NEONATAL POLYCYTHEMIA
:
It is defined as venous PCV more than 65%
(capillary PCV is 15% higher than venous PCV).
CAUSES:
1.Increased intrauterine erythropoiesis
e.g. IUGR, postdate, trisomies.
2.Secondary to RBC transfusion
e.g. delayed cord clamping(>3min.), twin to twin
transfusion.
3.Increased capillary permeability & plasma loss
e.g. prematurity, hypoxia. cold stress.
CLINICAL
FEATURES:
!
Commonly asymptomatic(only plethoric).
!
Symptoms(are related to increased blood viscosity
and decreased organs perfusion): lethargy,
irritability, poor feeding, hypoglycemia,
convulsions, NEC, peripheral gangrene,
renal vein thrombosis.
TREATMENT
:
If venous PCV is >65% and no symptoms:
observation.
If PCV is >70% or >65% with symptoms:
do partial exchange transfusion with normal saline
aiming a PCV of less than 55%.
Volume of exchange(ml)=
blood volume x (observed PCV
-
desired PCV )
/observed PCV.
(Blood volume: in term infants=80-90 ml/kg
in preterm=90-100ml/kg).