Week 11: Chp 43: Hypoparathyroidism

Question 1

Can be classified as?

Answer 1

idiopathic (unknown), acquired, or reversible

Question 2

What is the most common cause of acquired hypoparathyroidism?

Answer 2

secondary to the removal of the parathyroid glands during total thyroidectomy or bilateral resection for cancer of the head and neck

Question 3

Reversible hypoparathyroidism may develop when?

Answer 3

secondary to iodine therapy for hyperthyroidism and with metastasis of malignant tumors

Question 4

What is suspected in patients who present with a spontaneous presentation of hypoparathyroidism with no identifiable cause?

Answer 4

an autoimmune disease

Question 5

What is the primary disorder associated with hypoparathyroidism?

Answer 5

Hypocalcemia

• because of the lack of parathyroid hormone (PTH), calcium is not mobilized from the bones, conserved in the kidneys, or absorbed in the small intestines
• vitamin D enters the body in an inactive form through dietary intake or ultraviolet rays and is activated in the kidneys based on actions of the PTH; it is activated vitamin D that leads to calcium absorption in the intestines

Question 6

Calcium plays a major role in what?

Answer 6

membrane potential and neuronal excitability and is needed for cardiac, skeletal, and smooth muscle contractions

Question 7

Clinical manifestations of Hypoparathyroidism

Answer 7

decreased serum calcium levels, numbness and tingling around the mouth or in the hands and feet, severe muscle cramps, spasms of the hands and feet, and tetany

• Chvostek signs
• Trousseau sign

Question 8

Two specific assessments that are observed in hypocalcemia

Answer 8

-Chvostek Signs
-Trousseau sign
>are associated with an increased risk of tetany that can result in laryngospasm and airway compromise

Question 9

What is a medical emergency when associated with tetany and laryngospasm?

Answer 9

hypocalcemia because this complicates placement of the endotracheal tube
-a tracheostomy tray (set up) is often placed at the bedside of patients at risk as a result of thyroid surgery or severe hypocalcemia

Question 10

Diagnostic Results consistent with hypoparathyroidism

Answer 10

low serum calcium levels, high serum phosphate levels, and low serum PTH levels

• serum magnesium levels are often evaluated to rule out hypomagnesemia as the cause of hypoparathyroidism, as low serum magnesium levels inhibit synthesis of PTH
• serum albumin levels are monitored because the majority of serum calcium is plasma protein bound; in the patient with both low calcium and albumin, an ionized (free) calcium evaluation is required to determine the extent of the hypocalcemia

Question 11

Hypoparathyroidism treatment is based on what?

Answer 11

whether the presentation is acute or insidious and focuses primarily on raising serum calcium levels

Question 12

Treatment for Acute hypocalcemia

Answer 12

Intravenous calcium (usually calcium gluconate or calcium chloride) is administered to the patient with acute hypocalcemia and then followed up with oral calcium and vitamin D supplementation

Question 13

With a history of cardiac disease, how should you administer IV?

Answer 13

IV administration should be slow to minimize hypotension and bradycardia

Question 14

Chronic Hypoparathyroidism is treated with?

Answer 14

oral calcium and vitamin D based on close monitoring of serum calcium levels

Question 15

The nurse correlates a positive Chvostek sign to hyposecretion of which hormone?

Answer 15

parathyroid hormone (PTH)

Question 16

The clinical signs of hypoparathyroidism is primarily linked to what?

Answer 16

the effects of low serum calcium levels

• decreased serum calcium levels
• tetany (spasms of the hands and feet; cramps), muscle cramps, carpopedal spasm (frequent and involuntary muscle contractions of the hands and feet)
• positive Chvostek’s Signs
• paresthesias of the hands and feet
• tingling of circumoral areas
• seizures
• prolonged QT interval
• resistance to digitalis linked to loss of inotropic effect
• hypotension and cardiac dysrythmias
• bone pain and skeletal deformities

Question 17

Nursing Diagnoses

Answer 17

• high risk for ineffective airway clearance r/t laryngospasm secondary to hypocalcemia
• decreased cardiac output r/t suppressed myocardial contractility secondary to hypocalcemia

Question 18

Nursing Assessments

Answer 18

• vital signs
• cardiac monitoring
• ionized calcium levels
• serum magnesium levels
• acid-base status
• neuromuscular activity

Question 19

Assessment: Vital Signs

Answer 19

hypotension may occur secondary to decreased myocardial contractility and cardiac dysrythmias

Question 20

Assessment: Cardiac monitoring

Answer 20

hypocalcemia may cause cardiac dysrythmias secondary to effects on cardiac automaticity

Question 21

Assessment: Ionized calcium levels

Answer 21

ionized calcium is the free and active form of calcium

-lets us see the severity of the hypocalcemia

Question 22

Assessment: Serum Magnesium Levels

Answer 22

hypomagnesemia interferes with PTH synthesis and contributes to hypocalcemia

Question 23

Assessment: Acid-base status

Answer 23

an alkaline pH increases binding of calcium to protein and results in decreased ionized calcium

Question 24

Assessment: Neuromuscular activity

Answer 24

insufficient free, ionized calcium at the neuromuscular junction results in excessive neuronal firing

Question 25

Nursing Actions

Answer 25

• administer calcium replacements

- administer vitamin D

Question 26

Actions: administer calcium replacements

Answer 26

raise serum calcium levels

-IV calcium is usually administered over 10 to 15 minutes

Question 27

Actions: administer vitamin D

Answer 27

vitamin D is needed for calcium absorption from the bowel

Question 28

Nursing Teaching

Answer 28

• medication regimen
• eat foods high in calcium but low in phosphorus
• signs of hypocalcemia and hypercalcemia

Question 29

Nursing Teaching: Medication Regimen

Answer 29

lifelong supplementation with calcium is necessary secondary to decreased synthesis or secretion of PTH

Question 30

Nursing Teaching: eat foods high in calcium but low in phosphorus

Answer 30

foods high in calcium assist in raising serum calcium levels
-foods high in phosphorus are to be avoided because phosphorus can bind with calcium in the serum, further decreasing calcium levels

Question 31

Evaluating Care Outcomes

Answer 31

compliance with the medication regimen, particularly calcium supplements, usually results in stable serum calcium levels
-because of intake of calcium supplements, it is important to ensure that the patient maintains adequate hydration

Question 32

High Calcium Foods used in the treatment of hypoparathyroidism

Answer 32

>Fruits and Fruit Juices:
-calcium and vitamin D-fortified orange juice
-rhubarb
-stewed figs
>Dark Green, Leafy Vegetables:
-collard greens
-kale
-mustard spinach
>Soy Products

Question 33

Laboratory Tests for Parathyroid Disorders

Answer 33

• Calcium
• Ionized Calcium
• Magnesium
• Phosphorus
• Vitamin D

Question 34

Lab Test: Calcium

Answer 34

> Normal Range: 8.2- 10.2 mg/dL

>Significance: decreased in hypoparathyroidism, increased in hyperparathyroidism

Question 35

Lab Test: Ionized Calcium

Answer 35

> Normal Range: 4.6- 5.3 mg/dL

>Significance: decreased in hypoparathyroidism, increased in hyperparathyroidism

Question 36

Lab Test: Magnesium

Answer 36

> Normal Range: 1.6- 2.2 mg/dL

>Significance: decreased in hypoparathyroidism; low serum magnesium levels inhibit synthesis of PTH

Question 37

Lab Test: Phosphorus

Answer 37

> Normal Range: 2.5- 4.5 mg/dL
Significance: increased in hypoparathyroidism,
decreased in hyperparathyroidism
(phosphorus can bind with calcium in the serum, further decreasing calcium levels)