1 Pediatric Intensive Care Unit, Department of Pediatrics, Clinics Hospital of the State University of Campinas (UNICAMP), Campinas, SP, Brazil.
2 Department of Pediatrics, Division of Pediatric Nephrology, University of Minnesota Masonic Children's Hospital, Minneapolis, MN, USA.
3 Pediatric Intensive Care Unit, Department of Pediatrics, Clinics Hospital of the State University of Campinas (UNICAMP), Campinas, SP, Brazil. thsouza@unicamp.br.