Thyroid Diseases Flashcards
Consider Possibility of Endocrine / Thyroid Changes When Assessing the Older Adult
Normal aging
- Decreased hormone production/secretion
- Altered hormone metabolism/activity
- Decreased target tissue response
Alteration in circadian rhythm
Changes of aging can mimic endocrine disorders
Hypothyroid symptoms of fatigue, constipation, mental impairment often missed because of sole attribution to aging
Thyroid Stimulating Hormone (TSH)
Anterior pituitary hormone
Stimulates thyroid gland to release hormones
2 – 10 U / mL
Serum levels
High = Defect within thyroid
Low = Defect in pituitary or hypothalamus
Thyroid Hormones
Regulate:
Energy metabolism
Growth & development
Dietary iodine necessary for synthesis
Triiodothyronine (T3)
More potent; greater metabolic effect
20 – 50 years: 70 – 205 ng/dL
> 50 years: 40 – 180 ng/dL
Thyroxine (T4)
Most abundant
Female 5 – 12 mcg/dL
Male 4 – 12 mcg/dL
Thyroid Antibodies
Anti-thyroglobulin antibody (Thyroid auto-antibody)
Marker for autoimmune thyroiditis
Normal: < 116 IU / mL
Anti-thyroid peroxidase antibody (Anti-TPO)
Normal: < 9 IU / mL
Increased levels:
Hashimoto’s thyroiditis
Thyrotoxicosis
Hypothyroidism
Thyroid cancer
Myxedema
Rheumatoid arthritis & collagen disease
Pernicious anemia
HYPERthyroidism
Sustained increase: Synthesis & release of thyroid hormones by thyroid gland
Occurs more often in women between 20 - 40 years
Grave’s Disease most common form
Other causes
Toxic nodular goiter
Thyroiditis
Excess iodine intake
Pituitary tumors
Thyroid cancer
Subclinical
TSH below 0.4 m IU/L
Normal T3 & T4 levels
Overt
Low or undetectable TSH
Increased T3 & T4 levels
Symptoms may or may not be present
Thyrotoxicosis
Physiologic effects / syndrome of hyper-metabolism
Results from increased circulating levels of T3, T4 or both
Hyperthyroidism & thyrotoxicosis usually occur together
HYPERthyroidism: Diagnostics
Decreased TSH (less than 0.4mU/L)
Increased free Thyroxine (free T4)
Total T3 & T4 (not definitive)
Radioactive iodine uptake (RAIU)
- —Distinguishes Graves’ disease from other forms of thyroiditis
Diagnostic Findings
Increased T3 & T4
Increased T3 resin uptake
Decreased or undetectable TSH
Chest x-ray showing enlarged heart
ECG: Tachycardia
Graves’ Disease
Autoimmune disease
—-Diffuse thyroid enlargement
—–Excess thyroid hormone secretion
Causative factors interact with genetic factors
Patients with female natal sex 5 times more likely to develop than those with male natal sex
Clinical Manifestations of Grave’s Disease
Effect of thyroid hormone excess
Increased metabolism
Increased tissue sensitivity to SNS stimulation
Goiter
Inspection, Palpation
Auscultation: Bruits
Ophthalmopathy; Abnormal eye appearance or function
Exophthalmos
Increased fat deposits & fluid
Eyeballs forced outward
Cardiovascular system
- Graves Disease
Systolic hypertension
Bounding, rapid pulse; palpitations
Increased cardiac output
Cardiac hypertrophy
Systolic murmurs
Dysrhythmias
Angina
Respiratory system
- Graves disease
Dyspnea on mild exertion
Increased respiratory rate
GI system
- Graves disease
Increased appetite, thirst
Weight loss
Diarrhea
Splenomegaly
Hepatomegaly
Skin
- Graves disease
Warm, smooth, moist skin
Thin, brittle nails
Hair loss
Fine, silky hair
Premature graying in patients with natal male sex
Diaphoresis
Vitiligo
Acropachy; Soft-tissue swelling & clubbing of fingers; palmar erythema
Musculoskeletal system
- Graves disease
Fatigue
Weakness
Proximal muscle wasting
Dependent edema
Osteoporosis
Intolerance to heat
Elevated basal temperature
Lid lag, stare
Eyelid retraction
Rapid speech
Nervous system
- Graves disease
Hyperactive deep tendon reflexes
Nervousness, fine tremors
Insomnia
Difficulty focusing eyes
Lability of mood, delirium
Lack of ability to concentrate
Stupor, coma
Reproductive system
- Graves disease
Menstrual irregularities
Amenorrhea
Decreased libido
Decreased fertility
Impotence & gynecomastia in patients with natal male sex
Acute Thyrotoxicosis Thyrotoxic Crisis OR “Thyroid Storm”)
Excessive amounts of hormones released
Life-threatening emergency
Death rare when treatment started early
Results from stressors
Thyroidectomy patients at risk
Manifestations
Severe tachycardia, heart failure
Shock (Cardiogenic)
Hyperthermia (up to 106° F [41.1° C])
Agitation
Seizures
Abdominal pain, vomiting, diarrhea
Delirium, coma
Acute Thyrotoxicosis Thyrotoxic Crisis OR “Thyroid Storm”)
Excessive amounts of hormones released
Life-threatening emergency
Death rare when treatment started early
Results from stressors
Thyroidectomy patients at risk
Manifestations
Severe tachycardia, heart failure
Shock (Cardiogenic)
Hyperthermia (up to 106° F [41.1° C])
Agitation
Seizures
Abdominal pain, vomiting, diarrhea
Delirium, coma
Acute Thyrotoxicosis Thyrotoxic Crisis OR “Thyroid Storm”)
- interprofessional care
Therapeutic goals
Block adverse effects of thyroid hormones
Suppress hormone oversecretion
Prevent complications
Three primary treatment options
Anti-thyroid medications
Radioactive iodine therapy (RAI)
Surgery
Evaluation
Relief / control of symptoms
No serious complications r/t disease or treatment
Adhere to therapeutic plan
Maintain nutritional balance
Acute Thyrotoxicosis Thyrotoxic Crisis OR “Thyroid Storm”)
- medication therapy
Useful in treatment of thyrotoxic states
Not considered curative
Anti-thyroid medications
Iodine
β-Adrenergic blockers
Anti-thyroid Medications
Propylthiouracil (PTU)
Methimazole (Tapazole)
Daily dose usually divided in three, every 8-hours
Initial daily doses:
15 mg (mild)
30 - 40 mg (moderate)
60 mg (severe)
Maintenance: 5 - 15 mg daily
Inhibit thyroid hormone synthesis
Improvement 1 - 2 weeks
Results 4 - 8 weeks
Therapy for 6 - 15 months
Iodine
Inhibits synthesis of T3 & T4
Blocks release into circulation
Decreases vascularity of thyroid making surgery safer & easier
Maximal effect within 1 - 2 weeks
Potassium iodine (SSKI)
250 mg or 0.25 mL three times per day (Dissolve in 4-ounces water, milk or juice)
Lugol’s solution (100 mg/mL potassium iodide & 50 mg/mL of iodine)
Hyperthyroidism: 1 mL three times per day
Prep for Thyroidectomy: 3 - 5 drops three times per day for 10-days
β-Adrenergic Blockers
Symptomatic relief of Thyrotoxicosis
Block effects of SNS stimulation; Decreases tachycardia, nervousness, irritability, tremors
Propranolol (Inderal)
Atenolol (Tenormin)
Preferred in patients with Asthma or CAD
Nutritional Therapy
High-calorie diet (4000 to 5000 cal/day)
6 full meals/day with snacks in between
Protein intake: 1 to 2 g/kg ideal body weight
Increased carbohydrate intake
Avoid highly seasoned foods, high-fiber foods, caffeine
Dietitian referral
HYPOthyroidism
Deficiency of thyroid hormone causing general slowing in metabolic rate
More common in patients with female natal sex than those with male natal sex
Subclinical
TSH greater than 4.5 mIU/L
T4 levels normal
Affects up to 10% of those with natal female sex over 60
Non-thyroidal illness syndrome (NTIS)
Critically ill patients
Low T3, T4, & TSH levels
HYPOthyroidism Diagnostics
History & physical examination
TSH & free T4
TSH increases with primary hypothyroidism
TSH decreases with secondary hypothyroidism
Thyroid antibodies (Autoimmune origin)
High cholesterol
High triglycerides
High creatine kinase (CK)
Low RBCs (anemia)
HYPOthyroidism
Etiology and Pathophysiology
Primary; Caused by destruction of thyroid tissue or defective hormone synthesis
Secondary:
Pituitary disease (decreased TSH)
Hypothalamic dysfunction or (decreased TSH)
Iodine deficiency
Atrophy of thyroid gland
Hashimoto’s thyroiditis
Graves’ disease
Treatment for hyperthyroidism
Drugs
Cretinism; physical deformity & learning disabilities caused by congenital thyroid deficiency
Thyroiditis
Acute infection and/or inflammation
Manifestations
Silent & painless
Sub-acute
Acute
Granulomatous (Bacterial or viral)
Chronic autoimmune (Hashimoto’s)
Most common cause of hypothyroid goiter
Management
NSAID’s
Corticosteroids (Prednisone)
Antibiotics
Surgical drainage
Patient teaching; Importance of adherence to plan
Clinical Manifestations of Hypothyroidism
Systemic effects characterized by slowing of body processes
Manifestations variable
Slow onset
Tired, lethargic, impaired memory, low initiative, weight gain
Clinical Manifestations of Hypothyroidism
Cardiovascular system
CV problems may be significant in patients with history of cardiovascular disease
Decreased cardiac contractility and output
Increased serum cholesterol & triglycerides
Anemia
Clinical Manifestations of Hypothyroidism
Respiratory
Low exercise tolerance
SOB on exertion
Clinical Manifestations of Hypothyroidism
GI system
Decreased appetite
Nausea, vomiting
Weight gain
Constipation
Distended abdomen
Enlarged, scaly tongue
Celiac disease
Clinical Manifestations of Hypothyroidism
Skin
Dry, thick, inelastic, cold skin
Thick, brittle nails
Dry, sparse, coarse hair
Poor turgor of mucosa
Generalized interstitial edema
Puffy face
Decreased sweating
Pallor
Increased susceptibility to infection
Increased sensitivity to opioids, barbiturates, anesthesia
Intolerance to cold
Decreased hearing
Sleepiness
Goiter
Clinical Manifestations of Hypothyroidism
Musculoskeletal system
Fatigue, weakness
Muscular aches & pains
Slow movements
Arthralgia
Clinical Manifestations of Hypothyroidism
Neurologic
Fatigue, lethargy
Personality, mood changes
Impaired memory, slowed speech, decreased initiative, somnolence
Clinical Manifestations of Hypothyroidism
Reproductive system
Prolonged menstrual periods or amenorrhea
Decreased libido, infertility
Common Features of Myxedema
Dull, puffy skin
Coarse, sparse hair
Periorbital edema
Prominent tongue
Interprofessional Care
Treatment goal; Restore euthyroid state as safely & rapidly as possible
Hormone therapy
Low-calorie diet
Relief / control of symptoms
Maintain euthyroid state
Maintain positive self-image
Adhere with lifelong thyroid therapy
Myxedema coma
Precipitated by infection, drugs, cold, trauma
Characterized by:
Impaired consciousness
Subnormal temperature
Hypotension
Hypoventilation
CV collapse
Treated with IV thyroid hormone
Patient Teaching: Hypothyroidism
Written instructions important
Need for lifelong therapy & regular follow-up care
Avoid abruptly stopping drugs
Side effects of medication
Signs & symptoms of hypothyroidism and hyperthyroidism
Comfortable, warm environment
Measures to prevent skin breakdown
Do not switch brands
Medication interactions
Avoid sedatives or use lowest dose possible
Measures to minimize constipation
Relapses occur if treatment is interrupted
Levothyroxine (Synthroid)
Low dose; Increased in 4 – 6 week intervals PRN based on TSH levels
Lifelong therapy
Monitor for tachycardia, especially:
During initiation of therapy
In the elderly
Teach - Notify Provider for:
Chest pain
Weight loss
Nervousness
Tremors
Insomnia
Thyroid Nodules & Cancer
Thyroid CA
Papillary (70-80%)
Follicular (10-15%)
Common in elderly
Medullary (5-10%)
Hereditary
Anaplastic (<5%)
Most aggressive
Primary sign: Painless, palpable nodule(s)
Treatment for Thyroid Cancer
Thyroidectomy: Primary treatment w/ Lymph node dissection PRN
Some patients may receive RAI
External beam radiation: Palliative treatment in metastatic cases
High-dose thyroid hormone therapy
Chemotherapy for advanced disease
Radioactive Iodine Therapy (RAI)
Treatment of choice for most non-pregnant adults; Damages, destroys thyroid tissue
Delayed response up to 3 months; Anti-thyroid drugs & β-blocker before & during first 3-months
Outpatient
Radiation Precautions:
Private toilet, double-flushing
Separate laundry daily
No food prep with bare hands
Avoid pregnant women/children for 7-days after treatment
80% have post-treatment hypothyroidism
Patient Teaching
Oral care (Thyroiditis / Parotiditis)
Water / ice chips
Salt & soda gargle
“Magic Mouthwash” (Antacid, Benadryl, Viscous Lidocaine)
Radiation precautions
Symptoms of hypothyroidism
Surgical Therapy
Thyroid cancer
Indications
Large goiter causing tracheal compression
Unresponsive to anti-thyroid therapy
Thyroid cancer
Not a candidate for RAI
Rapid reduction in T3 & T4 levels
Subtotal Thyroidectomy
Preferred procedure
Removal of up to 90% of thyroid
Minimally invasive procedures possible
Endoscopic
Robotic surgery
Preoperative Care for Thyroidectomy
Administration of medications to achieve euthyroid state
Administration of iodine to decrease vascularity
Patient teaching
Comfort & safety measures
Leg exercises, head support, neck ROM
Routine postoperative care
Thyroidectomy: Post-op Assessment
Frequent vital signs
Assess for signs of:
Hemorrhage
Tracheal compression
Avoid flexion / tension on suture lines
Semi-Fowler’s position
Support head with pillow(s)
Difficulty speaking?
Voice hoarse?
Smile symmetrical?
Tongue midline?
Monitor for 72-hours
Chvostek’s
Trousseau’s
Caloric adjustment?
Complete thyroidectomy?
Life long thyroid hormone replacement
Postoperative Care for Thyroidectomy
Monitor for complications
Hypothyroidism
Hypocalcemia
Hemorrhage
Laryngeal nerve damage
Thyrotoxicosis
Infection
Maintain patent airway
Oxygen, suction equipment, tracheostomy tray in patient’s room
Monitor for laryngeal stridor
Assess frequently during first 24-hours for hemorrhage or tracheal compression
Semi-Fowler’s position
Support head with pillows to avoid tension on suture line
Monitor vital signs
Signs of hypocalcemia
IV calcium readily available
Ambulation
Psychosocial support
Discharge Teaching
Thyroid cancer
Monitor hormone balance periodically
Decrease caloric intake
Adequate but not excessive iodine intake
Regular exercise
Avoid high environmental temperature
Regular follow-up care
Complete thyroidectomy
Symptoms of hypothyroidism
Need for lifelong thyroid hormone replacement
HYPERparathyroidism
Parathyroid hormone (PTH) regulates Calcium & Phosphate levels
HYPERcalcemia
HYPOphosphatemia
Decreased bone density
Weakness
Increased urinary calcium
Calculi
Stimulates biologically active Vitamin D, which increases Ca+ uptake and hypercalcemia
HYPERparathyroidism
Primary
Primary (30-70 years of age)
Increased secretion of PTH; Disorders of Ca+, phosphate, bone metabolism
Benign tumors
HYPERparathyroidism
Secondary
Secondary; Compensatory to conditions that cause HYPOcalcemia
Vitamin D deficiency
Malabsorption
CKD
HYPERphosphatemia
HYPERparathyroidism
Tertiary
Tertiary; Hyperplasia of parathyroid & loss of negative feedback from circulating Ca+
Kidney transplant s/p long term hemodialysis
Surgery for HYPERparathyroidism
Most effective treatment for Primary & Secondary
Criteria
Serum Ca+ > 12
HYPERcalciuria > 400 mg / day
Decreased bone density
Partial or complete
Auto-transplantation of normal tissue
If not, Ca+ supplements for life
HYPOparathyroidism (Uncommon) & Treatment of Tetany
Re-breathing in a paper bag or rebreather oxygen mask may partially relieve muscle cramps & mild tetany by decreasing serum pH
SLOW IV administration:
Calcium Chloride (CaCl)
Venous irritation, inflammation
Careful infusion, check IV patency
Calcium Gluconate
500 mg – 2 Grams
Rate not more than 200 mg/min
ECG monitoring advised
High serum Ca+
Hypotension
Arrhythmias
Cardiac arrest
Oral Ca+ supplements
Correct HYPOmagnesemia
Vitamin D to enhance GI absorption of Ca+
Dark, green vegetables
Soy products & tofu
Spinach & Rhubarb (inhibit absorption of Ca+)
