ECMO-/ECLS

symptoms of poor oxygen delivery or increased oxygen demand are vague and
nondescript consisting of poor weight gain, tachycardia, apnea, persistent
oxygen requirement or prolonged mechanical ventilation and lactic acidosis.
Common practice in the 1970’s and 1980’s were to maintain a hematocrit
of 40% in premature infants [6]. A trend towards more restrictive policies has
been seen over the last several decades. Neonates are subject to the same
complications from transfusion found in adults. Additionally, more severe
consequences of transfusion of packed red blood cells have been described
including the development of bronchopulmonary dysplasia [7,8], retinopathy of
prematurity [9] and necrotizing enterocolitis [10]. It is felt that these outcomes
may be due to the inflammatory modulators that are found from presence of
leukocytes in non-irradiated red blood cells.
The largest study to date evaluating a transfusion threshold in
premature infants is the Premature Infants in Need of Transfusion (PINT). This
study randomized 451 infants to a low or high hemoglobin threshold. There was
no difference in the associated mortality, presence of retinopathy of prematurity
or bronchopulmonary dysplasia between the two groups. Additionally, there was
no statistically significant difference in the rates of intracranial hemorrhage or
brain injury (18.5% vs. 21.1%) between the low and high threshold groups [11].
This study supported previous thoughts that a high transfusion threshold subjects
the infant to more risks of transfusion but does not confer any physiologic
benefits.