HYPOTHYROIDISM
This is a condition that arises from inadequate amounts of thyroid hormone in the bloodstream.
When the thyroid dysfunction is due to failure of the pituitary gland, it is known as secondary hypothyroidism, when failure of the hypothalamus is the underlying cause, the term tertiary hypothyroidism used. When thyroid deficiency is present at birth, the condition is known as cretinism.
Causes
1. Primary hypothyroidism.
a. Autoimmune disease (Hashimoto's Thyroiditis)
b. Use of radioactive iodine.
c. Destructions, suppression or removal of all or some of the thyroid tissue by thyroidectomy.
d. Dietary iodide deficiency.
e. Subacute Thyroiditis
f. Lithium therapy.
g. Overtreatment with antithyroid drugs.
2. Secondary hypothyroidism Caused by inadequate secretion of TSH caused by disease of The pituitary gland (i.e. Tumor, necrosis).
Pathophysiology
General depression of most cellular enzyme systems and oxidative processes occurs. Inadequate secretion of thyroid hormone leads to a general slowing of all physical and mental processes. The metabolic activity of all cells of the body decreases, reducing oxygen consumption, decreasing oxidation of nutrients for energy and producing less body heat.
[The s/s of the disorder range from vague, non-specific complaints that make diagnosis difficult, to severe symptoms that may be life-threatening if unrecognized and untreated].
Clinical Manifestations
1. Fatigue and lethargy.
2. Weight gain [even without an increase in food intake.]
3. Hair loss, brittle nails and dry skin, numbness and tingling of the fingers.
4. Voice-husky Patient may complain of hoarseness. Menorrhagia or amenorrhea, may have difficulty conceiving or may experiences spontaneous abortion; decreased libido.
5. Temperature and Pulse Subnormal,
6. The skin becomes thickened because of an accumulation of mucopolysaccharides in the subcutaneous tissues. Hair thins, loss of the lateral one-third of eyebrow... The face becomes expressionless and the mask like.
7. Severe constipation, [decreased peristalsis], intolerance of cold.
8. At first the patient may be irritable and may, complain of fatigue, but as the condition progresses, the emotional responses are subdued. The mental process becomes dulled and the patient appears apathetic. Speech is slow, the tongue enlarges and hands and feet increase in size. The advanced myxedematous state may produce personality changes.
Diagnostic Evaluation
1. Low T3, and T4 levels.
2. Elevated TSH levels in primary hypothyroidism.
3. Elevation of serum cholesterol.
4. ECG- sinus bradycardia, [low voltage of QRS complexes and flat or inverted T waves]
Management
1. Synthetic levothyroxine (Synthroid) treats hypothyroidism and suppresses nontoxic goitre Dosage based on patient's normal or suppressed serum TSH concentration. [If replacement therapy is adequate, the symptoms of myxoedema disappear and normal metabolic activity is resumed].
2. Maintain vital functions. ABCs determine CO, retention and is a guide to assisted Ventilation to combat hypoventilation.
3. Fluids are administered cautiously because of the danger of water intoxication
Complications
1. Myxoedema, coma [hypotension, unresponsiveness, bradycardia, hypoventilation, hyponatremia, (possibly) convulsions, hypothermis, cerebral hypoxia)
2. High mortality rate in myxedema coma
Nursing Interventions
1. Support the patient by assisting with care and hygiene while encouraging him to participate in activities within his tolerance, to prevent complications of immobility.
2. Space activities to promote rest and exercise
3. Assist with self-care activities when fatigued
4. Monitor patient's response to increasing activities,
5. Provide extra layer of clothing or extra blanket to minimize heat loss.
6. Avoid and discourage use of external heat sources. (e.g. Heating pads, electric or warming blankets)] reduces the risk of peripheral vasodilatation and vascular collapse.
7. Prevent chilling to avoid increasing metabolic rate, which, in turn, places strain on the heart. Provide bed socks, bed jacket and warm environment.
8. Monitor vital signs frequently to detect changes in CV status and ability to respond to stress
9. Monitor ECG tracings to detect arrhythmia and deterioration of cardiovascular status. Report occurrence of angina and be alert for S/S of MI and cardiac failure. [Angina may occur because of rapid thyroid displacement in the presence of coronary disease 2ยบ to hypothyroid state. CCF and tachydysrhythmias may worsen during the transition from hypothyroid to normal metabolic state.
10, Encourage increased fluid intake within limits of fluid restriction. Provide a high fibre diet, monitor bowel function [to treatment constipation.]
11. Explain rationale for thyroid hormone replacement. Describe effects and S/S of over and underdose of medication to patient.
12. Monitor respiratory rate, depth and pattern, encourage deep breathing and coughing, administer medication (hypnotics, sedatives) with caution, maintain patent airway through suction and ventilatory support if indicated.
13. Advise patient to control, dietary intake, limit calories and reduce weight
14 Orient patients explain to patient and family that change in cognitive and mental functioning is a result of disease process.
13. Teach patient to space activities to promote rest and exercise and to gradually increase the level of activity as tolerated. [Activity intolerance R/T reduced metabolic rate).
16. Patient and family may require assistance and counseling to deal with the emotional concerns and reactions that occurred.
