"Rwandan National Neonatal Protocol: Hyperbilirubinemia"
by Dr. Bwiza-Muhire Hippolyte.
Introduction.
Hello.
I'm called Dr. Bwiza-Muhire Hippolyte.
I'm a pediatrician and member of Rwanda Paediatric Association.
Today, I'm going to talk about hyperbilirubinemia.
Overview.
By the end of this chapter, participants
will you be able to recognize risk
factors for hyperbilirubinemia in full term and premature
infants, to understand how to assess hyperbilirubinemia
on a physical exam and initiate laboratory testing,
to determine, initiate, and manage
appropriate treatment for hyperbilirubinemia
in the neonate.
Pathophysiology, Assessment, and Treatment.
Bilirubin is a yellow substance created as the body replaces
old red blood cells.
It is broken down by the liver and removed
from the body in the stool.
High levels of bilirubin called hyperbilirubinemia
makes the skin and the sclera of the eyes
look yellow, a condition known as jaundice.
Physiologic jaundice occurs in the first two weeks
of life due to a normal rise in indirect bilirubin
while the newborn's metabolism and excretion system are still
immature.
It typically peaks at the bilirubin
of about 12 milligrams per deciliter
in the first weeks of life and then resolves spontaneously
over the first month of life.
Physiologic jaundice rarely occurs in the first day
after birth and usually does not require treatment.
Non-physiologic jaundice is a sign
of more extreme hyperbilirubinemia
and involves a peak bilirubin greater than 12 milligrams
per deciliter.
That often occurs earlier than with physiologic jaundice.
It can be direct, indirect, or both.
It is typically due to an underlying condition
and requires further evaluation and treatment.
Causes can include sepsis, hypothyroidism,
and congenital syphilis.
Neonatal hyperbilirubinemia can be
due to physiologic jaundice, non-physiologic jaundice,
or both.
Newborns increased breakdown of heme-containing red blood cells
results in increased release of bilirubin.
Therefore, conditions in which there
is increased red blood cell breakdown, like hemorrhage
or hemolysis, will exacerbate hyperbilirubinemia.
Newborns also have a decreased metabolism
and excretion of bilirubin.
This is a complex process requiring both hepatic function
and intestinal excretion.
Conditions in which there is decreased metabolism,
such as liver disease or decreased intestinal excretion
of bilirubin, such as being NPO on IV fluids,
will also exacerbate hyperbilirubinemia.
Risk factors for hyperbilirubinemia
include prematurity, low birth weight, hemolysis, sepsis,
and inborn errors of metabolism.
Physiologic and non-physiologic jaundice peaks
earlier and higher in preterm, low birth weight infants
due to decreased metabolism of bilirubin
caused by immature hepatic function
and decreased excretion of bilirubin
due to decreased enteral intake.
High levels of bilirubin can cause
brain damage making prompt screening and treatment
critical.
Ideally, hyperbilirubinemia is diagnosed
with a serum bilirubin measurement of total, direct,
and indirect bilirubin.
If it is not possible to measure serum bilirubin,
a rough estimate can be made by physical examination.
Scleral icterus correlates with a bilirubin
of about 5 mg per deciliter.
Jaundice of the palms and soles correlates
with a bilirubin of greater than 20 mg per deciliter.
Measure bilirubin if an infant has jaundice
on day of life zero, is preterm with jaundice
on day of life one, or has jaundice
below the chest at any age.
Jaundice below the chest, especially
on the palms and the soles, should cause concern.
Consider additional factors that could worsen jaundice
such as sepsis and hemolysis.
Laboratory testing to assess for hemolysis and sepsis
would include a full blood count, blood type of mother,
Coombs, CRP, and blood culture.
When the hyperbilirubinemia requires treatment
depends on the degree of production, metabolism,
and the excretion of bilirubin.
If there is evidence of moderate to severe jaundice
by physical exam, start phototherapy
regardless of serum bilirubin laboratory measurements.
Jaundice of palms and soles is consistent with a bilirubin
level of at least 20 milligram per deciliter, which
is equal to 340 micromole per liter.
Use these tables to determine the phototherapy treatment
and exchange transfusion thresholds.
Bilirubin conversion is 1 milligram per deciliter
equals 17.1 micromole per liter.
To start phototherapy, place the newborn in the bassinet
or an incubator if the newborn is low birth weight less than 2
kg, and an incubator if available.
Ensure that the newborn is naked except for a diaper
and wearing protective eyewear at all times.
Position the phototherapy source at an appropriate distance
above the newborn's body, which varies based
on the type of light source.
Phototherapy should be continuous
without interruptions except during feedings.
While newborns are receiving phototherapy,
closely monitor temperature, hydration status,
and lab test results.
Check temperature every three hours
considering that the normal range is
36.5 to 37.5 degrees Celsius.
Phototherapy causes increased evaporative fluid losses.
So fluid intake should be increased by 20 mL/kg per day.
Ensure that the newborn is a feeding well, seven or eight
times per day or on IV fluids, and urinating at least six
times per day.
Dehydration, hemoconcentrates bilirubin
and it should be avoided.
If initial total bilirubin is over 20 mg/dL,
repeat the measurement in 6 to 12 hours.
If initial total bilirubin is less than 20 mg/dL,
repeat in 24 hours if the newborn is not
on full volume feeds or 24 hours if the newborn is
on full volume feeds.
There are additional measures that
can be taken if the newborns bilirubin levels continue
to rise despite phototherapy.
If this is the case and the newborn's bilirubin is still
over 20 mg/dL, which is equal to 340 micromole per liter,
feed the newborn under phototherapy
lights rather than removing the newborn from the phototherapy
during feedings.
Ensure that the newborn is naked with no hat, blanket,
or clothing covering his skin ensuring that all skin is
exposed to phototherapy.
If the newborn is not already receiving IV fluid, start an IV
and provide hydration.
Provide an additional 20 to 40 mL/kg per day
to total fluid intake and consider whether IV fluid
boluses may be necessary.
Continue enteral intake by mouth or by nasogastric tube
to promote excretion of metabolized bilirubin.
Cover the incubator walls with white sheet
to create a reflective surface if needed.
But, be careful not to cover the ventilation system.
If bilirubin exceeds 25 mg per deciliter,
which is equal to 425 micromole per liter,
and is not improving with phototherapy,
apply the previous measures and give a 10 to 20
mL/kg normal saline bolus.
Strongly consider nasogastric tube feeding
until the newborn's bilirubin levels
fall below 425 micromole per liter
to either supplement or intake.
Or if the newborn is not orally feeding well,
give roughly 150 mL/kg per day of milk via a nasogastric tube.
Exchange transfusion is a treatment
for extreme hyperbilirubinemia and it
should be considered if bilirubin
is above 425 micromole per liter and continues to rise.
Phototherapy should be discontinued
once total serum bilirubin levels falls below treatment
thresholds in the table.
After discontinuing phototherapy,
recheck total bilirubin levels after 24 hours.
If bilirubin is above the treatment threshold,
restart phototherapy.
Remember the following additional considerations
when treating a newborn with hyperbilirubinemia.
Treat other conditions which may worsen hyperbilirubinemia.
If sepsis is suspected, monitor full blood count and initiate
antibiotics.
If hemolysis is suspected, monitor hemoglobin and assess
for blood type incompatibility.
Assess for, and treat malaria.
Case Studies.
The following case studies will help
us to review this material.
You are caring for baby Robert, a three-day-old term baby,
who is recovering from transient tachypnea of the newborn,
and is ready to go home today.
When you are doing his discharge physical exam,
you not that his sclera are jaundiced,
but not his palms or soles.
He otherwise looks well.
Now with a comfortable respiratory exam,
feeding well, voiding and stooling regularly.
You send serum bilirubin level and it comes back
at 170 micromoles per liter, which
is 10 milligrams per deciliter.
What should you do?
This is a physiologic jaundice and does not require
any therapy at this point.
You should proceed with discharging the baby to home.
And as with any other patients, if the family
observes progressive jaundice, this
is a danger sign that requires that they should
seek further medical attention.
The next patient is Sabina, a 1.9 kg 32 weeks
gestational girl who is four days old.
She is being treated for a presumed perinately acquired
infection based on her mother having
presented with signs of chorioamnionitis
and respiratory symptoms.
She is on half volume feeds.
On rounds today, you notice that her sclera are jaundiced.
When you look at her palms and the soles,
they are also slightly jaundiced.
You sent off a serum bilirubin level
and it comes back at 15 mg/dL.
What should you do?
This is non-physiologic jaundice.
Based on the guidelines, you should start phototherapy.
What should you do if you cannot run a bilirubin level given her
history and her physical exam?
You should start phototherapy because it is presumably
quite high, given the jaundice of her palms and soles.
When should you measure the next level?
According to the protocol, because the level is
less than 20 and she's on half volume feeds,
the next level should be measured in 12 hours.
Once she is under the phototherapy lights,
what other parts of her care should you focus on?
You need to take her temperature every three hours
and increase her fluid intake by 20 mL/kg per day
to accommodate for the increased insensible losses
of the lights.
After being under phototherapy for two days,
her bilirubin comes back at 10 mg/dL.
What do you do?
You discontinue the phototherapy and check another level
once she has been off phototherapy for 24 hours.
That level comes back at a 9 mg/dL.
What do you do?
Her jaundice has been treated and you do not
need to check it again unless you see a physical exam
findings concerning for jaundice.
This chart summarizes the assessment and treatment
of hyperbilirubinemia.
Summary.
Having completed this chapter, you
should now be able to recognize risk factors
for hyperbilirubinemia in full term and premature infants.
To understand how to assess for hyperbilirubinemia
on physical exam and initiate laboratory testing.
Determine, initiate, and manage appropriate treatment
for hyperbilirubinemia in the neonate.
Keep in mind the following key points on hyperbilirubinemia.
Hyperbilirubinemia occurs when an infant's bilirubin levels
become too high, leading to jaundice.
The major risk factors for hyperbilirubinemia
are prematurity, low birth weight, hemolysis, sepsis,
inborn errors of metabolism.
Assessment for hyperbilirubinemia
can be conducted by measuring serum bilirubin levels
or by estimation based on the physical exam.
Hyperbilirubinemia is usually treated with phototherapy.
Treatment thresholds are defined by serum bilirubin levels.
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