Ignatavicius: Medical-Surgical Nursing, 7th Edition

Chapter 64: Assessment of the Endocrine System

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ANATOMY AND PHYSIOLOGY REVIEW

The endocrine system is made up of glands in many tissues and organs in a variety of body areas.

A key feature of all endocrine glands is the secretion of hormones. Hormones are natural chemicals that exert their effects on specific tissues known as target

tissues. Target tissues are usually located some distance from the endocrine gland, with no direct

physical connection between the endocrine gland and its target tissue. For this reason, endocrine glands are called “ductless” glands and must use the blood to

transport secreted hormones to the target tissues. Endocrine glands include the hypothalamus, pituitary gland, adrenal glands, thyroid gland,

islet cells of the pancreas, parathyroid glands, and gonads. Hormones recognize their target tissues and exert their actions by binding to receptor sites on

or within the target tissue cells. Each receptor site type is specific for only one hormone. Hormone-receptor actions work in a “lock and key” manner in that only the correct hormone

key can bind to and activate the receptor site or lock. Binding a hormone to its receptor causes the target tissue to change its activity. Therefore, hormones produce specific responses even though they circulate throughout the

body. Disorders of the endocrine system are related to either an excess or a deficiency of a specific

hormone or to a defect at its receptor site. The onset of these disorders can be either slow and insidious or abrupt and life threatening. The control of cellular function by any hormone depends on a series of reactions working

through negative feedback control mechanisms. When a condition starts to move away from the normal range and a specific action or

response is needed to correct this change, secretion of the hormone capable of causing the correct response is stimulated until the need or demand is met.

As the correction occurs, hormone secretion decreases and may halt. This control for hormone synthesis is “negative feedback” because the hormone causes the

opposite action of the initial condition change. Some hormones have more complex interactions, with a series of reactions in which more

than one endocrine gland, as well as the final target tissue, is stimulated.

ASSESSMENT METHODS

Although endocrine problems can disturb any health pattern, the patterns most commonly affected are nutritional-metabolic, activity, elimination, sleep, and sexuality-reproductive.

Copyright © 2013, 2010, 2006, 2002 by Saunders, an imprint of Elsevier Inc.

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These data are combined with physical, psychosocial, and laboratory findings for a complete assessment of endocrine function.

Age and gender of the patient provide baseline assessment data. Certain disorders such as diabetes mellitus, loss of ovarian function, and decreased thyroid

function are more common in older than in younger patients. Manifestations of endocrine disorders can be gender related, such as the sexual effects of

hyperpituitarism and hypopituitarism. Thyroid problems are much more common in women than in men. Assess the patient for a history of endocrine dysfunction, manifestations that could indicate

an endocrine disorder, especially those that have required hospitalization. Ask the patient about other family members with endocrine disorders because some

endocrine problems have a genetic component. Ask the patient what prescribed and over-the-counter drugs were or are taken on a regular

basis because some drugs can alter endocrine function. The use of exogenous hormone drugs, when not needed for hormone replacement, can cause

serious dysfunction in many endocrine glands. Use the opportunity to warn patients about the dangers of misusing or abusing hormone-

based drugs such as androgens and thyroid hormones. Nutritional changes or GI tract disturbances reflect different endocrine problems. Ask about a history of nausea, vomiting, and abdominal pain. Rapid changes in weight without diet changes can signal the onset of a number of endocrine

disorders, including diabetes mellitus and thyroid problems. Dietary deficiencies, especially of protein and iodide-containing foods, may be a cause of an

endocrine disorder. Encourage patients to eat a well-balanced diet that includes at least 60 g of protein daily, less

animal fat, and fewer concentrated simple sugars. Ask the patient about any family history of obesity, growth or development difficulties,

diabetes mellitus, infertility, or thyroid disorders, which may have an autosomal dominant, recessive, or cluster pattern of inheritance.

Focus on the patient’s reason for seeking health care, asking questions about onset of symptoms, past history of problem, and effect on daily activities.

Explore changes in energy levels, elimination patterns, sexual and reproductive functions, and physical features.

Use a head-to-toe approach to inspect the patient, observing general appearance, and assessing height, weight, fat distribution, and muscle mass in relation to age.

When examining the head, focus on abnormalities of facial structure, features, and expression.

Check the lower half of the neck for a visible enlargement of the thyroid gland. Skin changes, such as hypo- or hyper-pigmentation, fungal skin infections, slow wound

healing, bruising, and petechiae, may reflect a specific endocrine dysfunction. Vitiligo or patchy areas of pigment loss with increased pigmentation at the edges is seen with

primary hypofunction of the adrenal. Inspect the patient’s fingernails for malformation, thickness, or brittleness, all of which may

suggest thyroid gland problems. Inspection of the trunk can show signs of specific endocrine dysfunction, such as truncal

obesity and the presence of a “buffalo hump” between the shoulders.

Copyright © 2013, 2010, 2006, 2002 by Saunders, an imprint of Elsevier Inc.

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Examination of the genitalia may reveal a dysfunction in hormone secretion. The thyroid gland is palpated for size, symmetry, general shape, and the presence of nodules

or other irregularities. Auscultate the chest for baseline vital signs and assess cardiac rate and rhythm. Information obtained from the history and physical examination may help to identify

psychosocial problems. Assess the patient’s coping skills, support systems, and health-related beliefs. Laboratory tests are an essential part of the diagnostic process, including tests of blood, urine,

and saliva. With underactivity of an endocrine gland, a stimulus may be provided to determine whether

the gland is capable of normal hormone production. Failure of the hormone level to rise with stimulation indicates hypofunction. Suppression tests are used when hormone levels are high or in the upper range of normal. Failure of suppression of hormone production during testing indicates hyperfunction. An assay measures the level of a specific hormone in blood or other body fluid. Anterior, posterior, and lateral skull x-rays may be used to view the sella turcica. Magnetic resonance imaging with contrast is the most sensitive method of imaging the

pituitary gland, although computed tomography scans can also evaluate. The thyroid, parathyroid glands, ovaries, and testes are evaluated by ultrasound. CT scans are also used to evaluate the adrenal glands, ovaries, and pancreas. Needle biopsy is a relatively safe and quick outpatient procedure used to indicate the

composition of thyroid nodules to determine whether surgical intervention is needed. Follow the laboratory’s procedures for collecting and handling specimens for endocrine

function studies. In venous sampling, blood samples are taken directly from veins that drain a specific

endocrine gland and hormone levels are measured. This test is used when a biopsy fails to identify a suspected mass.

Endocrine problems can change a patient’s behaviors, personality, perception of self, and psychological responses.

Encourage the patient to express his or her feelings and concerns about a change in appearance, sexual function, or fertility as a result of a possible endocrine problem.

Explain all diagnostic procedures, restrictions, and follow-up care to the patient scheduled for tests.

Patients with endocrine problems may require lifelong drugs and follow-up care.

Copyright © 2013, 2010, 2006, 2002 by Saunders, an imprint of Elsevier Inc.

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