This document discusses surgical closure of patent ductus arteriosus (PDA) in premature infants. It provides guidelines for when surgical referral is appropriate, such as when two courses of medication have failed to close a large PDA. The success rate of medication closure is 79% for infants over 1750g and lower for infants under 800g. The document outlines pre-operative testing and guidelines for the surgery including echocardiogram, bloodwork and discussions between medical teams. Potential complications are discussed such as hemorrhage, recurrent ductal patency and respiratory problems. Post-ligation cardiac syndrome is also summarized, which can involve low blood pressure, increased ventilation needs, and interventions like inotropic support.
2. PDA Ligation in Preterms
Surgical ligation is performed for PDA closure when medical
treatment fails or is contraindicated.
The success rate of indomethacin therapy for PDA closure is 79% if
birth weight is < 1750 g.
The failure rate is up to 40–50% if birth weight is < 800g.
Fragility of the tissues and also duct is a challenge on a low birth
weight infant compared to a normal weight one
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3. Protocol for Surgical Referral
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Premature neonates < 29/40 all get an Echo within 4-24 hours after birth
PDA > 1.5mm are treated with a course of indomethacin/ibuprofen.
Ductus still significantly open on Re-Echo after the 1st course of NSAIDs,
then a 2nd course is given.
If the 2nd course of NSAIDs fails to close the ductus and it remains large
or problematic --- Causing high ventilation requirements/failure to wean
off ventilation --- decision may be to refer that baby to cardiology for
consideration of Surgical closure
4. Guidelines for Surgical Management
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Decision for PDA ligation should be a Consensus among: the Neonatologist on
service, Cardiologist performing 2D ECHO . and the Paediatric cardiothoracic
surgeon performing the procedure.
All PDA ligation in our institute need a JCC discussion .
A PDA may be considered for ligation if it is large both size and shunt volume,
with clinical indicators of pulmonary over-circulation (Intubated with escalating
respiratory support) with or without clinical indicators of systemic hypo-perfusion.
The side of arch , PDA dimensions and any other cardiac anomaly is clearly
Documented.
The reason for surgical ligation of the Ductus arteriosus should be clearly
indicated and documented by the neonatologist on service.
5. Guidelines for Surgical Management
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Echocardiogram should be performed by paediatric cardiologist at least once
before PDA ligation to exclude duct-dependent congenital heart disease .
Rule out spontaneous duct closure prior to surgery- Clinical / Echo
On the day before PDA ligation surgery:
-Chest x-ray: As baseline prior to surgery.
- Complete blood count.( Platelet count )
- Coagulation profile
- Group & Hold – 1 PRBC/ 1 Platelet
- Rule out MRSA/MSSA
12. Case Discussion
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Kid was born with Extreme prematurity (24 weeks)
Extremely low birth weight (639 g)
Respiratory Distress – Consistent with Hyaline membrane disease- Intubated
Gastric Perforation – Day 12 of life – Laprotomy done.
MRSA Bacteraemia – positive blood culture – treated with 2 week
Vancomycin
MRSA Conjunctivitis – treated with 5 days of chloramphenicol
Patent ductus arteriosus -Dilated LV , Increasing size pf PDA – 1.6 TO 1.8
mm – Referred for PDA ligation.
15. POSTNATAL CMV INFECTION
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Initial Urine CMV on was negative (result sent as part of work-up for
causes of gastric perforation).
Repeat urine CMV was sent on day 31 of life to investigate
unexplained thrombocytopenia (nadir 60) and mildly abnormal liver
enzymes (ALT 70).
There was also an associated fever to 38 on day 30 of life (thought
to be transfusion related).
The repeat urine CMV was later found to be positive.
Severe respiratory deterioration in his last few hours of life was
likely related to a CMV infection or pneumonitis
16. Post Ligation Cardiac Syndrome
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PLCS is characterised clinically by a fall in systolic blood
pressure (usually < 3rd centile for age) requiring one or more
cardiotropic agents, and increasing ventilator requirements,
necessitating an increase in mean air way pressure and FiO2
by at least 20%.
Do a Chest x-ray within one hour of surgical intervention to
exclude air leaks or hyperinflation.
2d Echo postoperatively – showcasing unobstructed arch and
closed ductus.
17. Post Ligation Cardiac Syndrome
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Pay close attention to post-operative respiratory management (consider frequent
blood gases) due to expected improvement of lung compliance after resolution of
pulmonary over circulation.
Consider an indwelling arterial line for enhanced blood pressure monitoring and 6-
8 hrly blood gas/lactate analysis.
Mean arterial pressure (MAP) may be less reliable in the setting of PDA ligation
due to trends seen in systolic (SAP) and diastolic (DAP) arterial pressure. The
decline in SAP secondary to LV dysfunction may be masked when MAP only is
considered.
Thresholds for intervention should include a SAP or DAP < 3rd percentile.
In the setting of low SAP, low fractional shortening, inodilator therapy is
preferable. Common agents used in this setting may include dobutamine or
milrinone
18. PDA ligation and adrenal insufficiency
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Hydrocortisone therapy is occasionally indicated
for refractory hypotension.
These patients are typified by an early fall in
both SAP and DAP.
Measurement of pre- and postoperative cortisol,
or a preoperative ACTH stimulation test may
guide any decisions related to steroid treatment.
19. Summary
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PDA ligation may lead to resolution of the primary clinical
problem, but potentially exposes the infant to significant
cardiorespiratory instability.
The physiologic changes accompanying PDA ligation and
multifactorial nature of the circulatory compromise require
focused neonatal cardiac care.
Standardized guidelines are likely to be beneficial, given
the predictable nature of the clinical deterioration.