Electrolytes (K+, Na+) Flashcards
etiologies of inadequate excretion of K+ (3)
renal failure
medication (spironolactone, triamterene, amiloride)
hypoaldosteronism (Addison’s, ACE inhibitors, renal tubular diseases)
causes of hyperkalemia (4)
false elevation
inadequate excretion by kidneys
redistribution of K+ from ICF —> ECF
excess administration
etiologies of K+ moving from ICF –> ECF (3)
tissue damage (rhabdo) acidosis low insulin
tx of hyperkalemia, fast (3) and slow (3)
Fast: Calcium chloride IV, Sodium bicarb IV to raise pH, insulin IV
Slow: diuretics (furosimide), cation resins, dialysis
weakness, numbness, tingling, flaccid paralysis, hypoactive DTRs, arrhythmias, cardiac arrest
hyperkalemia
tall, peaked T waves (early)
flattened P waves, prolonged PR interval, widened QRS complex (later)
hyperkalemia
malaise, weakness, cramps, constipation, paralysis, polyuria, polydipsia, arrhythmias, hypotension
Hypokalemia
flattened T waves, ST depression, U waves
hypokalemia
hypokalemia causes (4)
inadequate intake, GI loss, renal loss, movement from ECF –> ICF
causes of inadequate K+ intake (2)
diuretics, poor diet
renal loss of K+ causes (2)
diuretics osmotic diuresis (hyperglycemia or EtOH)
causes of K+ moving ECF —> ICF (3)
metabolic alkalosis
insulin
mineralocorticoid excess (hyperaldosteronism, Cushing’s, steroid use)
hypokalemia tx, fast & slow (4)
Fast: KCl IV, checking serum every 2-4h
Slow: oral supplements
- check for hypomagnesia
- correct underlying cause
aldosterone actions (2)
- increase renal sodium reabsorption
2. increase renal potassium secretion
thirst, decreased sweating, dry mucous membranes, CNS depression, weakness & muscle cramps, low BP, increased pulse suggest?
hypovolemia
edema, hypertension, JVD, hepatojugular reflex, SOB, orthopnea, PND suggest?
hypervolemia
what are the body’s priorities for fluid regulation?
volume
pH
electrolytes
hypernatremia is defined as?
serum Na+ >145 mEq/L
tx for central diabetes insipidus?
dDAVP nasal spray- ADH analogue
nephrogenic diabetes insipidus tx? (4)
thiazide diuretics
amiloride (K+ sparing diuretic)
chlorpropamide (oral antidiabetic agent)
NSAIDs- Indomethacin
hyponatremia is defined as?
serum Na+ <135 mEq/L
what is the most common electrolyte abnormality in hospitalized patients?
hyponatremia due to hypotonic fluid use
hyponatremia tx? (3)
restrict fluids if hyper/euvolemic
replace fluid w/ isotonic saline if hypovolemic
vasopressin antagonists for chronic hyponatremia
SIADH is a disorder of?
impaired renal free water excretion
high serum Na+
dilute urine
associated with?
diabetes insipidus
low serum osmolality
high urine osmolality
is characteristic of?
SIADH
low Na+ but normal serum osmolality could indicate?
psuedohyponatremia
causes of hyponatremia w/ hypervolemia
fluid overload conditions
causes of hyponatremia w/ euvolemia (4)
hypothyroidism
SIADH
diuretic use
adrenal insufficiency
