2. • B/O Pooja Venkatesh ,Twin -2, B wt 2.2 kg
delivered through NVD in Bapuji hospital,cried
immediately after birth.(23/10/2016).
• Twin 1, B.wt-2.1kg Male
• Baby was found to be plethoric hence shifted to
NICU at 12 HOL.
• With Diagnosis of: Term/Male/SGA/Twin -
2/Polycythemia
3. • At 14 HOL,Twin 2-Hb-24gm/dl and PCV -74%.
• At 14 HOL Twin 1 :hb-11.5gm%,PCV-39%
• Baby was started on IV fluids ,1.5 times the
maintenance.
• Repeat CBC at 36 HOL showed Hb-25.6% and HCT -
73.2%.
• TSB at 36 HOL -12.2mg/dl warranting phototheraphy.
4. • In view persistently high HCT ,Partial
exchange transfusion was done at 46 HOL.
• HCT was corrected upto 62%,replacement
fluid was Normal saline.
• Post exchange HCT was 65%.
5. • Baby was started on breast feeding from D3 of
life.
• Baby received phototheraphy upto D6 of life.
• No documented hypoglycemic episodes
through out NICU stay.
• Baby discharged on D7 with HCT -60%.
6. Viscosity:
• The viscosity of a fluid is a measure of
its resistance to gradual deformation by shear
stress or tensile stress.
• For liquids, it corresponds to the informal
concept of "thickness"; forexample, honey has a
much higher viscosity than water.
• Plasma at 37°C is about 1.8-times more viscous
than water at the same temperature; therefore,
the relative viscosity of plasma (compared to
water) is about 1.8.
8. • Viscosity depends on Hematocrit, plasma proteins
(especially albumin , fibrinogen), deformability of
erythrocytes, erythrocyte aggregation , interaction of
cell components with vessel walls .
• The gold standard - measurement of viscosity is a
whole blood viscometer that can accurately measure
the viscosity of blood (expressed in centipoise)
• Hyperviscosity is blood viscosity >14.6 centipoise,
measured at a shear rate of 11.5 per second
• Whole blood viscometers are not universally available
• 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
9. Definition:
• Neonatal polycythemia defined in as a Venous
HCT >65%.
• Incidence .95%-1.5%
• This cut-off has been chosen based on the
observation that blood viscosity exponentially
increases above a Hct of 65% or Hemoglobin
concentration higher than 22.0 g/dl
- a statistical definition of infants at risk.
- neither based upon the risk for symptoms or for
complications.
10. Factors influence normally HCT
1. Gestational age
• HCT increases progressively with increasing
gestational age, thus NP may occur at much
higher rates in post term than in preterm
infants (Due to normal variation of Hct)
11.
12. 2. Degree of placental transfusion
• At term, the total fetoplacental blood volume is
about 115 ml/kg fetal weight, and is distributed in
the "normal" full-term infant after birth as
approximately 70 ml/kg in the infant, with 45
ml/kg remaining in the placenta. This distribution
may vary considerably, as more or less blood may
remain in the placenta.
• The main factors influencing placental
transfusion are time of cord clamping, position of
the delivered infant in relation to the placenta,
onset of respiration, presence or not of
intrauterine hypoxia, and presence or not of cord
compression
13. Degree of placental transfusion..contd
A. Time of cord clamping Within 30 to 45 seconds
following birth, the umbilical arteries are
functionally closed, while blood flow from
placenta to fetus through the umbilical vein may
continue for a few additional minutes . When the
infant is delivered at or below the introitus level,
if the cord is not clamped, her/his blood volume
will increase in a stepwise manner, reaching 55%
additional volume after 3 minutes
B. Position of the delivered infant in relation to the
placenta In vaginally delivered infants who are
kept 50 to 60 cm above the placenta, placental
transfusion does not occur . In contrast, if they
are maintained 40 cm below the placenta,
placental transfusion is hastened
14. Degree of placental transfusion..contd
C. Onset of respiration: Onset of respiration
through generating a negative intrathoracic
pressure and presumably increasing the
placental-fetal transfusion process
D. Presence or not of intrauterine hypoxia Acute
intrapartum and intrauterine asphyxia can be
accompanied by an increase in hematocrit
(presumably through increased transcapillary
escape of plasma).
E. Presence or not of cord compression Because
the umbilical vein is more compressible than the
umbilical arteries, infants born with a tight nuchal
cord may actually have low blood volume at birth
F. Dehydration- Relative loss of water from body
15. 3. Site of blood sampling :Capillary HCT is generally
higher than venous HCT which in turn is higher
than "central" HCT (from umbilical vein) .
Capillary HCT from warmed heels correlates well
with venous HCT
4. Time of blood sampling Hematocrit rises from
values obtained at birth (from cord venous or
arterial sampling) to reach a peak at 2 hours of
age, staying at a plateau for 2 additional hours,
then decreases to go back to values close to cord
blood values by 12 to 18 hours of age.
17. 1. Normovolemic Polycythemia condition where
normal intravascular volume is present despite an
increase in red cell mass. It results from increased
RBC production due to placental insufficiency and/or
chronic intrauterine hypoxia
-Intrauterine Growth Restriction
-Maternal Pregnancy Induced Hypertension
-Maternal Diabetes Mellitus
-Prolonged Intrauterine Tobacco Exposure
-Postmaturity
-High Altitude
18. 2. Hypervolemic polycythemia occurs when
higher than average blood volume is
accompanied by an increased red cell mass
acute transfusion to the fetus such as
- maternal-fetal transfusion
-twin-to-twin transfusion
- Delayed cord clamping
3. Hypovolemic polycythemia occurs secondary
to a relative increase in number of
erythrocytes to plasma volume
-intravascular dehydration
19. EFFECTS AND COMPLICATIONS OF
POLYCYTHEMIA
A. Hyperviscosity leads to a reduction in cerebral blood
flow decreased blood flow to the brain→ decrease
supply to the brain of other substances carried by
plasma, such as glucose, amino acids
B. Increased cellular breakdown of the increased red cell
mass Increased breakdown of red cells in NP may be a
significant contributing factor of neonatal
hyperbilirubinemia
C. Hemodynamic effects of hypervolemia or of
hypovolemia hypervolemia may lead to congestive
heart failure, pulmonary edema, and cardiorespiratory
failure hypovolemia can lead to hypoxic-ischemic injury
to vital organs.
22. Indications for polycythemia
screening
Do not routinely screen well term newborns for this
syndrome, because there are few data showing that
treatment of asymptomatic patients with partial
exchange transfusion is beneficial in the long term
• Small for gestational age (SGA) neonates
• Large for gestational age (LGA) neonates
• Infants of diabetic mothers (IDM)
• Newborns with morphological features of growth
restriction
• Monochorionic twins especially the recipient twin
• Babies looking plethoric
23.
24.
25. A. Once other causes of illness have been
considered and excluded (e.g., sepsis,
pneumonia, hypoglycemia), any child with
symptoms that could be due to hyperviscosity
should be considered for partial exchange
transfusion if the peripheral venous
hematocrit is >65%.
B. Asymptomatic infants with a peripheral
venous hematocrit between 60% and 70% can
usually be managed by increasing fluid intake
and repeating the hematocrit in 4 to 6 hours.
26. C. Exchange transfusion when the peripheral
venous hematocrit is >70% in the absence of
symptoms, but this is a controversial
D. The following formula can be used to
calculate the exchange with normal saline that
will bring the hematocrit to 50% to 60%. In
infants with polycythemia, the blood volume
varies inversely with the birth weight.
27. Volume to be exchanged is calculated by the
following equation:
Volume (mL) =
(Initial Hct – Desired Hct) x Weight(kg) x 90 mL
Initial Hct
-Desired Hct should be 55%.
-Hypervolemia is common in polycythemia; use
90 mL/kg as estimated blood volume.
-Volume to be exchanged in a term infant is
almost always in the range of 25-30 mL/kg. If
calculated volume is outside this range, re-
check the calculations.
28. TECHNICAL ASPECTS OF PET
• Which Diluting Fluid Should Be Used
- Plasma, 5% Albumin, NS, Or Ringer Solution
- It Did Not Find Clinically Differences
- NS Is The Optimal Fluid (Cheapest, With Less
Potential Side-effects)
• Vessels Used.-UAC,UVC, periphreal vessels
• Aim for a target, post PET HCT of 55%.
29. Conclusions:
1. PCT is a venous hematocrit of at least 65%.
Such a number is much more likely to be
significant in an infant >6 hours than it is at 2-
4 hours of age.
2. Symptoms/complications of polycythemia are
unlikely to be related to a hematocrit of <
65%.
3. There is no evidence that PET alters the
neurologic or developmental outcomes of
asymptomatic polycythemic neonates.
30.
31. Recommendations:
1. Routine screening for polycythemia is not
recommended.
2. Routine performance of PET in asymptomatic infants
is not recommended.
3. Screening for symptoms should be performed
carefully and documented in all infants with
polycythemia.
4. Normality of blood glucose should be documented in
all infants found to have polycythemia.
5. PET causes a prompt relief of symptoms. the presence
of symptoms (or of hypoglycemia) should lead to
perform PET.
32. 6. PET should be performed as early as possible
whenever symptoms are present, in view of
the potential for more severe symptoms and
complications to develop. Before proceeding
with PET, it appears that there is a need for
thorough, timely, clinical and physical
assessment of the newborn.
7. If performed, PET should be done with normal
saline
37. Neonatal Management:
• Donor- resuscitation at birth , rapid IV acess to
treat hypotension,PRBC transfusion for
anemia,correction of hypoglycemia.
• Reciepent –PET
• PPHN and TTTS
38. References:
• Dana Mathews,Bertil Glader.Erythrocytes disorders in
infancy.Avery’s diseases of Newborn,9thed:1102-1106.
• Deidre O.Polycythemia.Manual of Neonatal Care,7th
ed:572-577.
• Polycythemia.The PGI Handbook of NICU Protocols 4th
ed:171-175,2010.
• Polycythemia.AIIMS Protocols in Neonatology 1st ed:202-
211,2016
• Habli.Twin to twin transfusion syndrome:A Comprehensive
update.Clin Perinatology2009;391-416
• De waal et al.Systematic review of optimal fluid for PET in
polycythemia.Arch disease Child fetal Neonatal ed
2006:F7-F10
• Werner EJ.Neonatal Polycythemia and hyperviscosity.Clin
Perinatology1995:693-710