Posterior Pituitary Gland Diseases

pathophysiology of posterior pituitary gland

stores and secretes vasopressin

vasopressin

synthetic form of ADH which controls the excretion of water by the kidneys

what is the posterior gland main purpose

regulation of water throughout the body

what is the targeted organ

kidneys

diabetes insipidus

disorder of the posterior pituitary gland that results in water loss from insufficient ADH

is diabetes insipidus really diabetes

no but symptoms mimic diabetes

simple terms of diabetes insipidus

what goes in, immediately comes out

what is the causes of diabetes insipidus

defect witht he hypothalamus or pituitary gland, infection, surgery, head injury, kidney failure

diabetes insipidus s/s

signs of dehydration, diluted urine, polyuria, polydipsia, polyphagia, change in LOC, weight loss

signs of dehydration

dry mouth, poor skin turgor, dry mucous membrane, hypotension, tachycardia, weak peripheral pulse, fatigue and weakness, hypovolemia

polyuria

voiding greater than 3 L/day

what electrolyte imbalance resembles diabetes insipidus

hypovolemia

BMP labs for diabetes insipidus

sodium, low potassium, elevated BUN and creatinine

what is the lab for sodium for diabetes insipidus

initially it would be normal but as the disease progresses sodium will increase which leads to hypernatremia

signs of low potassium

dysrrhythmias

CBC labs for diabetes insipidus

elevated hemoglobin and hemacrit

what is another lab for diabetes insipidus

24 hour urine

how to collect 24 hour urine

first time voiding - dump it out
after the first time, start to collect it in a hat
pour the urine in the hat in a collection jug
keep the jug on ice

what to do if something else were to be in the urine hat

repeat the proccess over again

diabetes insipidus medical interventions

identify the cause, desmopressin, fluids

what is priority for diabetes insipidus

treat whatever is causing it

desmopressin

synthetic form of vasopressin to stop from voiding; vasoconstrictor

contraindication for desmopressin

CAD patients

adverse effect of desmopressin

fluid retention, water overload; water toxicity

s/s of water toxicity

persistent headaches, acute confusion and n/v

how does water toxicity happen with desmopressin

results from hypernatremia which can dilute the sodium making the pt go into hyponatrema

rate of starting desmopressin

low and slow

what fluids are given for diabetes insipidus

hypotonic

diabetes insipidus nursing interventions

strict i/o, avoid diuretic diet, daily weights, monitor for hypervolemia, positive therapeutic change, monitor for irregular heartbeats, report signs of dehydration

daily weights

same scale, time and clothes

report weight change of 2.2 lbs/day

how does hypervolemia occur with diabetes insipidus

overcorrecting

SIADH

disorder of the posterior pituitary gland that results in water gain from excessive ADH

causes of SIADH

malignancies, pulmonary disorders, medications, trauma, CNS disorders

which electrolyte imbalance resembles SIADH

hypervolemia

SIADH s/s

signs of fluid overload (hypervolemia), dark amber color and dysuria, oliguria, changes in LOC, weight gain

SIADH BMP labs

low sodium, elevated potassium, decreased BUN and creatinine

why would sodium levels be low for SIADH

water dilutes the sodium; hyponatremia

s/s of hyponatremia

headaches, altered LOC, seizures, coma, lethargy, hypotension, tachycardia

high potassium s/s

hyperkalemia; arrhythmias, irritability, tachycardia

CBC labs for SIADH

decreased H&H

urinalysis of SIADH

dark amber color urine and high urine specific gravity (concentration)

SIADH medical interventions

identify the cause, diuretics, fluids

what is priority for treating SIADH

treat whatever is causing SIADH

what diuretic should be given for SIADH

furosemide

fluids for SIADH

restrict fluids of 500-1000 mL/day and strict i/o

what to do if sodium continues to drop

give sodium tablets or administer a low amount of hypertonic fluid (3% saline) to increase sodium

SIADH nursing interventions

provide a safe quiet environment, strict i/o, seizure precautions, daily weights, monitor sodium levels, signs of heart failure, assess neurological status

why should nurses provide a safe quiet environment for SIADH patients

overstimulation, keep pt in low stimuli

what should we see if sodium levels are low

edema but not pitting edema

signs of heart failure for SIADH

SOB, dysrhythmias, crackles in the lungs