Rwandan National Neonatal Protocol: Cardiology by Dr. Emmanuel Rusingiza.
Introduction.
Hello.
My name is Emmanuel Rusingiza.
I am a pediatric cardiologist at Kigali University Teaching
Hospital, called also CHUK.
Today I'm going to talk on a chapter
on cardiovascular diseases in newborns.
Overview.
By the end of this chapter, participants
should be able to identify two presenting symptoms of patent
ductus arteriosus, identify methods
for non-pharmacological support of an infant with PDA,
identify methods for pharmacological treatment
of an infant with a PDA.
Understanding Patent Ductus Arteriosus.
Patent ductus arteriosus, or PDA,
is the major cardiovascular risk for newborns.
PDA is postnatal persistence of the normal fetal vessel
that joins the pulmonary artery to the aorta.
The ductus arteriosis is a blood vessel
that shunts blood away from the infant's lungs
to the systemic circulation.
After the infant is born and the lungs fill with air,
it's no longer needed, and it usually
closes in the first several days after birth.
If the ductus arteriosis does not close after birth,
it results in abnormal blood flow
between the aorta and pulmonary artery, two major blood
vessels that carry blood from the heart.
PDA is most common in premature patients.
There is also an increased risk for PDA in settings of hypoxia.
PDA can also occur as a congenital defect in newborns of any gestational age.
In these cases, PDA is often associated
with the more complex congenital heart disease.
In preterm infants, blood is typically
shunted through the PDA from left to right.
This increases blood flow to the lungs,
resulting in tachypnea, crackles,
and respiratory distress due to pulmonary overcirculation.
Consequently, blood flow to the body decreases
and the patient's systemic blood pressure decreases.
Some signs and symptoms of PDA can
be identified by physical exam.
Flow through the ductus creates a systolic or continuous murmur
at the left sternal border.
The pulmonary overcirculation manifests
as tachypnea, increased work of breathing,
and pulmonary hemorrhage.
The systemic hypotension with diastolic runoff
through the ductus can be identified
by wide pulse pressure, bounding pulses, and palmar pulses,
often accompanied by a hyperactive pericardium.
To confirm a diagnosis of PDA, a chest X-ray or echocardiography
can be obtained if available.
Look for pulmonary edema or cardiomegaly
on the chest X-ray.
There are two types of PDA management--
non-pharmacological and pharmacological.
Non-pharmacological management involves
supporting increased respiratory needs
and restricting fluid to about 80% of maintenance fluids.
If there is evidence of significantly decreased
perfusion-- for example, decreased urine output or low
blood pressure--
hold enteral feeds due to decreased intestinal perfusion
and risk of necrotizing enterocolitis.
Necrotizing enterocolitis is caused
by decreased blood flow to the intestines, which
leads to localized necrosis, bacterial entry
into the bloodstream, and subsequent sepsis.
Pharmacological management of PDA
involves giving a medication that
is directed at closing the PDA.
This is typically given to infants
who have a PDA in the setting of prematurity.
One pharmacological option is enteral ibuprofen.
The first dose should be 10 mg per kg,
followed by a dose of 5 mg per kg 24 hours later.
Then another 5 mg per kg dose 24 hours after the second
for a total of three doses.
If the ductus remains open, the course can be repeated once.
If not, this approach is less likely to be
effective in babies older than one month.
There is a real risk of intestinal perforation
associated with ibuprofen treatment.
Ibuprofen is contraindicated in setting
of marked thrombocytopenia, less than 50,000,
bleeding disorders, impaired renal function,
and hyperbilirubinemia approaching
exchange transfusion levels.
Pharmacological management of PDA--
that is part of a broader congenital heart defect.
It's different from the treatment of PDA
in the setting of prematurity.
When managing PDA is a congenital defect,
consider the risks and benefits of diuretics,
specifically Furosemide at a dose
of 1 milligram per kilogram per day, IV or enteral.
If medical treatment is contraindicated or has failed,
the PDA may need to be repaired surgically.
Case Studies.
To review the content from this chapter,
we will look at the case of a newborn named Jean Claude.
He is five days old, 29 weeks of gestation age.
He had been steadily weaning in nasal cannula oxygen. Today,
his oxygen saturation has fallen from 95% to 87%.
He is also tachypneic and has retractions and mild
nasal flaring.
In addition to the potential pulmonary cause
of his respiratory dcompensation, what cardiac condition
should you consider?
These symptoms suggest that Jean Claude has PDA.
His respiratory symptoms are due to left to right shunting
with pulmonary over-circulation, causing tachypnea, increased
work of breathing, and hypoxia.
What else would you look for during a physical exam
to support this cardiac diagnosis?
On cardiac exam, he may also have a systolic or continuous
murmur at the upper left sternal border
due to the turbulent blood flowing through the PDA.
He could also have hyperactive precordium, bounding
peripheral pulses, and palpable palmar pulses.
You complete your exam and decide that Jean Claude
has likely a PDA.
What are some non-pharmacological treatments
you could try first to support him hoping
his ductus closes on its own?
Support his increased respiratory
needs with nasal cannula oxygen or CPAP if available.
Restrict fluids to around 80% of maintenance fluids.
If you see evidence of significantly decreased
systemic perfusion, such as decreased urine
output or low blood pressure, hold enteral
feeds due to the decreased intestinal perfusion.
After three days of non-pharmacological support,
his ductus does not seem to have closed by physical exam,
and his respiratory condition is worsening.
What pharmacological treatment can you offer?
Since Jean Claude is a preterm newborn
of less than 14 days of age, attempt
to close the PDA with enteral ibuprofen.
Provide a first dose of 10 mg per kg, then 5 mg per kg doses
every 24 hours, times two doses.
This course of three doses may be repeated once.
When giving ibuprofen, what are the contraindications
and the risks?
Contradictions include thrombocytopenia,
less than 50,000, bleeding disorders, impaired
renal function, and hyperbilirubinemia approaching
exchange transfusion levels.
Rare intestinal perforation is one risk of this treatment.
Summary.
You have now completed this chapter
and you should be able to identify
two presenting symptoms of patent ductus arteriosus,
identify methods for non-pharmacological support
of an infant with patent ductus arteriosus,
identify methods for pharmacological treatment
of an infant with PDA.
Keep in mind the following key points
from this cardiovascular chapter.
Patent ductus arteriosus is postnatal persistence
of the normal fetal vessel that joins the pulmonary artery
to the aorta.
PDA is most common in premature infants.
It can be diagnosed using a physical exam
and by looking for signs of pulmonary over-circulation
and systemic hypotension.
PDA can be managed with both pharmacological
and non-pharmacological treatments.
Pharmacological management of PDA
differs from premature infants and infants
with congenital cardiac defects.
Thank you for watching.
Please help us improve the content by providing us
with some feedback.