Exam 3 - Fluid Balance, Electrolyte Imbalances and Replacement Flashcards
what does body fluid do
- transports nutrients and waste to and from cells
- solvent for electrolytes and non-electrolytes
- helps maintain body temperature, digestion, and elimination, acid-base balance, and lubrication of joints and body tissues
body fluid
- water that contains dissolved or suspended substances such as glucose, electrolytes, and proteins
intracellular fluid
- inside the cells
- 70%
extracellular fluid
- outside the cells
- 30%
interstitial fluid
- between the cells
intravascular fluid
- plasma
- liquid part of the blood
diffusion
- movement of molecules from an area of high concentration to a lower concentration
- movement stops when concentrations are equal in both areas
osmosis
- movement of water down a concentration gradient
- moves from low solute to high solute concentration
- movement stops when concentration differences disappear
- water follows electrolytes
colloids
- substances that increase osmotic pressure
- move fluid from interstitial compartment to plasma compartment
- three primary: albumin, globulin, fibrinogen
- can be measured with total protein level
- decreased with age and overall nutrition
hydrostatic pressure
- pushes fluid out of capillary
- force of fluid in compartment pushing against a cell membrane
- generated by BP
- happens at capillary level, pushes water out of vascular system into interstitial
- aids supply of nutrients to body tissues
oncotic pressure
- aka osmotic pressure
- pulls fluid into capillary
- cause by plasma colloids in solution; major colloid - albumin
- protein has lots of colloids, interstitial space has little
- plasma attracts water, pulling fluid from tissue space into vascular space
electrolyte
- influence: fluid balance, acid base balance, nerve impulses, muscle contraction, heart rhythm, etc
- substances that are electrically charged when in solution
- function with one another collaboratively, one balance affects the other
intracellular concentration
- potassium +
- magnesium +
- phosphorous -
extracellular concentration
- sodium +
- chloride -
- bicarbonate -
- calcium +
hyponatremia
- causes: GI losses, renal losses, skin losses, fasting diets, polydipsia, excess hypotonic fluid
- s/s: confusion/altered LOC, anorexia, muscle weakness, seizures/coma
- treatment: slow sodium replacement, PO/IV, fluid restriction, treat underlying problem
- sodium bicarbonate
dilutional hyponatremia
- hypervolemic
- result of taking in too much water
- s/s: increased BP, weight gain, bounding rapid pulse, increased urine specific gravity
depletion hyponatremia
- hypovolemic
- too much fluid and sodium loss
- s/s: decreased BP, tachycardia, dry skin, weight loss, decreased urine specific gravity
sodium bicarbonate for hyponatremia
- indication: metabolic acidosis
- MOA: dissociates to provide bicarbonate ion which neutralizes ion concentration and raises blood and urinary pH; increases concentration of sodium in plasma
- do not give IV for hyponatremia it is vesicant at high concentrations
- SE: edema, cerebral hemorrhage, hypernatremia, etc
- NC: monitor cardiac, ABGs, and electrolytes
hypernatremia
- cause: IV fluids, tube feeds - excessive sodium intake; not enough water intake or too much water loss - cognitively impaired, diarrhea, high fever, heat stroke; profound diuresis
- s/s: alter LOC/confusion, seizure, coma, extreme thirst, dry sticky mucous membranes, muscle cramps
- treatment: excess sodium - remove sodium; water loss - add water; do this over a 48 hour period to avoid edema of cerebral cells
potassium
- intracellular cation
- helps regulate excitability and electrical status
- controls intracellular osmolality
- diet is the main source
- kidneys are the main source of potassium loss
sodium
- main ECF cation
- governs osmolality
- influences water distribution
- acid-base balance
- activates muscle and nerve cells
hypokalemia
- causes: renal or GI losses; diuresis; acid base disorders
- s/s: cardiac rhythm disturbances and can be lethal
- treatment: potassium chloride (KCl)
potassium chloride (KCl) for hypokalemia
indications: treat/prevent K+ depletions when dietary measures prove inadequate
- NC: oral/liquids - dilute with water or juice to lessen GI distress, large pills, may cause GI bleeds/ulcers
- NEVER GIVE IV PUSH
- only give to pts with documents urine output
- contraindicated: renal failure and dialysis
- serious ADR with undiluted potassium; ventricular fibrillation
hyperkalemia
- causes: decreased potassium output; massive cell injury; drugs (potassium sparing diuretics, ACE, ARBs, NSAIDs)
- s/s: cardiac rhythm disturbances
- treatment: diuretics; sodium polystyrene sulfonate; D50/insulin
sodium polystyrene sulfonate for hyperkalemia
- class: cation exchange resins
- route: oral and rectal suspension, oral and rectal powder, rectal enema
- indication: to treat high levels of potassium in the blood
- MOA: binds to potassium in the digestive tract replacing potassium ions for sodium ions
- precaution: only in patients with normal bowel function
- SE: intestinal obstruction and intestinal necrosis
D50/Insulin for hyperkalemia
- combo shifts potassium into the cell temporarily
- usually give 10 units of regular insulin and 1 ampule of D50
magnesium
- helps to stabilize cardiac muscle cells
- blocks/controls movement of K+ out of cardiac cells
- helps to stabilize smooth muscle
hypomagnesemia
- cause: diuresis, GI or renal losses, limited intake, alcohol abuse, pancreatitis, hyperglycemia
- s/s: hyperactive reflexes, confusion, cramps, tremors, seizures
- SE: nystagmus
- treatment: treat cause; oral and IV; replace over several days and can give IV push if necessary
magnesium sulfate and magnesium oxide for hypomagnesia
- MOA: replaces magnesium
- IV or PO
- indication: prevent/treat seizures in pre-eclampsia, treat cardiac rhythm disturbances
- SE: hypermagnesium - confusion, sluggish, slow movements, abnormal heart rhythm; can burn when given IV
- magnesium oxide = antacid, given for long-term low magnesium
hypermagnesia
- causes: increased intake accompanied by renal failure; OB patients
- s/s: lethargy, floppiness, muscle weakness, decreased reflexes, flushed/warm skin, decreased pulse/BP
- treatment: stop replacement; if chronic disease intake - dialysis
calcium
- hormones released by the thyroid and parathyroid glands are controllers of the amount of calcium that is released from and absorbed into the bone
- majority of calcium is in the bone
hypocalcemia
- causes: unable to mobilize from bone, hypoparathyroidism, hypomagnesemia, renal failure, increased binding, decreased vitD, acute pancreatitis, thyroid and parathyroid surgery
- s/s: increased neuromuscular excitability, paresthesias, bone pain, tetany
- cardiac insufficiency: prolonged QT leads to fatal arrhythmia
- Chvostek and Trousseau
- treatment: IV and oral calcium
positive Chvostek’s sign
- ipsilateral twitching of the circumoral muscles in response to gentle tapping of the facial nerve just anterior to the ear
positive Trousseau’s sign
- carpal spasm upon inflation of a BP cuff to 20mmHg above the patients systolic blood pressure for three minutes
treatment of hypocalcemia
- IV calcium: calcium chloride; calcium gluconate
- oral calcium: elemental calcium, calcium carbonate; may also need vitamin D
hypercalcemia
- cause: hyperparathyroidism, cancers
- s/s: calcium acts like a sedative, fatigue, lethargy, confusion, weakness, seizures, coma, kidney stones
- treatment: adequate hydration, increased urine output, diuretics and NaCl, dialysis in renal failure
phosphorous
- calcium and phosphorous work together inversely
- found in bone and intracellular
- organic and inorganic forms
- role in bone and ATP formation
- part of DNA and RNA
- acid-base buffer
- normal function of WBCs and platelets
hypophosphatemia
- causes: decreased absorption, antacid overdose, severe diarrhea, increased kidney elimination, malnutrition
- s/s: mild-moderate few; severe - tremor, paresthesia, impaired WBC function, platelet dysfunction
- treatment: IV or oral replacement; given IV over a long period of time; increased oral intake; take care wit CKD or hypercalcemia - increased risk of calcifications
hyperphosphatemia
- causes: kidney failure, laxatives/enemas with phosphorous, shift from intra to extracellular, massive trauma or heat stroke, hypoparathyroidism
- s/s: usually asymptomatic, symptoms of hypocalcemia
- treatment: treat the cause; calcium - based phosphate binders; hemodialysis - renal failure