Neonatal Polycythemia

Presentation & Risk Factors

• Definition: Venous hematocrit >= 65% or hemoglobin >= 22 g/dL.
• Risk Factors: Twin-twin transfusion syndrome, SGA/IUGR, Infant of Diabetic Mother (IDM), significantly delayed cord clamping.
• Symptoms stemming from hyperviscosity: Plethora (ruddy/dark red appearance), lethargy, profound hypotonia, poor feeding.
• Severe complications: Hypoglycemia (due to RBC glucose consumption), thrombosis (especially renal vein), NEC, seizures, respiratory distress.

Diagnostic Workup

• Confirm hematocrit via central VENOUS sample (capillary/heelstick samples are falsely elevated by up to 15%).
• Stat glucose (hypoglycemia is intensely common).
• Bilirubin monitoring (high turnover of massive RBC volume leads directly to severe hyperbilirubinemia).
• Monitor platelets (thrombocytopenia mapping) and calcium (hypocalcemia protocol) closely.

Management Algorithm

• Asymptomatic fluid management: Increase enteral or IV fluids by 20-30 mL/kg/day. Recheck venous Hct in 4-6 hours.
• Symptomatic OR venous Hct > 70%: Perform Isovolumetric Partial Exchange Transfusion (PET) using normal saline to lower hematocrit to target 50-55%.
• Formula for PET Vol: [Blood Volume x (Observed Hct - Desired Hct)] / Observed Hct. (Estimate neonatal BV at 80-90 mL/kg depending on prematurity).
• Observe strictly for necrotizing enterocolitis post-PET via daily abdominal girth checks.

Diagnostic & Management Algorithm

• Polycythemia Partial Exchange Transfusion Algorithm: [START] Central Venous Hct > 70% OR (Hct 65-69% AND Symptomatic) -> [CALCULATION] Vol to exchange = BW(kg) * 80 * (Observed Hct - Target Hct [50]) / Observed Hct -> [PROCEDURE] Place UVC, draw blood while simultaneously infusing equal volume of Normal Saline via PIV

References

1. Alsafafi M, et al. Neonatal polycythemia. Neoreviews.
2. Ozek E, Soll R, Schimmel MS. Partial exchange transfusion to prevent neurodevelopmental disability in infants with polycythemia. Cochrane Database Syst Rev.