Patent_ductus_Arteriosus_flashcards

Question 1

What is Patent Ductus Arteriosus (PDA)?

Answer 1

PDA is a form of congenital heart defect.

Question 2

How is PDA generally classified?

Answer 2

PDA is generally classed as ‘acyanotic’.

Question 3

What can uncorrected PDA eventually result in?

Answer 3

Uncorrected PDA can eventually result in late cyanosis in the lower extremities, termed differential cyanosis.

Question 4

Where is the connection in PDA?

Answer 4

In PDA, there is a connection between the pulmonary trunk and descending aorta.

Question 5

What causes the ductus arteriosus to close after birth?

Answer 5

The ductus arteriosus usually closes with the first breaths due to increased pulmonary flow which enhances prostaglandin clearance.

Question 6

In which groups is PDA more common?

Answer 6

PDA is more common in premature babies, babies born at high altitude, or those with maternal rubella infection in the first trimester.

Question 7

What are some features of PDA?

Answer 7

Features of PDA include a left subclavicular thrill, continuous ‘machinery’ murmur, large volume bounding collapsing pulse, wide pulse pressure, and heaving apex beat.

Question 8

What kind of murmur is associated with PDA?

Answer 8

A continuous ‘machinery’ murmur is associated with PDA.

Question 9

Describe the pulse in PDA.

Answer 9

The pulse in PDA is large volume, bounding, and collapsing.

Question 10

What is the management for PDA?

Answer 10

Management for PDA includes the use of indomethacin or ibuprofen.

Question 11

How does indomethacin or ibuprofen help in PDA?

Answer 11

Indomethacin or ibuprofen inhibits prostaglandin synthesis, which closes the connection in the majority of cases.

Question 12

What is the role of prostaglandin E1 in PDA management?

Answer 12

If PDA is associated with another congenital heart defect amenable to surgery, prostaglandin E1 is useful to keep the duct open until after surgical repair.

Question 13

Summarise Patent ductus arteriosus

Answer 13

Patent ductus arteriosus

Overview
a form of congenital heart defect
generally classed as ‘acyanotic’. However, uncorrected can eventually result in late cyanosis in the lower extremities, termed differential cyanosis
connection between the pulmonary trunk and descending aorta
usually, the ductus arteriosus closes with the first breaths due to increased pulmonary flow which enhances prostaglandins clearance
more common in premature babies, born at high altitude or maternal rubella infection in the first trimester

Features
left subclavicular thrill
continuous ‘machinery’ murmur
large volume, bounding, collapsing pulse
wide pulse pressure
heaving apex beat

Management
indomethacin or ibuprofen
given to the neonate
inhibits prostaglandin synthesis
closes the connection in the majority of cases
if associated with another congenital heart defect amenable to surgery then prostaglandin E1 is useful to keep the duct open until after surgical repair

Question 14

You are asked to review a neonate born pre-term at 35 weeks, 36-hours after delivery with no complications.

On examination, you find a left subclavicular thrill and notice a continuous ‘machinery-like’ murmur. You also discover a bounding pulse and note a widened pulse pressure.
There is no evidence of cyanosis, nor crackles on auscultation.

Upon reviewing the notes and history with the mother, there were no problems during the pregnancy, nor any abnormal findings on antenatal scans or screening. There is no family history of any significant disease.

Given the likely diagnosis, what would be the most appropriate management option?

Give indomethacin to the mother
Give indomethacin to the neonate
Reassure the mother and monitor over the coming months
Request a review from the surgical team
Give prostaglandin E1 to the neonate

Answer 14

Give indomethacin to the neonate

Indomethacin or ibuprofen is used in patent ductus arteriosus to promote duct closure

Giving indomethacin to the neonate is the correct answer, as the examination findings point toward a diagnosis of patent ductus arteriosus (PDA). The ductus arteriosus usually closes with the first breaths, which clear the prostaglandins keeping it open. When this does not occur, indomethacin or ibuprofen can be given, as these inhibit prostaglandin synthesis.

Giving indomethacin to the mother would not achieve this - it needs to be given to the neonate.

Prostaglandin would have the opposite effect, and would maintain the PDA’s patency. This would be useful if surgical repair was warranted - if a congenital heart disease was also discovered upon investigation. The lack of family history, and normal screening/scans during pregnancy make that unlikely in this scenario.

The same applies to the option of getting the surgeons involved.

Reassuring the mother and monitoring over the coming months would not be appropriate. For now, the baby is acyanotic, but if left untreated, can lead to pulmonary hypertension, or Eisenmenger’s syndrome - reversal of the shunt from left-to-right (acyanotic), to right-to-left (cyanotic).

Question 15

The ward doctor is asked to review a 12-hour-old neonate, born at 34 weeks gestation to a healthy mother during an otherwise-uncomplicated vaginal delivery. On examination, the neonate looks comfortable. A continuous ‘machinery-like’ murmur is noted on auscultation of the heart, as well as a left-sided thrill. The apex beat appears to be heaving on palpation. A widened pulse pressure is noted. There is no visible cyanosis. An echocardiogram is subsequently performed which confirms the diagnosis, and rules out any other cardiac problems.

Given the likely diagnosis, what is the most appropriate management at this stage?

Indomethacin given to the neonate
Percutaneous intervention
Refer for elective surgery
Refer for urgent surgery
Prostaglandin E1 given to the neonate

Answer 15

Indomethacin given to the neonate

Patent ductus arteriosus: indomethacin is given to the neonate in the postnatal period, not to the mother in the antenatal period

The likely diagnosis here, given the findings, is that of patent ductus arteriosus (PDA). The correct answer is therefore giving indomethacin to the neonate, as this prompts duct closure in the majority of cases.

The echocardiogram ruled out other defects - however, if another defect was present, it may be preferable to use prostaglandin E1 to keep the duct open until after surgical repair.

At this stage, referral for surgery is thus unwarranted.

Percutaneous closure may be used for duct closure in older children, to avoid surgery. However, this would not be suitable in a neonate.

Question 16

A 28-year-old pregnant female attends a routine clinic appointment. She is concerned because one of her fetal ultrasound reports shows evidence of a large patent ductus arteriosus in the fetus. She has read on the internet that indomethacin can treat this condition, and wants to know more about the drug.

What will you tell the mother about the administration of this drug?

It is given to the mother if repeat fetal ultrasound shows a large patent ductus arteriosus
It is given to the newborn right after delivery
It is given to the newborn if the echocardiogram shows patent ductus arteriosus one week after delivery
It is not used for closing the patent ductus arteriosus as it keeps the ductus arteriosus open
It is given to the mother between week 26 and 28 of pregnancy

Answer 16

It is given to the newborn if the echocardiogram shows patent ductus arteriosus one week after delivery

Patent ductus arteriosus: indomethacin is given to the neonate in the postnatal period, not to the mother in the antenatal period
Important for meLess important
Patent ductus arteriosus (PDA) is a non-cyanotic congenital heart disorder. It is a type of left-right shunt in which blood passes from the aorta to the pulmonary vessel via the patent ductus arteriosus. Newborns may have a normal presentation, but on auscultation, a continuous machine-like murmur is characteristic. Indomethacin is the drug of choice for treating the patent ductus arteriosus in a newborn. It acts by inhibiting prostaglandin E2.

PDA is commonly found in premature babies. It is observed for spontaneous closure in asymptomatic patients. Symptomatic babies undergo an echocardiogram a few days after birth. Depending on the echocardiogram findings, the PDA is managed medically or surgically. Medical management involves giving indomethacin or ibuprofen to the newborn. Giving these medicines to the mother has no role in the closure of the PDA. Prophylactically treating a newborn right after delivery is also not recommended.

Prostaglandin analogues can keep the ductus arteriosus patent after birth. They are given to the baby after delivery and are useful in managing some congenital heart diseases.

Question 17

A 12-hour-old newborn, born at 34 weeks to a healthy mother, is currently undergoing a check whilst on the ward. The baby appears healthy on general inspection and the mother reports no concerns so far. On examination, a large volume, collapsing pulse is noted, and a heaving apex beat, as well as a left subclavicular thrill. On auscultation of heart sounds, the doctor notes a continuous ‘machinery-like’ murmur.

The doctor arranges an urgent echocardiogram, which confirms her suspected diagnosis. No other abnormalities or defects are demonstrated on the echo.

Given the findings and likely diagnosis, what would be the most appropriate initial management?

Arrange a routine surgical opinion
Arrange an urgent surgical opinion
Give indomethacin to the neonate
Monitor and repeat serial echocardiograms over the first three months of life
Give prostaglandin E1 to the neonate

Answer 17

Give indomethacin to the neonate

Indomethacin or ibuprofen is used in patent ductus arteriosus to promote duct closure

The likely diagnosis here, given the examination findings, is that of pulmonary ductus arteriosus (PDA). The ‘machinery-like’ murmur described is classical of PDA. The most appropriate management here would be giving indomethacin (or ibuprofen) to the neonate, as this would block prostaglandin production. Prostaglandins keep the duct open, and so blockage usually causes the duct to close.

Giving prostaglandin E1 is incorrect - this would be used to keep the duct open. Doing this would be useful if another congenital heart defect had been found on the echocardiogram, until after surgical repair. However, the question states that the echocardiogram was normal, apart from the PDA.

Routine and urgent surgical referrals are incorrect, for the reason above - no other defects were found and so first-line management should be indomethacin. In the small number of cases where this is unsuccessful, referral to surgery would then be warranted.

Monitoring and repeating echocardiograms is incorrect - as explained above, this defect requires medical intervention to prompt its closure. Monitoring alone, without intervention, is not sufficient.

Question 18

buzz words

buzz words

Answer 18

neonate born pre-term
left subclavicular thrill
continuous ‘machinery-like’ murmur
bounding pulse - a large volume, collapsing pulse
heaving apex beat - The apex beat appears to be heaving on palpation.
widened pulse pressure.
no evidence of cyanosis, nor crackles on auscultation
uncomplicated vaginal delivery

Question 19

A premature infant is admitted to hospital following signs of heart failure soon after birth. She has poor feeding associated with heavy sweating and tiring out. This has resulted in her not gaining weight as expected. Her parents also report irritability and periods of apnoea.

On examination, bounding peripheral pulses and a continuous machinery murmur are identified. An echocardiogram shows left ventricular enlargement and a shunt between two of the great vessels. A patent ductus arteriosus (PDA) is suspected.

What non-surgical intervention could be used to manage this patient?

Aspirin
Caffeine citrate
Furosemide
Indomethacin
Prostaglandin E2

Answer 19

Indomethacin

Indomethacin or ibuprofen is used in patent ductus arteriosus to promote duct closure

Indomethacin is the correct answer. This patient has a patent ductus arteriosus (PDA) causing her symptoms. PDA describes the incomplete closure of the ductus arteriosus after birth. In utero, this vessel allows blood to bypass the immature fetal lungs. However, if the duct remains patent after birth a large amount of blood can bypass the functioning lungs resulting in reduced oxygen saturation and a murmur.

The ductus arteriosus is maintained by prostaglandin E2, so medications like indomethacin or ibuprofen which inhibit prostaglandin synthesis can be effective methods for closing the duct. However, sometimes surgery may be required to close particularly large PDAs.

Prostaglandin E2 is the wrong answer here. It is used to keep the ductus arteriosus patent, not close it. This may be indicated in complex congenital heart defects where a shunt is necessary to maintain life (e.g. transposition of the great arteries).

Aspirin is an incorrect answer. Aspirin should not be given to children under the age of 16 due to the risk of Reye’s syndrome. It is indicated in Kawasaki disease and for its anti-platelet effect in some situations.

Caffeine citrate is another incorrect answer. Caffeine citrate is indicated for neonates with apnoea, however it is not the best option here as it will not close the PDA.

Furosemide is not the correct answer. It can be used to improve symptoms in neonatal heart failure, however it is not the best option here. There is no evidence of fluid overload, so furosemide may worsen symptoms in this case and will not close the PDA.

Question 20

A 1-year-old girl is noted to have a continuous murmur, loudest at the left sternal edge. She is not cyanosed. A diagnosis of patent ductus arteriosus is suspected. What pulse abnormality is most associated with this condition?

Collapsing pulse
Bisferiens pulse
Pulsus parodoxus
‘Jerky’ pulse
Pulsus alternans

Answer 20

Collapsing pulse

Patent ductus arteriosus - large volume, bounding, collapsing pulse

The correct answer is Collapsing pulse. In patent ductus arteriosus (PDA), the ductus arteriosus, which normally closes shortly after birth, remains open. This results in a left-to-right shunt from the aorta to the pulmonary artery, leading to increased stroke volume and subsequently a rapid rise and fall of arterial pressure - hence a collapsing pulse. The collapsing pulse is characterised by a forceful upstroke followed by a rapid drop in systolic pressure, giving it a ‘water-hammer’ feel.

Bisferiens pulse is incorrect. Bisferiens pulse is characterised by two peaks in systole and can be felt as a double beat for each cardiac cycle. This type of pulse is typically associated with conditions like hypertrophic cardiomyopathy or severe aortic regurgitation, not PDA.

Pulsus paradoxus is also incorrect. Pulsus paradoxus refers to an exaggerated decrease in pulse amplitude during inspiration and can be seen in conditions such as cardiac tamponade or severe asthma - again not typically associated with PDA.

The ‘Jerky’ pulse option is incorrect too. A ‘jerky’ pulse, also known as pulsus bisferiens, describes a double-peaked (or ‘jerky’) sensation when palpating the radial artery. It’s most commonly associated with combined stenosis and regurgitation of the aortic valve.

Lastly, Pulsus alternans is incorrect as well. Pulsus alternans refers to alternating strong and weak pulses which may indicate left ventricular failure or other serious cardiac disease but it’s not specifically associated with patent ductus arteriosus.