PDA COPY

Question 1

What is the function of the ductus arteriosus (DA) in fetal circulation?

Answer 1

The DA connects the pulmonary artery to the descending aorta, allowing blood to bypass non-ventilated fetal lungs.

Question 2

What percentage of right ventricular output flows through the DA in utero?

Answer 2

~90%

Question 3

What maintains DA patency during fetal life?

Answer 3

Low oxygen tension (PaO2) and high levels of prostaglandin E2 (PGE2).

Question 4

What triggers the closure of the ductus arteriosus after birth?

Answer 4

Increase in PaO2 and decrease in PGE2.

Question 5

When does functional closure of the DA typically occur?

Answer 5

Within 72 hours postnatally.

Question 6

What completes anatomical closure of the DA?

Answer 6

Intimal thickening and fibrosis, generally by 4 months of age.

Question 7

What is the effect of umbilical cord clamping on the DA?

Answer 7

Increases systemic vascular resistance (SVR).

Question 8

How does lung expansion affect the ductus arteriosus?

Answer 8

Decreases pulmonary vascular resistance (PVR) and increases pulmonary blood flow.

Question 9

What role does oxygenation play in the closure of the DA?

Answer 9

Increases reduce PGE2 production and enhance its metabolism.

Question 10

What factors prevent closure of the DA in preterm infants?

Answer 10

• Immature pulmonary and renal metabolism
• Increased nitric oxide (NO) from oxygen therapy
• Immature ductal muscle structure
• Sepsis, RDS, and other comorbidities

Question 11

What are clinical manifestations of hemodynamically significant PDA (hsPDA)?

Answer 11

• Systolic murmur
• Bounding peripheral pulses
• Widened pulse pressure (>20 mmHg)
• Tachycardia
• Escalating oxygen needs
• Decreased urine output

Question 12

What is the gold standard for diagnosing PDA?

Answer 12

Echocardiography.

Question 13

What do elevated levels of BNP or NT-proBNP indicate?

Answer 13

Ventricular stress from volume overload.

Question 14

What is a common outcome for ELBW infants with PDA within the first 8 days?

Answer 14

Spontaneous closure.

Question 15

What is a conservative treatment strategy for PDA?

Answer 15

• Optimize fluid balance
• Diuretics may improve symptoms
• Ensure adequate oxygenation

Question 16

What is the mechanism of action of indomethacin?

Answer 16

Non-selective inhibition of COX-1 and COX-2, reducing PGE2 synthesis.

Question 17

When is indomethacin most effective?

Answer 17

When given within the first 3 days of life.

Question 18

What are the adverse effects of indomethacin?

Answer 18

• ↓ cerebral perfusion
• ↓ urine output
• Risk for spontaneous intestinal perforation (SIP)

Question 19

What is the standard dosing for ibuprofen in PDA management?

Answer 19

10 mg/kg IV or PO initially, followed by 5 mg/kg at 24 and 48 hours.

Question 20

What are the advantages of using ibuprofen compared to indomethacin?

Answer 20

May be safer in terms of renal, GI, and cerebral perfusion.

Question 21

What is the dosing for acetaminophen in PDA management?

Answer 21

7.5–15 mg/kg q6h for 3–7 days IV or PO.

Question 22

What are the potential adverse effects of acetaminophen?

Answer 22

• Hepatotoxicity
• Transient elevations in AST, ALT, GGT

Question 23

What is indicated when pharmacologic therapy for PDA fails?

Answer 23

Surgical management.

Question 24

What are some risks associated with surgical management of PDA?

Answer 24

• Vocal cord paralysis
• Chylothorax
• Pneumothorax
• Ductal tear

Question 25

What is the role of Alprostadil (PGE1) in managing ductal-dependent lesions?

Answer 25

Maintains ductal patency for congenital heart disease.

Question 26

What are the adverse effects of long-term use of Alprostadil?

Answer 26

* Hypotension * Apnea * Feeding intolerance

Question 27

What supportive measures should be taken for PDA management?

Answer 27

* Conservative fluid restriction * Maintain optimal ventilator settings

Question 28

Fill in the blank: The half-life of Alprostadil is approximately _______.

Answer 28

1 minute