title: The authors reply.
authors: Pediatric Critical Care Unit, Department of Pediatrics, Complejo Asistencial Universitario de León, León, Spain; Pediatric Emergency and Critical Care Division, Clinical Universitary Hospital, University of Santiago de Compostela, Institute of Investigation of Santiago (IDIS), Santiago de Compostela, Santiago, Spain, and Research Network on Maternal and Child Health and Development II (Red SAMID II), Spanish Health Institute Carlos III, Madrid, Spain.
authors: Paula
authors: P
authors: Alonso-Quintela
authors: Ignacio
authors: I
authors: Oulego-Erroz
authors: Antonio
authors: A
authors: Rodríguez-Nuñez
mesh_terms: D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D002405:Catheterization, Central Venous / Q000379:methods*; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D014463:Ultrasonography; D014684:Venae Cavae / Q000000981:diagnostic imaging*