Persistent PDA is diagnosed when the Ductus Arteriosus does not close after 72 hours
Ductus arteriosus- Is important for foetal circulation and it allows communication between pulmonary artery and the aortic arch distal to the left subclavian artery. This shunt allows oxygenated blood from the placenta to bypass the uninflated fetal lungs and enter the systemic circulation.
DA closes soon after birth normally within 48 hours- Closure happens due to factors as increasing arterial PaO2 decreasing prostaglandin levels and bradykinin the vessel wall dies and changes to ligamentum arteriosus.
Who is at risk – PDA can be seen in patients of all ages Premature infants are at risk of PDA – inversely associated with degree of prematurity particularly high incidence if GA < 29 weeks PDA correlates inversely with birth weight and gestational age - seen in about 30 % of infants with birth weigh < 1500 gms - 40 % of infants with birth weight 751-1000 gms & - 50 % of those weighing 501-750 gms Other risk factors in premature infants include - maternal rubella - respiratory distress syndrome - high volume of IV fluids in the 1st week - sepsis - prolonged rupture of membranes - furosemide - male sex ( BMJ Best practice mentions female sex ) - use of certain antibiotics and antacids It is also thought that genetic factors may play a role PDA accounts for 5% to 10 % of all congenital heart disease in term infants
Congenital heart disease – PDA is a type of congenital heart disease It leads to -Left to right shunt which is the commonest physiology seen in patients with congenital heart disease Diagnosis is clinical based on clinical signs and supported by imaging.
Problems – Clinical complications are dependent on the the degree of left to right shunting through the ductus.
increased pulmonary overcirculation causes increased pulmonary venous pressure pulmonary oedema in severe cases pulmonary haemorrhage congestive cardiac failure endarteritis aneurysms of ductus arteriosus recurrent laryngeal nerve paralysis aortic dissection.
PDA is also associated with other significant morbidities like increased rate of chronic lung disease , hypotension , pulmonary haemorrhage , IVH ( intraventricular haemorrhage ) , NEC ( Necrotizing enterocolitis ) and mortality
Wide range of presentations – Can be asymptomatic Clinically apparent PDA Symptomatic PDA Haemodynamically significant PDA or haemodynamically non significant. Some PDAs may cause only minimum symptoms like breathlessness-this depends on the magnitude of the shunt and the status of the pulmonary vasculature.
Symptoms may not be apparent in the first few post-natal days and can include bounding pulse active precordium continuous murmur – located at the upper left sternal border often referred to as machinery murmur wide pulse pressure low diastolic BP hypotension hepatomegaly renal dysfunction.
congestive cardiac failure (moderate to larger PDA due to pulmonary overcirculation and let heart volume overload ) very premature infants -would be dealt by pediatricians in neonatal units full term infants with small PDA may be asymptomatic infants with larger PDAs may show non-specific features as - tachypnoea , irritability , poor feeding , diaphoreses - failure to thrive - prone to increased respiratory symptoms with URTIs older child may c/o SOB and reduced exercise tolerance
Echocardiography- Accurate diagnosis relies on ultrasound and Echocardiography is the mainstay of diagnosis.
CXR – cardiomegaly b/l lung field haziness suggestive of pulmonary oedema air bronchograms.
Management – Treatment will depend on - if the infant is premature - full term infants and children ( to prevent complications as heart failure , increased pulmonary pressure endarteritis ) Closure of PDA can be achieved by - medical ( pharmacological ) - catheter device closure - surgery
- BMJ Best Practice Patent Ductus Arteriosus
- Dice, James E, and Jatinder Bhatia. “Patent ductus arteriosus: an overview.” The journal of pediatric pharmacology and therapeutics : JPPT : the official journal of PPAG vol. 12,3 (2007): 138-46. doi:10.5863/1551-6776-12.3.138
- Gillam-Krakauer, Maria, and Jeff Reese. “Diagnosis and Management of Patent Ductus Arteriosus.” NeoReviews vol. 19,7 (2018): e394-e402. doi:10.1542/neo.19-7-e394
- Patent Ductus Arteriosus in Premature Neonates
Olachi J. Mezu-Ndubuisi,1 Ghanshyam Agarwal,2 Aarti Raghavan,1 Jennifer T. Pham,3
Kirsten H. Ohler3 and Akhil Maheshwari Drugs 2012; 72 (7): 907-916
- Congenital Heart Diseases https://pedclerk.bsd.uchicago.edu/sites/pedclerk.uchicago.edu/files/uploads/Congenital%20Cardiac%20Defects.pdf
- Pathophysiology of Congenital Heart Diseases
Devyani Chowdhury, MBBS, FAAP, FACC
Consultant, Department of Paediatric Cardiology, St. Stephens Hospital, Tis Hazari, Delhi
- Hermes-DeSantis, E., Clyman, R. Patent ductus arteriosus: pathophysiology and management. J Perinatol 26, S14–S18 (2006). https://doi.org/10.1038/sj.jp.7211465
Patent ductus arteriosus (PDA) : medical treatment and indications for surgical closure https://www.clinicalguidelines.scot.nhs.uk/ggc-paediatric-guidelines/ggc-guidelines/neonatology/patent-ductus-arteriosus-pda-medical-treatment-and-indications-for-surgical-closure/
- Patent Ductus Arteriosus https://www.slhd.nsw.gov.au/rpa/neonatal/html/docs/pda.pdf
Patent Ductus Arteriosus Douglas J. Schneider and John W. Moore https://www.slhd.nsw.gov.au/rpa/neonatal/html/docs/pda.pdf
- Patent ductus arteriosus: pathophysiology and management Journal of Perinatology (2006) 26, S14–S18