iv fluid and electrolytes Flashcards
central venous access devices (CVADs)
catheters placed in large blood vessels of ppl who need freq or special access to the vascular system
hydrostatic pressure
pressure pushing out of cell
oncotic pressure
pressure keeping fluids in cells
hypertonic solution
- what kind of fluids?
solution that has higher osmolality than plasma, draws water out of cell
–> D5.45, D5.9, D5LR, 3% Sodium
hypotonic solutions
–> what kind of fluids?
solution with an osmolality lower than plasma, pulls fluid back into cells
–> 0.45, 0.33, 0.22, D5W
isotonic solutions
–> what kind of fluids?
solution with osmolality the same as plasma, will cause no fluid change
–> LR, 0.9 NS
osmolality
measure number milliosmoles/kg of water
what is the most common fluid and electrolyte disorder ?
dehydration
body water % for infant, adult, elderly?
infant = 75%
adult = 60%
elderly = 55%
osmosis
diffusion of water across a semipermeable membrane
explain why there are fluid movement changes at the capillary arterial/venous end of capillaries?
t/f: isotonic solutions only expands intravascular space
true
what are other regulations for fluid balance (7)
- hypothalamus/pituitary (thirst center)
- renal –> RAAS
- cardiac –> ANP and BNP
- stress
- GI (vomit, diarrhea)
- Insensible losses (sweating, burns)
- Lymphatic system (drain)
explain how hypothalamus/pituitary gland can regulate dehydration?
dehydration (H2O deficit) –> hypothalamus osmo-receptors stimulated –> pituitary gland secretes ADH –> kidneys reabsorb water –> osmolality falls
explain how kidneys can regulate dehydration?
dehydration = decreased renal perfusion –> renin increases –> angiotensin increases –> aldosterone increases –> Na retention and water
explain how cardiac system can regulate excess/high bp?
increase in atrial pressure –> increase in ANP and BNP –> excretion of Na and H2O
t/f: stress leads to the excretion of fluid
false = stress leads to retaining fluid
what are considerations for elderly populations and fluid?
- decreased body water % (45-55%)
- decreased thirst mech, confusion
- decreased mobility, GFR, organ function
- increased moisture loss
- increased drug interactions
normal lab values for osmolality?
275-295
normal lab values for BUN?
8-25
normal lab values for urine specific gravity?
1.010 - 1.030
normal lab values for Na+ ?
135-145n
normal lab values for K+ ?
3.5-5.0
normal lab values for hematocrit ?
45%-55%
how can you tell if a fluid imbalance has moved to an intracellular problem ?
CNS changes (confusion)
what to administer to pt with ECFVD?
why?
ECFVD = dehydration
–> admin isotonic solution to replenish vascular system (LR, 0.9NS)
what to administer pt with ICFVD?
why?
ICFVD = cells are shrinking (rare unless elder with acute water loss)
–> admin hypotonic fluid to push fluids back into cells (0.45, D5W)
what to administer to pt with ECFVE?
why?
ECFVE = intravascular hypovolemia
–> admin isotonic fluid for irrigations
–> admin diuretics to get rid of excess
what to administer pt with third spacing?
why?
third spacing –> fluid in interstitial (useless) space
–> admin albumin then hypertonic to shift fluids to vascular space to get rid of it
–> admin diuretics once in vascular space
what to administer to pt with ICFVE?
why?
ICFVE = water intoxication
–> admin hypertonic solution to bring fluid out of cells (3% NaCl)
–> admin diuretics to get rid of excess
what are some causes of hyponatremia?
- drinking too much water
- SIADH
- not replenishing Na+
what are some clinical manifestations of hyponatremia?
(SALT LOSS)
- seizure, stupor
- abdominal pain, cramping (high GI motility)
- lethargic
- tendon reflex decrease
- loss of urine output
- overactive bowel
- spasms of muscle
- shallow respirations
what are some causes of hypernatremia?
- water loss (ADH insufficiency)
- Na+ gain
- aldosterone excess
what are some clinical manifestations of hypernatremia?
(FRIED)
- fatigue
- restless/really agitated
- increased tendon reflex
- extreme thirst
- decreased urine output
what are some causes for hypokalemia?
- increased GI losses
- decreased K+ intake
- K+ wasting diuretic
what are some clinical manifestations of hypokalemia?
(7 Ls)
- lethargic
- low, shallow respirations
- limp muscles
- lethal cardiac dysrhythmias
- low BP, low HR
- leg cramp
- LOTS of urine
what are some causes for hyperkalemia?
- renal failure (K+ retention)
- injured cells/burns
- K+ sparing diuretics
what are some clinical manifestations for hyperkalemia?
(MURDER)
- muscle weakness
- urine output little to none
- respiratory failure
- decreased cardiac contractibility
- early muscle twitch
- rhythm changes (heart)
ekg for hypkalemia
“u wave”
- flat t wave
- st depression
ekg for hyperkalemia
(tall tented t wave)
- peaked t wave
- st elevation
