Prompt

A 26-week, 780 g ventilated preterm at day 5 develops bounding pulses, a widened pulse pressure (52/24) and oliguria. The functional echocardiogram shows a 2.1 mm duct with diastolic flow reversal in the descending aorta. The examiner asks: 'Is this duct significant, and what is your management?'

Opening answer to give if asked to summarise

A patent ductus arteriosus in the preterm infant is persistent postnatal patency of the ductus, which fails to close because its immature smooth muscle contracts weakly to oxygen and remains sensitive to the relaxing prostaglandins. ^[13] It becomes haemodynamically significant when the falling pulmonary vascular resistance opens a large left-to-right shunt, producing pulmonary over-circulation and systemic diastolic steal. This infant's bounding pulses, widened pulse pressure with a low diastolic, oliguria, and a 2.1 mm duct with diastolic flow reversal are all hallmarks of significance. My management is expectant-first — supportive care while trending the end-organ signs — escalating to pharmacological closure (ibuprofen, or paracetamol given the renal picture) only if the compromise progresses, because the BeNeDuct and PDA-TOLERATE trials showed no benefit of routine early closure. ^[1] ^[11]

Branch 1 — Is this duct significant?

Examiner: "Is this ductus arteriosus haemodynamically significant, and how do you decide?" ^[13]

Significance is a clinical and echocardiographic constellation, not a single number. ^[13]

Bedside: bounding pulses, hyperdynamic precordium, widened pulse pressure with a low diastolic, and end-organ signs (oliguria, rising creatinine, escalating oxygen need). ^[13]
Echo: duct diameter above 1.5 mm (here 2.1 mm), left atrial-to-aortic root ratio above 1.5, diastolic flow reversal in the descending aorta, increased left ventricular output. ^[13]

This infant meets the criteria on both the clinical and the echo axes, with the renal and respiratory compromise confirming that the shunt is causing end-organ harm. ^[13]

References7Show

[1]Hundscheid T, Onland W, Kooi EMW, et al Expectant Management or Early Ibuprofen for Patent Ductus Arteriosus. N Engl J Med, 2023.PMID 36477458
[2]Mitra S, Florez ID, Tamayo ME, et al Association of Placebo, Indomethacin, Ibuprofen, and Acetaminophen With Closure of Hemodynamically Significant Patent Ductus Arteriosus in Preterm Infants: A Systematic Review and Meta-analysis. JAMA, 2018.PMID 29584842
[4]Jasani B, Mitra S, Shah PS Paracetamol (acetaminophen) for patent ductus arteriosus in preterm or low birth weight infants. Cochrane Database Syst Rev, 2022.PMID 36519620
[6]Clyman RI, Liebowitz M, Kaempf J, et al PDA-TOLERATE Trial: An Exploratory Randomized Controlled Trial of Treatment of Moderate-to-Large Patent Ductus Arteriosus at 1 Week of Age. J Pediatr, 2019.PMID 30340932
[10]Weisz DE, McNamara PJ Patent ductus arteriosus ligation and adverse outcomes: causality or bias? J Clin Neonatol, 2014.PMID 25024972
[11]Mitra S, Scrivens A, Fiander M, et al Early treatment versus expectant management of hemodynamically significant patent ductus arteriosus for preterm infants. Cochrane Database Syst Rev, 2025.PMID 40548426
[13]Mitra S, Weisz D, Jain A, et al Management of the patent ductus arteriosus in preterm infants. Paediatr Child Health, 2022.PMID 35273674

Branch 1 — Is this duct significant?

Examiner: "Is this ductus arteriosus haemodynamically significant, and how do you decide?" ^[13]

Significance is a clinical and echocardiographic constellation, not a single number. ^[13]

Bedside: bounding pulses, hyperdynamic precordium, widened pulse pressure with a low diastolic, and end-organ signs (oliguria, rising creatinine, escalating oxygen need). ^[13]

Echo: duct diameter above 1.5 mm (here 2.1 mm), left atrial-to-aortic root ratio above 1.5, diastolic flow reversal in the descending aorta, increased left ventricular output. ^[13]

This infant meets the criteria on both the clinical and the echo axes, with the renal and respiratory compromise confirming that the shunt is causing end-organ harm. ^[13]

References7Show

[1]Hundscheid T, Onland W, Kooi EMW, et al Expectant Management or Early Ibuprofen for Patent Ductus Arteriosus. N Engl J Med, 2023.PMID 36477458
[2]Mitra S, Florez ID, Tamayo ME, et al Association of Placebo, Indomethacin, Ibuprofen, and Acetaminophen With Closure of Hemodynamically Significant Patent Ductus Arteriosus in Preterm Infants: A Systematic Review and Meta-analysis. JAMA, 2018.PMID 29584842
[4]Jasani B, Mitra S, Shah PS Paracetamol (acetaminophen) for patent ductus arteriosus in preterm or low birth weight infants. Cochrane Database Syst Rev, 2022.PMID 36519620
[6]Clyman RI, Liebowitz M, Kaempf J, et al PDA-TOLERATE Trial: An Exploratory Randomized Controlled Trial of Treatment of Moderate-to-Large Patent Ductus Arteriosus at 1 Week of Age. J Pediatr, 2019.PMID 30340932
[10]Weisz DE, McNamara PJ Patent ductus arteriosus ligation and adverse outcomes: causality or bias? J Clin Neonatol, 2014.PMID 25024972
[11]Mitra S, Scrivens A, Fiander M, et al Early treatment versus expectant management of hemodynamically significant patent ductus arteriosus for preterm infants. Cochrane Database Syst Rev, 2025.PMID 40548426
[13]Mitra S, Weisz D, Jain A, et al Management of the patent ductus arteriosus in preterm infants. Paediatr Child Health, 2022.PMID 35273674

Patent ductus arteriosus in preterm infants — branching viva

Branch 1 — Is this duct significant?

Patent ductus arteriosus in preterm infants — branching viva

Branch 1 — Is this duct significant?