What are the management strategies for preterm vs term infants with patent ductus arteriosus (PDA)?

Management of Patent Ductus Arteriosus: Preterm vs Term Infants

Preterm and term infants with PDA require fundamentally different management approaches—preterm infants need careful consideration of medical therapy with NSAIDs or watchful waiting due to high spontaneous closure rates and treatment risks, while term infants and older children should undergo transcatheter device closure as the definitive treatment of choice. 1, 2, 3

Preterm Infant PDA Management

Initial Assessment and Conservative Approach

• Confirm hemodynamically significant PDA through echocardiography with color Doppler before initiating any treatment, as many preterm PDAs close spontaneously 2, 3
• The trend over the last decade has shifted toward less aggressive treatment of PDA in preterm infants, recognizing that not all PDAs require intervention 4
• Monitor for signs of hemodynamically significant PDA including pulmonary edema, prolonged ventilation requirements, and systemic hypoperfusion 4, 5

Pharmacological Treatment Options for Symptomatic Preterm PDA

Prophylactic indomethacin should be considered only in highly selected extremely low gestational age newborns (<26 weeks' gestation, <750g birth weight), as it reduces severe intraventricular hemorrhage (RR 0.66) and need for invasive PDA closure (RR 0.51), though it does not affect death or neurodevelopmental disability 4, 6

For symptomatic PDA requiring treatment:

• Ibuprofen (10 mg/kg IV initially, then 5 mg/kg at 24-hour intervals for 2 doses) is the preferred first-line agent, with lower risk of necrotizing enterocolitis compared to indomethacin (RR 0.68) 3, 6
• Oral ibuprofen is more effective than IV ibuprofen for PDA closure (RR 0.38) and should be used when feasible 6
• Indomethacin (0.2-0.25 mg/kg/dose every 12 hours for 3 doses orally) remains effective with 81% response rates, though carries higher NEC risk 7, 6
• Acetaminophen (15 mg/kg every 8 hours orally) can achieve PDA closure within 48 hours and may be considered when NSAIDs are contraindicated or have failed, with lower NEC risk than indomethacin (RR 0.42) 8, 6

Critical Monitoring During Medical Therapy

• Monitor renal function before and during NSAID treatment, assessing for oliguria and rising creatinine 3
• Assess for bleeding or bruising during treatment, as NSAIDs affect platelet function 3
• Avoid NSAIDs in infants with active bleeding (especially intracranial or gastrointestinal), renal dysfunction, or thrombocytopenia 3
• Serial echocardiograms are essential to monitor treatment response 3, 7

Surgical Intervention in Preterm Infants

• Surgical ligation is indicated when pharmacological treatment fails in symptomatic infants, or for critically large PDAs refractory to medical management 2
• Consider second course of medical therapy before proceeding to surgery if first course fails 2, 3
• Prophylactic surgical ligation reduces NEC (RR 0.25) but is not routinely recommended 6

Special Considerations for Very Low Birth Weight Infants

• Exercise caution in VLBW infants due to immature ductal muscle and higher risk of intraventricular hemorrhage 2
• Avoid rapid fluid administration, which may increase left-to-right shunting and cause pulmonary edema 2
• Fluid restriction reduces NEC risk (RR 0.43) and should be implemented 6

Term Infant and Older Children PDA Management

Diagnostic Confirmation

• Echocardiography with color Doppler in parasternal short-axis view is the key diagnostic technique 9, 3
• Measure transpulmonary gradient with continuous-wave Doppler to estimate pulmonary artery pressure 3
• Cardiac catheterization is indicated when pulmonary vascular resistance is significantly elevated or echocardiography is non-diagnostic 9, 3

Indications for Closure in Term Infants/Children

Definite indications (Class I):

• Signs of left ventricular volume overload (LV dilatation) 9, 1
• Pulmonary hypertension with PAP <2/3 systemic pressure or PVR <2/3 systemic vascular resistance 9, 1
• Prior history of endarteritis 1, 3

Reasonable to consider (Class IIa):

• Small asymptomatic PDAs with continuous murmur (normal LV and PAP) by catheter device 9, 1, 3
• PAH with PAP >2/3 systemic pressure but net left-to-right shunt (Qp:Qs >1.5) or demonstrable pulmonary vascular reactivity 9, 1

Contraindication (Class III):

• Silent duct (very small, no murmur) should not be closed 9
• Eisenmenger physiology with net right-to-left shunt is an absolute contraindication 3

Treatment Method: Device Closure First-Line

Transcatheter device closure is the method of choice for term infants and older children, prioritized over surgical intervention whenever technically feasible 9, 1, 3

Advantages of device closure:

• Superior safety profile compared to surgery 1
• Particularly important in adults where ductal calcification and tissue friability make surgical manipulation hazardous 1, 3
• Success rate exceeds 95% with low mortality 3
• Standard practice includes 50-100 U/kg unfractionated heparin at implantation 3

Surgical Closure: Reserved Scenarios Only

Surgery should only be considered when:

• PDA is too large for device closure 1, 3
• Distorted ductal anatomy precludes device closure 1, 3
• Calcified PDA in adults (consult ACHD interventional cardiologists first) 1, 3
• Concomitant cardiac surgery required for other indications 1, 3

Critical Pitfall to Avoid

Always measure oxygen saturation in both feet and both hands to detect differential cyanosis from right-to-left shunting, which indicates Eisenmenger physiology and contraindicates closure 1

Post-Closure Management

For successfully closed PDA:

• Discharge from follow-up once complete closure documented by transthoracic echocardiography 1, 3
• Discontinue endocarditis prophylaxis 6 months after complete closure 9, 1
• Follow-up every 5 years for device closure patients due to limited long-term data, with residual shunt occurring in up to 10% 9, 1

For small PDAs without intervention:

• Routine follow-up every 3-5 years is recommended 3
• Endocarditis prophylaxis indicated until closure confirmed 9

Key Differences Summary

The fundamental distinction is that preterm PDA is a transitional physiologic problem often managed conservatively or with medical therapy, while term PDA is a structural defect requiring definitive mechanical closure 1, 2, 4. Preterm infants face risks from both the PDA itself (IVH, NEC, BPD) and from treatment interventions, necessitating selective treatment of only hemodynamically significant cases 4, 6, 5. In contrast, term infants and children benefit from definitive closure via transcatheter devices to prevent long-term complications including heart failure, pulmonary vascular disease, and endocarditis 9, 1, 3.