complex: endocrine II

exam 2

hormones classification

• amines and amino acids - epinephrine, thyroid hormones

• peptides, polypeptides, proteins, glycoproteins - TRH, FSH, GH

• steroids - corticosteroids

• fatty acid derivatives - retinoids

function of the endocrine system

• coordinating cellular interaction

• metabolism/growth and development

• fluid and electrolyte balance

• acid-base balance

• adaptation

• reproduction

• aging

• response to adverse conditions

endocrine review of systems

any changes in:

• energy level

• tolerance to heat/cold

• weight

• thirst, frequency of urination

• bowel function

• body proportions: muscle mass, fat, fluid distribution

• secondary sex characteristics, sex dysfunction

• menstrual cycle

• concentration, sleep patterns, mood

• vision

• joint pain

diagnostics for endocrine diagnosis

• blood - hormones, autoantibodies, secondary effects, radioimmunoassay (antigen levels)

• urine - hormone, metabolites, 24h collections

• stimulation - confirms hypofunction by testing response

• suppression - detects hyperfunction (failure of negative feedback)

• imaging - radioactive scanning, MRI, CT, ultrasonography, positron emission tomography (PET), dual energy x-ray absorptiometry)

• genetics - more routine. identification of specific genes rt endocrine disorders. detects gene mutation

diabetes insipidus (DI)

• Hypo- ADH

• deficiency or resistance of antidiuretic hormone aka ADH or vasopressin

• decreased ADH =water loss

• s/s:dilute polyuria and polydipsia

types of DI

1. Central DI: lack of vasopressin production or secretion

2. Nephrogenic DI: renal resistance to vasopressin

3. Dipsogenic DI/Primary DI: excessive water intake

4. Gestational DI: excess vasopressinase

all result in excessive hypotonic urine but tx varies

causes of central DI

• trauma to hypothalamus, infundibulum, or pituitary

  (head trauma, neurosurgery, brain tumors, surgical ablation/irradiation/resection of pituitary, CNS infection, inflammation)

causes of nephrogenic DI

• failure of renal tubules to respond to ADH

  (congenital, injury, medications (lithium, amphotericin B, declomycin), hypokalemia, hypercalcemia

causes of dipsogenic DI

• hypothalamus defect (thirst mechanism)

  (head injury, surgery, infection, inflammation, tumor)

causes of gestational DI

• rare, excessive vasopressinase activity (pregnancy)

physical exam for DI

• neuro - HA, dizziness, lethargy, confusion

• HEENT - dry mucous membranes, decreased skin turgor

• cardiac - tachycardia, thready weak pulse

• GI - increased PO liquids

• GU - increased UO

• muscle skeletal - twitching, spasms, weakness

• psychological - irritable

• VS - hypotensive, tachycardia

key assessment findings in DI

• onset - insidious or abrupt

• large volume of urine output in absence of ADH (>250 ml/hr) = polyuria

• dilute urine = urine specific gravity of <1.005

• polydipsia (2-20L of fluid daily)

• hypernatremia (>145 mEq/L)

• restricting fluids ineffective

diagnostics for DI

• fluid deprivation test

• plasma levels of ADH - low (CDI) versus normal (NDI)

• plasma and urine osmolality

• serum osmolality

• desmopressin trial (synthetic vasopressin)

tx for central DI

1. correct/treat underlying etiology

2. replace ADH (DDAVP - desmopressin acetate, 1-deamino-8-D-arginine vasopressin) oral/intranasal

3. fluid replacement with hypotonic solutions

4. chlorpropamide and thiazide diuretic prn for mild form ?

tx for nephrogenic DI

• correct/treat underlying etiology

• mild salt restriction

• prostaglandin inhibitors ?

• chlorpropamide and thiazide diuretic ?

Nursing Diagnosis for DI

• deficient fluid volume

• Decreased cardiac output

• electrolyte imbalance

• nausea

• knowledge deficit

nursing interventions for DI

• I&O, foley insertion

• frequent weights

• monitor VS (tachycardia, hypotension)

• PE - neuro checks, mucous membranes

• IVF & medication administration (side effects)

• ample access to free water ?

• diet restriction (low salt, low protein for NDI)

• psychological support

• education

*tx risks - water intoxication, dehydration, electrolyte imbalance, seizures death

syndrome of inappropriate antidiuretic hormone (SIADH)

• hyper-ADH

• excessive ADH (vasopressin) secretion

• excessive water retention - causes hyponatremia (dilutional) and hypervolemia

causes of SIADH

• lung disorders (lung CA, PNA, pneumothorax) ?

• CNS disorders (head injury, brain tumors or infections) = direct overstimulation of pituitary gland (increased ADH)

• meds - phenothiazines, TCAs, thiazide diuretics, nicotine

• infection

• hypothyroidism ?

clinical manifestation of SIADH

• neuro - HA, AMS, lethargy, delirium, seizures, coma, paralysis

• cardiac - HTN, peripheral edema

• pulmonary - SOB, crackles

• GI - anorexia, nausea and vomiting (early), abdominal pain

• GU - decreased UO

• MS - cramping, weakness

• psychiatric - irritability

SIADH diagnostics

• serum hypoosmolality - decreased 2 degree dilution (280 mOsm/kg)

• serum hyponatremia - decreased 2 degree dilution (136 - 145 mmol/l)

• urine hyperosmolarity - increased 2 degree oliguria (100 mOsm/kg)

• urine hypernatremia - increased 2 degree oliguria (20 mEq/l)

• plasma levels of ADH - normal or elevated

• renal function - normal

SIADH management

• acute symptomatic vs chronic asymptomatic

• identify and eliminate underlying cause

• fluid restriction (1-1.5/d)

• salt tablets PO - increase sodium level

• loop diuretics - promote water excretion

• Urea powder PO - promotes osmotic water loss

• vasopressin-2 antagonist - vaptan therapy blocks ADH activity in kidneys

• frequent sodium labs

• 0.9% saline IVF in some types ?

tx of emergent symptomatic hyponatremia

hypertonic saline (3% saline) if severely symptomatic

• commonly rate limited to prevent osmotic demyelination syndrome (ODS)

• ODS occurs due to rapid sodium correction causing myelin sheath damage (brain stem)

• small bolus used in severely symptomatic states

• sodium deficit formula for milder cases

nursing interventions for SIADH

• monitor VS and serum sodium

• monitor I&O closely

• fluid restrictions

• frequent neuro checks for pts at risks

• telemetry

• supplemental salt, oxygen prn

• urine and blood chemistries

• support measures

• educational - pathology, procedures, meds, tx

tx risks - electrolyte imbalance, ODS, seizures, coma, death

parathyroid glands

• four glands on the posterior thyroid gland

• parathyroid glands secrete parathyroid hormone (parathormone) aka PTH

• increased PTH - increased blood calcium, decreased blood phosphorus

• thyroid secretes calcitonin (and T3, T4)

• PTH, calcitonin, and vit. D regulate calcium and phosphorus

hyperparathyroidism

• overproduction of parathyroid hormone

• increased calcium levels and characterized by bones softening and kidney stones

• hypercalcemia > 10.5 mg/dl (normal range 8.5 - 10.2 mg/dl)

hyperparathyroidism incidence

• one of most common hormone disorders

• occurs 2 to 4 times more often in women

types of hyperparathyroidism

• primary - enlargement of one or more of the glands which leads to an overproduction of PTH (80 - 90% of cases)

• secondary - overactivity of parathyroids due to low calcium e.g. vit. D deficiency, CKD

• tertiary - due to chronic secondary hyperparathyroidism e.g. kidney, transplant, ESRD on dialysis

role of calcium

• bone and tooth health

• facilitates bodily/cellular functions

• stabilizes cells membranes

• activities muscle concentrations

• initiates neurotransmission

• maintain depolarized states

• endocrine cell use

• activates/stabilizes enzymes

• motility, metabolic processes, proliferation, etc

clinical manifestations for hyperparathyroidism

• neuro - fatigue, muscle weakness

• cardiac - arrhythmias (short QT interval)

• GI - nausea, vomiting, constipation, anorexia

• GU - nephrolithiasis, kidney damage

• MS - skeletal/joint pain, absent reflexes

• psych - irritability, neurosis, psychoses

diagnostics for hyperparathyroidism

• lab analysis

  • elevated calcium and PTH levels

  • radioimmunoassay for PTH

  • double antibody parathyroid hormone test

• radiologic

  • X-ray and bone scans

  • US, CT, MRI, thallium scan, fine-needle biopsy

medical tx for asymptomatic hyperparathyroidism

primary hyperparathyroidism - surgery

• parathyroidectomy for asymptomatic pts with primary hyperparathyroidism meeting 1 or more of these criteria:

  1. younger than 50yrs of age

  2. those unable/unlikely to follow up

  3. serum Ca+ more than 1mg/dL above normal

  4. GFR < 60 mL/min

  5. urinary calcium > 400 mg/day

  6. bone density with T score < -2.5 (osteoporosis)

  7. presence of nephrolithiasis or nephrocalcinosis

medical tx for symptomatic hyperparathyroidism

• promote urinary excretion

  • rehydrate - require fluid intake of >2000ml. promotes calcium excretion. avoid thiazide and dehydration

  • loop diuretic - inhibits calcium reabsorption in LOH

• increase GI excretion

  • glucocorticoids - affect vit D and decreased calcium reabsorption)

• prevent bone resorption (calcium released from bone)

  • oral phosphates - decreases calcium, short term only - CaPO4 deposits

  • bisphosphonates (osteoporosis), calcitonin - inhibits osteoclasts (bone catabolism)

• diet - limit calcium

• mobility - weight bearing-aids with bone resorption

hypercalcemic crisis

• when - extreme elevation of serum calcium levels > 13 - 14mg/dL (normal 8.6 - 10.2)

• what - life threatening neurologic, cardiovascular, and kidney symptoms

tx for hypercalcemic crisis

• rapid rehydration - large volume IV isotonic saline fluids (INS to keep UOP at 100 ml - 150ml/hr)

• emergent cocktail - calcitonin and corticosteroids

• dialysis - used in emergent situation not responding to tx

nursing interventions for hyperparathyroidism

• ongoing assessment - neuromuscular, cardiac

• hydration therapy - I&O

• mobility - weight bearing (bone building)

• diet - hydration, limit calcium, laxatives, protein (if ulcer)

• med administration - routine vs emergent, surgery

• blood work - calcium, phosphorous, PTH, vit D

• monitor/tele - arrhythmias

tx risks - electrolyte imbalance, arrhythmias, tetany

parathyroidectomy nursing management

• maintain ABCs, use high semi-fowlers position

• promote hydration and ambulation

• monitor for tetany post-op

• education: need for follow up - hypocalcemia

Hypoparathyroidism

• deficiency of PTH

• low PTH = hypocalcemia (loss through bone, kidney, GI)

• hyperphosphatemia

• types - acquired, autoimmune, congenital, familial, postoperative parathyroidectomy hyperparathyroidism is leading cause (acquired)

clinical manifestations for hypoparathyroidism

• tetany due to impaired neuromuscular signal, irritability, muscle hypertonia

• hypocalcemia lowers the threshold for neuronal activation

• tremors, spasmodic or uncoordinated contractions

• numbness, tingling, cramps, stiffness

• anxiety, irritability, depression, delirium

• ECG changes and hypotension (cardiovascular/cardiopulmonary collapse)

assessment findings:

• trousseau sign

• positive chvostek

diagnostics for hypoparathyroidism

lab studies:

• low serum calcium (normal - 8.6 - 10.2 mg/dl)

• low serum vit. D (normal - 20 - 50 mg/dl)

• elevated phosphate levels (normal: 2.4 - 4.1 mg/dl)

  radiologic:

  • bone shows increased density

  • calcification of subcutaneous tissue (or parts of brain)

medical management for hypoparathyroidism

• identify and treat etiology - tx depends on symptoms and cause

• goal - normalization of serum calcium level (goal 9 or 10 mg/dl)

• medication cocktail - calcium, magnesium, and vitamin D2 or D3, thiazide diuretic ?

• low stimulus environment (due to neuromuscular irritability)

• calcium supplementation - calcium salts and calcium gluconate

• aluminum hydroxide gel or aluminum carbonate (gelusil, amphojel) after meals binds phosphate and promotes GI excretion

• following parathyroidectomy: if hypocalcemia and tetany present, emergent tx with IV calcium gluconate, and sedative agents and resp. support prn

diet for hypoparathyroidism

• high calcium (green leafy vegetable, broccoli, kale fortified OJ, breakfast cereals)

• low phosphorus diet (limit milk/products, egg yolks, soft drinks)

• low oxalates (limit spinach, meats, nuts)

nursing interventions

• ongoing assessment - neuro (seizures), tetany, cardiac, pulmonary

• postoperative care - s/p para/thyoidectomy, radical neck dissection - detect early signs of low calcium, related complications (tetany, seizures, resp distress)

• med admin - calcium gluconate IV for emergencies; several meds, arrhythmias, (cardiac hx)

• cardiac monitoring - arrhythmias

• education - diet modifications, meds, restrictions, signs/symptoms of hypo/hypercalcemia

______ typically contraindicated

calcium gluconate and digoxin

• digoxin can exacerbate cardiac hypokalemia symptoms

• calcium and digoxin increase systolic contraction and synergistic effect resulting in fatal arrhythmias