Notes
Description
Congenital hypothyroidism (CH) is inadequate thyroid hormone production in newborn infants.
- At one time referred to by now unacceptable term “cretinism“, congenital hypothyroidism is associated with either the congenital absence of a thyroid gland or the inability of the thyroid gland to secrete thyroid hormone.
- It can occur because of an anatomic defect in the gland, an inborn error of thyroid metabolism, or iodine deficiency.
- Lower TSH screening cutoffs may also be driving this increase in diagnosis, although altered ethnicities of the screened population, increased multiple and premature births, and iodine status are contributing factors.
- In the 1920s, adequate dietary intake of iodine was found to prevent endemic goiter and cretinism.
- The term sporadic cretinism was initially used to describe the random occurrence of cretinism in nonendemic areas; the cause of these abnormalities was identified as nonfunctioning or absent thyroid glands.
Pathophysiology
The thyroid gland develops from the buccopharyngeal cavity between 4 and 10 weeks’ gestation.
- The thyroid arises from the fourth branchial pouches and ultimately ends up as a bilobed organ in the neck.
- By 10-11 weeks’ gestation, the fetal thyroid is capable of producing thyroid hormone; by 18-20 weeks’ gestation, blood levels of T4 have reached term levels.
- The thyroid gland uses tyrosine and iodine to manufacture T4 and triiodothyronine (T3).
- Inborn errors of thyroid metabolism can result in congenital hypothyroidism in children with anatomically normal thyroid glands.
- T4 is the primary thyronine produced by the thyroid gland; only 10-40% of circulating T3 is released from the thyroid gland.
- T3 is the primary mediator of the biologic effects of thyroid hormone and does so by interacting with a specific nuclear receptor; receptor abnormalities can result in thyroid hormone resistance.
- The major carrier proteins for circulating thyroid hormones are thyroid-binding globulin (TBG), thyroid-binding prealbumin (TBPA), and albumin.
- Infants born with low levels of TBG, as in congenital TBG deficiency, have low total T4 levels but are physiologically normal; familial congenital TBG deficiency can occur as an X-linked recessive or autosomal recessive condition.
- The most critical period for the effect of thyroid hormone on brain development is the first few months of life.
Statistics and Incidences
CH is the most common neonatal endocrine disorder, and historically, thyroid dysgenesis was thought to account for approximately 80% of cases.
- An increased incidence of congenital hypothyroidism is observed in twins; twin births are approximately 12 times as likely to have congenital hypothyroidism as singletons.
- Usually, only one twin is hypothyroid, but a common in-utero exposure can cause hypothyroidism in both.
- Most studies of congenital hypothyroidism suggest a female-to-male ratio of a 2:1; Devos et al showed that much of the discrepancy is accounted for by infants with thyroid ectopy.
- In central Africa, where iodine deficiency occurs along with excess dietary cyanate from cassava (Manihot esculenta), as many as 10% of newborns may have both low cord blood T4 concentration and TSH concentrations over 100 mU/L.
Clinical Manifestations
The physical findings of hypothyroidism may or may not be present at birth.
- Decreased activity. Often, affected infants are described as “good babies” because they rarely cry and they sleep most of the time.
- Large anterior fontanelle. A large anterior fontanelle is mostly found in infants with CH, with delayed closure.
- Poor feeding and weight gain. A child with CH mostly sleeps and rarely feeds, resulting in poor weight gain.
- Small stature or poor growth. There is a delay in the development of children with CH, with poor growth as one of the findings.
- Jaundice. The yellow coloration of the skin and sclera in newborns with jaundice is the result of accumulation of unconjugated bilirubin.
Assessment and Diagnostic Findings
Diagnosis of primary hypothyroidism is confirmed by demonstrating decreased levels of serum thyroid hormone (total or free T4) and elevated levels of thyroid-stimulating hormone (TSH).
- Newborn screening. Screening for congenital hypothyroidism is recommended when a baby is 3 days old; testing should be performed before discharge or within 7 days of birth; false-positive TSH elevations may be found in specimens collected at 24-48 hours after birth, and false-negative results may be found in critically ill newborns or post-transfusion infants.
- T4 levels. Low or low-normal serum total T4 levels in the setting of a serum TSH within the reference range suggests TBG deficiency; this congenital disorder causes no pathologic consequence; however, it should be recognized to avoid unnecessary thyroid hormone administration.
- Ultrasonography and scintigraphy. Ultrasound and thyroid scintigraphy help determine the anatomy and function of the thyroid gland as well as the etiology of congential hypothyroidism; ultrasound lacks sensitivity for detecting small ectopic glands but is the gold standard for measuring thyroid dimensions; scintigraphy (using technetium-99m or iodine-123) provides an etiologic diagnosis in most cases and can aid in distinguishing congenital hypothyroidism from transient hyperthyrotropinemia.
- Radiography. A lateral radiograph of the knee may be obtained to look for the distal femoral epiphysis; this ossification center appears at about 36 weeks’ gestation; its absence in a term or postterm infant indicates prenatal effects of hypothyroidism.
Medical Management
The thyroid hormone must be replaced as soon as the diagnosis is made. The goal of treatment in congenital hypothyroidism is to correct hypothyroidism and ensure normal growth and neuropsychological development.
- Levothyroxine. Only levothyroxine is recommended for treatment; it has been established as safe, effective, inexpensive, easily administered, and easily monitored.
- Diet. Dietary iodide supplementation in iodine-deficient areas can prevent endemic cretinism but does not have a major effect on sporadic congenital hypothyroidism; soy-based formulas may decrease the absorption of levothyroxine; this is not a contraindication to their use, even in infants with congenital hypothyroidism; switching an infant from a milk-based formula to a soy-based formula may increase the dose of thyroid hormone needed to maintain a euthyroid status.
Pharmacologic Management
The drug of choice for CH is only Levothyroxine.
- Thyroid hormones. These agents are administered to supplement thyroid hormone in patients with hypothyroidism. Levothyroxine is the preferred form of thyroid hormone replacement in all patients with hypothyroidism.
Nursing Management
Nursing care of a child with congenital hypothyroidism include the following:
Nursing Assessment
Assessment of a child with congenital hypothyroidism include:
- History. Family history should be carefully reviewed for information about similarly affected infants or family members with unexplained mental retardation; maternal history of a thyroid disorder and mode of treatment, whether before or during pregnancy, can occasionally provide the etiology of the infant’s problem.
- Physical exam. Physical exam may show signs of coarse facial features, macroglossia, large fontanelles, umbilical hernia, developmental delay, pallor, myxedema, and goiter.
Nursing Diagnosis
Based on the assessment data, the major nursing diagnosis for congenital hypothyroidism are:
- Imbalanced nutrition: more than body requirements related to greater intake than metabolic needs as evidenced by hypotonia or decreased activity level.
- Deficient knowledge related to lack of exposure to hypothyroidism and unfamiliarity with information sources.
- Fatigue related to impaired metabolic state.
Nursing Care Planning and Goals
Main Article: 3 Hypothyroidism Nursing Care Plans
The major nursing care planning goals for congenital hypothyroidism are:
- Client will maintain a stable weight and takes in necessary nutrients.
- Family members/caregivers will verbalize correct information about hypothyroidism and taking thyroid hormone replacement.
- Family members/caregivers will identify basis of fatigue and individual areas of control.
- Family members/caregivers will verbalize reduction of fatigue and increased ability to complete desired activities.
Nursing Interventions
The nursing interventions are:
- Maintain a stable weight. Educate the client and family regarding body weight changes in hypothyroidism; collaborate with a dietician to determine client’s caloric needs; encourage the intake of foods rich in fiber; encourage a low-cholesterol, low-calorie, low-saturated-fat diet.
- Learn more about the disease. Provide information about hypothyroidism; educate the client and family regarding thyroid hormones; emphasize the importance of rest periods.
- Reduce fatigue. Note daily energy patterns; plan care to allow individually adequate rest periods; schedule activities for periods when the client has the most energy; promote an environment conducive to relieve fatigue.
Evaluation
Goals are met as evidenced by:
- Client maintained a stable weight and takes in necessary nutrients.
- Family members/caregivers verbalized correct information about hypothyroidism and taking thyroid hormone replacement.
- Family members/caregivers identified basis of fatigue and individual areas of control.
- Family members/caregivers verbalized reduction of fatigue and increased ability to complete desired activities.
Documentation Guidelines
Documentation in a child with congenital hypothyroidism include:
- Individual findings, including factors affecting, interactions, nature of social exchanges, specifics of individual behavior.
- Intake and output.
- Cultural and religious beliefs, and expectations.
- Plan of care.
- Teaching plan.
- Responses to interventions, teaching, and actions performed.
- Attainment or progress toward desired outcome.
Practice Exam
[mtouchquiz 781 title=off]
Nursing Care Plan
Imbalanced Nutrition: More Than Body Requirements
Imbalanced Nutrition: More Than Body Requirements: Intake of nutrients that exceeds metabolic needs.
May be related to
- Greater intake than metabolic needs.
Possibly evidenced by
- Decreased appetite.
- Sedentary activity level.
- Weight gain.
Desired Outcomes
- Client will maintain a stable weight and takes in necessary nutrients.
Nursing Interventions | Rationale |
---|---|
Assess the client’s weight. | Due to excess fluid volume and low basal metabolic rate, clients with hypothyroidism experience weight gain and difficulty losing extra weight |
Assess the client’s appetite. | Clients with hypothyroidism have decreased appetite. This opposite relationship between weight gain and decreased appetite is a manifestation finding in hypothyroidism. |
Provide a food diary to the client. | Looking into the client’s food intake over the 24 hours will provide a baseline data for an individualized nutritional plan for the client’s changing metabolic needs. |
Educate the client and family regarding body weight changes in hypothyroidism. | Teaching the client and family will make them understand the opposite relationship between appetite and weight gain in hypothyroidism. During the start of the thyroid hormone replacement therapy, the client can experience loss of weight. However, there will be an increased in appetite. This change may require a calorie controlled diet to prevent additional weight gain. |
Collaborate with a dietician to determine client’s caloric needs. | The dietician can calculate the appropriate caloric requirements to maintain nutrient intake and achieve a stable weight. |
Encourage the client to eat six small meals throughout the day. | This will make sure that the client has an adequate intake of nutrients in the client with decreased energy levels. |
Provide assistance and encouragement as needed during mealtime. | Due to a decrease energy levels, the client will need the support to ensure the adequate intake of essential nutrients. |
Encourage the intake of foods rich in fiber. | Hypothyroidism slows the action of the digestive tract causing constipation. |
Encourage te client to follow a low-cholesterol, low-calorie, low-saturated-fat diet. | When thyroid hormone levels are low, the body doesn’t break down and remove bad cholesterol as efficiently as usual; Also, since the client has slow metabolism, he/she requires fewer calories to support metabolic need |
Deficient Knowledge
Deficient Knowledge: Absence or deficiency of cognitive information related to a specific topic.
May be related to
- Lack of exposure to hypothyroidism.
- New disease process.
- Unfamiliarity with information resources.
Possibly evidenced by
- Limited questioning about hypothyroidism and taking thyroid hormone replacement.
- Verbalization of lack of information about the disease and its management.
Desired Outcomes
- Client and family members will verbalize correct information about hypothyroidism and taking thyroid hormone replacement.
Nursing Interventions | Rationale |
---|---|
Assess the client’s knowledge of hypothyroidism and thyroid hormone replacement therapy. | Client teaching should begin with the current knowledge about the disease and its management. |
Provide information about hypothyroidism. | Clients experiencing hypothyroidism may have impaired memory, confusion, hearing loss, and a decrease attention span. These neurologic changes can hinder with learning new information. Teaching sessions should be planned at times when the client is best able to concentrate. Recalling of information is needed to facilitate learning. Using written information reinforces verbal presentation. |
Educate the client and family regarding thyroid hormones.
|
Levothyroxine sodium (Synthroid) is a manmade thyroid hormone that is used to treat hypothyroidism.Thyroid hormone should be taken on a regular basis to achieve a hormone balance.
The client is initially given a small dose that gradually increases until a euthyroid state is achieved. When the thyroid hormone level increases, the client experiences insomnia and weight loss. The client should report symptoms such as chest pain/palpitations; these happen due to the increased metabolic and oxygen consumption. |
Emphasized the importance of rest periods. | Avoid undue fatigue; As euthyroid state is achieved, activity level will eventually increase. |
Encourage the client to follow appointments for blood workups (T3, T4, and TSH levels). | These levels help determine the effectiveness of pharmacotherapy |
Describe signs and symptoms of over- and underdosage of the medications. | This will serve as check for client to determine if the therapeutic levels are met. |
Encourage the client to have medical identification about hormone therapy and to inform all health care provider. | Medical identification provides other health care providers with information to guide decisions about care. Levothyroxine is highly protein bound in circulation. This drug characteristic contributes to many drug interactions. The client needs to notify all health care providers about taking this drug. |
Fatigue
Fatigue: An overwhelming, sustained sense of exhaustion and decreased capacity for physical and mental work at usual level.
May be related to
- Impaired metabolic state.
Possibly evidenced by
- Lethargic or listless.
- Compromise concentration.
- Increased rest requirements.
- Unable to complete desired activities.
- Verbalizes overwhelming lack of energy.
Desired Outcomes
- Client will identify basis of fatigue and individual areas of control.
- Client will verbalize reduction of fatigue and increased ability to complete desired activities.
Nursing Interventions | Rationale |
---|---|
Assess the client’s ability to perform activities of daily living (ADLs). | The client may experience fatigue with minimal exertion due to a slow metabolic rate. This symptom hinder the client’s ability to perform daily activities (e.g., self-care, eating) |
Note daily energy patterns. | This will help in determining pattern/timing of activity. |
Assess the client’s energy level and muscle strength and muscle tone. | Slow metabolism can result in decreased energy levels. The muscle may be weaker and joints stiffer due to mucin deposits in joints and interstitial spaces. This type of cellular edema may contribute to delayed muscle contraction and relaxation. The client may report generalized weakness and muscle pain. |
Plan care to allow individually adequate rest periods. Schedule activities for periods when the client has the most energy. | This will ensure maximize participation. |
Provide stimulation through conversation and non stressful activities. | Promotes interest without putting too much stress to the client. |
Promote an environment conducive to relieve fatigue. | The client with hypothyroidism often complains of being cold even in a warm environment. |