Week 11 - SIADH

Question 1

what are 2 disorders of the posterior pituitary gland

Answer 1

• syndrome of inappropriate antidiuretic hormone (SIADH)

- diabetes insipidus

Question 2

what is SIADH

Answer 2

• disorder due to excessive ADH secretion

- elevated ADH despite normal or low plasma osmolarity (low conc.)

Question 3

what are causes of SIADH (4)

Answer 3

• brain injury
• cancer paraneoplastic syndrome
• resp causes
• drug induced

Question 4

what types of brain injuries can cause SIADH (4)

Answer 4

• trauma
• infection
• hydrocephalus
• MS

Question 5

what are resp causes of SIADH (3)

Answer 5

• pulmonary infection
• cystic fibrosis
• asthma

Question 6

list 3 examples of drugs that can cause SIADH

Answer 6

• antiseizure
• antidepressants
• opiates

Question 7

what are the effects of antidiuretic hormone

Answer 7

• increased antidiuretic hormone –> increased water reabsorption –> increased intravascular fluid vol –> dilutional hyponatremia & decreased serum osmolality

Question 8

what are the manifestations of SIADH (4)

Answer 8

• fluid retention
• decreased urine output
• increased body weight
• symptoms of hyponatremia

Question 9

what are symptoms of hyponatremia (9)

Answer 9

• muscle cramps, twitching, and weakness
• vomitting
• abdom cramps
• anorexia
• lethargy
• confusion
• HA
• seizure
• coma

Question 10

what is considered hyponatremia

Answer 10

<134 mEq/L

Question 11

what is the urine specific gravity like during SIADH

Answer 11

• greater than 1.005 (high)

Question 12

what is the urine sodium conc during SIADH

Answer 12

> 40 with normal sodium intake

Question 13

how is SIADH diagnosed

Answer 13

• simultaneous measurements of serum & urine osmality (serum low, urine high)
• decreased serum Na
• decreased Hgb and Hct

Question 14

what are treatments for SIADH

Answer 14

• treat underlying cause
• fluid restriction
• if very symptomatic (severe confusion, seizures, coma) give hypertonic saline

Question 15

what is the role of the nurse for a pt with SIADH

Answer 15

monitor:

• sudden weight gain
• urine w increased conc
• changes in LOC
• vitals