1. Patent Ductus Ateriosus
Neonatal Intensive Care Nursery
Night Curriculum Series

2. Fetal Circulation Pulmonary Vascular Resistance: HIGH
During Fetal Life:
What is the resistance in the Pulmonary Vasculature?
What is the systemic vascular resistance?
Which direction does blood shunt through the Ductus Arteriosus?
PDA: RL Shunting
Pulmonary Vascular
Resistance: HIGH
Systemic Vascular
Resistance: LOW

3. What Major Changes in Infant Circulation occur following birth?
Lungs:
Lungs expand
PaO2↑’s Pulmonary vasodilatation
Drop in pulmonary vascular resistance.
Systemic Circulation:
Resistance ↑’s with placental removal
PDA:
flow reverses to L R shunting
Begins to functionally close due to ↑ PaO2, and decreased PGE2 levels

4. 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

5. What is in your initial differential for this infant’s respiratory distress?
Respiratory Distress Syndrome (RDS)
Pneumothorax
Pulmonary Hemorrhage
Cardiac
Persistent Ductus Arteriosus (PDA)
Ductal Dependent Heart Lesion ID
Sepsis
Pneumonia GI
NEC
Neuro:
IVH
Seizures

6. 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

7. What is the likely cause of this infants respiratory distress?
Respiratory Distress Syndrome
PDA
Sepsis
NEC

8. What is the likely cause of this infants respiratory distress?
Respiratory Distress Syndrome
PDA
Sepsis
NEC

9. 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)
Widened pulse pressure that is greater than 25 mmHg or if the difference between the systolic and diastolic blood pressure (BP) exceeds half of the value of the systolic BP
Respiratory Sx: Tachypnea, Apnea, CO2, increased vent settings

10. What further diagnostic studies could be done to confirm this?
CXR
Echocardiogram

11. What findings on this CXR are suggestive of a PDA?
Increased Pulmonary vascular makings
Cardiomegaly
Uptodate.com

12. Echocardiogram
Gold standard for diagnosing PDA
Taken from Neo Reviews

13. 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

14. 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.

15. What makes a PDA Hemodynamically Significant?
Pulmonary Overcirculation (↑ Qp)
Systemic Hypoperfusion (↓ Qs)
Oxygenation failure
Increased Vent Requirements
Pulmonary Edema Cardiomegaly
Systemic Hypotension
End-Organ Hypoperfusion
Renal Insufficiency
NEC
IVH
Acidosis (metabolic, lactic)

16. What are three main options for treatment?
Conservative/Supportive Management
Pharmacotherapy
Surgery

17. What Supportive Measures can you take in an infant with a symptomatic PDA?
Ventilator Strategies:
Adequate Oxygenation
Permissive Hypercapnea
Use of PEEP
Mild Fluid restriction: ml/kg/day
Heme: Maintenance of HCT 35-40%

18. Pharmacotherapy What 2 agents are typically used? Indomethacin
Ibuprofen

19. Your Patient is on indocin
The team decides to treat your patient with indomethacin...
How does indomethacin help close a PDA?

20. Indomethacin MOA: Adverse-Effects:
Cyclooxygenase inhibitor
COX enzyme necessary for generating PGE2 (potent vasodilator)
Adverse-Effects:
reduces cerebral, gastrointestinal, and renal blood flow
Decreased urine output
Platelet dysfunction
Would you continue/start feeds on this infant?
given concern for increased risk of NEC many neonatologists hold feeds during indomethacin therapy

21. 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

22. Complications to watch for…
What are you going to instruct the RN to notify you about in this patient?
Decreased Urine Output
Indocin should be held if UOP < 1 ml/kg/h
Abdominal Changes
Signs/Sx of bleeding
Are there any labs you would like to check before/after starting indomethacin?
CBC: to check platelets
BMP: to check BUN and Creatinine

23. 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

24. Surgical Ligation Indications? Complications?
Persistent Symptomatic PDA after 1-2 trials of Indomethacin or Motrin
Contraindication to Indomethacin or Motrin
Complications?
recurrent laryngeal nerve paralysis
blood pressure fluctuations
respiratory compromise
infection
intraventricular hemorrhage
chylothorax
BPD
death

25. Surgical Ligation Long Term Outcomes
Current studies do not demonstrate that ligation decreases incidence of BPD
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

26. Objectives Clinical Findings and Symptoms Consistent with PDA
Diagnosis of PDA
Complications of PDA
Indications for treatment
Treatment Options
Complications of Treatment

27. 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,
Masalli, R. Optimal Fluid Management in Premature Infants with PDA. Neoreviews 2010; 11:
Philips , Joseph B. Management of patent ductus arteriosus in premature infants. UptoDate (
Phillips, J. Pathophysiology, clinical manifestations, and diagnosis of patent ductus arteriosus in premature infants. UptoDate (
Nelson Text Book of Pediatrics