In preterm infants, cardiac output increases when haematocrit decreases.1 Red cell transport (RCT), which is the product of the cardiac output and haematocrit and represents the oxygen-carrying capacity, increases after neonatal red cell transfusion for anaemia.2 3 We wanted to test if a low RCT could predict a beneficial clinical response (decrease in bradycardia frequency) to red cell transfusion. Eleven preterm infants (table 1) were studied before and 24 h after a 20 ml/kg red cell transfusion that was given based on pre-established criteria.4 Infants …