Thyroid Gland Disorders

Thyroid Gland Disorders
Formation of Thyroid Hormone
1. Iodide trapping- Diet (GIT) 4. Organification - Thyroglobulin + Iodine
2. Formation of Thyroglobulin 5. Coupling - Mono + Di compounds
3. Peroxidation - Iodide – iodine 6. T4 and T3 formation
Wolff-Chaikoff Effect
• Increasing doses of I
-
increase hormone synthesis initially
• Higher doses cause cessation of hormone formation.
• This effect is countered by the Iodide leak from normal thyroid tissue.
• Patients with autoimmune thyroiditis may fail to adapt and become hypothyroid.
Jod-Basedow Effect
• Opposite of the Wolff-Chaikoff effect
• Excessive iodine loads induce hyperthyroidism
• Observed in hyperthyroid disease processes
– Graves’ disease
– Toxic multinodular goiter
– Toxic adenoma
• This effect may lead to symptomatic thyrotoxicosis in patients who receive large iodine doses from
– Dietary changes
– Contrast administration
– Iodine containing medication (Amiodarone)
TRH
• Produced by Hypothalamus
• Release is pulsatile, circadian
• Downregulated by T
3

• Travels through portal venous system to adenohypophysis
• Stimulates TSH formation
• Produced by Adenohypophysis Thyrotrophs
• Upregulated by TRH
• Downregulated by T
4
, T
3

• Travels through portal venous system to cavernous sinus, body.
• Stimulates several processes
– Iodine uptake
– Colloid endocytosis
– Growth of thyroid gland
Thyroid Hormone
• Majority of circulating hormone is T
4

– 98.5% T
4

– 1.5% T
3

• Total Hormone load is influenced by serum binding proteins
– Albumin 15%
– Thyroid Binding Globulin 70%
– Transthyretin 10%
• Regulation is based on the free component of thyroid hormone
Function of Thyroid Hormone
• Increases BMR
• Increase heat production
• Basically increased metabolism

Disorders of the Thyroid Gland
HYPOsecretion: HYPOTHYROIDISM
• A hypothyroid state characterized by decreased secretions of T3 and T4
• CAUSES: Hypofunctioning tumor, Pituitary tumor, Ablation therapy, Surgical removal of thyroid
Pathophysiology: Decreased T
3
and T
4
Decreased basal metabolism
• Two Forms
1. Endemic- Diet
2. Sporadic- goiterogenous foods
ASSESSMENT findings for Hypothyroidism
1. Lethargy and fatigue 7. Dry hair and skin, loss of body hair
2. Weakness and paresthesia 8. Generalized puffiness and edema around the eyes and face
3. COLD intolerance 9. Forgetfulness and memory loss
4. Weight gain 10. Slowness of movement
5. Bradycardia 11. Menstrual irregularities and cardiac irregularities
6. Constipation
NURSING INTERVENTIONS
1. Monitor VS especially HR
2. Administer hormone replacement: usually Levothyroxine( Synthroid) - should be taken on an empty
stomach
3. Instruct patient to eat LOW calorie, LOW cholesterol and LOW fat diet
4. Manage constipation appropriately
5. Provide a WARM environment
6. Avoid sedatives and narcotics because of increased sensitivity to these medications
7. Instruct patient to report chest pain promptly
Complication
Myxedema Coma
• a drastic decrease in metabolic rate, hypoventilation leading to metabolic acidosis, hypothermia
and hypotension
- coma - medical emergency
• Tx: TH replacement, levothyroxine Na
HYPERfunctioning: HYPERTHYROIDISM
• Called GRAVE’S DISEASE
• A hyperthyroid state characterized by increased circulating T3 and T4
• CAUSES: Auto-immune disorder, toxic goiter and tumor
Pathophysiology: Increased hormone activity Increased basal metabolism
ASSESSMENT Findings for Hyperthyroidism
1. Weight loss 7. Warm skin
2. HEAT intolerance 8. Diaphoresis
3. Hypertension 9. Smooth and soft skin
4. Tachycardia and palpitations 10. Oligomenorrhea to amenorrhea
5. Exopthalmos 11. Fine tremors and nervousness
6. Diarrhea 12. Irritability, mood swings, personality changes and agitation
NURSING INTERVENTIONS
1. Provide adequate rest periods in a quiet room
2. Administer anti-thyroid medications that block hormone synthesis - Methimazole and PTU
3. Provide a HIGH-calorie diet, HIGH protein
4. Manage diarrhea
5. Provide a cool and quiet environment
6. Avoid giving stimulants
7. Provide eye care
- Hypoallergenic tape for eyelid closure
8. Administer PROPRANOLOL for tachycardia
9. Administer IODINE preparation - Lugol’s solution and SSKI to inhibit the release of T3 and T4
10. Prepare clients for radioactive iodine therapy
11. Prepare patient for thyroidectomy
12. Manage thyroid storm appropriately
Complication
Thyroid Storm
• An acute LIFE-threatening condition characterized by excessive thyroid hormones in the body
• Characterized by high fever, tachycardia, delirium, dehydration and extreme irritability.
• CAUSE: Manipulation of the thyroid during surgery causing the release of excessive hormones in
the blood
ASSESSMENT Findings for Thyroid Storm
1. HIGH fever 4. Delirium, personality changes
2. Tachycardia and Tachypnea 5. Severe vomiting and diarrhea
3. Systolic HYPERtension 6. Restlessness, Agitation, confusion and Seizures
NURSING INTERVENTIONS
1. Maintain PATENT airway and adequate ventilation
2. Administer anti-thyroid medications such as Lugol’s solution, Propranolol, and Glucocorticoids
3. Monitor VS
4. Monitor Cardiac rhythms
5. Administer PARACETAMOL (not Aspirin) for FEVER
6. Manage Seizures as required.
7. Provide a quiet environment
THYROIDECTOMY
• Removal of the thyroid gland
PRE-OPERATIVE CARE - Thyroidectomy
1. Obtain VS and weight
2. Assess for Electrolyte levels, glucose levels and T
3
/T
4
levels
3. Provide pre-operative teaching like coughing and deep breathing, early ambulation and support of the
neck when moving
4. Administer prescribed medications- Lugol’s to decrease size,
– KISS, NaI
5. Assess for signs of hypocalcemia
– (+) Trosseau’s and (+) Chvostek’s signs
Major Complications
1. Bleeding 3. Hypocalcemia
2. Laryngeal nerve damage 4. Thyroid storm
POST-OPERATIVE CARE - Thyroidectomy
1. Position patient: Semi-Fowler’s, neck on neutral position
2. Monitor for respiratory distress - apparatus at bedside: tracheostomy set, O2 tank, and suction machine
3. Check for edema and bleeding by noting the dressing anteriorly and at the back of the neck
4. Limit client talking
5. Assess for HOARSENESS
• Expected to be present only initially, limit excess vocalization
• If persistent, may indicate damage to laryngeal nerve
6. Monitor for Laryngeal Nerve damage – Respiratory distress, Dysphonia, voice changes, Dysphagia and
restlessness
7. Monitor for signs of HYPOCALCEMIA and tetany due to trauma of the parathyroid
8. Prepare Calcium gluconate
9. Monitor for thyroid storm
Disorders of the Parathyroid Gland
Hypo-functioning: HYPOPARATHYROIDISM
• Hypo-secretion of parathyroid hormone
• CAUSES: tumor, removal of the gland during thyroid surgery
Pathophysiology: Decreased PTH Deranged calcium metabolism
ASSESSMENT Findings for Hypoparathyroidism
1. Signs of HYPOCALCEMIA 5. Bronchospasms, laryngospasms, and dysphagia
2. Numbness and tingling sensation on the face 6. Cardiac dysrhythmias
3. Muscle cramps 7. Hypotension
4. (+) Trosseau’s and (+) Chvostek’s signs 8. Anxiety, irritability and depression
NURSING INTERVENTIONS
1. Monitor VS and signs of HYPOcalcemia
2. Initiate seizure precautions and management
3. Place a tracheostomy set, O2 tank, and suction at the bedside
4. Prepare CALCIUM gluconate
5. Provide a HIGH-calcium and LOW phosphate diet
6. Advise client to eat Vitamin D rich foods
7. Administer Phosphate binding drugs
Hyper-functioning: HYPERPARATHYROIDISM
• Hyper-secretion of the gland
• CAUSE: Tumor
Pathophysiology: Increased PTH Increased CALCIUM levels in the body
ASSESSMENT Findings for Hyperparathyroidism
1. Fatigue and muscle weakness/pain 5. Constipation
2. Skeletal pain and tenderness 6. Hypertension
3. Fractures 7. Cardiac Dysrhythmias
4. Anorexia/N/V epigastric pain 8. Renal Stones
NURSING INTERVENTIONS
1. Monitor VS, Cardiac rhythm, I and O
2. Monitor for signs of renal stones, skeletal fractures. Strain all urine.
3. Provide adequate fluids- force fluids
4. Administer prescribed Furosemide to lower calcium levels
5. Administer NORMAL saline
6. Administer calcium chelators
7. Administer CALCITONIN
8. Prepare the patient for surgery