Polycythemia in The Newborn

• Normal pcv in the newborn is 45-64%.
• Polycythemia in the newborn is venous haematocrit ≥ 65%.
• Also known as hyper viscosity syndrome, defined as viscosity more than 2SD above the mean.

• With an increase in haematocrit, viscosity increases.
• There is resistance to blood flow leading to ischemia, resulting in hypoxia and ultimately anaerobic glycolysis with acidosis.
• RBCs clump together to form thrombi resulting in micro infarcts.

Associated with Increased Volemia:

• Delayed Cord Clamping
• Cord Stripping
• Malpositioning
• Maternal-Fetal Transfusion
• Twin-Twin Transfusion

Associated with Placental Insufficiency:

• Small for Gestational Age (SGA)
• Post Term
• Babies born to mothers with Sickle Cell Anemia (SCA), Hypertension in Pregnancy, Renal Disorders, and Eisenmenger Syndrome

Other Causes:

• Congenital Adrenal Hyperplasia (CAH)
• Infant of the Diabetic Mother
• Beckwith-Wiedemann Syndrome
• Trisomy 13, 18, 21
• Neonatal Thyrotoxicosis

• Common features are plethora, lethargy, weak suck, hypotonia, respiratory distress.

CNS (Central Nervous System):

• Lethargy
• Convulsions

RS (Respiratory System):

• Respiratory distress
• Cyanosis

CVS (Cardiovascular System):

• Cyanosis
• Features of heart failure

UGS (Urinary and Genital System):

• Oliguria
• Haematuria
• Priapism

ABD (Abdomen):

• Features of necrotizing enterocolitis (NEC)

Associated Features:

• Hypoglycemia
• Hypocalcemia
• Thrombocytopenia

• Diagnosis is very simple, however, it requires an index of suspicion, especially in Small for Gestational Age (SGA), Large for Gestational Age (LGA), and plethoric babies.
• VENOUS PCV (Venous Packed Cell Volume) measurement is used for confirmation.

• Partial Exchange Transfusion (PET)
• Who to Treat:
• PCV 65 – 69% with symptoms
• PCV ≥ 70% ± symptoms
• Volume of exchange = blood volume × ^{(observed PCV – desired PCV)}/_{observed PCV}
• Where:
• Observed PCV = PCV of patient
• Desired PCV is the normal PCV (50 – 55)
• Blood volume = 80mls/kg

Procedure of PET (Partial Exchange Transfusion)

• Two vascular accesses are required: venous and arterial (usually using the umbilical vein).
• A plasma expander is needed (options include plasma, dextran, commonly normal saline in Ilorin).
• The procedure involves two individuals:
• One person removes blood from the arterial access.
• The other person infuses the plasma expander.
• These actions are performed synchronously until the total calculated volume is exchanged.