NUR 650 Exam 3 - Endocrine System UPDATED ACTUAL
Questions and CORRECT Answers
Diseases of the Posterior Pituitary SIADH (too much ADH)
Diabetes Insipidus (too little or no ADH)
Antidiuretic hormone (Vasopressin) Antidiuretic hormone is a hormone secreted by the posterior pituitary
signals kidneys to retain water
The most common endocrine disorder other than T2DM SIADH
Syndrome of inappropriate antidiuretic hormone High levels of ADH in the presence of normal physiologic stimuli for its release
(SIADH)
Ectopic secretion of ADH is the most common cause; is also common after
surgery and some cancers (most commonly small cell lung cancers
S/S of SIADH Hyponatremia: sodium <135 mEq/L
Hypoosmolality: <280 mOsm/kg (Serum is very dilute, has a lot of water)
Urine hyperosmolality (concentrated urine): higher than serum osmolality (normal
urine sodium)
Hypervolemia (no peripheral edema)
Weight gain
Serum sodium levels below 110–115 mEq/L: can cause severe and sometimes
irreversible neurologic damage
SIADH Diagnosis patient must have normal renal, adrenal, and thyroid function
(SIADH is a dx of exclusion - difficult to accurately measure serum ADH levels)
SIADH Sodium Levels and urine hyponatremia and hypo osmolality
Hyponatremia is seen in a patient with SIADH as a result of excess retention of
water
Kidneys continue to retain water and make very concentrated urine
Patients have TOO much water and it is DILUTING out their sodium
, SIADH Tx Emergency correction of severe hyponatremia by the administration of
hypertonic saline
Most important: fluid restriction between 800 and1000 mL/day
Diabetes insipidus (DI) Characterized by the inability of the kidney to increase permeability to water.
Excretion of large volumes of dilute urine
Increase in plasma osmolality: 300 mm or more, depending on adequate water
intake
Urine output: 8-12 L/day; normal output: 1-2 L/day
s/s of DI Polyuria, nocturia, continual thirst (polydipsia)
Low urine-specific gravity: <1.010 (dilute)
(Partial or total inability to concentrate the urine)
Low urine osmolality (<200 mOsmL/kg)
Hypernatremia, hypotension, and dehydration (can affect LOC)
Diuresis
DI Testing/dx No gold standard lab test
Low Plasma vasopressin level - can confirm central DI
Normal vasopressin level - nephrogenic form of DI
Vasopressin challenge test can be done in a supervised setting (patients with
central DI will see improvement with treatment, nephrogenic DI will have no
response)
DI Tx Fluid replacement at a rate no greater than 500-750ml/hr - avoid hyperglycemia,
fluid volume overload, and overly rapid correction of hypernatremia
Reduce serum sodium by 0.5 moles/liter every hour (if faster, increased risk for
cerebral edema)
Neurogenic DI pituitary lesion or damage - tumor, aneurysm, infection, traumatic brain injury
Insufficient amounts of ADH - Kidneys cannot retain any water that the body
needs
Nephrogenic GI genetic or acquired due to a disease affecting the nephron
Insensitivity of the renal collecting tubules to ADH - fail to conserve water
Questions and CORRECT Answers
Diseases of the Posterior Pituitary SIADH (too much ADH)
Diabetes Insipidus (too little or no ADH)
Antidiuretic hormone (Vasopressin) Antidiuretic hormone is a hormone secreted by the posterior pituitary
signals kidneys to retain water
The most common endocrine disorder other than T2DM SIADH
Syndrome of inappropriate antidiuretic hormone High levels of ADH in the presence of normal physiologic stimuli for its release
(SIADH)
Ectopic secretion of ADH is the most common cause; is also common after
surgery and some cancers (most commonly small cell lung cancers
S/S of SIADH Hyponatremia: sodium <135 mEq/L
Hypoosmolality: <280 mOsm/kg (Serum is very dilute, has a lot of water)
Urine hyperosmolality (concentrated urine): higher than serum osmolality (normal
urine sodium)
Hypervolemia (no peripheral edema)
Weight gain
Serum sodium levels below 110–115 mEq/L: can cause severe and sometimes
irreversible neurologic damage
SIADH Diagnosis patient must have normal renal, adrenal, and thyroid function
(SIADH is a dx of exclusion - difficult to accurately measure serum ADH levels)
SIADH Sodium Levels and urine hyponatremia and hypo osmolality
Hyponatremia is seen in a patient with SIADH as a result of excess retention of
water
Kidneys continue to retain water and make very concentrated urine
Patients have TOO much water and it is DILUTING out their sodium
, SIADH Tx Emergency correction of severe hyponatremia by the administration of
hypertonic saline
Most important: fluid restriction between 800 and1000 mL/day
Diabetes insipidus (DI) Characterized by the inability of the kidney to increase permeability to water.
Excretion of large volumes of dilute urine
Increase in plasma osmolality: 300 mm or more, depending on adequate water
intake
Urine output: 8-12 L/day; normal output: 1-2 L/day
s/s of DI Polyuria, nocturia, continual thirst (polydipsia)
Low urine-specific gravity: <1.010 (dilute)
(Partial or total inability to concentrate the urine)
Low urine osmolality (<200 mOsmL/kg)
Hypernatremia, hypotension, and dehydration (can affect LOC)
Diuresis
DI Testing/dx No gold standard lab test
Low Plasma vasopressin level - can confirm central DI
Normal vasopressin level - nephrogenic form of DI
Vasopressin challenge test can be done in a supervised setting (patients with
central DI will see improvement with treatment, nephrogenic DI will have no
response)
DI Tx Fluid replacement at a rate no greater than 500-750ml/hr - avoid hyperglycemia,
fluid volume overload, and overly rapid correction of hypernatremia
Reduce serum sodium by 0.5 moles/liter every hour (if faster, increased risk for
cerebral edema)
Neurogenic DI pituitary lesion or damage - tumor, aneurysm, infection, traumatic brain injury
Insufficient amounts of ADH - Kidneys cannot retain any water that the body
needs
Nephrogenic GI genetic or acquired due to a disease affecting the nephron
Insensitivity of the renal collecting tubules to ADH - fail to conserve water
