Medical Care
Therapy in newborns with polycythemia is based on both the measured central venous hematocrit (Hct) level and the presence or absence of symptoms. [17] Careful monitoring of vital signs, respiratory function, and levels of bilirubin, glucose, electrolytes, and urine output is needed in newborns with polycythemia, and it is very often the only required intervention in these infants.
Treatment for asymptomatic patients
In asymptomatic patients with a Hct level of 65-75%, perform cardiorespiratory monitoring and monitoring of Hct and glucose levels every 6-12 hours, and observe the patient for symptoms. Continue this monitoring for at least 24 hours or until the Hct level declines.
Fluid boluses of crystalloids such as normal saline (NS) are often administed to polycythemic newborns with a Hct value between 65% to 75% with the goal of peventing the Hct from increasing to levels that require treatment with partial exchange transfusion (PET). However, this practice is not usually successful. A study comprising 55 asymptomatic infants with Hct levels between 65% and 75% showed that treating them with NS boluses did not reduce either their subsequent Hct values or their need for a PET. [18]
In asymptomatic patients with a Hct level of more than 75% on repeated measurements, consider adminstering PET although evidence is lacking as to its efficacy.
Treatment for symptomatic patients
In symptomatic patients with a Hct level of 60-65%, consider alternative explanations for the symptoms/signs. Although polycythemia and hyperviscosity may be the etiology, other causes for the manifestations must be excluded.
In symptomatic patients with a Hct level more than 65% with symptoms attributable to polycythemia and hyperviscosity, consider PET to resolve the organ dysfunction. Treatment of polycythemia with PET remains controversial in terms of changing neurologic outcome. The Committee of the Fetus and Newborn of the American Academy of Pediatrics states, "The accepted treatment of polycythemia is partial exchange transfusion (PET)." However, the group also acknowledges that no evidence suggests that exchange transfusion affects the long-term outcome. [19, 20]
PET
Informed consent must be obtained as exchange transfusions have multiple risks. Use of a blood product (eg, albumin) in an exchange transfusion may result in the transmission of infection. Infections related to blood products can be avoided by using NS, which is sterile and which has been shown to be as effective as albumin. Note that umbilical PET increases the risk of necrotizing enterocolitis (NEC), especially if colloid is used.
Perform PET using an umbilical venous catheter to reduce the central Hct level to 50-55%. Sterile technique is required.
The total blood volume to be exchanged is determined as follows:
[blood volume (patient's Hct – desired Hct)]/(patient's Hct), where blood volume = the patient's weight in kilograms multiplied by 90 mL/kg.
NS is the replacement fluid of choice for exchange transfusions because it is effective and inexpensive. As alternatives, plasma protein fraction (Plasmanate), 5% albumin, or fresh frozen plasma can be used. However, none of these products is more effective than NS. In addition, both 5% albumin and fresh frozen plasma are blood products, and certain religious beliefs prohibit their use. Lastly, these colloid products have been associated with complications such as NEC.
An exchange transfusion can be performed in three ways, depending on the type of vascular access that is available. Regardless of the method used, aliquots should not exceed approximately 5 mL/kg delivered or be removed over 2-3 minutes.
With the umbilical venous catheter in place, use a push-pull technique. With this technique, the withdrawal of blood is alternated with the administration of replacement fluid through the single catheter. Do not remove more than 5 mL/kg in any single withdrawal.
Feedings may cautiously be introduced hours after completing the PET.
Outpatient care
After the infant is discharged, clinicians should perform routine newborn follow-up care.
