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Patent Ductus Arteriosus (PDA) in Preterm Infants | FAQ’s

August 29, 2019


(bright music)>>A patent ductus arteriosus or PDA is a normal blood vessel
that occurs in all infants while they’re still in
their mother’s womb. It’s a small blood vessel that
allows the blood to bypass the lungs that are not
needed before they’re born. Once a baby is born, this
blood vessel will normally close down over the first
two to three days of life. This is stimulated by the
increase in oxygen levels and the drop in
prostaglandins that are coming from the placenta and
inflation of the lungs. (bright music) In premature infants, the
PDA often is less likely to close than it is in full-term infants. This is due to a variety of reasons. One is that there’s less muscle in the actual blood vessel
wall to help it constrict down. Also, in pre-term infants
who have lung disease, they don’t get the same increase in oxygen and drop in their pulmonary pressures. PDAs are much more
common, the more immature and the smaller the babies are. In infants who are born
before 28 weeks gestation, approximately two-thirds of these babies will have a patent ductus arteriosus. (bright music) If the PDA stays open, blood can flow into the lungs causing over circulation and potential congestive heart failure, which can lead to worsening
respiratory symptoms. In addition, it can be a
cause of severe hypotension or low blood pressure. In some cases, it can
divert blood flow away from vital organs such as the kidneys and cause kidney failure. (bright music) We have some medical therapies that will close the PDA in our infants. Medications we commonly use
are indomethacin or ibuprofen. These can be successful in
about two-thirds of the cases. Complications do occur with any medication and can cause GI distress,
decreased kidney function and can also promote increased bleeding. Other medications have been
tried such as an acetaminophen, but these have been shown
to be less effective. When medical treatment doesn’t work or the infant is too unstable
to tolerate these medications, we often proceed to a surgical procedure. This requires the baby
to have surgery to have a ligation of this duct, so
it’s a opening of the chest. Obviously, this can have
lots of complications, undergoing anesthesia,
surgery, risk of infections and bleeding, in addition to the concern that there may be long-term
developmental disabilities associated with this procedure. (bright music) Increase in evidence has been mounting, but PDAs do not need to
be treated as aggressively as they have been historically. As people have started to
treat these less frequently, they have found that
looking at these infants that they’ve tolerated not being treated, and that they may have a better outcome. But most of these studies
have been criticized because those infants not treated may be the less sick infants and thus be having the better
outcome because of that. (bright music) Research done at the John
Hopkins Children’s Center is part of a multicenter
trial was recently published. This was a prospective randomized study where infants who are born prematurely who had a PDA were randomized to either get the
standard medical treatment or to be monitored conservatively. Those infants who were
monitored conservatively were allowed to have treatment if they have showed evidence of worsening respiratory symptoms, hypotension or renal failure. But what was interesting is that the need for surgical ligation in
both groups was identical. And in fact, there was
no increase risk in any of the adverse outcomes such
as necrotizing enterocolitis or bronchopulmonary dysplasia, that are often worried that
they are associated with a PDA. Those infants who were treated, surprisingly ended up with
higher rates of infection, delays in their feeding
and an increased mortality. The result of the study
is that it’s now known to be safe to monitor
children who are asymptomatic with a PDA to see if they’ll
allow them to slowly close on their own without the worry
of adverse long-term effects. If they are symptomatic,
such as the hypotension, respiratory symptoms or renal failure, it is appropriate to treat these infants. Clearly for surgical treatment, they need to be at a children’s center where the surgery can be done safely. (bright music)

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