- Polycythemia is defined as a central venous hematocrit in excess of 65%
- Hyperviscosity of blood at this high hematocrit compromises
microcirculation in various organs and makes the infant symptomatic.
- Hemodilution with a partial exchange transfusion is the treatment of
- A randomized trial has shown that normal saline (crystalloid) is as
effective as albumin (colloid) when used as replacement fluid in partial
exchange transfusion for the treatment of polycythemia. Normal saline is
easily available, relatively inexpensive, and free of infection hazard.
Alternatives for hemodilution
- Albumin (5%) also can be
used as a diluent for partial exchange transfusion.
- Advantage: retained in the intravascular space longer than a crystalloid
solution because of its high oncotic pressure, thereby offering the
theoretical advantage of a greater and more sustained hemodilution.
- Disadvantage: potential risk of
protein leakage into the extravascular compartment, resulting in
interstitial and pulmonary edema. Moreover, as a biologic product, albumin
has a potential risk of infection.
- Fresh frozen plasma has a
similar theoretical advantage to albumin with regard to efficient hemodilution,
but it contains fibrinogen, which increases
the viscosity of blood. Accordingly, fresh frozen plasma is relatively
less effective in reducing high viscosity. Moreover, as a biologic product, it
has the potential risk of infection.
- Glucose as a diluent for
partial exchange transfusion is discouraged. The large bolus of glucose
infusion that accompanies a partial exchange transfusion may cause
hyperglycemia. The high
osmolality (approximately 500 mOsm/L) of a 10% glucose solution also carries
the risk of fluid shifts induced by a high osmotic load.
- Plasma substitute, which
can be used as a diluent for partial exchange transfusion, has similar
theoretical advantages and potential risks as
albumin and fresh frozen plasma, but it offers
no advantage over normal saline and is more expensive.
Lindemann R, Haga P. Evaluation and treatment of polycythemia in the
neonate. In: Christensen RD, ed. Hematologic Problems of the Neonate.
Philadelphia, Pa: WB Saunders Co; 2000:171-183
Wong W, Fox TF, Lee CH, et al. Randomised controlled trial: comparison
of colloid or crystalloid for partial exchange transfusion for
treatment of neonatal polycythemia. Arch Dis Child Fetal Neonatal Ed.