fluid and electrolytes Flashcards
describe intracellular
-in the cell
-ICF is critical for maintaining cell size
-70% of total body fluid
-about 40% of adult body weight is from ICF
describe extracellular
-outside cell
-30% of total body fluid and ~20% of body weight
describe intravascular fluid
plasma of the blood -> blood volume, impacts HR and BP
describe interstitial fluid
surrounds cells (like tissue)
describe trans cellular fluid
cerebrospinal, pleural, peritoneal, synovial, digestive secretions, sweat
what is osmolarity
concentration of particles in a solution (or its pullin power)
describe isotonic
-when osmolarity is equivalent to plasma
-isotonic fluid remains in the intravascular space
-no shift in cell size
describe hypertonic
-when osmolarity is greater than plasma
-hypertonic fluids pull water from the cells and into the intravascular spaces
-cells shrink
describe hypotonic
-when the osmolarity is less than plasma
-hypotonic fluids move from the intravascular spce to the ICF
-cells swell
give two examples of isotonic IV solutions
normal saline, lactated ringers
what does normal saline do
expand extracellular compartment, treat hypovolemia, hyponatremia, hyercalcemia, metabolic alkalosis
what does LR do
contains multiple electroltes in the same concentration as in plasma, treats hypovolemia, burns, and GI losses
give and example of hypertonic IV solution
5% dextrose in lactated ringers (D5LR)
what does D5LR do?
replaces electrolytes, provides calories, shifts fluid from cells to vascular space expanding vascular volume
give an example of hypotonic IV solution
half strength normal saline (0.45%)
what does hald strength normal saline do
often used as maintenance fluid, provides Na, Cl, and free water
describe fluid balance
-generally balance is achieved with oral intake of fluid matching the output of the kidney
-perfect balance is not always met every day, but over 2-3 days
-output can be sensible or insensible
what is sensible output
-things you can measure
-UOP, emesis, wound drainage, suction
what is insensible output
-harder to account for and not measurable
-sweat, respiratory vapors
describe volume overload
positive I&O balance
findings:
-crackles
-JVD
-edema
-dyspnea/SOB
describe volume deficit
negative I&O balance
findings:
-hypotension
-increased HR
-fatigue
-pale and cool
-dry mucus membranes
-dizziness
what are seom causes of abnormal fluid status
-CHF
-small bowel obstruction
-kidney disease
-liver dysfunction
kidneys, liver, heart, and GI
what are some tests to evaluate fluid balance
-CMP
-urinalysis
-daily weight
-telemetry
what organs and systems manage sluid and electrolyte balance
-kidneys
-heart and vascular
-lungs
-nervous system
-GI
organs and systems manage sluid and electrolyte balance
kidneys
-filter 180L of plasma/day while excreting ~1.5L/day
-manage ECF volume and osmolarity
-regulates electrolyte levels by retaining or eliminating
organs and systems manage sluid and electrolyte balance
heart and vascular
-circulate fluid, adequate perfusion pressure in kidneys for filtration
-stretch receptors respond to changes in olume and stimulate fluid retention when hypovolemia is present
organs and systems manage sluid and electrolyte balance
lungs
water vapor excreted/lost per day ~300ml/day
organs and systems manage sluid and electrolyte balance
nervous system
-osmoreceptors sense changes in ECF concentration and stimulate the pituitary gland to release or inhibit release of ADH
-thirst center in the hypothalamus is activated by cellular dehydration
organs and systems manage sluid and electrolyte balance
GI track
absorbs water and nutrients
hormonal control of fluid and electrolyte balance
adrenal glands
-aldosterone secretion causes sodium (and water) retention and potassium loss
-excess cortisol secretion can cause the same effect of aldosterone
hormonal control of fluid and electrolyte balance
pituitary gland
manages ADH
hormonal control of fluid and electrolyte balance
what does ADH do
-allows the body to retain water
-released when osmotic pressure of ECF is greater than that of cells, when blood volume is decreased
-suppressed when osmotic pressure of the ECF is less than that of the cells, or when blood volume is increased
hormonal control of fluid and electrolyte balance
thyroid gland
thyroxine secretion released to increased blood flow including to the kidneys, whey increases flitration rate and UOP
hormonal control of fluid and electrolyte balance
parathyroid gland
regulates calciuma dn phosphate balance through parathyroid hormone (PTH)
hormonal control of fluid and electrolyte balance
what does PTH do
-influences bone reabsorption, calcium absorption from the intestines and calcium reabsorption from the kidneys
-increased PTH causes increased blood calcium and decreased phosphate
-decreased PTH causes decreased calcium and increased phosphate
name some different fluid volume problems
-fluid volume deficit/hypovolemia
-dehydration
-fluid volume excess
describe fluid volume deficit/hypovolemia
-low circulating volume
-loss of fluid and solutes from ECF
describe dehydration
loss of total body water, results in increased serum sodium
describe fluid volume excess
-retaining sodium and water in ECF
-intravascular excess = hypervolemia
-interstitial excess = edema
name and descrie a fluid distribution problem
third spacing
-fluid moves into transcellular compartments (pleural, peritoneal, pericardial, joints, or bowels) or interstitial spaces
-causes hypovolemia (fluid is unavailable for use)
-no drastic change in weight
what are electrolytes
the basis for chemical interactions in the body necessary for metabolism and other functions
name some cations
sodium, potassium, calcium, hydrogen, magnesium
name some anions
chloride, bicarbonate, phosphate
-natremia
sodium
-kalemia
potassium
-calcemia
calcium
-magnesia
magnesium
-phosphatemia
phosphorus
-chloremia
chloride
hyponatremia
causes
diuretics, GI losses, excessive water intake
hyponatremia
symptoms
confusion, lethargy, twitching, seizures, coma
hyponatremia
treatment
-encourage sodium rich food
-seizure precautions
hypernatremia
causes
-poor oral intake
-increased fluid losses
-increased salt intake
-enteral feeding without water
hypernatremia
symptoms
-hallucinations
-lethargy
-seizures
-coma
hypernatremia
treatment
-gradual rehydration
-sodium restricted diet
hypokalemia
causes
-vomiting
-diarrhea
-GI losses
-diuretics
-poor intake
-polyuria
hypokalemia
symptoms
-cardiac arrhythmias (increased excitability of cardiac tissue)
-paresthesia
-postural hypotension
-EKG changes
hypokalemia
treatment
-critical values can be life threatening
-PO (needs to be diluted)
-IVPB
-never IV push
-monitor cardiac function/EKG/BP
hyperkalemia
causes
-end stage renal disease
-acidosis
-burns
-tissue trauma
-diuretics
hyperkalemia
symptoms
-vage muscle weakness
-cardiac arrhythmias (decreased cardiac excitibility)
-cardiac arrest
-peak T wave
hyperkalemia
treatment
-kayexalate (binds K in GI tract and causes excretion via BM) this is used if pt is alert
-severes tx with CA (cardioprotective), insulin, and glucose
-can treat with diuretics and dialysis
if Mg is low, what else usually is too?
K
hypomagnesia
causes
-chronic alcoholism
-diarrhea
-NG suction
-drugs
hypomagnesia
symptoms
tachyarrhythmias
hypomagnesia
treatment
monitor condition of airway bc laryngeal sridor can occur
hypermagnesia
causes
rare, ESRD or IV magnesium
hypermagnesia
symptoms
-hypotension
-flushing
-drowsiness
hypermagnesia
treatment
-admin of calcium gluconate
-diuretics or dialysis
hypocalcemia
causes
-surgical
-excessive administration of citrated blood
hypocalcemia
symptoms
-cardiac arrhythmias
-spasm of laryngeal muscles
hypocalcemia
treatment
-seizure precautions
-monitor airway
-replace calcium
hypercalcemia
causes
-hyperparathyroidism
-cancers
hypercalcemia
symptoms
cardiac arrest
hypercalcemia
treatment
monitor EKG changes
what are the clinical manifestations of hypocalcemia
increased excitability of muscles and nerves
what two test are used to determine hypocalcemia
-chvosteks sign
-trousseau sign
describe chvosteks sign
tapping on facial nerve just anterior to the ear produces tetany (involuntary twitching) on the ipsilateral side of the patients face/upper lip
describe trousseau sign
inflate BP cuff above NSBP range. positive response in a pt with hypocalcemia is a wrist metacarpal and phalangeal/thumb flexiion
hypophosphatemia
causes
-refeeding after starvation
-alcohol withdrawal
hypophosphatemia
symptoms
respiratory failure
hypophosphatemia
treatment
replace carefully and slowly. can cause hypocalcemia
hyperphosphatemia
causes
ERSD, chemotherapy
hyperphosphatemia
symptoms
-tetany
-long term can lead to calcification of soft tissues
hyperphosphatemia
treatment
phosphate binders given with meals
describe history assessment of fluid and eectrolyte balance
risk factors:
-illnesses (DM, HF, renal failure)
-abnormal fluid losses (vomiting, diarrhea, draining wounds), burns, trauma, surgery
-medications (laxatives, diuretics)
-weight changes
-lab studies (CBC electrolytes, BUN, creatinine, specific gravity)
describe physical exam forthe assessment of fluid and electrolyte balance
-skin (turgor, mucous membranes)
-cardiac (edema, HR, rhythm, BP, JVD)
-respiratory (lung sounds)
-neuromuscular (mental status, reflexes, muscle tone)
what are some nursing diagnoses for fluid and electrolyte imbalance
-excess fluid volume
-deficient fluid volume
-impaired oral mucous membrane integrity r/t fluid volume deficit
what are some preventions of fluid and electrolyte imbalance
-education
-monitor I&O, daily weights, labs
what are some treatments of fluid and electrolyte imbalance
-fluid management
-encourage or restrict oral fluid intake
-IV fluid administration as prescribed
describe encouraging oral fluid intake
offer preferred fluids, set goals, always have some fluids available for the pt
describe restricing oral fluid intake
set goals, use smaller cups, provide ice chips instead, avoid salty foods, keep drinks out of sight, good oral hygiene, communicate with other caregivers
describe electrolyte management
-administer replacement electrolytes as ordered
-be aware of admin instructions. many IV preparations must be diluted and given very slowly (over hours!)
escribe med management for fluid and electrolyte imbalance
diuretics may be ordered to assist with fluid or ekectrolyte imbalance
