Patent Ductus Arteriosus: what it is and what it causes

By Cristiano Antonino On Mar 22, 2023

In patent ductus arteriosus (PDA), the lumen of the ductus remains open after birth

The ductus arteriosus is a fetal blood vessel that connects the pulmonary artery to the descending aorta.

In patent ductus arteriosus (PDA), the lumen of the ductus remains open after birth.

This creates a left to right shunt of blood from the aorta to the pulmonary artery and results in recirculation of pulmonary blood through the lungs.

The prognosis is good if the shunt is small or surgical repair is effective.

Genetics: Congenital heart defects appear to run in families and sometimes occur with other genetic problems, such as Down syndrome.
Age: Patent ductus arteriosus is more common in premature babies. Also, babies with other types of congenital heart defects often have a patent ductus arteriosus.
Gender: PDA is twice as common in girls as in boys.

Experiencing any of the following conditions during pregnancy can increase the risk of having a baby with a heart defect.

Rubella infection: Becoming infected with rubella (German measles) while pregnant can increase the risk of fetal heart defects. The rubella virus crosses the placenta and spreads through the fetus’s circulatory system damaging blood vessels and organs, including the heart.
Poorly controlled diabetes: Uncontrolled diabetes in the mother in turn affects the fetus’s blood sugar causing various damaging effects to the developing fetus.
Drug or alcohol use or exposure to certain substances: Use of certain medications, alcohol or drugs, or exposure to chemicals or radiation during pregnancy can harm the developing fetus.
Presence of other congenital heart defects. Babies with other types of congenital heart defects often have a patent ductus arteriosus.

PDA is found in 1 of every 2, 500 to 5, 000 infants.

It affects twice as many females as males.

Prematurity. PDA is most prevalent in premature neonates, probably as a result of abnormalities in oxygenation.
Prostaglandin E. The relaxant action of prostaglandin E prevents ductal spasm and contracture necessary for closure.
Other congenital defects. PDA commonly accompanies rubella syndrome and may be associated with other congenital defects, such as coarctation of the aorta, ventricular septal defect, and pulmonary and aortic stenoses.

Initially, PDA may produce no clinical effects, but in time it can precipitate pulmonary vascular disease, causing symptoms to appear by age 40.

Respiratory distress. A large PDA usually produces respiratory distress.
Heart failure. There are signs of heart failure due to the tremendous volume of blood shunted to the lungs through a patent ductus and the increased workload on the left side of the heart
Low immune system. The patient has a high susceptibility to respiratory tract infections.
Slow motor development. The patient’s motor skills expand and develop slower than the average person does.
Physical underdevelopment. One of the signs of heart disease is the physical underdevelopment of the patient’s body.
Heart murmur. Auscultation reveals a continuous murmur best
Bounding peripheral pulses. Peripheral arterial pulses are bounding; also called Corrigan’s pulse.
Widened pulse pressure. Pulse pressure is widened because of an elevation in the systolic blood pressure, and primarily, a drop in the diastolic pressure.

Left-sided heart failure. The left-to-right shunting of the blood renders the cardiac muscles of the left chamber overworked and leads to heart failure.
Pulmonary artery hypertension. There is increased pulmonary venous return leading to pulmonary hypertension.

Chest x-ray. Chest x-ray may show increased pulmonary vascular findings, prominent pulmonary arteries, and left ventricle and aorta enlargement.
Electrocardiography (ECG). ECG may be normal or may indicate left atrial or ventricular hypertrophy and in pulmonary vascular disease, biventricular hypertrophy.
Echocardiography. Echocardiography detects and helps determine the size of PDA.

Asymptomatic children do not require immediate treatment but those with heart failure require the following:
Fluid restriction. Fluids should be restricted or controlled to avoid overloading the heart.

Medications for the patient with PDA include:

Prostaglandin analogs. The ductus arteriosus can be induced to remain open by administering prostaglandin analogs such as alprostadil (a prostaglandin E1 analog).
Antibiotics. Before surgery, children with PDA require antibiotics to protect against infective endocarditis.
Indomethacin. Indomethacin is a prostaglandin inhibitor that’s an alternative to surgery in premature neonates and induces ductus spasm and closure.

Other forms of therapy include surgical interventions such as:

Cardiac catheterization. In cardiac catheterization, a plug or coil is deposited in the ductus to stop the shunting.
Ligation. The DA may be closed by ligation, wherein the DA is manually tied shut, or with intravascular coils or plugs that leads to formation of a thrombus in the DA.

Nursing management for a patient with patent ductus arteriosus include:

Assessment should focus on:

Activity and rest. The nurse should assess for weakness, fatigue, dizziness, a sense of pulsing, and even sleep disorders.
Circulation. Circulatory assessment should include history trigger conditions, history of heart murmurs and palpitations, BP, and pulse pressure.
Food and fluids. The nurse should assess for dysphagia and changes in body weight.

Based on the assessment data, the major nursing diagnoses include:

Activity intolerance related to imbalance between oxygen consumption of the body and supply of oxygen to the cells.
Anxiety related to hospital care or lack of support system.
Deficient knowledge related to the condition and treatment needs.

The major goals for the patient are:

Patent ductus arteriosus necessitates careful monitoring, patient and family teaching, and emotional support.

Signs and symptoms. Watch carefully for signs of PDA in premature infants.
Monitoring. Frequently assess vital signs, ECG, electrolyte levels, and intake and output.
Adverse effects of indomethacin. If the infant receives indomethacin for ductus closure, watch for possible adverse effects, such as diarrhea, jaundice, bleeding, and renal dysfunction.
Preoperative instructions. Before surgery, carefully explain all treatments and tests to parents, including the child, and tell them about expected IV lines, monitoring equipment, and postoperative procedures.
Postoperative procedures. Immediately after surgery, the child may have a central venous pressure catheter and an arterial line in place, so careful assessment of vital signs, intake and output, and arterial and venous pressures are needed, as well as pain relief.