[1] Complejo Asistencial Univ Leon, Pediat Intens Care Unit, Altos De Nava S-N, Leon 24002, Spain
[2] Spanish Soc Neonatol SENeo, Working Grp Ultrasound, Valencia, Spain
[3] Spanish Soc Pediat Intens Care SECIP, Working Grp Bedside Ultrasound, Madrid, Spain
[4] Univ Leon, Biomed Inst Leon, Leon, Spain
[5] Hosp Univ Puerta Mar Cadiz, Neonatal Intens Care Unit, Cadiz, Spain
[6] Puerta Mar Univ Hosp, Biomed Res & Innovat Inst Cadiz INiBICA, Res Unit, Cadiz, Spain
[7] Hosp Clin Barcelona, Neonatal Intens Care Unit, Barcelona, Spain
[8] Ctr Maternal Fetal & Neonatal Med BCNatal, Barcelona, Spain
[9] Hosp Univ La Paz, Neonatal Intens Care Unit, Madrid, Spain
[10] Hosp Univ Basurto, Neonatal Intens Care Unit, Bilbao, Spain
[11] Hosp Univ, Neonatal Intens Care Unit, 12 Octubre, Madrid, Spain
[12] Res Inst Hosp, 12 Octubre Imasl2, Madrid, Spain
[13] Complejo Hosp Santiago de Compostela, Intermediate & Crit Care Unit, Pediat Emergency, Santiago De Compostela, Spain
[14] Hlth Res Inst Santiago de Compostela IDIS, Santiago De Compostela, Spain
[15] Univ Santiago de Compostela, CLINURSID Res Grp, Santiago De Compostela, Spain