Patent Ductus Ateriosus
Neonatal Intensive Care Nursery
Night Curriculum Series
Fetal Circulation
During Fetal
Life:
1. What is the
resistance in
the
Pulmonary
Vasculature?
2. What is the
systemic
vascular
resistance?
3. Which
direction
does blood
shunt
through the
Ductus
Arteriosus?
PDA: RL
Shunting
Pulmonary
Vascular
Resistance: HIGH
Systemic
Vascular
Resistance:
LOW
What Major Changes in Infant
Circulation occur following birth?
• Lungs:
o Lungs expand
o PaO2↑’s Pulmonary vasodilatation
o Drop in pulmonary vascular resistance.
• Systemic Circulation:
o Resistance ↑’s with placental removal
• PDA:
o flow reverses to L R shunting
o Begins to functionally close due to ↑ PaO2, and decreased PGE2 levels
Case
• Called to the bedside of a 5 day old 25 week infant
with worsening respiratory distress. He is requiring
higher O2 settings and continues to have multiple
desaturations despite increased ventilator settings
What is in your initial differential
for this infant’s respiratory distress?
• Respiratory:
o Respiratory Distress Syndrome
(RDS)
o Pneumothorax
o Pulmonary Hemorrhage
• Cardiac
o Persistent Ductus Arteriosus
(PDA)
o Ductal Dependent Heart Lesion
• ID
o Sepsis
o Pneumonia
• GI
o NEC
• Neuro:
o IVH
o Seizures
Physical Exam
Vitals: 160, RR 68, BP 45/20, SaO2 85%
Weight: 980 grams (up 80 grams from 1 day prior)
HEENT: unremarkable
Pulm: tachypneic, decreased lung sounds at bases,
crackles heard bilaterally posterior lung fields
• CV: 3/6 systolic murmur loudest at LUSB, bounding
palmar pulses, active precordium, 2+femoral
pulses, CR <2 seconds
• Abdomen: soft, active bowel sounds
• Skin: warm, dry
•
•
•
•
What is the likely cause of this
infants respiratory distress?
A.
B.
C.
D.
Respiratory Distress Syndrome
PDA
Sepsis
NEC
What is the likely cause of this
infants respiratory distress?
A. Respiratory Distress Syndrome
B. PDA
C. Sepsis
D. NEC
What Physical Exam findings
are consistent with PDA?
Cardiac: Active Precordium,
Widened Pulse Pressure,
Bounding Pulses
Murmur: systolic at
LUSB/Left
Infraclavicular, may
progress to continuous
(machinery)
Respiratory Sx:
Tachypnea, Apnea,
CO2, increased vent
settings
What further diagnostic studies
could be done to confirm this?
• CXR
• Echocardiogram
What findings on this CXR are
suggestive of a PDA?
Increased
Pulmonary
vascular
makings
Uptodate.com
Cardiomegaly
Echocardiogram
• Gold standard for diagnosing PDA
Taken from Neo Reviews
Which Infants are at
greatest risk?
• The Youngest: risk increases with decreasing
gestational age
• The Smallest: 80% of ELBW infants (BW <1000g) with a
murmur progress to large persistent PDAs
What are complications of having
hemodynamically significant PDA?
•
•
•
•
•
•
•
•
Pulmonary Edema
Pulmonary Hemorrhage
BPD
NEC
Heart Failure
IVH
Prolonged ventilator/O2 support
Longer Duration of hospitalization.
What makes a PDA
Hemodynamically Significant?
Pulmonary Overcirculation (↑ Qp)
Oxygenation failure
Increased Vent
Requirements
Pulmonary Edema
Cardiomegaly
Systemic Hypoperfusion (↓ Qs)
Systemic Hypotension
End-Organ Hypoperfusion
Renal Insufficiency
NEC
IVH
Acidosis (metabolic, lactic)
What are three main
options for treatment?
1. Conservative/Supportive Management
2. Pharmacotherapy
3. Surgery
What Supportive Measures can you take in
an infant with a symptomatic PDA?
• Ventilator Strategies:
o Adequate Oxygenation
o Permissive Hypercapnea
o Use of PEEP
• Mild Fluid restriction: 110-130 ml/kg/day
• Heme: Maintenance of HCT 35-40%
Pharmacotherapy
• What 2 agents are typically used?
o Indomethacin
o Ibuprofen
Your Patient is on indocin
• The team decides to treat your patient with
indomethacin...
• How does indomethacin help close a PDA?
• MOA:
Indomethacin
o Cyclooxygenase inhibitor
o COX enzyme necessary for generating PGE2 (potent vasodilator)
• Adverse-Effects:
o reduces cerebral, gastrointestinal, and renal blood flow
o Decreased urine output
o Platelet dysfunction
• Would you continue/start feeds on this infant?
o given concern for increased risk of NEC many neonatologists hold feeds
during indomethacin therapy
What are some contraindications to
indomethacin?
 Proven/ suspected infection
 Active bleeding
 e.g. IVH, NEC
 Thrombocytopenia and/or coagulation defects
 Necrotizing enterocolitis
 Severe Renal Impairment
 Congenital heart disease with ductal dependent
lesion
Complications to watch for…
• What are you going to instruct the RN to notify you about
in this patient?
o Decreased Urine Output
• Indocin should be held if UOP < 1 ml/kg/h
o Abdominal Changes
o Signs/Sx of bleeding
• Are there any labs you would like to check before/after
starting indomethacin?
o CBC: to check platelets
o BMP: to check BUN and Creatinine
After two trials of indocin your patient
still has a symptomatic PDA what next
steps might you take?
• Continue supportive therapy through ventilator and
fluid management
• If infant continues to require high ventilator support
and echo demonstrates a large PDA consider
surgical ligation
• Indications?
Surgical Ligation
o Persistent Symptomatic PDA after 1-2 trials of Indomethacin or Motrin
o Contraindication to Indomethacin or Motrin
• Complications?
o
o
o
o
o
o
o
o
recurrent laryngeal nerve paralysis
blood pressure fluctuations
respiratory compromise
infection
intraventricular hemorrhage
chylothorax
BPD
death
Surgical Ligation
• Long Term Outcomes
o Current studies do not demonstrate that ligation
decreases incidence of BPD
o Some data to suggest infants that have surgical ligation
are at greater risk for neurocognitive delays
• Surgery should only be used for infants that have
failed medical management and are symptomatic
Objectives
•
•
•
•
•
•
Clinical Findings and Symptoms Consistent with PDA
Diagnosis of PDA
Complications of PDA
Indications for treatment
Treatment Options
Complications of Treatment
References:
• Chorne N, Leonard C, Piecuch R, Clyman RI. Patent
ductus arteriosus and its treatment as risk factors for
neonatal and neurodevelopmental morbidity. Pediatrics.
2007;119(6):1165.
• Gien, J. Controversied in the Management of Patent
Ductus Arteriosus. Neoreviews 2008: 9, 477-482
• Masalli, R. Optimal Fluid Management in Premature
Infants with PDA. Neoreviews 2010; 11: 495-502
• Philips , Joseph B. Management of patent ductus
arteriosus in premature infants. UptoDate
(www.uptodate.com)
• Phillips, J. Pathophysiology, clinical manifestations, and
diagnosis of patent ductus arteriosus in premature
infants. UptoDate (www.uptodate.com)
• Nelson Text Book of Pediatrics