Fluid and Electrolytes Exam 3 Flashcards
what is osmosis
the movement of WATER down a concentration gradient
-moves from a region of LOW solute concentration to a region of HIGH solute concentration THROUGH A SEMIPERMEABLE MEMBRANE
when does osmosis stop
when concentration differences disappear
OR
when hydrostatic pressure builds and opposes further movement
what is diffusion
movement of MOLECULES from an area of high concentration to a lower concentration
when does movement stop for diffusion
when concentrations are equal in both areas
what are colloids
substances that increase colloid oncotic pressure
-they move fluid from the interstitial compartment to plasma (blood) compartment
what are the 3 primary colloids
albumin, globulin, fibrinogen
does colloid oncotic pressure increase or decrease with age and malnutrition
DECREASE
what is hydrostatic pressure
force of fluid in compartment pushing against a cell membrane (or vessel wall)
THINK CAPILLARY LEVEL - major force that pushes water OUT of the vascular system into interstitial space
how is hydrostatic pressure generated
generated by blood pressure
what is oncotic pressure
OR colloid osmotic pressure
caused by plasma colloids in solution
fill in the blank:
Hydrostatic pressure pushed fluid _______ of the capillary
OUT
Fill in the blank:
Oncotic pressure pulls fluid ______ the capillary
INTO
what are electrolytes
substances that are ELECTRICALLY charged when in solution
what do electrolytes influence
fluid balance, acid base balance, nerve impulses, muscle contraction, heart rhythm, and other cell functions
what are concentrations of electrolytes dependent on
intake, absorption, distribution, excretion
what electrolytes live inside the cell (intracellular)
potassium
magnesium
phosphorous
what electrolytes live outside the cells (extracellular)
sodium
chloride
bicarbonate
normal sodium lab value
136-145meq/L
normal potassium lab value
3.5-5.0meq/L
normal magnesium lab values
1.7-2.2 mg/dl
normal calcium lab values
9-11 mg/dL
normal phosphate lab values
3.2-4.3 mg/dL
what is sodium
influences water distribution
aids in acid-base balance
activates muscle and nerve cells
Someone has a sodium of < 136 meq/L… what is that called
Hyponatremia
Someone has a sodium of > 145 meq/L… what is that called
Hypernatremia
what are causes of hyponatremia
GI losses –> diarrhea, vomiting, fistulas, NG suction
renal losses –> diuretics, adrenal insufficiency
skin losses –> burns, wound damage
fasting diets, polydipsia (water intoxication)
excess hypotonic fluid
S/S of hyponatremia
confusion/altered LOC
anorexia, muscle weakness
can lead to seizures/coma
what is dilutional hyponatremia
low sodium because of too much fluid HYPERVOLEMIC this person has too much water/fluid on board -increase BP -weight gain -bounding rapid pulse
what is depletional hyponatremia
not enough volume on board HYPOVOLEMIC -low BP -tachy pulse -weight loss -decreased urine sp. gravity
hyponatremia treatment
- sodium replacement (SLOWLY)
- PO/IV
- IV NS (0.9%)
- Fluid restriction
- treat underlying problem
causes of hypernatremia
- IV fluids, tube feeds, near drowning in salt water –> excess sodium intake
- not enough water intake or too much water loss –> cognitively impaired, diarrhea, high fever, heatstroke
- profound diuresis
S/S of hypernatremia
alter LOC/Confusion, seizure, coma
extreme thirst (hyperosmolality)
dry, sticky mucous membranes
muscle cramps
treatment for hypernatremia
If H20 loss is cause ADD WATER
if sodium excess is cause REMOVE SODIUM
what is potassium
helps regulate cell excitability and electrical status
helps control intracellular osmolality
Potassium < 3.5 meq/L is?
Hypokalemia
Potassium > 5.0 meq/L is?
Hyperkalemia
what is the main source of potassium loss
Kidneys
Causes of hypokalemia
renal or GI losses - diuresis
acid base disorders
S/S of hypokalemia
Cardiac rhythm disturbances –> can be lethal
muscle weakness, leg cramps
decreased bowel motility - constipation, nausea, ileus
treatment for hypokalemia
GIVE POTASSIUM
causes of hyperkalemia
decreased potassium OUTPUT (renal failure, not peeing)
burns, crush injuries, sepsis –> anything with massive cell injury
drugs - potassium sparing diuretics, ACE, ARBs, NSAIDs
S/S for hyperkalemia
cardiac rhythm disturbances
muscle weakness, cramps
abdominal cramping, diarrhea, vomiting
what is D50/Insulin
for hyerkalemia
combo shifts potassium into the cell temporarily
usually give 10units of regular insulin and 1 ampule of D50
what is magnesium
helps stabilize cardiac muscle cells
- blocks/controls movement of K+ out of cardiac cells
- helps to stabilize smooth muscle
what are causes of hypomagnesemia
diuresis, GI or renal losses, limited intake (fasting or starvation), alcohol abuse, pancreatitis, hyperglycemia
S/S of hypomagnesemia
hyperactive reflexes, confusion, cramps, tremors, seizures
nystagmus
-over active muscles
treatment for hypomagnesemia
giving magnesium
Orally: mylanta, magnesium sulfate
IV: magnesium sulfate - replace over several days, can give IV push if necessary
causes of hypermagnesemia
increased intake accompanied by renal failure
- chronic renal failure who take milk of mag
- OB patients
S/S of hypermagnesemia
lethargy, floppiness, muscle weakness, decreased reflexes, flushed/warm skin, decreased pulse/BP
what is calcium
hormones released by the thyroid and parathyroid glands
-thyroid and parathyroid are controllers for the amount of calcium that is released from and absorbed into the bone
causes of hypocalcemia
calcium unable to mobilize from bone increased renal loss increased binding decreased intake of absorption (decreased Vitamin D) acute pancreatitis thyroid and parathyroid surgery
S/S of hypocalcemia
increased neuromuscular excitability -parasthesias (numbness/tingling) -muscle cramps -bone pain -tetany -laryngeal spasm -hyperactive reflexes cardiac insufficiency
positive Chvostek’s -twitching
positive Trousseau’s - spasm
causes of hypercalcemia
hyperparathyroidism, cancers
S/S for hypercalcemia
calcium acts like a sedative, fatigue, lethargy, confusion, weakness, leading to seizures, coma
treatment of hypercalcemia
adequate hydration
increased urine output
diuretics and NaCl
dialysis in renal failure
calcium and phosphate work together, ___ serum calcium = _____ phosphate
low serum calcium = high phosphate
phosphorus
role in bone formation
essential for ATP formation and enzymes needed for glucose, protein, and fat metabolism
acid-base buffer
causes of hypophosphatemia
decreased absorption antacids overdose severe diarrhea incerased kidney elimination malnutrition
S/S of hypophosphatemia
tremor paresthesia confusion to coma seizure muscle weakness joint stiffness bone pain hemolytic anemia Plt dysfunction impaired WBC function
causes of hyperphosphatemia
kidney failure
laxatives/enemas with phosphorus
shift from intra- to extra cellular compartment
hypoparathyroidism
S/S of hyperphosphatemia
usually asymptomatic
S/S usually related to hypocalcemia
Hypophosphatemia treatment
IV or oral replacement
-Given IV over a LONG period of time
increase oral intake
take care with CKD or hypercalcemia
-increased risk of calcifications
hyperphosphatemia treatment
treat the cause
- calcium-based phosphate binders
- hemodialysis - renal failure
