Patients
We recruited acutely ill children , aged 1 month to 18 years, and elevated pro-BNP levels (over 300pg/mL)18,19 with final diagnosis of A) isolated cardiac disease (with and without heart failure) or B) systemic inflammatory disease / sepsis without heart involvement or C) systemic inflammatory disease and heart involvement as in the case of the acute rheumatic carditis, the Kawasaki disease or the syndrome of pediatric multisystem inflammation temporally related to SARS-CoV-2 (PIMS-TS).
Specifically, at the time of first evaluation, all children with an acute or previous history of heart disease (with and without signs and symptoms of respiratory distress) or with signs and symptoms of suspected systemic inflammatory disease or sepsis (with and without signs and symptoms of respiratory distress) underwent pro-BNP level assay and lung ultrasound evaluation. Furthermore, all children, belonging to these categories, were subjected to anamnesis, clinical and vital parameters evaluation, evaluation of inflammation indices, always at the first evaluation. In particular, blood tests including C-reactive protein (CRP) and white blood cell count (WCC) and in some cases also procalcitonin (PCT) were performed for all patients. In addition, all were subjected to microbiological tests (molecular and cultural) of the airways to exclude acute upper or lower respiratory tract infections. Further investigations were performed only when deemed necessary by the evaluating pediatricians (troponin dosage, echocardiogram, chest x-ray and other microbiological tests as appropriate).
Finally, keeping in mind the objective of the study - to define whetheracutely ill children with cardio-pulmonary interactions had a specific and different lung ultrasound pattern from other categories of patients with primary infectious lung disease and / or completely healthy patients - we enrolled patients belonging to these other two categories. In particular we analyzed the epidemiological and clinical data - as well as the LUS findings - of 1) patients with acute lower respiratory tract infections (in particular bronchiolitisascertained by culture and molecular examinations of the upper airways) aged between 1 month and 2 years and 2) completely healthy infants, then comparing these data with those of the study population of acutely ill children .