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NURSING CARE OF PATIENTS WITH TETRALOGY OF FALLOT

I.INTRODUCTION

In the embryo, the heart begins to beat at 4 weeks of age, even before its nerve supply has been established. If a person lives to be 80 years old, his or her heart cont inues to beat an average of 100,000 times a day, every day for each of those 80 yearstrying to squeeze a tennis ball 70 times a minute. After a few minutes, your arm muscles would begin to tire. Then imagine increasing your squeezing rate to 120 times a minute. Most of us could not keep that up very long, but that is what the heart doeexercise. A healthy heart can increase its rate and force of contraction to meet the bodys need for more oxygen, then return to its resting rate and keep on beating as if nothing very extraordinary had happened. In fact, it isnt extraordinary at all; this is thheart is meant to do.

The primary function of the heart is to pump blood through the arteries, capillaries, and veins. As we learned in the previous lectures, blood transports oxygen and nutrients and has other important functions as well. The heart is the pump that keepcirculating properly.

ANATOMY & PHYSIOLOGY OF THE HEARTThe heart is a four-chambered, muscular organ that lies in the ch est cavity, under the protection of the ribs, slightly to the left of the sternum. The heart sits within a loose, fluid-filled sac, called the pericardium. The four chambers of the heart includand right atria and the left and right ventricles. The atria sit next to each other above the ventricles. The atria and ventricles are separated from each other by one-way valves. The right and left sides of the heart are separated by a wall of tissue ca

septum. There is normally no mixing of blood between the two atria, except during fetal life, and there is never mixing of blood between the two ventricles in a healthy heart. Connective tissue surrounds all chambers. The heart is extensively innervatedThe left side of the heart pumps blood through the systemic circulation, which reaches all cells of the body except those involved with gas exchange in the lungs. The right side of the heart pumps blood through the pulmonary circulation, which deliv

only to the lungs to be oxygenated.As blood passes each cell of the body in the systemic circulation, carbon dioxide and other cellular waste products are added to the blood, while oxygen and nutrients are delivered from the blood to the cells. In the pulmonary circuit, the opposite

carbon dioxide is eliminated from the blood and o xygen is added. By continual cycling of the blood through the pulmonary and systemic circulations, oxygen supply and waste removal are ensured for all cells.(Black, Hawks & Keene, 2002-p.1362; Marieb & Hoehn-2007)

II. TETRALOGY OF FALLOT (TOF)

A. BACKGROUNDTetralogy of Fallot (TOF) is a congenital heart defect which is classically understood to involve four anatomical abnormalities. It is the most common cyanotic heart defect, representing 55-70%, and the most common cause of blue baby synd

was described in 1672 by Niels Stensen, in 1773 by Edward Sandifort, and in 1888 by the French physician tienne-Louis Arthur Fallot, for whom it is named.TOF occurs in approximately 400 per million live births. Its cause is thought to be du e to environmental or genetic factors or a combination. It is assoc iated with chromosome 22 deletions and diGeorge syndrome. Specific genetic ass

include:JAG1, NKX2-5, ZFPM2, VEGF. It occurs slightly more often in males than in females. Embryology studies show that it is a result of anterior malalignment of the conal septum, resulting in the clinical combination of a VSD, pulmonary stenosoverriding aorta. Right ventricular hypertrophy results from this combination, which causes resistance to blood flow from the right ventricle (American Heart Association, 2010).

B. DEFINITION OF RELATED TERMS:1. Stenosis is a constriction or narrowing of a duct, passage, or opening in the body.2. Aorta is the main artery in mammals that carries blood from the left ventricle of the heart to all the branch arteries in the body except those in the lungs.3. Hypertrophyis a growth in size of an organ through an increase in the size, rather than the number, of its cells4. Valve is a membranous structure in a hollow organ or vessel such as the heart or a vein that prevents the return flow of fluid p assing through it by folding or closing.

(Sommers & Beery, 2007)

C. ANATOMIC MORPHOLOGY1. Primary four malformations

"Tetralogy" denotes a four-part phenomenon in various fields, including literature, and the four parts the syndrome's name implies are its four signs. As such, by definition, tetralogy of Fallot involves exactly four heart malformatiopresent together:a. Pulmonary Stenosis

This defect is a narrowing of the p ulmonary valve and the passage through which blood flows from the right ventricle to the pulmonary artery. Normally, oxygen-poor blood from the right ventricle flows through the pulmonary valve

pulmonary artery, and out to the lungs to pick up oxygen. In pulmonary stenosis, the heart has to work harder than normal to pump blood and not enough blood reaches the lungs.b. Overriding Aorta

This is a defect in the aorta, the main artery that carries oxygen-rich blood to the body. In a healthy heart, the aorta is attached to the left ventricle. This allows only oxygen-rich blood to flow to the body.In tetralogy of Fallot, the aorta is between the left and right ventricles, directly over the VSD. As a result, oxygen-poor blood from the right ventricle flows directly into the aorta instead of into the pulmonary artery to the lungs.

c. Ventricular Septal Defect(VSD)The heart has a wall that separates the two chambers on its left side from the two chambers on its right side. This wall is called a septum. The septum prevents blood from mixing between the two sides of the heart. A VSD is a h

part of the septum that separates the ventricles, the lower chambers of the heart. The hole allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood from the right ventricle.d. Right Ventricular Hypertrophy

This defect occurs if the right ventricle thickens because the heart has to pump harder than it should to move blood through the narrowed pulmonary valve.(Medscape, 2009)
http://en.wikipedia.org/wiki/Congenital_heart_defecthttp://en.wikipedia.org/wiki/Blue_baby_syndromehttp://en.wikipedia.org/wiki/Niels_Stensenhttp://en.wikipedia.org/wiki/Etienne_Fallothttp://en.wikipedia.org/wiki/DiGeorge_syndromehttp://en.wikipedia.org/wiki/JAG1http://en.wikipedia.org/wiki/NKX2-5http://en.wikipedia.org/wiki/NKX2-5http://en.wikipedia.org/wiki/ZFPM2http://en.wikipedia.org/wiki/VEGFhttp://en.wikipedia.org/wiki/Embryologyhttp://en.wikipedia.org/w/index.php?title=Conal_septum&action=edit&redlink=1http://en.wikipedia.org/wiki/Tetralogyhttp://en.wikipedia.org/wiki/Literaturehttp://en.wikipedia.org/wiki/Medical_signhttp://en.wikipedia.org/wiki/Hearthttp://en.wikipedia.org/wiki/Pulmonary_stenosishttp://en.wikipedia.org/wiki/Overriding_aortahttp://en.wikipedia.org/wiki/Ventricular_septal_defecthttp://en.wikipedia.org/wiki/Right_ventricular_hypertrophyhttp://en.wikipedia.org/wiki/Right_ventricular_hypertrophyhttp://en.wikipedia.org/wiki/Ventricular_septal_defecthttp://en.wikipedia.org/wiki/Overriding_aortahttp://en.wikipedia.org/wiki/Pulmonary_stenosishttp://en.wikipedia.org/wiki/Hearthttp://en.wikipedia.org/wiki/Medical_signhttp://en.wikipedia.org/wiki/Literaturehttp://en.wikipedia.org/wiki/Tetralogyhttp://en.wikipedia.org/w/index.php?title=Conal_septum&action=edit&redlink=1http://en.wikipedia.org/wiki/Embryologyhttp://en.wikipedia.org/wiki/VEGFhttp://en.wikipedia.org/wiki/ZFPM2http://en.wikipedia.org/wiki/NKX2-5http://en.wikipedia.org/wiki/JAG1http://en.wikipedia.org/wiki/DiGeorge_syndromehttp://en.wikipedia.org/wiki/Etienne_Fallothttp://en.wikipedia.org/wiki/Niels_Stensenhttp://en.wikipedia.org/wiki/Blue_baby_syndromehttp://en.wikipedia.org/wiki/Congenital_heart_defect


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2. Other anomaliesIn addition, tetralogy of Fallot may present with other anatomical anomalies, including: stenosis of the left pulmonary artery, in 40% of patients a bicuspid pulmonary valve, in 40% of patients right-sided aortic arch, in 25% of patients coronary artery anomalies, in 10% of patients a foramen ovale or atrial septal defect, in which case the syndrome is sometimes called a pentalogy of Fallot an atrioventricular septal defect partially or totally anomalous pulmonary venous return forked ribs and scoliosis

Tetralogy of Fallot with pulmonary atresia (pseudotruncus arteriosus) is a severe variant in which there is complete obstruction (atresia) of the right ventricular outflow tract, causing an absence of the pulmonary trunk during edevelopment. In these individuals, blood shunts completely from the right ventricle to the left where it is pumped only through the aorta. The lungs are perfused via extensive collaterals from the systemic arteries, and sometimes also via tharteriosus (Medscape, 2010).

D. PATHOPHYSIOLOGY & SYMPTOMSTetralogy of Fallot results in low oxygenation of blood due to the mixing of oxygenated and deoxygenated blood in the left ventricle via the VSD and preferential flow of the mixed blood from both ventricles through the aorta because of the ob

to flow through the pulmonary valve. This is known as a right-to-left shunt. The primary symptom is low blood oxygen saturation with or withou t cyanosis from birth or developing in the first year of life. If the baby is not cyanotic then it is soreferred to as a "pink tet". Other symptoms include a heart murmur which may range from almost imperceptible to very loud, difficulty in feeding, failure to gain weight, retarded growth and physical development, dyspnea on exertion, clubbfingers and toes, and polycythemia.

Children with tetralogy of Fallot may develop "tet spells". The precise mechanism of these episodes is in doubt, but presumably results from a transient increase in resistance to blood flow to the lungs with increased preferential flow of desblood to the body. Tet spells are characterized by a sudden, marked increase in cyanosis followed by syncope, and may result in hypoxic brain injury and death. Older children will often squat during a tet spell, which cuts off circulation to the ltherefore improves blood flow to the brain and vital organs (Budd & Gardiner, 1999-pp. 111-112).

E. MEDICAL & SURGICAL MANAGEMENT/TREATMENT1. Emergency management of tet spells

Prior to corrective surgery, children with tetralogy of Fallot may be prone to consequential acute hypoxia (tet spells), characterized by sudden cyanosis and syncope. These may be treated with beta-blockers such as propranolol, but acutemay require rapid intervention withmorphine to reduce ventilatory drive and a vasopressor such as epinephrine, phenylephrine, or norepinephrine to increase blood pressure. Oxygen is effective in treating spells because it is a potent pvasodilator and systemic vasoconstrictor. This allows more blood flow to the lungs. There are also simple procedures such as squatting in the knee-ch est position which increases aortic wave reflection, increasing pressu re on the left side of tdecreasing the right to left shunt thus decreasing the amount of deoxygenated blood entering the systemic circulation.

2. Palliative SurgeryThe condition was initially thought untreatable until surgeon Alfred Blalock, cardiologist Helen B. Taussig, and lab assistant Vivien Thomas at Johns Hopkins University developed a palliative surgical procedure, which involved fo

anastomosis between the subclavian artery and the pulmonary artery. It was actually Helen Taussig who convinced Alfred Blalock that the shunt was going to work. This redirected a large portion of the partially oxygenated blood leaving for the body into the lungs, increasing flow through the pulmonary circuit, and greatly relieving symptoms in patients. The first Blalock-Thomas-Taussig shunt surgery was performed on 15-month old Eileen Saxon on November 29, 1dramatic results.

The Potts shunt and the Waterston-Cooley shunt are other shunt procedures which were developed for the same purpose. These are no longer used.Currently, Blalock-Thomas-Taussig shunts are not normally performed on infants with TOF except for severe variants such as TOF with pulmonary atresia (pseudotruncus arteriosus).

3. Total Surgical RepairThe Blalock-Thomas-Taussig procedure was the on ly surgical treatment until the first total surgical repair was performed in 1954. Between 1944 and when total repair became available at major surgical centers in the early 1960s, many in

children were treated palliatively with Blalock(-Thomas)-Taussig procedu res.This first total repair was performed by C. Walton Lillehei at the University of Minnesota in 1954 on a 11 year old boy. The first successful total repair on an infant at on e years of age, was performed in 1991, on Brittany Leska, now Brittane

Total repair initially carried a high mortality risk which has consistently improved over the years. Surgery is now often carried out in infants 1 year of age or younger with a


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Poor weight gain and/or feeding behavior Frequent respiratory infections Prior murmurs Respiratory difficulties, such as tachypnea, dyspnea and shortness of breath Cyanosis Recent streptococcal infection of the child Exercise intolerance of the child (e.g., during feeding)

b. Physical Examination Inspection

Nutritional State-Failure to thrive or poor weight gain is associated with heart disease. Color-Cyanosis is a common feature of CHD, and pallor is associated with poor perfusion. Chest deformities-An enlarged heart sometimes distorts the chest configuration. Unusual pulsations-Visible pulsation of the neck veins are seen in some patients. Respiratory excursion-This refers to the ease or difficulty in respiration (e.g., tacypnea, dyspnea, presence of expiratory grunt). Clubbing of fingers-This is associated with cyanosis.

Palpation and Percussion Chest-These maneuvers help discern heart size and other characteristics (e.g. th rills) associated with heart disease. Abdomen-Hepatomegaly and/or splenomegaly may be evident. Peripheral pulses-Rate, regularity, and amplitude (strength) may reveal discrepancies.

Auscultation Heart rate and rhythm-Listen for fast heart rate (tachycardia), slow heart rate (bradycardia), or irregular rhythms. Character of heart sounds-listen for distinct or muffled sounds.

((Wong & Hockenberry-Eaton, 2001 p.933)c. Diagnostic Evaluation

By using several tests, the doctor can confirm the diagnosis.

Chest X-ray. A typical sign of tetralogy of Fallot on an X-ray is a "boot-shaped" heart, because the right ventricle is enlarged. Complete blood count. This is a test to measure the number of each type of cell in the blood. In tetralogy of Fallot, the number of red blood cells may be abnormally high (erythrocytosis) as the body attempts to increase the oxyge

the blood.

Echocardiography. Echocardiograms use high-pitched sound waves, inaudible to the human ear, to produce an image of the heart. Sound waves bounce off your baby's heart and produce moving images that can be viewed oscreen. This test is used to diagnose tetralogy of Fallot by assessing whether a ventricular septal defect is present, the structure of the pulmonary valve, and the function of the right ventricle and the position of the ao rta.

Electrocardiogram. An electrocardiogram records the electrical activity in the heart each time it contracts. During this procedure, patches with wires (electrodes) are placed on your baby's chest, wrists and ankles. The electrodes electrical activity, which is recorded on paper. This test helps determine if your baby's right ventricle is enlarged (ventricular hypertrophy) and if the heart rhythm is regular.

Cardiac catheterization. During this procedure, your doctor inserts a thin flexible tube (catheter) into an artery or vein in your baby's groin and threads it up to his or her heart. A dye is injected through the catheter to make yoheart structures visible on X-ray pictures. The catheter also measures pressure in the chambers of the heart and in the blood vessels.

(MayoClinic-2009)

2. Nursing Diagnoses & Corresponding ManagementAll diagnoses used for children with left to right shunts can be applied to the child with right to left shunts. The nu rsing diagnosis and subsequent plan of care must be individualized for each patient.

1. Altered tissue perfusion related to hypercyanotic episodesExpected outcome: The child will remain free of signs of decreased tissue perfusion, as evidenced by absence of profound cyanosis, normal activity level or affect for child, and normal respiratory status and oxygen satuchild.

Intervention Rationale

Keep child as stress-free as possible by anticipating andmeeting the infants feeding and comfort needs properly.

Monitor for signs of hypercyanosis and notify physician ifnoted.

Administer propanolol as ordered, ensuring correctdosage.

Monitor glucose level every 4-6 hours if the child is NPOand receiving propanolol. Notify physician if glucose level

Crying and/or agitation may precipitate hypercyanotic episodes.

Severe hypercyanotic episodes can result in metabolic acidosis and can terminatelimpness, syncope, seizures, cardiovascular accidents and death.

Propanolol, a beta-blocker, is used for palliative treatment of hypercyanotic episodes. Propanolol can cause hypoglycemia if given when patient is NPO or hypovolemic.


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is less than 60 mg/dL. If hypercyanotic episode occurs, place child in knee-chest

position and notify physician.

Administer other therapies as ordered, such as oxygenand medication, ensuring correct dosage, route andeffectiveness.

Place child in safe environment (with parent). Instruct patient or family on the signs and symptoms of

hypercyanotic episodes.

Knee-chest position is thought to increase pulmonary blood flow by increasing systemicvascular resistance and to improve systemic arterial oxygen saturation by decreasingvenous return so that smaller amounts of highly saturated blood reach the heart.Toddlers and other children with unrepaired TOF may squat to obtain this position andrelieve chronic hypoxia. However, most defects are corrected by this age.

Oxygen is needed to improve oxygenation and prevent profound hypoxemia. Morphinemay be used as a calming agent, and sodium bicarbonate may be used to correctmetabolic acidosis.

Decreases stress and prevents further deterioration due to stress. These episodes may occur at home, and parents need to able to recognize them and have

a plan of action should they occur.

2. Risk for impaired gas exchange related to inadequate ventilator support, pulmonary hypertension, atelectasis, and CHFExpected outcome: The child maintains adequate gas exchange, as evidenced by normal respiratory status and oxygen saturation for child.


Monitor respiratory status every 1-2 hours, assessingrespiratory rate, breath sounds, and chest expirations, useof accessory muscles, nasal flaring and retractions. Notifyphysician of significant changes.

Assess/verify ventilator settings every shift and as neededwith changes in the childs condition.

Ensure endotracheal tube security. Restrain hands of intubated children. Verify endotracheal tube position by chest auscultation

every 1-2 hours or by chest x-ray, as needed. Suction endotracheal tube every 2-4 hours, as required.

Administer sedation/paralytics, as ordered, ensuringcorrect dosage and effectiveness.

Early signs of inadequate gas exchange are exhibited by respiratory difficulty (i. e., anincrease in breaths per minute, nasal flaring, retractions, and use of accessory muscles.

To ensure that settings are as ordered and that ventilator adjustments are made withchanges in respiratory status

To avoid inadvertent dislodgement of the tube To avoid inadvertent dislodgement/removal of the tube Proper ventilator support is dependent on correct tube placement.

To ensure patency and remove unwanted secretions

Medications are often necessary with children receiving mechanical ventilation.Sedatives can ease pain and anxiety; paralytics will prevent movement.

3. Risk for decreased cardiac output related to CHFExpected outcome: The child maintains adequate cardiac output, as evidenced by absence of sinus tachycardia and diaphoresis, warm extremities free of mottling, urine output greater than 1-2 ml/kg/hr, normal respiratory sand oxygen saturation for child, absence of jaundice, and nonpalpable liver.


Obtain vital sign parameters for each child and set monitorlimits accordingly. Vital signs that may be normal for

children without cardiac disease may not be normal for

the child with cardiac disease.

Obtain vital signs every 1-4 hours, as ordered, anddocument. Notify physician outside prescribed

parameters. Assess for signs and symptoms of increasing heart failure

every 2-8 hours. Note any edema in extremities, trunk,head and neck.

Obtain body weight every 12-24 hours using same scale atapproximately same time of day, and alert physician ifexcessive weight gain (>50 g/day in infants; >200 g/day inchildren).

Children with CHF will experience changes in their breathing patterns and other vital signsdue to increasing at-rest fluid retention. Baseline vital signs with appropriate monitoringparameters will assist in determining if patient status improves or deteriorates. Normalsfor these children may fall outside the range of expected normals.

Same as above.

CHF can progress fairly rapidly, so subtle changes are important. Because of decreasedvenous return, fluid pools in the lower extremities.

Fluid retention may not always be evident by visual inspection. Weight changes mayindicate the bodys inability to get rid of excess fluid. Weighing at approximately the sametime of day ensures consistency.

Children with CHF will not wet as many diapers or will urinate less due to fluid retention.


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Maintain accurate input and output records. Notifyphysician if urine output is

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