Fig. 1

Percentage of neonatal units that indicate red blood cell transfusions when hematocrit is lower than 21 %, 24 %, 30 %, 35 %, 40 % or 45 %, according to clinical characteristics of newborns and need for respiratory support or surgery. MV: mechanical ventilation; MAP: mean airway pressure; FiO₂: inspired oxygen fraction; retic: reticulocytes count