Pituitary gland disorders include acromegaly, Cushing's syndrome, diabetes insipidus, empty sella syndrome, hypopituitarism and pituitary tumors. Pituitary problems can be caused by pituitary tumors, most of which are benign.
2. Pituitary Gland.
The pituitary is located at
the base of the brain, in
a small depression of the
sphenoid bone (sella
turcica).
Purpose: control the
activity of many other
endocrine glands.
â Master glandâ
Has two lobes, the
anterior & posterior
lobes.
3. Anatomy
Anterior lobe: glandular tissue,
accounts for 75% of total weight.
Hormones in this lobe are
controlled by regulating hormones
from the hypothalmus (stimulate or
inhibit)
Posterior: nerve tissue & contains
axons that originate in the
hypothalmus. Therefore this lobe
does not produce hormones but
stores those produced by the
neurosecretory cells in the
hypothalmus. Release of
hormones is triggered by receptors
in the hypothalmus.
4. Terms
Trophic hormones:
hormones that control the
secretion of hormones by
other glands. Example: TSH
stimulates the thyroid to
secrete hormones.
Effector hormones: produce
an effect directly when
secreted. Example ADH
stimulates kidneys
7. Anterior Pituitary Secretes:
GH: stimulates growth of bone and muscle ,
promotes protein synthesis and fat metabolism.
ACTH (Adrenocorticotropin ): stimulates adrenal gland
cortex secretion of mineralcorticoids (aldosterone) &
glucocorticoids (cortisol).
TSH: stimulates thyroid to increase secretion of
thyroxine, its control is from regulating hormones in
the hypothalmus.
8. Anterior Pituitary Contâd
Prolactin: stimulates milk production from the
breasts after childbirth to enable nursing. Oxytoxin
from posterior lobe controls milk ejection.
FSH: promotes sperm production in men and
stimulates the ovaries to enable ovulation in
women. LH and FSH work together to cause
normal function of the ovaries and testes.
LH: regulates testosterone in men and estrogen,
progesterone in women.
9. Posterior Pituitary
Antidiuretic hormone or ADH - also called
vasopressin, vasoconstricts arterioles to
increase arterial pressure; increases water
reabsorption in distal tubules.
Oxytocin: stimulates uterus to contract at
childbirth; stimulates mammary ducts to
contract (milk ejection in lactation).
13. Disorders occur most often in the anterior
pituitary
The anterior pituitary hormones regulates
growth, metabolic activity and sexual
development.
Major causes include: tumors, pituitary
infarction, genetic disorders.
Pathologic consequences of pituitary disorders
are 1) hyperpituitarism, 2) hypopituitarism, 3) local
compression of brain tissue by expanding tumor
15. Hyperfunction
Results in excess production and
secretion of one or more hormones
such as GH, PRL, ACTH.
Most common cause is a benign
adenoma.
16. Anterior pituitary adenoma, a benign
tumor which is classified according to
size, degree of invasiveness and the
hormone secreted.
Prolactin and GH are the hormones most
commonly over-produced by adenomas.
Pituitary Adenoma
17. Adenomaâs Contâd
Changes in neurological
function may occur as
adenomas compress
surrounding tissue.
Manifestations include
headaches, visual defects and
increased ICP.
Treatment is surgical resection
through transphenoidal
hypophysectomy
18. Increased GH
Increased GH:
Gigantism &
Acromegaly
a statue of Robert
Wadlow, the "Alton
Giant," who
measured 8 feet 11
inches at the time of
his death.
Young 12 y/o male
standing with his
mother
19. Gigantism is the result of GH
hypersecretion before the
closure of the epiphyseal
plates (childhood).
ďŹ Abnormally tall but body
proportions are normal
Acromegaly is over secretion
of GH in adulthood
ďŹ Continued growth of boney,
connective tissue leads to
disproportionate enlargement of
tissue..
24. Diagnosis
History & physical exam
Investigation includes:
ďŹ GH analysis (glucose tolerance) Normally
GH concentarion falls with oral glucose; in
acromegaly it does not.
ďŹ Prolactin levels as well as other pituitary
function tests
ďŹ MRI or CT & visual field tests to determine
size and position of the adenoma.
ďŹ Bone scan
26. Drug treatment of
Acromegaly
Dopamine agonists: Dopamine agonists work
on specialist markers (dopamine receptors)
on the surface of the tumor to inhibit GH
release from the tumour (Parlodel).
Somatostatin: growth hormone receptor
antagonist decreases the action of GH on
target tissues. (octreocide acetate)
Dopamine agonists are taken by mouth but in
general are less effective than somatostatin
analogues, which have to be injected.
28. Hypopituitarism- Anterior Pituitary
Decreased GH in child: Dwarfism
Condition of being
undersized
There are many forms of
dwarfism
Dwarfism related to pituitary
gland is the result of
insufficient GH
Pituitary dwarfism is
successfully treated by
administering human growth
hormone
29. Hypopituitarism (Adult)- GH
Lack of GH leads to:
ďŹ Increased CV
disease
ďŹ Excessive tiredness
ďŹ Anxiety
ďŹ Depression
ďŹ Reduced âquality of
lifeâ
ďŹ Possible premature
death
30. Hyperprolactemia
Prolactin levels are normally high during
pregnancy and lactation.
Symptoms of hyperprolactemia include;
ďŹ discharge from breasts (galactorrhoea)
ďŹ oligomenorrhoea or amenorrhoea in
women
ďŹ reduced libido and potency in men
ďŹ pressure effects (e.g. headache and
visual disturbance) - more commonly in
men
31. Treatment is surgery, radiation, or
medical therapy with drugs that will
suppress the production of prolactin
ďŹ Urgent: deterioration in vision
ďŹ Important:
ďŹ successful RX. results in restoration of
fertility
ďŹ Patients may be predisposed to problems
related to osteoporosis
ďŹ Ask about erectile function & reassure
client that it is part of the disease and can
be treated.
32. Increased ACTH:Cushingâs Disease
Cushing's is a disorder in which the adrenal glands
are producing too much cortisol (hypercotisolism).
If the source of the problem is the pituitary gland,
then the correct name is Cushing's Disease
whereas, if it originates anywhere else (adrenal
tumors, long term steroid administration) then the
correct name is Cushing's Syndrome.
Cushingâs Disease is caused by pituitary
hypersecretion of ACTH.
33. Etiology - Hypercortisolism
Iatrogenic hypercortisolism resulting from
medical intervention is most common cause of
Cushing Syndrome.
Pituitary hyper secretion and pituitary tumors
account for 70% of Cushingâs Disease. Adrenal
tumors account for 30%.
Ectopic secretion of ACTH by tumors located
outside the pituitary gland are rare cause of the
syndrome and associated with increased
morbidity/mortality (ie oat cell ca).
34. Symptoms
psychiatric disturbance (often
characterized by amplification of previous
personality traits)
moon face - particularly filling in of the
temporal fossa
weight gain - central obesity
muscle wasting and proximal myopathy
(patients have difficulty standing from a
seated position without use of arms)
thin skin * - tendency to bruise
hirsutism (caused by androgen excess)
violaceous striae
38. Diagnosis
24 hr urine cortisol levels
Serum sodium levels
Serum potassium levels
Serum glucose
Serum ACTH in Cushing Disease
ACTH suppression test to identify cause
Dexamethasone supression test: cause
pituitary or adrenal
Radiological exam to reveal pituitary or
adrenal tumor
39. Treatment
Transphenoidal surgery if the condition is due
to a pituitary tumor
Where surgery is contraindicated or fails to
reduce cortisol levels, adrenalectomy and/or
pituitary radiation may be necessary.
Adrenocortical Inhibitors: (metapyrone,
aminogluthimide) are only effective short-
term.
Diet: low calorie, carbohydrate & salt. High
potassium.
40.
41. Priority Nursing
Diagnoses
Fluid volume excess
Risk for infection
Risk for injury
Activity intolerance
Anxiety
Knowledge deficit
Risk for impaired tissue integrity
44. Post op care for cranial surgery (CSF
leak, ICP etc.)
Hydrocortisone therapy, some on a long-
term basis
If surgery results in hypopituitarism,
long-term hormone replacement therapy
will be required
Moods swings and depression may be a
serious problem that may take months to
treat
48. Posterior Lobe Disorders
SIADH & diabetes insipidus are major
disorders of the posterior
pituitaryâŚâŚhowever
Even if posterior lobe becomes
damaged, hormonal deficiencies usually
do not develop becauseâŚâŚ??
50. SIADH
Syndrome of Inappropriate Anti-Diuretic
Hormone
Too much ADH produced or secreted.
SIADH commonly results from malignancies,
CHF, & CVA - resulting in damage to the
hypothalamus or pituitary which causes failure
of the feedback loop that regulates ADH.
Client retains water causing dilutional
hyponaetremia & decreased osmolality.
Decreased serum osmolality cause water to
move into cells
51.
52. Signs and Symptoms
Lethargy & weakness
Confusion or changes in neurological status
Cerebral edema
Muscle cramps
Decreased urine output
Weight gain without edema
Hypertension
(Note: b/c of the low Na, edema will not
accompany the FVE)
53. Assessment
Serum sodium low
Serum osmolality low
Urine osmolality disproportionately
elevated in relation to the serum
osmolality
Urine specific gravity elevated
Plasma ADH elevated
55. Treatment of SIADH
Treat underlying cause
Hypertonic or isotonic IV solution
Monitor for signs of fluid and electrolyte
imbalance
Monitor for neurological effects
Monitor in and out
Weigh
Restrict fluid intake
Medic Alert
Lithium inhibits action of ADH to promote
water excretion.
58. Diabetes Insipitus (DI)
DI is usually insidious but can occur with
damage to the hypothalamus or the pituitary.
(neurogenic DI)
May be a result of defect in renal tubules, do
not respond to ADH (nephrogenic DI)
Decreased production or release of ADH
results in massive water loss
Leads to hypovolemic & dehydration.
59. Clinical Manifestations
Polyuria of more than 3 litres per 24
hours in adults (may be up to 20!)
Urine specific gravity low
Polydipsia (excessive drinking)
Weight loss
Dry skin & mucous membranes
Possible hypovolemia, hypotension,
electrolyte imbalance
60. Diagnostic Tests
Serum sodium
Urine specific gravity
Serum osmolality
Urine osmolality
Serum ADH levels
Vasopressin test and water deprivation
test: increased hyperosmolality is
diagnostic for DI.
61. Management
Medical management includes
Rehydration IV fluids (hypotonic)
Symptom management
ADH replacement (vasopressin)
For nephrogenic DI: thiazide diuretics,
mild salt depletion, prostaglandin
inhibitors (i.e. ibuprophen)
62. Nursing
1.Monitor for signs of fluid and
electrolyte imbalance
2.Monitor in and out
3.Daily weight
4.Monitor for excessive thirst or output
5.Assess serum and urine values
(decreased SG, decreased urine
osmolality, high serum osmolality are
early indicators
63. POSSIBLE NURSING DIAGNOSIS
Fluid Volume Deficit
Risk for Injury r/t altered LOC
Risk for Altered Health Maintenance
Sleep Pattern Disturbance r/t urinary
frequency or anxiety
Altered Urinary Elimination r/t excess
urinary output
Body Image
Altered sexuality
64. Panhypopituitarism
When both the anterior and posterior fail to
secrete hormones, the condition is called
panhypopituitarism.
Causes include tumors, infection, injury,
iatrogenic (radiation, surgery), infarction
Manifestations donât occur until 75% of pituitary
has been obliterated.
Treatment involves removal of cause and
hormone replacement (adrenaocortical
insufficiency, thyroid hormone, sex hormones)
65. Know
The what these conditions are & difference b/t
a) Cushingsâ Disease & Cushingsâ Syndrome
b) Giantism &Acromegaly
c) Dwarfism
d) Diabetes Insipidus vs. Diabetes Mellitus
Consider Nursing Diagnosis related to these
conditions
66. What role does the pituitary
gland play in fluid and
electrolyte balance?
67. How BV is regulated:
When the HYPOTHALMUS senses a decrease in serum
sodium or increase in serum potassium, it sends a
message to the PITUITARY to release adenocorticotropic
hormone (ACTH). ACTH stimulates ADRENAL CORTEX
to release ALDOSTERONE. It regulates water balance by
facilitating sodium reabsorption in renal tubules. As sodium
is reabsorbed potassium is excreted by kidneys. As
sodium reabsorbed, the circulating blood volume
increases through water reabsorbtion resulting in
increased BV and Increased BP.
69. Sodium Balance
Maintained by ADH secreted from posterior
pituitary
Depends what is ingested & how it is absorbed
Increased sodium intake leads to increased
extracellular fluid volume
Decreased sodium intake leads to decreased
extracellular fluid volume
Increased sodium levels leads to increased
thirst, release of ADH, retention of water by
kidneys & dilution of blood
Decreased sodium levels leads to suppression
of thirst, suppression of ADH secretion, &
excretion of water by kidneys
70. Abdominal cramps
Altered LOC
Muscle twitching, weakness
Nausea
Dry mucous membrane
BP alterations depending on depletional or
dilutional hyponatremia
Poor skin turgor, weight changes r/t fluid
Tachycardia
71. Potassium is responsible for:
a) Neuromuscular excitability and muscle
contraction
b) Important in glycogen formation and
protein synthesis
c) Correction of imbalances of acid-base
metabolism
72. A slight decrease has profound implications for
neuromuscular and cardiac function.
Prolonged gastric , recent ileostomy, villous
adenoma, inadequate intake, excess output,
drugs such as diuretics, corticosteroids, insulin,
some antibiotics like Pen K, as well as diseases
causing any of the above.
Foods high in potassium:
chocolate, dried fruit, nuts & seeds, oranges, bananas, apricots,
cantaloupes, potatoes, mushrooms, tomatoes, carrots
74. Neuromuscular signs & symptoms
of hypokalemia include:
a) confusion & irritability
b) diminished deep tendon reflexes
c) Parkinsonian type tremors
75. Questions to ask when assessing
potassium imbalance in clients
Is client taking antacids? - may interfere
Is clients renal status worsening?
Is the client taking meds that could raise or
lower potassium?
Was the blood sample valid? (IV site)
How is fluid intake/output
76. If you were walking across the
Sahara Desert with no water. The
amount of ADH hormone secreted
would be:
a) Increased
b) Decreased
c) Stay the same
77. Giving a hypertonic IV
solution to a client may
cause too much fluid to be:
a) pulled from cells into the bloodstream
b) pulled out of the bloodstream into the
cells
c) pushed out of the bloodstream into
extravascular space
78. Thirst
Eating highly salty foods and losing
fluids lead to an increase in extracellular
fluid osmolality. This leads to drying of
mucous membrane, which stimulates
the thirst center in hypothalamus. This
mechanism is less effective in
elderly, thus they are more prone to
dehydration. Also it takes a while for
this response to occur. Anticipate!
