Final Exam - Endocrine problems part 2 (Unit 12): Disorders of the Posterior Pituitary Gland

Question 1

What does SIADH stand for ?

Answer 1

Syndrome of Inappropriate Antidiuretic Hormone

Question 2

What does ADH stand for ?

Answer 2

Antidiuretic Hormone

Question 3

_____ plays a major role in the regulation of water balance and osmolarity ?

Answer 3

ADH (Antidiuretic Hormone)

Question 4

SIADH occurs when ?

Answer 4

When ADH is released despite normal or low plasma osmolarity

Question 5

What is another name for SIADH ?

Answer 5

“Fluid retainers” !

fluid overload

Question 6

What is the most common cause of SIADH ?

Answer 6

Malignancy , esp. small cell lung cancer

Question 7

What is SIADH characterized by ?

Answer 7

• Fluid retention
• Weight gain
• Concentrated urine
• Serum hypoosmolality
• dilution hyponatremia
• Low urine output

Question 8

In SIADH, low plasma osmolality and serum sodium can cause what ?

Answer 8

Cerebral edema
              =
- lethargy
- confusion
- HA
- seizure
- coma

Question 9

What labs are used to determine if SIADH Is present/the cause ?

Answer 9

• Serum Sodium < 134 mEq/L (dilution hyponatremia)
• Serum osmolarity < 280 most/kg (blood serum is very dilute)
• Urine specific gravity greater than 1.025 (urine is very concentrated)

Question 10

Dangerously low sodium increases the risk for what ?

Answer 10

Seizures

Question 11

What is the Tx for SIADH ?

Answer 11

• Daily weights
• I &O’s
• Diuretics (monitor for K+ loss)
• Prevent injury r/t low Na+ (seizure risk)

Question 12

If a pt with SIADH has mild symptoms and their sodium is greater than 125mEq/L, what is the Tx ?

Answer 12

Tx may me daily fluid restriction to 800 to 1000mL

Question 13

If a pt with SIADH has a sodium level less than 120mEq/L, what will their Tx be ?

Answer 13

IV hypertonic saline solution (3% to 5%)

Question 14

Diabetes Insipidus is the complete opposite of what ?

Answer 14

SIADH

Question 15

What is Diabetes Insipidus ?

Answer 15

Decreased secretion of ADH, or decreased renal response to ADH

Question 16

People with Diabetes Insipidus are constantly doing what ?

Answer 16

Urinating

Question 17

What are Clinical Manifestations of Diabetes Insipidus ?

Answer 17

• Polydipsia
• Polyuria (5 to 20 L/day)
• Elevated serum osmolarity (blood serum is very concentrated)

Question 18

How does the urine present in pt’s with Diabetes Insipidus ?

Answer 18

• Low urine specific gravity
• Low urine osmolarity

** Urine is very diluted (clear) **

Question 19

In pt’s with Diabetes Insipidus, all they want to do is what ?

Answer 19

Drink water !

Question 20

Elevated serum osmolarity is a clinical manifestation of DI, how do most people compensate for this ?

Answer 20

by drinking lots and lots of water ! so serum osmolarity may be normal

Question 21

In pt’s with DI, if oral fluid intake can not keep up with urinary losses, what can occur ?

Answer 21

Severe dehydration can occur

Question 22

What is the Tx for Diabetes Insipidus ?

Answer 22

• Daily weights
• I & O’s
• Check urine S.G.
• Give oral or IV fluids in amounts equal to urine output (want to keep them hydrated)

Question 23

What is the hormone replacement of choice for central DI ?

Answer 23

Desmopression acetate (DDAVP), an analog of ADH

Question 24

ADH is released by what ?

Answer 24

The posterior pituitary gland

Question 25

ADH is released in response to any of the 3 what ?

Answer 25

• low blood volume in the body
• low BP
• Hypernatremia (increased serum (blood) osmolarity)

Question 26

When ADH is released from the posterior pituitary gland, what does it do to the kidneys ?

Answer 26

Causes the kidneys to reabsorb more water!

Thus,

• increasing blood volume
• increasing BP
• helps to dilute the blood, to bing the osmolarity back to a normal level

Question 27

What is the main symptom of DI ?

Answer 27

Excreting LARGE amounts of dilute urine

the kidneys are not reabsorbing the water as we should be

Question 28

SIADH is caused by what ?

Answer 28

Excess ADH is released from the posterior pituitary gland

• Even though the blood is very dilute, the posterior pituitary gland still releases ADH, even though it should not !

Question 29

How does SIADH result in fluid overload ?

Answer 29

1. the posterior pituitary gland releases ADH even though the blood is very dilute or normal
2. B/c the posterior pituitary gland is releasing all this extra ADH inappropriately, its causing the kidneys to reabsorb more water RESULTING IN: fluid overload