COVID-19 por hisopado nasal, mediante real time transcription polymerasa chain reaction o antígeno. El desenlace primario fue la asociación entre valores altos de PCr en plasma al ingreso sanatorial (≥8 mg/L) y el requerimiento de ARM durante la internación. Resultados: De los 1.242 pacientes enrolados, 19,4% requirieron ARM y 11,7% fallecieron durante la internación. La PCr de los pacientes que requirieron ARM fue mayor que la de los que no la requirieron (9,45 [5,20-18,70] mg/L vs 4,95 [1,80-10,70] mg/L; p < 0,01). La PCr analizada como variable continua (OR = 1,39; IC95% 1,21-1,60; p < 0,001) y como variable categórica (≥8 mg/L) (OR = 2,66; IC95% 2,19-3,78; p < 0,001) presentó una asociación significativa con el requerimiento de ARM durante la internación. Secundariamente, se encontró una asociación significativa entre PCr y mortalidad intrahospitalaria. Conclusión: El valor de PCr en plasma al ingreso sanatorial podría predecir la evolución clínica en pacientes adultos internados por COVID-19. Resultados: De los 1.242 pacientes enrolados, 19,4% requirieron ARM y 11,7% fallecieron durante la internación. La PCr de los pacientes que requirieron ARM fue mayor que la de los que no la requirieron (9,45 [5,20-18,70] mg/L vs 4,95 [1,80-10,70] mg/L; p < 0,01). La PCr analizada como variable continua (OR = 1,39; IC95% 1,21-1,60; p < 0,001) y como variable categórica (≥8 mg/L) (OR = 2,66; IC95% 2,19-3,78; p < 0,001) presentó una asociación significativa con el requerimiento de ARM durante la internación. Secundariamente, se encontró una asociación significativa entre PCr y mortalidad intrahospitalaria. Conclusión: El valor de PCr en plasma al ingreso sanatorial podría predecir la evolución clínica en pacientes adultos internados por COVID-19.

Predictive Factors for Physiotherapy Session Length at an Adult Intensive Care Unit: A Longitudinal Panel Study.

OBJECTIVE: To identify predictive factors for the length of physiotherapy sessions for adult intensive care unit (ICU) patients. DESIGN: Longitudinal panel study. SETTING: ICU of a secondary-care public teaching hospital, the University Hospital at the University of Sao Paulo, Brazil. PARTICIPANTS: Medical and surgical patients who received physiotherapy (N=181) assessed in 339 physiotherapy sessions. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The study investigator followed physiotherapists during their work shift and timed the physiotherapy session's length with a stopwatch. The association between session length and patient, physiotherapist, and service-related factors was evaluated by a mixed model. RESULTS: Assessed in this study were 339 physiotherapy sessions during 79 periods of observation that involved 181 patients and 19 physiotherapists. Median session length was 29 (interquartile range: 22.6-38.9) minutes; median number of patients assisted per physiotherapist per 6-hour shift was 5 (4-5). Physiotherapist's median age was 35 (26-39) years old, and median ICU experience was 13.0 (0.4-16.0) years. Patients were mostly older adults who were post surgery and had been at the ICU for 5 (2-9) days. Factors associated with physiotherapy session length (min) were the following: performing both motor- and respiratory-related physiotherapy procedures during the session (ß=6.5; 95% confidence interval [CI], 3.8-9.2), altered chest x-ray (ß=2.8; 95% CI, 0.3-5.3), ICU mobility scale (IMS) (ß=1.2; 95% CI, 0.4-2.0), contraindication to any level of out-of-bed mobilization (ß=-6.9; 95% CI, -10.5 to -3.3), afternoon shift (ß=-4.0; 95% CI, -6.7 to -1.4), and Barthel index (ß=-0.2; 95% CI, -0.3 to -0.1). CONCLUSIONS: The factors associated with longer session lengths were performing both motor- and respiratory-related physiotherapy procedures during the session, altered chest x-ray, and the IMS. Contraindication to any level of out-of-bed mobilization and sessions performed during the afternoon shift (vs the morning shift) were associated with shorter session lengths.

Ayudantías universitarias: influencia académica percibida en el desempeño en el examen de residencias médicas municipales / Teaching assistants: perceived academic influence on performance in municipal medical residency exams

Introducción: el ejercicio de la docencia universitaria por parte de estudiantes de Medicina ofrecería múltiples beneficios. Sin embargo, no hay evidencia de que mejore el desempeño en los exámenes estandarizados en el posgrado. El objetivo de este estudio fue describir la diferencia de los puntajes en el examen de residencias médicas municipales entre ayudantes y no ayudantes, y evaluar la autopercepción del efecto de ser ayudante sobre el desempeño en dicho examen y sobre las habilidades académicas. Métodos: estudio observacional, descriptivo, de corte transversal, con un muestreo por conveniencia de médicos participantes del examen de residencias médicas municipales de la Ciudad Autónoma de Buenos Aires (CABA) de 2018, a partir del listado oficial. Se excluyeron aquellos a quienes fue imposible contactar, que se negaran a participar o cuya identidad discrepara con la de la persona seleccionada para incluir en el estudio. Resultados: de los 3579 médicos que concursaron en el examen de residencias médicas básicas municipales de CABA 2018, se tomó una muestra aleatoria de 300 sujetos, de los cuales se contactó a 87. De ellos, 20 sujetos cumplían con criterios de exclusión; por lo tanto fueron 67 sujetos los que finalmente participaron del estudio. La proporción de respuestas con respecto a los sujetos que pudieron ser contactados mediante redes sociales fue 77%. El puntaje de examen entre los ayudantes fue de 32,3 ± 5,7 puntos mientras que entre los no ayudantes fue 29,5 ± 6,1 puntos. Entre los ayudantes, el 68% informó percibir que el hecho de haber realizado una ayudantía en el pregrado tuvo un efecto de levemente a muy positivo sobre su desempeño en el examen, un 76% refirió la profundización de conocimientos específicos, el 73% informó una mejoría en sus habilidades comunicacionales y el 59% una mayor capacidad para jerarquizar contenidos. Conclusión: el desarrollo de una actividad docente en el pregrado sería percibida por quienes la desarrollan como una actividad promotora de habilidades comunicacionales y de jerarquización de contenidos y, ulteriormente, como una influencia positiva en el desempeño académico en el examen de residencias médicas municipales. Estas conclusiones deben confirmarse con estudios futuros. (AU)

Introduction: medical students could benefit from teaching university courses. However, there is no evidence showing that this activity improves academic performance on standardized tests in graduate school. The objective of this study was to describe the differences in scores on the municipal medical residency exam between physicians who were teaching assistants and those who weren't, and to evaluate the self-perception of the effect of being a teaching assistant on the performance on this exam and on academic skills in general. Methods: this is an observational, descriptive, cross-sectional study, with a convenience sample of physicians participating in the 2018 municipal medical residency exam of the Autonomous City of Buenos Aires (CABA) based on official lists. Those who could not be contacted, refused to participate, or whose identity diverged from the person selected to include in the study, were excluded. Results: of the 3,579 physicians who participated in the basic municipal medical residency exam in CABA 2018, a random sample of 300 subjects was taken, of which 87 were contacted. Of those, 20 subjects met the exclusion criteria, having 67 subjects finally participating in the study. The proportion of subjects who could be contacted through social networks was 77%. The exam score among physicians who were teaching assistants was 32.3 ± 5.7 points while among the non-teaching assistants it was 29.5 ± 6.1 points. Among the teaching assistants, 68% perceived that the fact of having been a teaching assistant as an undergraduate had a slight to very positive effect on their performance in the exam, 76% referred the deepening of their specific knowledge on the subject they taught, 73% reported an improvement in their communication skills, and 59% referred a greater ability to rank content. Conclusions: undergraduate teaching would be perceived as an activity that promotes communication skills and ability to rank content and, therefore, as a positive influence on academic performance in the municipal medical residency exam. These conclusions need to be confirmed with future studies. (AU)

Hemodynamically significant prosthesis-patient mismatch can be predicted and is associated with early prosthetic valve dysfunction in aortic bioprosthesis.

OBJECTIVES: To evaluate the accuracy of predicted prosthesis-patient mismatch (PPM) regarding actual PPM measured postoperatively. To assess the association between PPM and prosthetic valve dysfunction. METHODS: Retrospective cohort study including adult patients after aortic valve replacement surgery with a biological prosthesis. Predicted PPM status was determined using mean reference effective orifice area indexed to total body surface (iEOA), without considering reference standard deviations. Postoperative PPM status was determined by measuring iEOA within the first 60 postoperative days. Prosthetic valve dysfunction was defined as thrombosis, pannus, valve degeneration, and/or disruption. RESULTS: 205 patients were enrolled between January 2003 and June 2017: predicted PPM was absent in 52 patients (25.4%), moderate in 137 patients (66.8%), and severe in 16 patients (7.8%). After surgery, the actual postoperative iEOA was measured: 53 (25.9%) did not have PPM, 73 had moderate PPM (35.6%), and 79 had severe PPM (38.5%). Predicted PPM identified the presence of hemodynamically significant actual postoperative PPM (OR = 2.56; 95%CI 1.30-5.05; P = .006), though not its degree of severity. Prosthetic valve dysfunction was more frequent among patients with hemodynamically significant PPM (53.9% vs. 11.3%; P < .001), compared to those without PPM. The association between PPM and prosthetic valve dysfunction was maintained after adjusting for gender, age, and ever-smoking (OR = 9.03; P < .001). The incidence of thrombosis or pannus was also nonsignificantly higher in patients with moderate or severe PPM. CONCLUSIONS: Predicted PPM identifies the presence, possibly not the severity, of actual postoperative PPM. Moderate or severe PPM is associated with prosthetic valve dysfunction. Actual postoperative prosthesis-patient mismatch measured within 60 postoperative days showed a distinctive hemodynamic profile and presented a stronger association with prosthetic valve dysfunction than predicted prosthesis-patient mismatch. A. Echocardiographic follow-up in patients according to the actual postoperative PPM measured within 60 postoperative days. B. Prediction of prosthetic valve dysfunction based on preoperative predicted PPM or on actual postoperative PPM within 60 postoperative days. PPM: prosthesis-patient mismatch. OR: Odds ratio.

Changes in cardiac Aquaporin expression during aortic valve replacement surgery with cardiopulmonary bypass.

OBJECTIVES: Cardiopulmonary bypass (CPB) use is an essential strategy for many cardiovascular surgeries. However, its use and duration have been associated with a higher rate of postoperative complications, such as low cardiac output syndrome due to myocardial oedema and dysfunction. Though Aquaporin water channels have been implicated in myocardial water balance, their specific role in this clinical scenario has not been established. METHODS: In a consecutive study of 17 patients with severe aortic stenosis undergoing aortic valve replacement surgery, 2 myocardial biopsies of the left ventricle were taken: 1 before and 1 after CPB use. Sociodemographic, clinical and laboratory data were collected. Western blot and immunohistochemistry studies were performed. RESULTS: After CPB use, there was a mean increase of ∼62% in Aquaporin 1 protein levels (P = 0.001) and a mean reduction of ∼38% in Aquaporin 4 protein levels (P = 0.030). In immunohistochemistry assays, Aquaporin 1 was found lining small blood vessels, while Aquaporin 4 formed a circular label in cardiomyocytes. There were no changes in the localization of either protein following CPB use. During the observed on-pump time interval, there was a 1.7%/min mean increase in Aquaporin 1 (P = 0.021) and a 2.5%/min mean decrease in Aquaporin 4 (P = 0.018). Myocardial interstitial oedema increased by 42% (95% confidence interval 31-54%) after CPB use. Patients who developed low cardiac output syndrome were in the upper half of the median percentage change of Aquaporin expression. CONCLUSION: Time-dependent changes in cardiac Aquaporin expression may be associated with myocardial oedema and dysfunction related to CPB use.

Calculation of the aortic arch angles from three-dimensional reconstructions of computed tomography scans: Comparison between an automated program and visual assessment.

BACKGROUND: The curvature of the aortic arch is associated with the risk of endoleak formation after thoracic endovascular aortic repair (TEVAR). However, the adequate assessment of the angles of the aorta continues to represent a major difficulty. We developed a new program based on three-dimensional (3D) reconstructions of computed tomography (CT) scans to objectively identify the location of the aortic points of maximum curvature, and to automatically calculate the main aortic arch angles, comparing final values with visual assessment methods. METHODS: This is a cross-sectional validation study of a convenience sample of subjects with multislice CT angiography scans of the thoracic aorta from an institutional imaging database. The center lumen line (CLL) of the aorta was determined semi-automatically using Endosize software. The points of maximum curvature on the CLL were determined by two methods: visually by two physicians and through a custom program. RESULTS: The study enrolled 9 subjects: 4 with thoracic aneurysms and 5 with normal aortas. The inter-observer and inter-method correlation, agreement and reliability for each of the 3D spatial coordinates of the points of maximum curvature were appropriate. However, the aortic angles determined by visual assessment showed a very low to moderate correlation and reliability with those determined by our custom program. CONCLUSION: An automated custom program can reflect clinician's intuitive assessment of the location of points of maximum curvature and translate it into aortic angles with an apparently higher precision, reducing potential error and user time.

Effects of Cross-Clamping on Vascular Mechanics: Comparing Waveform Analysis With a Numerical Model.

BACKGROUND: Immediate changes in vascular mechanics during aortic cross-clamping remain widely unknown. By using a numerical model of the arterial network, vascular compliance and resistance can be estimated and the time constant of pressure waves can be calculated and compared with results from the classic arterial waveform analysis. METHODS: Experimental data were registered from continuous invasive radial artery pressure measurements from 11 patients undergoing vascular surgery. A stable set of beats were chosen immediately before and after each clamping event. Through the arterial waveform analysis, the time constant was calculated for each individual beat and for a mean beat of each condition as to compare with numerical simulations. Overall proportional changes in resistance and compliance during clamping and unclamping were calculated using the numerical model. RESULTS: Arterial waveform analysis of individual beats indicated a significant 10% median reduction in the time constant after clamping, and a significant 17% median increase in the time constant after unclamping. There was a positive correlation between waveform analysis and numerical values of the time constant, which was moderate (ρ = 0.51; P = 0.01486) during clamping and strong (ρ = 0.77; P ≤ 0.0001) during unclamping. After clamping, there was a significant 16% increase in the mean resistance and a significant 23% decrease in the mean compliance. After unclamping, there was a significant 19% decrease in the mean resistance and a significant 56% increase in the mean compliance. CONCLUSIONS: There are significant hemodynamic changes in vascular compliance and resistance during aortic clamping and unclamping. Numerical computer models can add information on the mechanisms of injury due to aortic clamping.

Impacto de diferentes modalidades de evaluación en el promedio de notas de estudiantes de Medicina: un estudio de intervención no aleatorizado / Impact of different types of evaluation on the average grade of medicine students: a non-randomized interventional study

Introducción: en el proceso de enseñanza-aprendizaje existen múltiples conflictos al momento de seleccionar el tipo de evaluación que debería aplicarse a estudiantes de Medicina. Nuestro objetivo es comparar diferencias en la media de notas de tres modalidades de examen (oral, escrito para desarrollar y preguntas de opción múltiple) para así determinar cómo estas podrían afectar el desempeño de los estudiantes de Medicina en el campo de la Farmacología. Material y métodos: estudio cuasi experimental con una intervención no aleatorizada en una muestra por conveniencia de estudiantes de Medicina. A fin de evaluar diferencias en la media de notas se hizo un análisis ANOVA para muestras pareadas y luego los correspondientes tests de T para muestras pareadas. Resultados: enrolamos inicialmente a 36 estudiantes; 7 fueron excluidos (4 por ausencia y 3 por abandono), y se obtuvieron 29 participantes. La media de notas del examen oral y la de preguntas de opción múltiple fueron ambas significativamente superiores a la del examen escrito para desarrollar (oral vs. escrito: diferencia 1,8 puntos; IC 95% 0,8 a 2,7; p < 0,01; opción múltiple vs. escrito: diferencia 2,1 puntos; IC 95% 1,4 a 2,9; p < 0,01). No hubo diferencias estadísticamente significativas entre las notas medias del examen oral y del examen de preguntas de opción múltiple (p = 0,37). Conclusión: los estudiantes de Medicina obtienen peores notas en el examen escrito para desarrollar en Farmacología, en relación con los exámenes oral y de preguntas de opción múltiple. Esto posiblemente se asocie al hecho de que aquella modalidad es menos frecuentemente empleada en la carrera de Medicina. (AU)

Introduction: in the teaching-learning process, there are many problems in the selection of the most suitable type of exam for evaluating medical students. Our target was to compare differences in the average grade of medical students upon taking three different types of exam (oral, written, and multiple-choice questions) to determine how these different types of exam may affect the performance of medical students in the area of Pharmacology. Material and methods: we conducted a quasi experimental study by applying a non-randomized intervention to a convenience sample of medical students. To evaluate differences in the average grades among three groups, an ANOVA analysis was applied followed by paired T-tests. Results: we initially enrolled 36 students; 7 were excluded (4 were absent and 3 abandoned the intervention), arriving at a total sum of 29 participants. The average grades of the oral exam and multiple-choice questions were both significantly higher than the written exam (oral vs. written: difference 1.8 points; 95%CI 0.8 to 2.7, p < 0.01; multiple-choice vs. written: difference 2.1 points, 95%CI 1.4 to 2.9, p < 0.01). There were no significant differences between the average grades on the oral exam and the multiple-choice exam (p = 0.37). Conclusion: medical students have worse grades on written exams in Pharmacology, as compared to oral and multiple-choice exams. This could possibly be associated with the fact that this type of exam is less frequently applied in Medical School. (AU)

Three-dimensional echocardiography for predicting postoperative ventricular volumes after surgical ventricular reconstruction of left ventricular aneurysm: A case-based presentation.

Three-dimensional transthoracic echocardiography (3DTTE) may have a role in predicting final left ventricular volumes and clinical response after the surgical ventricular reconstruction (SVR) of left ventricular aneurysms and pseudoaneurysms. Left ventricle final volumes can be calculated through "virtual aneurysmectomy." We present a patient with a huge ventricular dilation combined with myocardial dissection, localized wall rupture, and aneurysm of the left ventricular apex after acute myocardial infarction in which accurate predictions from 3DTTE suggest potential clinical value.

The dicrotic notch analyzed by a numerical model.

Divergent concepts on the origin of the dicrotic notch are widespread in medical literature and education. Since most medical textbooks explain the origin of the dicrotic notch as caused by the aortic valve closure itself, this is commonly transmitted in medical physiology courses. We present clinical data and numerical simulations to demonstrate that reflected pressure waves could participate as one of the causes of the dicrotic notch. Our experimental data from continuous arterial pressure measurements from adult patients undergoing vascular surgery suggest that isolated changes in peripheral vascular resistance using an intravenous bolus of phenylephrine (a selective alpha 1-receptor agonist and thus a potent vasoconstrictor) modify the dicrotic notch. We then explore the mechanisms behind this phenomenon by using a numerical model based on integrated axisymmetric Navier-Stokes equations to compute the hemodynamic flow. Our model illustrates clearly how modifications in peripheral artery resistance may result in changes in the amplitude of the dicrotic notch by modifying reflected pressure waves. We believe that this could be a useful tool in teaching medical physiology courses.

Nuevas drogas en el tratamiento de la obesidad y el sobrepeso / New drugs for the treatment of obesity and overweight / Novas drogas no tratamento da Obesidade e Sobrepeso

a obesidad y el sobrepeso se asocian con un mayor riesgo de mortalidad global y de padecer numerosas patologías crónicas, y son muy difíciles de tratar. Es por esto que la implementación de medidas farmacológicas seguras y eficaces reviste una suprema importancia. La lorcaserina y la combinación fentermina/topiramato son nuevas opciones farmacológicas aprobadas en el año 2012 por la FDA (Food and Drugs Administration de los Estados Unidos), a pesar de su compleja forma de administración, y los requerimientos de un programa de entrenamiento y de monitoreo de postmarketing. En el artículo se describen las nuevas drogas aprobadas, sus mecanismos de acción, efectos adversos, características farmacocinéticas su uso en situaciones especiales, y los inconvenientes con las drogas previamente aprobadas y que fueron retiradas del mercado.Palabras clave: obesidad, sobrepeso, topiramato, fentermina, lorcaserin

besity and overweight are associated with an increased risk of overall mortality and the development of many chronic diseases, and they are very difficult to treat. That is why the implementation of safe and effective pharmacological measures is of paramount importance. Lorcaserin and the combination of phentermine/topiramate are two new pharmacological therapies for chronic weight management. They were approved in 2012 by the U.S. Food and Drug Administration, despite concerns over its complex form of administration and the requirement of a training and post-marketing surveillance program.This article describes newly approved drugs, their mechanisms of action, side effects, pharmacokinetics, and their use in special situations, along with the drawbacks of previously approved drugs that were withdrawn from the market.

A obesidade e o sobrepeso são associados a um maiorrisco de mortalidade global e ao padecimento de numerosaspatologias crônicas, e são muito difícies de tratar. É poristo que a implementação de medidas farmaco lógicasseguras e eficazes possui uma suprema importância.A lorcaserina e a combinação fentemina/topiramato sãonovas opções farmacológicas aprovadas no ano 2012pela FDA (Food and Drugs Administration de los EstadosUnidos), apesar da sua complexa forma de administração, eos requerimentos de um programa de treinamento e demonitoramento de postmarketing. No artigo estão descritas as novas drogas aprova das,seus mecanismos de ação, efeitos adversos, característicasfarmacocinéticas, seu uso em situações especiais, e osinconvenientes com as drogas previamente aprovadas eque foram retiradas do mercado.