PERFUSION CONCEPT

CARDIAC ASSESSMENT

Respirations

• Infant: 30-60

• Children: 20-40

Pulse

• Infant: 100-150bpm

• Child: 80-100bpm

Blood pressure

• Compare upper extremity and lower extremity

Auscultation

• Murmurs

Activity level/tolerance

CONGENITAL HEART DEFECTS (CHD)

Incidence: 6 – 13 per 1000 live births

• About 2 or 3 of these are symptomatic in first year of life

Major cause of death in first year of life (after prematurity)

• About 1/3 of infants with CHD will have disease serious enough to result in death or will require cardiac catheterization or cardiac surgery within first year of life

Most common anomaly = Ventricular Septal Defect (VSD)

Cause Multifactorial 85% and unknown

• Chromosomal/genetic = 10% to 12%

• Maternal or environmental causes = 1% to 2%

• Maternal alcohol use: FAS 50% have CHD

• Maternal illness: Rubella, viral illnesses, and DM

28% of children with CHD have another recognized anomaly (trisomy 21, 13,18)

Complications of CHD

heart failure, hypoxemia, growth failure, developmental delay, and pulmonary vascular disease

HEMODYNAMIC CHARACTERISTICS OF CONGENITAL HEART DEFECTS (CHD)

• Disorders with increased pulmonary blood flow: ventricular septal defect (VSD)

• Disorders with decreased pulmonary blood flow: tetralogy of Fallot

NEWBORN PRESENTATION

• A murmur - most common reason for consulting cardiology, but a murmur is not the most urgent indication of CHD in newborns

• Cyanosis and/or diminished femoral pulses or shock in a newborn should be considered critical congenital heart disease until provenotherwise

NEWBORN SCREENING FOR CHD

• The Secretary of Health and Human Services, Fall of 2011, recommended screening for Critical Congenital Heart Disease using pulse oximetry be added to the uniform newborn screening panel.

• AAP has also endorsed and recommended.

• Implementation will be considered by each state

• NJ enacted law in 2011; PA 2014

SCREENING RECOMMENDATIONS

• Targeting healthy newborns in newborn nurseries

• After 24 hours of age

• Right hand and one foot

• Negative: >95% in both with a less than 3% difference between both

Positive:

• Oxygen saturation <90% in either extremity

• SpO2 90-94% in both upper and lower extremities on 3 measurements, each separated by 1 hour

• SpO2 difference >3% between the upper and lower extremities on 3 measurements, each separated by 1 hour

True positives will need an echo and exclusion of infectious or pulmonary issues.

OLDER CHILD PRESENTATION WITH CHD

• Chest pain

• Decreased activity level

• Syncope

• Thin, not very tall; doesn’t look strong;underweight

VENTRICULAR SEPTAL DEFECT (VSD)

• Develops when the muscular wall (septum) separating the right and left ventricles does not fully form, creating a hole between the ventricles

oxygenated blood leaks from left ventricle to right ventricle (left to right shunt) instead of flowing into the aorta

• Most common congenital heart defect (30%), estimated to occur in 2 - 6 per 1,000 live births.

• It can lead to heart failure, pulmonary hypertension, endocarditis, dysrhythmias, and delayed growth.

• Small holes may heal on their own, whereas large holes may require surgical repair.

In a left to right shunt, blood that just returned from the lungs crosses the VSD and goes back to the lungs again—-Increased pulmonary blood flow.

SYMPTOMS OF VSD

Size of the ventricular septal opening affects the type and severity as well as the age they first occur.

• Signs of heart failure around 4 to 8 weeks of age

Common symptoms include:

• Harsh (loud, blowing), holosystolic murmur located at the LLSB

• Disinterest in feeding, or tiring while feeding

• Poor weight gain

• Fatigue

• Color change and/or sweating with nipple feeding in the infant

• Tachypnea, SOB, pulmonary edema

Congential Defects Symptoms

• increased fatigue

• murmurs

• increased risk of endocarditis

• chronic heart failure

• growth retardation

TESTS, PROCEDURES AND DIAGNOSIS OF VENTRICULAR SEPTAL DEFECT

• Laboratory tests: increased hematocrit, hemoglobin, and RBC count associated with polycythemia

• Chest X-ray: with a VSD, the heart may be enlarged due to the right ventricle handling larger amounts of blood flow than normal. Also, there may be changes that take place in the lungs due to extra blood flow that can be seen on an X-ray.

• Electrocardiogram (ECG or EKG)

• Echocardiogram (or “echo”): show pattern of blood flow through the septal opening, and determine how large the opening is, as well as how much blood is passing through it.

• Cardiac catheterization: invasive procedure gives very detailed information about structures inside heart.

TREATMENT FOR VENTRICULAR SEPTAL DEFECT

• Spontaneous closure of small VSDs occurs in about half of children by age 2 years

• Repair of larger defects by 2 years of age recommended to prevent development of pulmonary vascular disease (pulmonary hypertension, heart failure)

• Long-term outcomes for surgically repaired VSDs = good

NURSING CARE - PROMOTING ADEQUATE NUTRITION for VSD

• Critical to foster growth and development and reduce risk for infection – daily weights; more frequent feedings with rest periods.

• Increased nutritional needs due to increased energy expenditure associated with increased cardiac and respiratory workloads.

• Orally, enterally, or parenterally - Supplemental gavage tube feedings

• Infants with a larger VSD may become tired when feeding and are not able to eat enough to gain weight.

VSD TREATMENT

• Infection control ****

• Surgical repair - goal to repair septal opening before permanent pulmonary vascular changes develop from excess blood flow and pressure. Repair indicated for defects causing symptoms, such as poor weight gain and rapid breathing.

• Surgical closure – suture closure of the VSD, transcatheter placement of a device in the defect, or Dacron patch closure

• Interventional cardiac catheterization: may be repaired by a cardiac catheterization procedure. One technique uses a device called a septal occluder.

VENTRICULAR SEPTAL DEFECT Medical Management

• Dopamine (Intropin) & Isoproterenol (Isuprel) positive inotropic effect—increased cardiac output, systolic and pulse pressures

• Generally, a Dacron or pericardial patch is placed over the lesion, although direct suturing may be used if the defect is minimal

• Palliative surgery – pulmonary artery banding – median sternotomy is made, a hypothermia blanket may be used for some infants

DEFECTS DECREASING PULMONARY BLOOD FLOW – TETRALOGY OF FALLOT

Syndrome represented by four defects (“RAPS”)

• Right ventricle hypertrophy

• Aorta displacement: Overriding aorta straddles the VSD

• Pulmonary stenosis (a narrowing of the pulmonary valve and outflow tract which obstructs blood flow from right ventricle to lungs)

• Septal defect,Ventricular (VSD)

Incidence: 7% - 10% of CHD; 4 – 5 per 10,000 live births

Surgical intervention usually required during first year of life

Excellent long-term survival, particularly for patients who are operated on at a young age, among whom survival is >90% 25 years after repair

Effects of TETRALOGY OF FALLOT

In some infants and children, there can be profound narrowing of the right ventricular outflow tract. Because of the severe narrowing, it is easier for the blood to cross the VSD right-to-left and go out the aorta instead of going to the lungs. If this is the case, the infant or child can become quite cyanotic.

SIGNS AND SYMPTOMS OF TOF

• Cyanosis

• Tachypnea

• Hypercyanotic spells (TET spells)

• Murmur

• Edema

• Clubbing of fingernails over time

• Polycythemia

RELIEVING HYPERCYANOTIC SPELLS (“TET” spells)

• Use a calm, comforting approach to your inventions; stressed, calm them down.

• Place the infant or child in a knee-to-chest position (squatting).

• Provide supplemental oxygen.

• Administer morphine sulfate (0.1 mg/kg IV, IM, or SQ).

• Supply IV fluids.

• Administer propranolol (0.1 mg/kg IV).

SURGICAL PROCEDURES for TOF

• Historically, TOF repair was performed in 2 stage procedures: Palliative shunt surgery in early infancy followed by intracardiac repair later in childhood (Blalock–Taussig shunt)

• At most centers, primary intracardiac repair - definitive correction involves patch closure of the ventricular septal defect and repair of the pulmonary valve and right ventricular outflow tract.

• At 6 months – 1 year of age

• Monitor for ventricular arrhythmias after corrective repair.

COMPLICATIONS OF VSD & TOF: HEART FAILURE IN CHILDREN

Some patients with minimal obstruction and increased pulmonary blood flow may develop heart failure symptoms and require pharmacologic treatment:

• Digoxin: A medication that helps strengthen the heart muscle, enabling it to pump more efficiently – not used in isolated VSD alone

• Diuretics: furosemide

• ACE inhibitors: Medications that lower the blood pressure in the body, making it easier for blood to be pumped from the left ventricle into the body – not used in TOF (increases TET spells)

PHARMACOLOGY EXEMPLAR: DIGOXIN THERAPY

Cardiac glycoside, antiarrhythmic agent

• Increases contractility of the heart muscle by decreasing conduction and increasing force

• Used for heart failure

Full-term infants: Total loading dose is 20 to 30 mcg/kg IV in divided doses, followed by a starting maintenance dose of 3 to 4.5 mcg/kg/dose IV b.i.d.

Full-term infants: Loading dose is 25 to 35 mcg/kg PO in divided doses, followed by maintenance dose of 3.8 to 5.6 mcg/kg/dose PO b.i.d.

• Prior to administering each dose, count apical pulse for 1 full minute, noting rate, rhythm, and quality. *Withhold if apical pulse is <60 in an adolescent, <70 child, <90 in an infant.*

• Monitor serum digoxin levels (therapeutic range: 0.8 – 2 ng/mL).

* Call provider before administering the drug.

Digoxin Therapy

Give at regular intervals, every 12 hours, 1 hour before or 2 hours after a feeding. If a dose is missed and more than 4 hours have elapsed, withhold the dose and give the dose at the regular time; if less than 4 hours have elapsed, give the missed dose. If the child vomits, do not give a second dose. Monitor potassium levels, as a decrease enhances the effects of digitalis, causing toxicity

SIGNS OF DIGOXIN TOXICITY

• Bradycardia

• Arrhythmia

• Nausea, vomiting, diarrhea

• Lethargy

Avoid rapid IV administration, as this may lead to systemic and coronary artery vasoconstriction - Infuse drug slowly over at least 5 minutes or longer.