What makes a PDA haemodynamically significant?

A duct is considered significant when it causes a meaningful left-to-right shunt and volume load on the heart. Key markers are a larger ductal diameter, an LA:Ao ratio above about 1.5, and a clinical picture of worsening respiratory or circulatory status, especially in very preterm infants.

How does this estimator weight the features?

Ductal diameter and LA:Ao ratio carry the most points because they directly reflect shunt magnitude. Extreme prematurity, very low weight, and high levels of respiratory support add further points. The total maps to a suggested management tier.

Why does postnatal age change the suggestion?

Indomethacin and ibuprofen close the duct most reliably in the first one to two weeks of life. Beyond about three weeks pharmacological closure is much less effective, so the tool shifts the suggestion toward surgical or device referral when the infant is older.

When is pharmacological closure contraindicated?

NSAID closure is avoided with significant renal impairment, low platelets or active bleeding, and necrotising enterocolitis. If you flag a contraindication the tool moves a pharmacological candidate toward surgical referral, since drug treatment is not safe.

Is this a validated clinical score?

No. It is a structured aggregator to support team discussion, not a published or validated decision rule. Many units now manage even significant ducts conservatively. Every treatment decision must be made by the neonatal and cardiology team for the individual baby.

What is the Neonatal PDA Treatment Candidacy Estimator?

Aggregates neonatal gestational age, weight, respiratory support, ductal diameter, and echo-derived LA:Ao ratio into a structured score that guides conservative, pharmacological, or surgical patent ductus arteriosus management. For neonatologists. It runs free in your browser on Gera Tools, with nothing uploaded.

Neonatal PDA Treatment Candidacy Estimator

Name: Neonatal PDA Treatment Candidacy Estimator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Deciding whether and how to treat a patent ductus arteriosus in a preterm infant is one of the more contested judgements in neonatology. This estimator gathers the features clinicians routinely weigh into one structured view to support that discussion, not to replace it.

How it works

The tool assigns points across recognised markers of a haemodynamically significant duct and respiratory burden, then maps the total to a management tier:

ductal diameter >= 2.0 mm        +3
LA:Ao ratio >= 1.8               +3
high-frequency ventilation       +3
gestational age < 26 weeks       +3
... lesser thresholds            +1 / +2 each

score <= 3   -> conservative (watchful waiting)
score 4-7    -> pharmacological closure
score >= 8   -> surgical / device referral

Two overrides then apply regardless of score. If the infant is more than three weeks old, the pharmacological window has largely closed and the suggestion shifts to surgical or device referral. If you flag an NSAID contraindication — renal failure, thrombocytopenia, necrotising enterocolitis, or active bleeding — a pharmacological candidate is likewise moved to referral because drug closure is unsafe.

The key echocardiographic features and why they matter

Ductal diameter directly reflects the cross-sectional area available for shunting. A duct of 2 mm or more can carry a substantial left-to-right flow in a very preterm infant whose pulmonary vascular resistance has fallen in the first days of life.

LA:Ao ratio (left atrial to aortic root ratio) is a downstream marker of volume load. As pulmonary blood flow rises through a significant duct, the left atrium receives more return from the lungs and enlarges relative to the aortic root. A ratio above 1.5 suggests increased preload; above 1.8 or 2.0 is more strongly associated with haemodynamic significance.

Respiratory support level matters because it reflects the pulmonary consequence of the shunt — a duct that the infant cannot compensate for manifests as escalating ventilator requirements.

The conservative shift in evidence

The field has moved substantially toward expectant management in recent years. Several randomised trials and large observational cohorts have shown that many ducts — including large ones — close spontaneously without NSAID treatment, and that routine pharmacological closure does not clearly improve neurodevelopmental outcomes. Current practice in many units is to treat only infants with clear haemodynamic compromise or who are failing to wean from ventilatory support, rather than all infants with an echocardiographically significant duct.

Important notes

This is deliberately a feature aggregator, not a published or validated clinical score. Treat the output as a structured prompt for the right team conversation, never as a standalone decision. Choice between watchful waiting, indomethacin, ibuprofen, paracetamol, surgical ligation, and transcatheter device closure depends on local expertise, gestational age, the infant’s full trajectory, and joint neonatal-cardiology assessment.