Chapter 26: Atrial Septal Defect (ASD) (Children)

Question 1

Atrial Septal Defect (ASD)

Answer 1

left-to-right shunt lesion (acyanotic)
-defect of the atria
-a congenital defect characterized by a hole in the wall between the atria
-results when the two septae fail to overlap properly
-two variations:
>primum ASD: high on the septal wall
>secundum ASD: low on the wall

Question 2

Normal fetal development of the Atria

Answer 2

In fetal development, the septal wall forms between the fourth and eighth weeks of life when two septae, the primum and secundum, stretch across the center of the common atrium; eventually these septae overlap (but not completely) and form a small opening called the foramen ovale (is a necessary structure during fetal life but should close within hours after birth, sometimes may persist until 1 year of life)
>ASD results when the two septae fail to overlap properly

Question 3

Signs and Symptoms

Answer 3

> possible murmur
-blowing to harsh systolic murmur heard best at 2nd intercostal space left sternal border
-may radiate to apex or back
possible right ventricle (RV) heave or a thrill (abnormal tremor accompanying a vascular or cardiac murmur felt on palpation)
possible right atrial enlargement caused by fluid overload from left-to-right shunting through the opening in the atrial wall
possible right ventricular enlargement, which is the source of the RV heave
right axis deviation (evidence of ventricular enlargement) on an ECG recording
a fixed, split, second heart sound
hepatomegaly as a result of this fluid overload
signs and symptoms of cardiac failure (gradually worsen with time unless defect is repaired)
-SOB
-respiratory distress
-periorbital edema
-failure to thrive
-increased respiratory infections may be noted
-risk for stroke b/c of the tendency of blood pooling leading to increased risk of thrombus formation

Question 4

Diagnosis

Answer 4

confirmed by echocardiography or cardiac catheterization

-chest x-ray and ECG support the diagnosis

Question 5

Nursing Care

Answer 5

focuses on postoperative management of the child

• if a closure device is used, the nurse is aware of signs and symptoms of complications of the device, such as bleeding, tamponade, or migration of the device
• s/s of chest pain, palpitations, sudden hypotension, an d dehydration or anemia warrant investigation

Question 6

Surgical Care

Answer 6

• without treatment, certain types of ASD may close spontaneously in the first year of life, and shows no outward signs of a malformation
• if not closed spontaneously, can be closed with a surgical procedure or interventional cardiology in which a closure device is inserted

Question 7

Postoperative Management

Answer 7

Provide immediate post-op care in the intensive care unit (ICU)
-record vital signs until child is stable
-monitor fluid status
-maintain vascular access systems via:
1. a peripheral IV is used to administer fluid and medications
2. a central venous pressure line is inserted via a large vessel in the neck or groin and is used to measure central venous pressure in the right atrium
3. intracardiac catheters are inserted in the right atrium, left atrium, and pulmonary artery and are used to measure the pressures inside the cardiac chambers that provide information about cardiac output, blood volume, pulmonary pressures, ventricular function, and drug therapy response
-maintain chest tubes that remove secretions and re-expand the lungs; check drainage for quantity and color
-assess for complications such as cardiac, neurological, pulmonary, renal, or hematological changes, infection, or delayed growth and development
-assess and maintain respiratory status:
>respiratory assessment is performed frequently, and oxygen is delivered via mechanical ventilation
>suction secretions
-monitor blood lab values for postoperative bleeding and post-pump electrolyte imbalances
-assess for s/s of infection
-manage pain via comfort measures and medication
-provide emotional support and information about home care
>consider the child’s level of development to provide developmentally appropriate care
>ensure rest, which is essential to promote healing and decrease the workload of the heart
>group nursing care to avoid imposing unnecessary fatigue and weakness

Question 8

Complications: Renal Failure

Answer 8

when the output is less than 1 mL/kg per hour along with an elevation in serum creatinine and blood urea nitrogen (BUN)

Question 9

Complications: Post-op Hemorrhage

Answer 9

when there is excessive chest tube drainage greater than 5 to 10 mL/kg in 1 hour or more than 3 mL/kg per hour in 3 consecutive hours