Wk 5 Fluids and Electrolytes Flashcards
Concentrations of electrolytes dependent on
intake, absorption, distribution, excretion
Intracellular electrolytes
Potassium, magnesium, phosphorus
Extracellular electrolytes
sodium, chloride, bicarbonate
Negative charged electrolytes
phosphorus, chlorides, bicarbonates (anions)
Positive charged electrolytes
sodium, potassium, calcium, magnesium (cations)
Normal lab values: sodium
136-145 meq/L
Normal lab values: potassium
3.5-5.0 meq/L
Normal lab values: magnesium
1.7-2.2 meq/dL
Normal lab values: calcium
9-11 mg/dL
Normal lab values: phosphate
3.2-4.3 mg/dL
Sodium <136
Hyponatremia
Sodium >145
Hypernatremia
Main extracellular fluid cation
Sodium, governs osmolality
Sodium highly influences water
distribution
Two other functions of sodium
Aids in acid-base balance
Activates muscle and nerve cells
Hyponatremia causes
diarrhea, vomiting, NG suction, fistula, polyuria, adrenal insufficiency, burns, wounds, fasting diets, drinking too much water, excess hypotonic fluid
Sodium is highly influential in
LOC because brain cells are sensitive to water and fluid shifts
If you don’t have enough fluid in the vascular space you will have
Cellular swelling, which in the brain causes LOC changes
Hyponatremia signs/symptoms
Confusion/altered LOC, anorexia and muscle weakness, seizures and coma
Electrolytes influence
fluid balance, acid-base balance, nerve impulses, muscle contractions, heart rhythms, etc.
Hyponatremia dilution
Too much water, hypervolemia
Hypervolemia causes
increase BP, weight gain, bounding rapid pulse, increase in urine specific gravity
Hyponatermia depletion
hypovolemia, absolute loss of sodium in some way, we’ve lost both sodium and fluid
Hypovalemia causes
decrease BP, tachycardia, dry skin, weight loss, decrease in urine specific gravity
With depletion hyponatremia you see
muscle weakness, altered LOC
Hyponatremia treatment
Sodium replacement, IV or PO, IV NS in a continuous replacement IV
Must replace sodium
slowly because you can have rapid shift of brain cell concentration
Dilution hyponatremia treatment
restrict fluids
Also
treat the cause!
Sometimes we replace using
sodium bicarbonate PO
ABG
arterial blood gas
If giving sodium bicarbonate PO then
1-3 hours after or before meals, it will be better absorbed that way
Hypernatremia
> 145
You cannot get hypernatremia by
eating really salty foods
Causes of hypernatremia
IV fluids, tube feedings, near drowning in salt water, not enough water intake or too much water loss, around diuresis
Low fluid intake or excess loss symptoms
cognitively impaired, diarrhea, high fever, heat stroke
Hypernatremia symptoms
altered LOC, confusion, seizure, coma, dry sticky mucous membranes, muscle cramps, extreme thirst
Hypernatremia treatment if low fluid balance
add water
if high sodium is cause
remove the sodium
too quick of a correction can be
deadly
Gradually correct sodium imbalances over
48 hours to avoid edema of cerebral cells
Hypokalemia
<3.5meq/L
Hyperkalemia
> 5.0meq/L
98% of potassium is
inside the cells
Potassium responsible for
cardiac and muscle cell contraction, cell excitability and electrical status
Main intracellular cation
potassium
Main source of potassium
diet
Main source of potassium loss
kidneys, polyuria
Renal or GI loss causes of potassium loss
DIURESIS! Diarrhea, vomitting, ileostomy
Acid base cause of hypernatremia
potassium shifts into extracellular space
Biggest sign or symptom of low potassium
cardiac rhythm disturbances, can be lethal
Other symptoms of hypokalemia
muscle weakness, leg cramps, low bowel motility
What causes hyperkalemia?
Urinary output is not enough, kidney failure, OR massive cell injury like burns, trauma, sepsis
Certain drugs can cause hyperkalemia
diuretics, ACEi, ARBs, NSAIDS
Signs/symptoms of hyperkalemia
Cardiac rhythm disturbances (peaked T waves), muscle weakness, cramps, GI upset
Magnesiums helps to stabilize cardiac muscles by
block and control movement of potassium out of cardiac cells
Magnesium also helps to stabilize
smooth muscle
hypomagnesemia causes
diuresis, GI or renal loss, low intake, alcohol abuse, pancreatitis, hyperglycemia
Signs and symptoms of low magnesium
hyperactive reflexes, confusion, cramps, tremors, seizures,
