Serum potassium changes following packed red cell transfusions in newborn infants

Abstract
The effect of packed red cell transfusions on serum K levels in sick newborn infants was studied. In 11 transfusions the infants'' serum K levels fell from a mean of 5.1 .+-. 1.2 meq/l (SD) to 4.9 .+-. 1.2 meq/1 within 1 h of the transfusion. Plasma K in stored packed red cells rose markedly within 48 h of drawing. In spite of this, the transfusion of 10 ml/kg of packed red cells did not affect the serum K concentration in the newborn infant.