Week 1 - Pituitary Disorders Flashcards
what hormone does the posterior pituitary store and secrete
- ADH
what is the fnxn of ADH
- plays major role in regulation of water balance and osmolarity
- plays major role in how the body retains water thru the kidneys
what are the two primary disorders of the pituitary gland
- syndrome of inappropriate antidiuretic hormone (SIADH)
- diabetes insipidus
what is SIADH
- condition caused by too much ADH
* think: Syndrome of Increased ADH*
what effect does increased ADH have on the kidneys? how does this effect intravascular fluid volume?
= increased water reabsorption in renal tubules
= increased intravascular fluid volume
how does increased ADH effect sodium and serum osmolality in SIADH
= dilutional hyponatremia & decreased serum osmolality
how would SIADH effect a pt’s BP? urine output? body weight?
- hypertension
- cause low urinary output with high specific gravity (very concentrated)
- increased body weight
what symptoms could the dilutional hyponatremia during SIADH cause? (9)
- muscle & abdominal cramps
- weakness
- vomiting
- seizures
- muscle twitching
- lethargy
- decreased LOC & confusion
- headaches
- coma if severe
1 kg of weight = ____ fluid
1kg = 1L of fluid
what should nurses monitor for a pt with, or possibly with, SIADH (10)
- LOC
- VS
- I&O
- low urine output w high specific gravity
- increased daily weight
- low K and Na lvls
- heart and lung sounds
- neurological assessments for decreased LOC
- observe for signs of hyponatremia
why should a nurse monitor heart and lung sounds for a pt with SIADH
- due to fluid overload which could cause pulmonary edema, etc.
what is the treatment goal for a pt with SIADH
- restore fluid volume & electrolyte balance
what is considered mild hyponatremia
- > 125 mmol/L
what would be the treatment for a pt with mild hyponatremia with SIADH? what should this cause (2)?
- fluid restriction of 800 - 1000 mL/day
- should result in gradual weight & increase Na
what is considered severe hyponatremia
< 120 mmol/L
what type of IV solution would be given to a pt with severe SIADH? how should it be given & why?
- IV hypertonic saline (3-5%)
- must be infused slowly to prevent fluid overload & to avoid too rapid of a rise in Na
why would a nurse give hypertonic saline to a pt with severe SIADH
- to remove fluid from the cells back into the vascular system so it can be urinated out
what would be the treatment for a pt with severe hyponatremia & SIADH? (4)
- fluid restriction of 500 mL/day
- IV hypertonic saline
- IV Lasix
- Tolvaptan (Samsca)
what is important to monitor with Lasix for a pt with SIADH
- monitor electrolytes carefully (may lose K+ and Na+)
- may need to supplement
what is tolvaptan (Samsca)
- a med that blocks ADH effect on renal tubules = decreased water reabsorption
why is close monitoring required with tolvaptan
- to prevent rapid correction of serum sodium lvl
what position should a pt’s head be in if they have SIADH & why
- HOB flat
- enhance venous return, increase left atrial filling pressure = reduced ADH release
what kind of diet should a pt with SIADH have
- diet high in Na and K
how can we help prevent patients with SIADH from injury (2)? why is this important?
- fluid overload and hyponatremia can cause confusion, changes in LOC, seizures, etc.
actions can include:
- padding the rails
- helping w ambulation
what is an important nursing care responsibility for a pt with SIADH r/t the fluid restrictions?
- oral care & ice chips
- can help relieve the thirst r/t fluid restriction
what should be included in discharge planning for someone w chronic SIADH (5)
- symptoms of fluid imbalances
- symptoms of electrolyte (especially Na and K) imbalances
- that ice chips and sugarless gum can help relieve thirst
- how to plan fluid intake
- if on diuretics, diet should be supplemented w Na and K+
what is diabetes insipidus
- conditions associated w low ADH
what are the 3 types of causes of DI
- central
- nephrogenic
- primary
what is central DI
- DI causes by interference w ADH synthesis, transport, or release
- such as a brain tumour, pituiatry tumour, head injury
what is nephrogenic DI
- DI caused by an inadequate response to ADH despite adequate lvls ( renal damage)
what is a primary DI
- DI caused by excessive water intake, due to a psych problem or lesion in the thirst center
what effect does DI have on BP? urine output & how much? water intake
- cause hypotension
- polyuria –> lots of urine (5-20 L/day) with low specific gravity & is often clear
- causes polydipsia
what effect does DI have on Na
- will cause hypernatremia
what symptoms should nurses monitor for with DI (12)
- polyuria & low specific gravity
- high Na
- weight loss
- polydipsia
- hypotension
- tachycardia
- dry mucous membranes and skin
- weakness
- NV
- muscle cramps
- confusion
- hypovolemic shock
what assessments can be used to confirm DI (3)
- history
- physical exam
- water deprivation test (read more on in textbook)
what is the treatment goal for pts with DI
- restore fluid volume and electrolyte balance
what does the treatment of DI depend on
- the type of cause
what is the treatment for central DI (2)
- acute: give hypotonic saline to replace fluid loss
- give DDAVP (desmopressin acetate
what is DDAVP
- an analog of ADH used as a hormone replacement f/t lack of ADH
what is the treatment for nephrogenic DI(3)
- diet low in sodium
- thiazide diuretics
- indomethacin (a type of NSAID)
how much sodium should a pt with nephrogenic DI have? why?
<3g daily
- thought to help retain water & decrease urine output
why are thiazide diuretics given for a pt with nephorgenic DI
- leads to lower GFR = increased water reabsorption
why is indomethacin used for nephrogenic DI
- increases renal response to ADH
what should you monitor for with a pt on DDAVP (2)
- waterintoxication
- hyponatremia
what is the treatment for a pt with primary DI (2)
- limit fluid intake
- treat psych disorder
describe nursing care for someone with DI (5)
- monitor I&O
- monitor daily weights
- monitor VS
- ensure adequate fluid at bedside & encourage drinking (unless primary)
- monitor effects of DDAVP
why is it important to monitor the effects of DDAVP for a pt with DI
- want to make sure its working but not too much
- monitor for under or over hydration and adjust accordingly
what would indicate a need for increasing the dosage of DDAVP
- increased urine volume with low specific gravity
what should you monitor for with a pt on DDAVP (7)
- water intoxication
- hyponatremia
- weight gain
- restlessness
- headache
- fluid input and output
- urine specific gravity
what would be included in discharge teaching for a pt with chronic DI (4)
need instructions w self management
- how to take DDAVP
- signs of hyponatremia, headache, etc. could indicate overdosage
- failure of improvement = underdosage
- must monitor weight daily & increase in weight could = fluid retention
