An autopsy study of the spectrum of severe COVID-19 in children: From SARS to different phenotypes of MIS-C

Background: COVID-19 in children is usually mild or asymptomatic, but severe and fatal paediatric cases have been described. The pathology of COVID-19 in children is not known; the proposed pathogenesis for severe cases includes immune-mediated mechanisms or the direct effect of SARS-CoV-2 on tissues. We describe the autopsy findings in five cases of paediatric COVID-19 and provide mechanistic insight into the mechanisms involved in the pathogenesis of the disease. Methods: Children and adolescents who died with COVID-19 between March 18 and August 15, 2020 were autopsied with a minimally invasive method. Tissue samples from all vital organs were analysed by histology, electron microscopy (EM), reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). Findings: Five patients were included, one male and four female, aged 7 months to 15 years. Two patients had severe diseases before SARS-CoV-2 infection: adrenal carcinoma and Edwards syndrome. Three patients were previously healthy and had multisystem inflammatory syndrome in children (MIS-C) with distinct clinical presentations: myocarditis, colitis, and acute encephalopathy with status epilepticus. Autopsy findings varied amongst patients and included mild to severe COVID-19 pneumonia, pulmonary microthrombosis, cerebral oedema with reactive gliosis, myocarditis, intestinal inflammation, and haemophagocytosis. SARSCoV- 2 was detected in all patients in lungs, heart and kidneys by at least one method (RT-PCR, IHC or EM), and in endothelial cells from heart and brain in two patients with MIS-C (IHC). In addition, we show for the first time the presence of SARS-CoV-2 in the brain tissue of a child with MIS-C with acute encephalopathy, and in the intestinal tissue of a child with acute colitis. Interpretation: SARS-CoV-2 can infect several cell and tissue types in paediatric patients, and the target organ for the...(AU)

Síndrome do desconforto respiratório: influência do manejo sobre o estado hemodinâmico de recém-nascidos pré-termo ≤ 32 semanas nas primeiras 24 horas de vida / Respiratory distress syndrome: influence of management on the hemodynamic status of ≤ 32-week preterm infants in the first 24 hours of life

RESUMO Objetivo: Investigar a influência do manejo da síndrome do desconforto respiratório sobre parâmetros clínicos e ecocardiográficos de avaliação hemodinâmica em recém-nascidos ≤ 32 semanas. Métodos: Foram avaliados prospectivamente 33 recém-nascidos ≤ 32 semanas, submetidos à ventilação mecânica invasiva. A necessidade de surfactante exógeno e os parâmetros clínicos e ecocardiográficos nas primeiras 24 horas de vida foram detalhadas nesse grupo de pacientes. Resultados: O valor da pressão média de vias aéreas foi significativamente maior nos recém-nascidos que necessitaram de inotrópicos [10,8 (8,8 - 23) cmH2O versus 9 (6,2 - 12) cmH2O; p = 0,04]. Houve correlação negativa entre pressão média de vias aéreas e integral velocidade-tempo da artéria pulmonar (r = -0,39; p = 0,026), débito do ventrículo direito (r = -0,43; p = 0,017) e medidas da excursão do plano do anel tricúspide (r = -0,37; p = 0,036). Verificou-se correlação negativa entre o número de doses de surfactante exógeno e: débito de ventrículo direito (r = -0,39; p = 0,028) e a integral velocidade-tempo da artéria pulmonar (r = -0,35; p = 0,043). Conclusão: Nos recém-nascidos ≤ 32 semanas em ventilação mecânica invasiva, elevações de pressão média de vias aéreas e do número de doses de surfactante correlacionam-se com piora da função cardíaca precoce. Aparentemente, o manejo mais agressivo da síndrome do desconforto respiratório contribui para a instabilidade hemodinâmica desses pacientes.

ABSTRACT Objective: To investigate the influence of respiratory distress syndrome management on clinical and echocardiographic parameters used for hemodynamic evaluation in ≤ 32- week newborns. Methods: Thirty-three ≤ 32-week newborns were prospectively evaluated and subjected to invasive mechanical ventilation. The need for exogenous surfactant and clinical and echocardiographic parameters in the first 24 hours of life was detailed in this group of patients. Results: The mean airway pressure was significantly higher in newborn infants who required inotropes [10.8 (8.8 - 23) cmH2O versus 9 (6.2 - 12) cmH2O; p = 0.04]. A negative correlation was found between the mean airway pressure and velocity-time integral of the pulmonary artery (r = -0.39; p = 0.026), right ventricular output (r = -0.43; p = 0.017) and measurements of the tricuspid annular plane excursion (r = -0.37; p = 0.036). A negative correlation was found between the number of doses of exogenous surfactant and the right ventricular output (r = -0.39; p = 0.028) and pulmonary artery velocity-time integral (r = -0.35; p = 0.043). Conclusion: In ≤ 32-week newborns under invasive mechanical ventilation, increases in the mean airway pressure and number of surfactant doses are correlated with the worsening of early cardiac function. Therefore, more aggressive management of respiratory distress syndrome may contribute to the hemodynamic instability of these patients.