Polycythemia in neonates can be a life threatening condition, a comorbidity due to many causes which needs immediate action. Here's my take on the same. My references are from, Nelson, Gomella, Cloherty. And Special thanks to Dr. Pavitra Viswanathan, who runs her Youtube channel by the name Pediatric Takes by Dr.Pavitra Viswanathan @pediatrictakesbydr.pavitra9813 and teaches Pediatrics. This presentation has hand written notes as well, which i've incorporated, in-spite of my handwriting, because i loved these. In case ppl need it to be typed, kindly reach me out, i'll type these as well.

1. Dr. Punit Tripathi
Polycythemia

2. Definition & Epidemiology
• Venous HCT > 65%
• or
• Venous Hb > 22 gm/dL
• 1 - 5 % in ter m neonates. Almost 1/2 of these have symptoms.

3. Hyperviscosity
Definition
• Viscosity > 14.6 centipedes at shear rate of 11.5 per second
• Or
• Viscosity > 2 SD of the mean.

4. Hyperviscosity
Causes
• Viscosity depends upon
• Red cell mass ( PCV / HCT) [ Most important in neonates]
• Plasma Protein (esp. Fibrinogen) [ Most important in adults ]
• Deformability of Erythrocytes - heighten the deformability, lower is
viscosity
• Erythrocyte aggregation
• Interaction of cell components with vessel wall

5. Hyperviscosity
Gold standard
• Measurement of viscosity is done by a whole blood viscometer that can
accurately measure the viscosity of blood. Because the erythrocyte number is
the most important factor affecting viscosity, measurement of the neonatal
HCT has been suggested as the best clinical screening test for identifying
infants with presumed Hyperviscosity.

6. Relationship between Viscosity and Hct
• Relationship between HCT and viscosity is linear below HCT of 60%, but
viscosity increases exponentially when HCT >/= 70%

7. Physiological changes in postnatal life
• Hematocrit peaks @2HOL - 60%
• @6 HOL - 57%
• @ 12-18 HOL - 52%

8. CAUSES OF RAISED HCT
A. Placental red Cell Transfusion
• 1. Cord stripping
• 2. Holding baby below mother
• 3. Maternal to Fetal transfusion
• 4. Twin twin transfusion
• 5. Forceful uterine contractions Before Cord Clamping
• 6. Delayed cord clamping
• Cord clamping @1 minute - blood volume = 80 ml/kg
• Cord clamping @2 minute - blood volume = 90 ml/kg

9. CAUSES OF RAISED HCT
B. Placental Insufficiency
(Chronic Intrauterine Hypoxia —> increased Fetal Erythropoiesis)
• 1. IUGR and SGA
• 2. Maternal Smoking
• 3. POST-TERM
• 4. Maternal Hypertension (per-eclampsia, Renal Disease)
• 5. Infants born to mother with Chronic Hypoxia (Heart Ds, Pulmonary Ds.)
• 6. Pregnancy at high Altitude

10. C. Others
• IODM (Increased Erythropoietin)
• LGA
• Infants with
• CAH, Beckwith - Weidmann Syndrome, Congenital Hypothyroidism,
Congenital Thyrotoxicosis, Trisomy 13, 18, 21
• Drugs (Maternal Use of Propanolol)
• Dehydration
• Sepsis
CAUSES OF RAISED HCT

13. Screening
• In high risk groups
• SGA, IUGR
• LGA
• IODM
• Monochorionic twins
• Schedule - 2, 6, 12, 24, 48, 72 HOL.

14. diagnosis
• Either cord blood or peripheral venous blood hematocrit
• If capillary blood Hct is >65% ——> do peripheral venous hematocrit
• Measure blood viscosity (if available).

16. Partial Exchange Therapy (PET)
• Removing some of blood volume and replacing it with NS to bring the Hct
down to 65%.
• Volume to be transfused (ml) =

18. Partial Exchange Therapy
• Blood can be withdrawn from umbilical vein and replaced with NS in peripheral
vein.
• Or
• By Push and Pull technique.
• S/e of PET - increased risk of NEC.