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83 Cards in this Set
- Front
- Back
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Negative Feedback Loop
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Hypothalamus
Releasing Factor X Anterior Pituitary Hormone A Target Organ Hormone B Biological Effects |
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Anterior Pituitary
(adenohypophysis) Growth Hormone (GH) |
Targets:
*All body tissue Function: *Growth and development of skeletal muscle and long bones *Affects a persons size and height *Role in protein, fat and carbohydrate metabolism |
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Thyroid Stimulating Hormone
(TSH) |
Targets:
*Thyroid Gland Function: *Stimulates synthesis and release of thyroid hormones *Stimulates growth and function of thyroid gland |
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Adrenocorticotropic Hormone
(ACTH) |
Targets:
*Adrenal Cortex Function: *Fosters growth of adrenal cortex *Stimulates secretion of corticosteroids |
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Gonadotropic Hormones
Follicle Stimulating Hormone (FSH) Lutenizing Hormone (LH) |
Targets:
*Reproductive organs FSH Function *Stimulates secretion of estrogen *Development of ova in females *Development of sperm in males LH Function: *Stimulates ovulation in females *Stimulates sex hormone secretion in both male and female |
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Prolactin
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Targets:
*Ovary and mammary glands in females Function: *Stimulates milk production in lactating women *Increases response of follicles to LH and FSH *Has unclear function in men |
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Posterior Pituitary
(neurohypophysis) |
*Composed of nerve tissue
*Essentially an extension of the hypothalamus *Stores antidiuretic hormone and oxytocin until their release is triggered by the appropriate response |
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Antidiuretic Hormone (ADH)
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Targets:
*Renal tubules and the vascular smooth muscle Function: *Promotes reabsorption of water *Vasoconstriction |
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Oxytocin
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Targets:
*Uterus and mammary glands Function: *Stimulates milk secretion *Contraction of uterine smooth muscle |
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Disorders Associated with the Pituitary Gland
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*Acromegaly
*Syndrome of inappropriate Antidiuretic Hormone (SIAH) *Diabetes Insipidus |
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Acromegaly
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Definition:
Growth Hormone Excess *Commonly affects middle-aged adults *Three out of every million adults will be diagnosed each year *Affects both men and women equally |
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Pathophysiology
Growth Hormone |
*Growth hormone is an anabolic hormone
*Promotes protein synthesis and mobilizes glucose and free fatty acids *Produced by anterior pituitary *Regulates growth Childhood deficiency children=dwarfism Childhood excess children=giantism Adult excess=acromegaly |
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Pathophysiology: Negative Feedback Loop
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Hypothalamus: GH-RH
Anterior Pituitary: GH Liver: Insulin-Like Growth Factor 1 (Somatomedin C) Stimulates growth of bones and soft tissue |
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Somatostatin
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*Helps regulate GH release
*Produced in the hypothalmus *Acts on the pituitary to inhibit GH release |
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Pathophysiology
Overproduction of GH |
*Overproduction is almost always caused by a benign pituitary adenoma (tumor)
*Pituitary tumor secretes GH despite elevated IGF-1 levels *Overproduction of GH leads to unwanted growth of bones and other soft tissue *Overproduction of GH results in hyperglycemia through insulin antagonism |
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Effects of Overproduction of GH Children
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Gigantism
*Excessive secretion of growth hormone during childhood before the closure of the bone growth plates. (Epiphysis) *Onset early childhood or puberty *May grow as tall as 8 feet and weigh more than 300 lbs *Very rare disorder *Most often caused by a benign pituitary tumor or “underlying medical condition” |
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Clinical Manifestation
Gigantism |
*Excess growth during childhood
*Frontal bossing and prominent jaw *Thickening of facial features *Disproportionately large hands and feet *Increased perspiration *Weakness *Fatigue *Irregular menstruation *Headache *Delayed onset of puberty *Double vision or difficulty with peripheral vision |
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Effects of Overproduction of GH Adults: Acromegaly
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*Unwanted growth of bones and other soft tissue
*Elevated blood glucose *Cardiomegaly *Left ventricular hypertrophy *Hypertension |
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Clinical Manifestations: Acromegaly
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*Abnormal soft tissue growth of hand and feet
*Bony changes alter facial features including spacing of the teeth *Thick coarse oily skin *Enlarged lips, nose and tongue *Deepening of voice: hypertrophy of vocal cords *Excessive sweating *Fatigue and weakness *Headaches *Impaired vision *Enlargement of liver, spleen, kidneys and heart |
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Diagnostic Studies: Acromegaly
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*History and Physical Examination
*Plasma GH *Plasma IGF-1 levels *IGF binding protein-3 levels *GH response to an oral glucose challenge *MRI *CT scan *Ophthalmologic examination |
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Treatment: Acromegaly
Goal is to return GH levels to normal |
Medical
-Pharmacological -Radiation Surgical -Transsphenoidal hypophysectomy -Stereotactic radiosurgery |
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Pharmacological Treatment: Acromegaly (3 Classifications)
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1. Somatostatin analogs
*Octreotide (Sandostatin) *Ocreotide (Depot, Sandostatin LAR) *Lanreotide SR (lpstyl) 2. Dopamine Agonists *Cabergoline (Dostinex) 3. GH receptor antagonists *Pegvisomant (Somavert) |
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Pharmacological Therapies Acromegaly: Octreotide
**Most common drug used** |
*Sandostatin, Sandostatin LAR Depot
*Most effective in suppressing GH release Mechanism of action: -Mimicking the suppressant actions of somatostatin on the pituitary -Used as primary therapy or as adjunct therapy to surgery or radiation |
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Pharmacological Therapies Acromegaly: Octreotide
**Most common drug used** |
Dosage:
*Sandostatin 100 mcg sc TID *Sandostatin LAR Depot 10-30 mg IM once a month Side effects: *Nausea, cramps, diarrhea, flatulence -usually subside within 1-2 weeks *Gallstones develop in 1 year in 25% of patients Expected Effects: *Normalization of GH and IGF-1 levels |
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Pharmacologic Therapies Acromegaly: Pegvisomant
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Mechanism of action:
*Binds to the same receptors in the body as growth hormone, and blocks the effect of growth hormone *Notify physician of latex allergy (top of vial is latex), diabetes, kidney disease or liver disease |
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Pharmacologic Therapies Acromegaly: Pegvisomant
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Dosage:
*1st dose of 40 mg SC, injected by physician then *10 mg daily SC, injected by patient *Monitor insulin-like growth factor (IGF-1) and liver function with regularly scheduled blood test Side Effects: *Flu-like symptoms, pain at the injection site, nausea or diarrhea Expected Effects: *Normalize serum levels of IGF-1 |
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Radiation Therapy
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*Considered secondary treatment option after surgery has failed to produce complete remission
*Used in combination with drugs *Used to reduce size of tumor before surgery *30-70% successful *Months-years for GH levels to normalize |
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Stereotactic Radiosurgery
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*Radiation delivered to a single site from multiple angles
*Used to occlude blood vessels feeding the tumor |
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Transsphenoidal Hypophysectomy
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Tumors < 10mm
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Immediate post-op care for Transphenoidal Hypophysectomy
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*HOB at least 30 degrees (decrease pressure)
*Assess for S&S cerebral edema (increased intracranial pressure *Incision in upper lip and gingiva *Hormone replacement for life *CSF leak - clear fluid check for glucose risk for meningitis |
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Post Op Nursing Care for Transsphenoidal Hypophysectomy Continued
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*Avoid coughing, straining
*Assess for CSF leak, meningitis *No tooth brush for 2 weeks, oral care *Assess for decreased ADH, adrenal & thyroid deficits |
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Nursing Process: Assessment
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*Abnormal signs and symptoms of abnormal growth (enlargement of lips, nose, tongue) (polyuria, polydipsia)
*Evaluate changes in physical size of each patient *Changes in appearance hands, feet *Give unconditional acceptance *Consider emotional support |
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Nursing Diagnosis: Acromegaly
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Actual
*Disturbed body image *Deficient fluid volume (polyuria) *Disturbed sleep pattern (swelling in tissue) *Disturbed sensory perceptions (enlarged pituitary gland) Risk *Risk for ineffective therapeutic regimen management secondary to expensive medications |
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Planning
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Patient Goals
*Accept and cope effectively with altered body image *Maintain adequate fluid volume *Experience restful sleep patterns *Develop no complications *Obtain long term follow-up care |
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Nursing Implementation
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*Offer reassurance
*Provide accurate information *If hormonal replacement is necessary provide explanation *Monitor for hyperglycemia *Monitor cardiovascular status; Angina, HTN, CHF |
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Nursing Implementation Cont.
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Preoperative Care
*Installation of antibiotic nose drops *Discussion of mouth breathing *Mouth care *Ambulation *Pain control *Activity *Hormone replacement *Avoid straining at stool (valsalva maneuver), vigorous coughing, and sneezing |
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Nursing Implementation Cont.
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Postoperative Care after transsphenoidal approach
*HOB elevated 30 degrees (prevent post-op HA *Monitor neurological status *Monitor for any clear nasal drainage and send to laboratory for glucose testing (CSF leak) risk for meningitis *Assess pain level *Provide mouth care |
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Nursing Implementation Cont.
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Postoperative care after stereotactic radiosurgery
*Monitor vital signs *Neurologic status *Fluid volume status *Monitor for possible complications (HA, seizures, N/V) *Provide pin site care *Monitor level of pain *Assess for Diabetes Insipidus |
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Nursing Implementation
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*Management of care
*Patient teaching -Hormone replacement (medications taken for life) |
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Nursing Implementation
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Psychosocial Integrity
*Unexpected body image changes *Grieving process |
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Evaluation (pt w/ GH excess) Expected Outcomes
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*Experience no postoperative complications
*Know how and when to take hormone replacement (if indicated) *State symptoms requiring immediate attention and appropriate actions *State the importance of long-term follow-up *Have a follow-up medical appointment |
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Syndrome of Inappropriate Antidiuretic Hormone SIADH
2nd disorder of pituitary hormone |
Definition:
*Overproduction or over secretion of ADH *ADH is also referred to as arginine vasopressin *Vasopressin -Synthesized in hypothalmus -Stored in posterior pituitary -regulation of water balance and osmolarity |
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Causes of SIADH
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*Malignant tumors (Small cell lung cancers)
*Central Nervous System Disorders *Drug Therapy *Hypothyroidism *Lung Infection (pneumonia, TB) *COPD *Positive Pressure Mechanical Ventilation |
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Clincal Manifestations of SIADH
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*Muscle cramps and weakness
*Low urine output *Increased body weight |
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Clincal Manifestations of SIADH: Sodium levels below 120mEq/L
(Normal sodium levels 135-145 mEq/L) |
*Vomiting
*Abdominal cramping *Muscle twitching *Seizures |
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Clinical Manifestations
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*As plasma osmolality and serum sodium levels continue to decline
-Lethary -Anorexia -Confusion (Cerebral Edema) -Headache -Seizures -Coma |
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Diagnostic Studies
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*Simultaneous measurements of urine and serum osmolality
*Dilutional hyponatremia is indicated by a serum sodium less than 134 mEq/L *Serum osmolality less than 280 mOsm/kg *Urine specific gravity greater than 1.003 *Decreased BUN, creatinine clearance, hemoglobin and hematocrit |
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Treatment
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Immediate goal is to restore normal fluid volume and osmolality
*Directed at underlying cause -Surgical removal of tumor -Avoid or discontinue medications that stimulate the release of ADH |
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Treatment
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Serum Sodium is greater than 125 mEq/L and symptoms are mild
*Restrict fluids to 800-1000 ml per day *Restriction should lead to a gradual daily reduction in weight *Progressive rise in serum sodium concentration and osmolality *Symptomatic improvement |
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Treatment: Severe Hyponatremia Serum Sodium Levels less than 120 mEq/L
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*IV hypertonic saline solution 3%-5% (seizures)
-slow infusion with a pump *Lasix (only if sodium is at least 125 mEq/L) K supplement may be needed *Fluid restriction of 500 ml/day |
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Treatment: Chronic SIADH
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*Water restriction of 800-1000 mL/day
*Declomycin (block effects of ADH on renal tubules) *Lithium (block effects of ADH on renal tubules) |
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Nursing Process: Assessment
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*Hourly vital signs
*Hourly I&O *Hourly measurement of urine specific gravity *Daily weights *Level of consciousness *Observe for signs of hyponatremia (seizures, N/V, muscle cramping *Monitor heart and lung sounds |
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Nursing Diagnosis
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Actual
*Fluid/Volume imbalance *Imbalanced nutrition Risk *Risk for injury r/t decreased LOC |
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Planning Patient Goals
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*Fluid volume and osmolality is restored
*Electrolyte imbalance is restored *Provide safe effective care *Address health maintenance/promotion issues *Establish outcomes |
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Nursing Implementation: Acute Onset SIADH
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*Fluid restriction of 1000 mL/day
*HOB flat or no more than 10 degrees (Venous return to heart) *Protect from injury (side rails up) *Seizure precautions *Frequent turning, positioning and ROM exercises if pt bedridden *Frequent oral hygiene (Fluid restriction) *Provide distractions to decrease the discomfort of thirst r/t fluid restriction |
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Nursing Implementation: Chronic SIADH
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*Patient teaching to self management
-Fluid restriction of 800-1000 mL/day -Sucking on ice chips or hard candy (decrease thirst) -Planning fluid intake -Supplemental NA and K if diuretic prescribed -Symptoms of fluid and electrolyte imbalance -Close follow-up care if treated with Declomycin (Nephrotoxic S/E Fungal infections) |
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Evaluation: Expected Outcomes
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*Maintain fluid and electrolyte balance
*State symptoms requiring immediate attention and appropriate actions *State the importance of long-term follow-up care |
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Diabetes Insipidus
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Definition:
*Group of conditions associated with underproduction or undersecretion of ADH or a decreased renal response to ADH Pt may experience nocturia |
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Classifications of Diabetes Insipidus
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*Central Diabetes Insipidus
*Nephrogenic Diabetes Insipidus *Dispogenic Diabetes Insipidus S/S Fluid Volume Deficit |
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Central Diabetes Insipidus
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Definition:
Any organic lesion of the hypothalmus, infundibular stem or posterior pituitary interferes with ADH synthesis, transport or release Cause: Brain tumor, head injury, brain surgery, CNS infection |
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Nephrogenic Diabetes Insipidus
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Definition:
There is adequate ADH but there is a decreased response to ADH in the kidney Cause: Drug therapy (lithium), renal damage, hereditary renal disease |
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Dispogenic Diabetes Insipidus
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Definition:
Associated with excessive water intake Cause: Structural lesion in thirst center or psychological disorder |
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Clinical Manifestations
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*Increased thirst (polydipsia)
*Increased urination (polyuria) *Urine output 5-20 L/day *Urine specific gravity less than 1.005 *Urine osmolality less than 100 mOsm/kg *Serum osmolality is usually greater 295 mOsm/kg |
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Clinical Manifestations
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Fluid volume deficit manifested by:
*Weight loss *Constipation *Poor skin turgor *Hypotension *Tachycardia *Shock *CNS manifestations -Irritability -Mental dullness -Coma |
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Clinical Manifestations of Central DI After Intracranial Surgery Triphasic pattern;
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Acute Phase:
-Abrupt onset of polyuria (w/in 24 hrs) Interphase: -Urine volume normalizes (2-5 days Third Phase: -Central DI is permanent -Apparent within 10-14 days postop |
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Diagnostic Studies
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*Identify cause first
*H&P (History & Physical) *Waster deprivation test DI following cranial surgery is usually permanent |
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Water Deprivation Test
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*Obtain baseline:
-Weight -Pulse -B/P -Urine and plasma osmolalities -Urine specific gravity *All fluids are held for 8-16 hours *Reassure patient throughout test *Assess B/P, weight and urine osmolality hourly |
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Water Deprivation Test cont.
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The test continues until:
*Urine osmolality stabilizes *Body weight declines by 5% *Orthostatic hypotension develops ADH is then given Urine osmolality is measured 1 hour later *In Central DI-the rise in urine osmolality after vasopressin exceeds 9% |
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Treatment
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*Goal is to maintain fluid & electrolyte balance
*Determine and treat primary cause Medical *Pharmacological *Nutritional |
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Pharmacological Treatment Central DI
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Acute Phase
*Hypotonic Saline IV titrated to replace urinary output *Hormone replacement: Desmopressin acetate (DDAVP) *ADH Replacement: -Aqueous vasopressin (Pitressin) -Vasopressin tannate -Lysine vasopressin (Diapid) *Carbamazepine (Tegretol) *Chlorpropamide (Diabinese) *Clofibrate (Atromid) |
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Pharmocological Therapy: Desmopressin (Drug of choice in treating Central DI)
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*DDAVP, Stimate
*Drug of choice when treating DI d/t prolonged effect, convenient route, decreased side effects (especially vasoconstriction) Mechanism of action: *Acts on the kidneys to reduce the flow of urine which increases the urine osmolality |
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Pharmacological Therapy: Desmopressin (Drug of choice in treating Central DI)
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Dosage:
*Adults: 0.1mL intranasally BID or 0.25-0.5mL SC or IV BID *Children: 0.05-0.3mL intranasally daily either in single dose or in 2 doses Side Effects: *Stuffy or runny nose *Upset stomach |
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Pharmacological Therapy: Desmopressin
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Side Effects:
*Water intoxication (excessive water retention -Early signs-drowsiness, listlessness, headache -Late signs-convulsions and terminal coma Expected Effects: *Normalization of urinary water excretion |
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Pharmacological Therapy: Vasopressin
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*Identical in structure to naturally occurring ADH
*Powerful vasoconstrictor Mechanism of action: *Acts on the kidneys to reduce the flow of urine which increases the urine osmolality |
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Pharmacological Therapy: Vasopressin
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Dosage:
*5-10 units IM or SC 3-4 times/day Side Effects: *Water intoxication -Early signs-drowsiness, listlessness, headache -Late signs-convulsions and terminal coma |
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Pharmacological Therapy: Vasopressin
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*Cardiovascular Effects (In patients with coronary insufficiency)
-Angina pectoris -Myocardial Infarction -Gangrene Expected Effects: *Normalization of urinary water excretion |
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Nutritional Treatment: Nephrogenic DI
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*Low Sodium Diet (decrease urine output)
*Thiazide diuretics -Slows glomerular filtration rates which allows the kidneys to reabsorb more water in the Loop of Henle and distal tubules -Hydrochlorothiazide (HydroDiuril) -Chlorothiazide (Diuril) *Indocin (NSAID) |
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Nursing Process: Assessment
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*Weight (daily)
*Pulse *B/P *I&O *Urine Specific Gravity *Urine Glucose |
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Nursing Diagnosis
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Actual
-Fluid volume imbalance -Disturbed sleep pattern -Impaired concept Risk -Risk for ineffective management of therapeutic regimen |
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Nursing Management: Planning, Patient Goals
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*Early detection
*Maintenance of adequate hydration *Experience restful sleep patterns *Patient teaching for long-term management *Obtain long term follow-up care |
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Nursing Implementation
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*Administer fluids IV or PO
*Administer hormone replacement *Keep adequate fluid at bedside *Maintain accurate I&O *Assess for fluid volume deficit frequently |
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Nursing Implementation
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*Provide support and reassurance
*Management of care (early detection) *Patient teaching to self management |
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Evaluation: Expected Outcomes
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*State symptoms requiring immediate attention and appropriate action
*Know how and when to take hormone replacement (if indicated) *State the importance of long-term follow-up *Have a follow-up appointment |
