Severe manifestations of SARS-CoV-2 in children and adolescents: from COVID-19 pneumonia to multisystem inflammatory syndrome: a multicentre study in pediatric intensive care units in Spain - García-Salido, A; de Carlos Vicente, J C; Belda Hofheinz, S; Spanish Pediatric Intensive Care Society working group on SARS-CoV-2 infection (Crit Care, 2020)