Department of Anesthesiology, Botucatu Medical School, Universidade Estadual Paulista, Botucatu, São Paulo, São Paulo, Brazil. Department of Anesthesiology, EsSEx, Hospital Central do Exército, Rio de Janeiro, Rio de Janeiro, Brazil. Department of Anesthesiology, Santa Casa de Misericórdia de Barra Mansa, Barra Mansa, Rio de Janeiro, Rio de Janeiro, Brazil. Department of Community Health and Epidemiology, Dalhousie University, Faculty of Medicine, Halifax, Canada. Institute of Science and Technology, Univ Estadual Paulista, São Paulo, São José dos Campos, Brazil. McMaster Institute of Urology, McMaster University, Hamilton, Ontario, Canada. Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.