Pituitary Flashcards
FUNCTIONS OF THE NEPHRON - Responds to ADH by reabsorbing water from the
collecting ducts
DISEASES OF THE POSTERIOR PITUITARY- Significant hormone alternation in the posterior pituitary usually related to
Significant hormone alternation in the posterior pituitary usually related to abnormal ADH
These pathological states have significant clinical effects on:
The modulation of body fluids and electrolytes
Cognitive function
SYNDROME OF INAPPROPRIATE ADH: SIADH ETIOLOGY (sia has ADH)
SIADH is characterized by ↑ ADH in spite of having normal or low plasma osmolarity
SIADH: PATHOPHYSIOLOGY - osmolality? (think…too much water)
Cardinal features of SIADH are the result of excess water retention
ADH acts on the renal collecting ducts increasing H2O reabsorption
Leads to:
Increased intravascular fluid volume → dilutional hyponatremia
Overall serum hypo-osmolality
SIADH: CLINICAL MANIFESTATION- main issue is low what?
Sx of SIADH are primarily related to hyponatremia
The severity and rapidity of low Na+ determines the extent of Sx:
SIADH: Criteria for dx - sodium
Criteria for dx:
hyponatremia: < 135 mEq/L (normal 135-145)
SIADH: TREATMENT - what % of sodium solution?
Correct underlying cause
Gradual correction of hyponatremia with hypertonic solutions e.g. 3% sodium
Vigilant monitoring of Na levels and mental status
SIADH: PHARMACOLOGIC TREATMENT - LASIX - when can you give it? - what number exactly
LASIX to promote UOP (only if Na >125 since Lasix can cause further Na loss)
SIADH: NURSING CONSIDERATIONS
Seizure precaution
Fluid restriction (minimize thirst with ice cold drinks, sugar free chewing gum, cold water sprays)
Monitor I/O
Daily weight
Monitor electrolytes
ADH DEFICIENCY: DIABETES INSIPIDUS - the 3 types
DI : Deficiency in ADH or decrease renal response to ADH
3 TYPES:
Central DI, Nephrogenic, Primary DI :
ADH DEFICIENCY: DIABETES INSIPIDUS - Nephrogenic (die don’t collect)
Nephrogenic: Inadequate response of renal collecting tubules to ADH even when levels are normal
DI: Pathophysiology - bladder?
Fluid and electrolyte imbalance d/t ↑urine output and ↑ serum osmo
Large bladder capacity and hydronephrosis in long standing DI
DI: CLINICAL MANIFESTATION - BP?
POLYURIA
POLYDIPSIA
NOCTURIA
HYPOTENSION
DI: EVALUATION - how many liters of urine a day?
Eliminate other differential diagnosis which may cause polyuria state
Dx criteria
Polyuria (2-20 L/day)
Polydipsia
DI: what medication?
IV fluid and hormone replacement DDAVP (desmopressin) (analog of ADH) SC, IV, IM, intranasal
DI: NURSING CONSIDERATIONS - what intranasal spray? (die is depressing)
Strict I&O
Monitor urine specific gravity
Daily weights
Goal is maintaining fluid and electrolyte balance
Discharge teaching with intranasal Desmopressin (synthetic vasopressin- increases water) BID
DISORDERS OF THE ANTERIOR PITUITARY
Disorders of the Anterior Pituitary may involve either hypopituitarism or hyperpituitarism
Hypopituitarism etiology:
Inadequate supply of the hypothalamic-releasing/inhibiting hormones
Damage to the pituitary stalk
Inability of the pituitary to produce hormones
HYPOPITUITARISM - Pituitary infarction (hemorrage) is seen in the setting of (little pitt and sheeran are pregnant)
Sheehan Syndrome: Ischemic pituitary necrosis caused by severe postpartum hemorrhage ( may lead to failure to lactate and amenorrhea)
HYPOPITUITARISM: s/sx
S/S vary depending on the degree of dysfunction and response of the target glands
HYPOPITUITARISM: EVALUATION (measure little brad’s hormones and MRI)
Simultaneous measurement of all trophic hormones from the pituitary and the target glands
Imaging: MRI, CT
HYPERPITUITARISM: GH HYPERSCRETION
Benign autonomic GH secreting pituitary adenoma
Acromegaly:
Gigantism:
ACROMEGALY: CLINICAL manifestation - and edema where?
Enlarged tongue, interstitial edema, coarse skin and body hair
ACROMEGALY: diagnosis (agro glucose)
Diagnosis:
MRI, CT, visual exam
Fails GH suppression during oral glucose tolerance test (GH levels fail to fall below 1/ng/ml)
Elevated IGF- 1 levels
meds - ACROMEGALY (aggro octavia and peg need meds)
Octreotide/lanreotide ( Somatostatin analogues)
Reduces elevated GH levels and causes tumor shrinkage
SQ or IM
Pegvisomant (Growth hormone receptor agonist)
Most effective treatment to date
Costly, given SQ
Cabergoline (Dopamine agonist):
Used off label to lower IGH1 levels
Given PO
Trans-sphenoidal Hypophysectomy (remove pituitary): Nursing consideration (trans needs hormones)
Preop teaching:
Avoid vigorous coughing, straining and sneezing to prevent CSF leakage
Need for life-long hormone replacement therapy after total hypophysectomy
Decrease or loss of fertility
post op care - Trans-sphenoidal Hypophysectomy: Common post-op complications (trans leaks)
Common post-op complications – epitaxis and CSF leak
nephron - Responds to aldosterone in the (alden is distant)
distal convoluted tubes to reabsorb Na and water in exchange for K
nephron - Acid base balance controlled by what 2 things?
Acid base balance by controlling H+ and HCO3-
nephron - ANF/ANP (anough w/ the bp)
lowers bp =
Responds to ANF/ANP (decrease sodium) to excrete Na and inhibits renin
Juxtaglomerular cells of kidney excretes renin in response to ↓ renal perfusion, ↓ arterial BP, ↓ ECF, ↓ serum Na and ↑ urinary Na
nephron - PTH (pth, just reabsorb it)
Responds to PTH by reabsorbing Ca and excreting Phos
Activates Vit D for proper Ca absorption in the GI
posterior pituitary - SIADH (too much is inappropriate)
SIADH - Syndrome of Inappropriate ADH
Excess ADH secretion results in water retention leading to serum hypo-osmolarity
posterior pituitary - Diabetes Insipidus
DI - Diabetes Insipidus
Insufficient secretion of ADH resulting in increased water loss leading to serum hyper-osmolarity
SIADH - most common causes - but from where? (sia has a tumor in her lungs)
Ectopically producing ADH tumor cells from SSC of lung in 70% of cases
Head trauma
SIADH - other causes (Sia has lung problems)
PNA, TB, CF, resp failure, Guillain-Barre
Post pituitary surgery as stored ADH is released
CNS disorders that cause SIADH (3 of them) (Sia and don)
encephalitis, meningitis, intracranial hemorrhage
meds for SIADH (sia is psychotic)
anti-psychotics, antidepressant,
SIADH - urine?
Concentrated urine (increased urine osmolality)
SIADH - Serum Na <134 mEq/L - where is the excess water?
- anorexia, DOE, fatigue, dulled sensorium, ↓ UOP- urine output
-peripheral edema usually absent (excess water remains in intravascular space)
SIADH - Serum Na < 120 mEq/L (120 min of vomiting)
- vomiting, abd cramps, muscle cramps
SIADH - Serum Na < 115 mEq/L (less than 120 is bad)
- cerebral edema may occur → confusion, lethargy, seizure, coma ( irreversible neurologic damage)
SIADH - criteria for diagnosis - Serum hypo-osmolality
(little oz and sia are less than 280 degrees)
Serum hypo-osmolality: < 280 mOsm/kg or 280 mmol/kg (normal 280-295)
SIADH - criteria for diagnosis - Urine hyperosmolality (ur in over 100, Sia)
Urine hyperosmolality >100 mOsm/kg
SIADH - criteria for diagnosis - renal functions, etc? (just make sure it’s not renal)
Normal renal, adrenal and thyroid function
SIADH - criteria for diagnosis - Absence of
pre-existing conditions that may alter volume status such as:
Heart failure
Renal insufficiency
Diuretic use
SIADH - Rapid correction leads to a (Sia in central point)
severe neurologic syndrome known as Central Pontine Myelinolysis
SIADH - Fluid restriction - how much?
Fluid restriction if hyponatremia is mild (800 to 1000 mL/24 hrs)
when does SIADH usually resolve w/ treatment?
Resolution usually occurs within 3 days: 2-3 kg of free water loss
SIADH treatment - STADOL (staled sia in the cns)
STADOL: Inhibits ADH secretion if it’s CNS etiology
SIADH treatment - CONIVAPTAN (captain agonizes over sia)
CONIVAPTAN: ADH receptor antagonist. IV therapy for hospital use for hyponatremia.
SIADH - DEMECLOCYCLINE (sia is in a chronic cycline)
DEMECLOCYCLINE : For chronic SIADH. Blocks ADH at the renal collecting tubules.
SIADH - treatment for ectopically secreted ADH? (ectopically screwed)
There is no drug therapy for ectopically secreted ADH
central DI (central CNS)
related to insufficient secretion by the CNS
primary DI (primarily psycho)
Chronic excessive intake of water; psychological component
Acquired nephrogenic DI (acquired die from kidney disease)
associated with disorders (pyelonephritis, uropathies, polycystic disease)
damage to renal tubules from medications: (Lithium, colchicine, Amphotericin B, diuretics, demeclocycline)
Genetic
DI - heart rhythm?
TACHYCARDIA
DI - sodium?
HYPERNATREMIA
DI - Low urine specific gravity: what number
Low urine specific gravity: < 1.005
DI - urine osmo - what number (DI oz, less than 100)
Low urine osmo : < 100 mOsm/kg
DI - sodium? what number?
Hypernatremia > 145mg/dL
DI - erum osmo - high or low, and what number? (Euro oz is almost 300)
High serum osmo > 295 mOsm/kg
DI - diagnosis (die during water deprivation)
Dx: Water deprivation test then administration of Desmopressin:
meds for central DI (central die gets Cs)
Chlorpropamide, Carbamazepine (antidiuretics)
meds for Nephrogenic DI - not what you’d think
Low Na diet to <3g/day helps to ↓ UOP
Thiazide diuretics (Na and water loss→ mild hypovolemia→ ↓ GFR → ↑ proximal Na and water reabsorption →less water and solutes delivered to distal tubules and collecting ducts leading to less urine loss
Indomethacin increases renal response to ADH
DI - S&S of hypernatremia
N/V, headache, lethargy, irritability, mental dullness, seizure
most common cause of hypopituitarism (little pitt has a tumor)
tumor or infarction of the gland
hypopituatarism - causes (little pitt has shock and sickle cell)
Shock
Sickle cell disease
hypopituatarism treatment
Permanent target gland hormone replacement with corticosteroids, thyroxine and sex hormones
hyperpitutarism - Acromegaly: - when does it occur? (the plate closure)
(Aggro after the fact)
rare and insidious (4 in1 million adults in the US)
somatic growth and organomegaly
Occurs after epiphyseal plate closure
hyperpituitarism - Gigantism: (giant lines before)
Linear growth before closure of epiphyseal plates
acromeglia - face- and what about chest?
Enlarged facial bones leading to protrusion of lower jaws (mandibular prognathism) and forehead (frontal bossing) and bones of the hands
Elongation of the ribs at the bone cartilage junction leading to barrel-chest
acromeglia - physical symptoms (agro headaches)
Headaches occur in 50-87% of cases, as well as seizures, visual disturbances, papilledema
Hypertension
Obstructive sleep apnea (OSA)
DM
acromeglia - treatment (agro radiation)
Surgery, radiation or pharmacotherapy or a combination of three
Trans-sphenoidal Hypophysectomy = Monitor for
visual and neuro changes (sign of hematoma)
Trans-sphenoidal Hypophysectomy - HOB
HOB at 30 degrees to avoid pressure on the Sella Tursica; reduces headache
Trans-sphenoidal Hypophysectomy - oral care
Gentle mouth care Q4hrs, no tooth brushing for 10 days so suture line stays intact, avoid coughing
Trans-sphenoidal Hypophysectomy = how to test for CSF?
Test any clear nasal draining for CSF (leaks usually resolve in 48-72hrs)
Glucose > 30mg/dL indicates CSF
Trans-sphenoidal Hypophysectomy -what is a common problem w/ the loss of ADH? and how to treat it?
Transient cerebral edema or DI common because of loss of ADH: treat with IV vasopressin
conivaptin - side effect? (captain has bad kidneys)
Nephrotoxic.
demecycline - side effects? (same)
Nephrotoxic and also a tetracycline which can increase risk for fungal infections
central DI - causes
Organic lesion of the hypothalamus or the pituitary interferes with ADH synthesis, transport, or release (brain tumors, thrombosis, infection, hypophysectomy)
Closed head trauma
DI - water deprivation test - central DI (central park water is rapidly declining)
pts with central DI respond with rapid decrease in UOP and increased in urine osmo.
hypopituitarism - causes - (little pitt hit his head w/ don)
Head trauma
Infections such as meningitis, syphilis, TB
Vascular malformation, subarachnoid bleed
Surgical ablation of tumor
hypopituatarism treatment - GH replacement (and what if secondary tumor forms?)
GH replacement: Costly, pre-pubertal children respond better that adults
Hypophysectomy or radiation if secondary to tumor
giantism - what happens? (IGF giants)
Subsequent increase production of insulin-like growth factor I (IGF-1)
giantism - problems (heart)
Increased mortality d/t cardiac hypertrophy, HTN, DM2 and malignancies
Selective hypopituitarism (select 1 or the other)
Deficiency of only one pituitary hormone
Panhypopituitarism
all hormones are absent
hypopituatarism -cortisol (little pitt has no cort)
Cortisol deficiency from lack of ACTH
potentially a life threatening condition
hypopituatarism - Thyroid
Thyroid deficiency from lack of TSH
hypopituatarism - Gonad failure
from lack of FSH and LH
hypopituatarism - GH
GH deficiency leading to pituitary dwarfism (Laron syndrome)
hypopituatarism - milk production
Milk production dysfunction d/t deficient PRL
DI - water depravation test - nephrogenic DI
Pt with nephrogenic DI will only have mild increase in urine osmo
DI - what is happening? (die can’t concentrate)
Patients with DI have partial or total inability to concentrate urine
meds for SIADH (Sia and tegan)
Tegretol (anticonvulsant), narcotics, anesthesia
acromegly - Octreotide/lanreotide (aggro octavia is not growing)
Octreotide/lanreotide ( Somatostatin analogues)
Reduces elevated GH levels and causes tumor shrinkage
SQ or IM
acromegly - Pegvisomant (aggro peg is really effective)
Pegvisomant (Growth hormone receptor agonist)
Most effective treatment to date
Costly, given SQ
acromegly - Cabergoline
Cabergoline (Dopamine agonist):
Used off label to lower IGH1 levels
Given PO
acromegly - joints?
Narrowing of the joint space leading to arthritis and joint pain
hypopituitarism - can cause what? (little pit and addy)
May also lead to Addisonian Crisis (acute decrease in cortisol levels)
SIADH - urine specific gravity (Sia higher than space)
or urine specific gravity of >1.025 (1.01 to 1.02)
acromeglia - treatment - what surgery? (agro trans)***
Hypophysectomy via Trans-sphenoidal approach to remove GH secreting adenoma
SIADH - kidneys? (Sia in the ducts)
collecting ducts***
hypoglycemia - when should you not use IV?
NO IV and unconscious pt: glucagon IM in deltoid
