Disorders of the thyroid gland

w. akpaloo

Objectives

• By the end of this lecture, the student should be able to:
• Describe what constitutes hyperthyroidism, its clinical manifestations, diagnosis, and management
• Use the nursing process as a framework for planning care for clients suffering from hyperthyroidism
• Describe with rational, preoperative and post operative nursing interventions for clients having subtotal thyroidectomy

Introduction

• Alteration in thyroid hormone (TH) production or use affects all major organ systems
• TH changes primarily affects metabolism, cardiovascular function GIT function and neuromuscular function
• Thyroid disorders: both hyperthyroidism and hypothyroidism (to be presented by student) are among the most common endocrine disorders

The client with Hyperthyroidism

The client with Hyperthyroidism

• Hyperthyroidism is also known as thyrotoxicosis
• It is the second most prevalent endocrine disorder after diabetes mellitus
• It is a disorder caused by excessive secretion of TH
• Primarily, TH increases metabolism and protein synthesis

The client with Hyperthyroidism

• Hyperthyroidism affects all major organ systems of the body
• If left untreated, significant weight loss and cardiac complications, including heart failure, may occur
• It affects women 8 times more frequently than men

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In hyperthyroidism

• There is increase in metabolic rate in hyperthyroidism
• The increase in metabolic rate and alterations in cardiac output, peripheral blood flow, oxygen consumption and body temperature are similar to those found in increased sympathetic nervous system activity

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In hyperthyroidism

• The effects of hyperthyroidism are the result of increased circulating levels of TH
• This hormonal excess increases metabolic rate and heightens the sympathetic nervous system’s physiologic response to simulation
• Cardiac rate and stroke volume are increased

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In hyperthyroidism

• Cardiac output and peripheral blood flow increases
• There is increased carbohydrate, protein and lipid metabolism
• Lipids are depleted
• Protein degradation increases resulting in negative nitrogen balance
• Over time, the hyper metabolic state results in caloric and nutritional deficiencies

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Causes

1. Autoimmune stimulation (as in Grave’s disease)
2. Excessive secretion of thyroid-stimulating hormone (TSH) by the pituitary gland
3. Thyroiditis
4. Neoplasm (such as toxic nodular goiter)
5. Excessive intake of thyroid medications
1. The most common aetiologies of hyperthyroidism are Grave’s disease and toxic multinodular goiter

Symptoms

• Weight loss despite increased appetite
• Excessive sweating
• Heat intolerance
• Tremors
• Nervousness and irritability
• Menstrual irregularity and sub-fertility
• Diarrhoea
• Insomnia
• Palpitations
• Increased sweating
• Hair loss in scalp, eyebrow, axillary

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Manifestations

Signs

• Staring or protruding eyes
• Tremors
• Moist palms
• Rapid pulse rate which may be irregular
• Heart failure
• Hair may become fine
• Skin is smooth and warm
• Emotional lability

Goitre often present but not always:

• Smooth and diffuse goitre in Grave's disease
• Irregular goitre in toxic multi-nodular goitre

Grave’s disease

• The most common cause of hyperthyroidism
• An autoimmune disorder
• 5 times common in women than men
• Cause is unknown but there is a hereditary link

Grave’s disease

• Clients with Grave’s disease have antibody that binds to the thyroid-stimulating hormone (TSH) receptors in the thyroid follicles and causes the thyroid cells to hyperfunction
• When the antibody binds to TSH receptors on the thyroid gland, it stimulates hormone synthesis and secretion, enlarging the gland

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Grave’s disease

• Clients with Grave’s disease have an enlarged thyroid gland (goiter) and manifestations of hyperthyroidism
• The goiter can result from excess TSH stimulation, abnormal growth stimulating immunoglobulins or substances that inhibit TH
• A goiter may be present in hyperthyroidism or hypothyroidism

Grave’s disease

• The ophthalmopathy of Grave’s disease manifest as proptosis and visual dysfunction
• Proptosis (forward displacement) occurs in about one-third of cases
• Exophthalmos – forward protrution of the eyeballs results from accumulation of inflammation by-products in the retro-orbital tissues
• The upper lids are often retracted and the person has a characteristic unblinking stare

Grave’s disease

• Proptosis is usually bilateral
• The client may experience blurred vision, diplopia, eye pain, lacrimation and photophobia
• The inability to close the eyelids completely over the protruding eyeballs increase the risk of corneal dryness, irritation, infection and ulceration
• The treatment of Grave’s disease may stabilize these symptoms but generally does not reverse these changes in the eyes

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Diagnosing hyperthyroidism

• Thyroid function test – free T3, free T4, TSH
• Thyroid ultrasound scan

Management

• Treatment of hyperthyroidism focuses on reducing the production of TH by the thyroid gland, thus establishing euthyroid (normal thyroid) state and preventing or treating complications
• Treatment may be either by medications, radioactive iodine therapy, or surgery depending client’s age and physical status

Medications

• Hyperthyroidism is treated with antithyroid medications to reduce TH production
• Therapeutics effects may not be seen for several weeks
• Propranolol, a beta blocker is part of the initial treatment
• Antithyroid medications: Methimezole (can be taken one daily dose), & Propylthiouracil (taken 3 times – inhibit TH production. They do not affect already formed hormones thus several weeks may elapse before the client experiences therapeutic effects.

Medication

• Nursing responsibilities: monitor side effects of the medications – agranulocytosis, hypothyroidism, pruritus rash, elevated temperature, anorexia, loss of taste, periorbital oedema, changes in menstruation
• Administer the drugs at the same time each day with meals to maintain stable blood levels
• Monitor for symptoms of hypothyroidism: fatigue , weight gain

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Radioactive iodine therapy

• Read on it

Surgery

• Enlarged thyroid gland that pressure on the oesophagus or trachea causes breathing or swallowing problems
• Theses cases will need removal of all or part of the gland
• A subtotal thyroidectomy is usually performed. This procedure leaves enough gland in place to produce an adequate amount of TH.

Surgery

• A total thyroidectomy is performed to treat cancer of the thyroid. The client will then require a lifelong hormone placement
• Before surgery the client should be in nearly a euthyroid state as possible
• The client may be given antithyroid drugs to reduce hormone levels and iodine preparation to decrease the vascularity and size of the gland (which also reduces the risk of haemorrhage during and after surgery)

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Nursing care of client having a subtotal thyroidectomy

Preoperative care

• Administer prescribed antithyroid medications and iodine preparations and monitor effects
• The antithyroid drugs are given before surgery to promote a euthyroid state
• Iodine preparations are given to clients before surgery to decrease vascularity of the gland in order to decrease the risk of haemorrhage

Nursing care of client having a subtotal thyroidectomy

Preoperative care

• Teach client to support the neck by placing both hands behind the neck when sitting up in bed, while moving about, and while coughing. Rational? Placing the hands behind the neck provides support for the suture line

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• Answer questions and allow time for client to verbalize concerns. Because the incisions are made at the base of the throat, clients (especially women) are often concerned about their appearance after surgery. Explain that the scar will eventually be only a thin line and that jewellery or scarves may be used to cover the scar

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Nursing care of client having a subtotal thyroidectomy

Preoperative care

• Teach the client to expect hoarseness due to generalized swelling at the suture line. This is expected to diminish with healing and is not caused by laryngeal nerve damage

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Nursing care of client having a subtotal thyroidectomy

Post operative care

• Provide comfort measures: administer analgesics as prescribed and monitor effectiveness. Place client in semi-fowlers position after recovery from anaesthesia; support head and neck with pillows. Semi-fowler’s position and supporting the head and neck decreases strain on the suture line

Nursing care of client having a subtotal thyroidectomy

• Perform focused assessments to monitor for complications:
• Haemorrhage – the danger of haemorrhage is greatest in the first 12 to 24 hr after surgery. assess dressing and area under client neck and shoulders for drainage. Monitor BP, pulse – for shock. Assess tightness of dressing (if present).
• Respiratory distress – monitor respiration. Assist client with cough and deep breathing. Have suction equipment, oxygen, and tracheostomy set available for immediate use.
• Laryngeal nerve damage – assess for the ability to speak aloud noting quality of tone of voice.
• Tetany – assess for signs of latent tetany due to calcium deficiency, including tingling of toes, fingers and lips, muscular twitches etc

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Nursing diagnoses

• Risk for decreased cardiac output
• Disturbed sensory perception: Visual
• Imbalanced nutrition: Less than body requirements
• Disturbed body image
• Low self-esteem