Neonatal Partial Exchange for Polycythemia
Why Use
Calculating the volume of whole blood for replacement by crystalloid can help achieve normalization of neonatal hematocrit and avoid complications associated with polycythemia.
When to Use
Neonatal polycythemia can occur during the first week of life, when the hematocrit is >65% or hemoglobin >22 g/dL. The increased viscosity associated with polycythemia impairs tissue oxygenation and can lead to congestive heart failure, CNS, pulmonary and renal complications or necrotizing enterocolitis (NEC). Partial exchanges can be used to achieve a decrease in hematocrit (generally a goal of 55-60% to avoid complications associated with large decreases) by replacing whole blood with crystalloid. Plasma replacement is generally avoided due to an association with NEC.
Formula
Pearls / Pitfalls
Crystalloid replacement is used due to an association between plasma replacement and NEC. Neonatal blood volume can be estimated as 85 mL per kg for full term neonates and 100 mL per kg for premature neonates.
Advice
The partial exchange procedure should be performed by an experienced clinical team member according to institutional policies. Replacement by crystalloid should be utilized to avoid an increased risk of NEC.