RESUMO
Resumen La ecografía pulmonar (EP) ha demostrado ser una herramienta útil para detectar el grado de compromiso pulmonar en neumonía y síndrome de distrés respiratorio agudo. El presente estudio evalúa la asociación entre la puntuación de EP de 12 regiones y el ingreso de terapia intermedia a terapia intensiva en pacientes con neumonía por COVID-19. Se incluyó un total de 115 pacientes con diagnóstico de neumonía confirmada por radiografía de tórax, por SARS-CoV-2, se realizó una EP junto con la evaluación de laboratorio que incluyó la medición de marcadores inflamatorios (linfocitos, proteína C reactiva, Dímero D, procalcitonina, ferritina, lactato deshidrogenasa y pro péptido natriurético de tipo B). Se utilizó una puntuación ecográfica pul monar que caracteriza el grado de afección pulmonar como leve, moderado y grave, y se comparó el resultado con los marcadores inflamatorios de laboratorio. En el análisis univariado se observó una asociación entre la puntuación de la EP, los niveles elevados de procalcitonina y péptido natriurético cerebral y el ingreso a terapia intensiva. En el análisis multivariado solo la puntuación de EP fue un predictor independiente de requerimiento de terapia intensiva.
Abstract Lung ultrasound (LUS) has shown to be a useful tool to detect the degree of pulmonary involvement in patients with pneumonia and acute respiratory distress syndrome. The present study evaluates the association of the 12-region lung ultrasound score and the requirements of intensive care unit, in patients with COVID-19 infection who were admitted to intermediate care in a specialized hospital; 115 patients with a diagnosis of pneumonia confirmed by chest radiography secondary to SARS-CoV-2 were included, LUS was performed together with the laboratory evaluation that included the measurement of inflammatory biomarkers (lymphocytes, C-reactive protein, D-dimer, procalcitonin, ferritin, lactate dehydrogenase, and pro B-type natriuretic peptide). Lung ultrasound score was used, characterizing the degree of lung involvement as mild, moderate, and severe, and the results were compared with inflammatory biomarkers. In the univariate analysis, an association was observed between the lung ultrasound score, elevated levels of procalcitonin and brain natriuretic peptide, and the admission to intensive care. In the multivariate analysis, only the lung ultrasound score was an independent predictor of need for intensive therapy.
RESUMO
Resumen Luego de la infección por SARS-CoV-2 se producen anticuerpos específicos y continúa siendo objeto de estudio su cinética, cuantificación y umbral protector. Nuestro objetivo fue estudiar la cinética de aparición de anticuerpos IgG/IgM anti SARS-CoV-2, magnitud de respuesta y duración en el tiempo, en 55 pacientes hospitalizados por COVID-19, y relacionar el patrón de respuesta con diferentes parámetros demográ ficos y clínicos. Medidas con un ensayo cualitativo automatizado, VIDAS® SARS-Cov-2 (Biomerieux - ELFA) se evaluaron las variaciones en la concentración de anticuerpos a lo largo del tiempo con un modelo generalizado de efectos fijos. Todos los pacientes seroconvirtieron IgM e IgG, al día 10 y 10.5 respectivamente, patrón sincrónico mayoritario; no siendo de utilidad la IgM aislada como indicador de respuesta aguda. La sensibilidad clínica fue: semana 1, 30%, semanas 2 y 3, 72%, 4: 91% y 8: 96%. IgG permaneció detectable hasta los 6 meses (período de seguimiento) con gran heterogeneidad de magnitud; IgM negativizó en el 90.9% de los pacientes. Observamos un nivel mayor de IgM en los pacientes > 56 años, y en hombres respecto a mujeres. En pacientes con enfer medad pulmonar obstructiva crónica la respuesta de IgM está aumentada; los inmunocomprometidos y aquellos con enfermedad pulmonar intersticial difusa tuvieron menor IgM e IgG respectivamente. De nuestro grupo de pacientes, aquellos que requirieron cuidados críticos, asistencia respiratoria mecánica y los que fallecieron no presentaron diferencias significativas en magnitud de respuesta humoral respecto de quienes tuvieron un curso menos grave. La metodología utilizada refleja adecuadamente la cinética de anticuerpos.
Abstract Specific antibodies are produced after infection by SARS-CoV2. Currently, the understanding of antibody responses following infection with SARS-CoV-2 is limited including the magnitude, duration of responses and correlates of protective immunity following infection. Here we intended to characterize humoral immune response in a cohort of 55 hospitalized patients for COVID-19 and its relationship with different demographic and clinical parameters. The ELFA assay VIDAS® SARS-Cov-2 (Biomerieux) measured IgG/IgM antibodies. Their concentration over time was evaluated with a fixed effects generalized linear model. All patients seroconverted IgM and IgG, at day 10 and 10.5 respectively, showing a majority synchronous pattern; IgM alone would not be useful as a marker of acute response. Clini cal sensitivity was: week 1, 30%, weeks 2 and 3, 72%, 4: 91% and 8: 96%. IgG seropositivity was sustained in patients up to 180 days (last time point measured), in contrast, IgM response was short-lived (91days) in 90.9% of patients. Longer term follow-up is needed to determine the duration of IgG responses. We observed a higher level of IgM in patients > 56 years, and in men compared to women. In chronic obstructive pulmonary disease patients, the IgM response is increased, while in immunocompromised and interstitial lung disease patients, IgM and IgG were lower, respectively. Those patients who required critical care, mechanical ventilation and those who died did not present significant differences in the magnitude of humoral response compared to those who had a less severe course. The methodology used adequately reflects the kinetics of antibodies.
RESUMO
RESUMO Objetivo: Avaliar uma nova abordagem fisiológica para a determinação do volume corrente em ventilação mecânica, de acordo com a capacidade inspiratória, e determinar se isso resulta em medidas mecânicas e de troca gasosa adequadas em cães saudáveis e em estado crítico. Métodos: Incluíram-se, neste estudo, 24 animais para avaliar o volume corrente expresso como porcentagem da capacidade inspiratória. Para mensuração da capacidade inspiratória, o ventilador mecânico foi regulado como segue: modo controle de pressão, com 35cmH2O de pressão de inspiração e pressão expiratória final de zero, por 5 segundos. Subsequentemente, estudaram-se dez cães em condições clínicas críticas. Resultados: Cães saudáveis ventilados com volume corrente que correspondia a 17% da capacidade inspiratória demonstraram mecânica respiratória normal e apresentaram os valores previstos de PaCO2 mais frequentemente do que os animais nos demais grupos. A pressão no sistema respiratório e a pressão transpulmonar foram significantemente mais elevadas nos cães em condição crítica, porém em todos os casos, estiveram abaixo de 15cmH2O. Conclusões: O volume corrente calculado com base na capacidade inspiratória de cada animal comprovou ser uma ferramenta útil e simples para o estabelecimento dos parâmetros do ventilador. Convém também realizar abordagem semelhante em outras espécies, inclusive no ser humano, quando se consideram as potenciais limitações da titulação do volume corrente, com base no peso corpóreo ideal calculado.
ABSTRACT Objective: To evaluate a novel physiological approach for setting the tidal volume in mechanical ventilation according to inspiratory capacity, and to determine if it results in an appropriate mechanical and gas exchange measurements in healthy and critically ill dogs. Methods: Twenty healthy animals were included in the study to assess the tidal volume expressed as a percentage of inspiratory capacity. For inspiratory capacity measurement, the mechanical ventilator was set as follows: pressure control mode with 35cmH2O of inspired pressure and zero end-expiratory pressure for 5 seconds. Subsequently, the animals were randomized into four groups and ventilated with a tidal volume corresponding to the different percentages of inspiratory capacity. Subsequently, ten critically ill dogs were studied. Results: Healthy dogs ventilated with a tidal volume of 17% of the inspiratory capacity showed normal respiratory mechanics and presented expected PaCO2 values more frequently than the other groups. The respiratory system and transpulmonary driving pressure were significantly higher among the critically ill dogs but below 15 cmH2O in all cases. Conclusions: The tidal volume based on the inspiratory capacity of each animal has proven to be a useful and simple tool when setting ventilator parameters. A similar approach should also be evaluated in other species, including human beings, if we consider the potential limitations of tidal volume titration based on the calculated ideal body weight.