Lecture 5 Electrolyte Imbalances Flashcards
how are electrolytes measured?
based on extracellular (serum) concentration of electrolytes in blood
what is the most abundant electrolyte in extracellular fluid?
sodium
what does sodium do?
muscle contraction and nerve impulses
what does calcium do?
transmits nerve impulses
regulates muscle contraction ad relaxation
cardiac conduction
blood coagulation
bone mineralization
where is potassium mostly concentrated?
98% is intracellular
what does potassium do?
conduction of nerve cells - skeletal muscle and cardiac muscle
what does magnesium do?
neuromuscular function - contraction and relaxation
vasodilation
causes of hyponatremia
diuretics
vomiting
kidney and liver issues
polydipsia
diarrhea
signs and symptoms of hyponatremia
neuro = lethargy, headache, confusion
seizures
gait disorders
nausea and vomiting
muscle weakness and spasms
hyponatremia treatment
sodium by mouth and 1-1.5 L fluid restriction
isotonic IV solution
Hypertonic solution for severe neuro changes
no more than 12 mEq sodium in 24 hours
hypernatremia
gain of excess sodium or excessive loss of water
causes of hypernatremia
- fluid deprivation
- sodium intake
- sodium retention with water loss
- fluid losses (diabetes insipidus)
- hyperventilation
signs and symptoms of hypernatremia
thirst
muscle weakness
dry mucous membranes
decreased UOP
mild fever
hallucinations and seizure
what is used to treat hypernatremia
hypotonic IV fluids
furosemide or thiazide
causes of hypokalemia
- increased potassium output, decreased intake
- too much insulin
- magnesium depletion
- increased aldosterone
- potassium wasting diuretics - furosemide, thiazide
signs and symptoms of hypokalemia
- arrhythmias, tachycardia
- muscle and GI cramping
- hypotension
- weakness
- respiratory depression
treating hypokalemia
- oral potassium supplement
- potassium IV infusion 10-20 mEq/hr, NEVER IV PUSH
- cardiac monitoring during infusion
causes of hyperkalemia
- potassium sparing diuretics
- acidosis
- cellular injury (because potassium more abundant intracellularly)
- low aldosterone
- renal failure with increased potassium intake
what does aldosterone do to potassium?
causes excretion of potassium
too much aldosterone = hypokalemia
too little aldosterone = hyperkalemia
signs and symptoms of hyperkalemia
- muscle twitching
- irritability
- low BP
- dysrhythmias
- abdominal cramping
- diarrhea
treating hyperkalemia
diet restriction
calcium gluconate
sodium bicarbonate
IV insulin
loop diuretics - potassium wasting
dialysis if severe
how is low calcium regulated?
- low calcium prompts parathyroid to release PTH
- draws calcium out of bones and tells kidneys and intestines to reabsorb calcium
how is high calcium regulated?
- thyroid gland releases calcitonin
- inhibits calcium reabsorption from bone
- encourages calcium to be deposited in bones or excreted
what is the relationship between calcium and phosphorus
inverse
less calcium = more phosphorus
more calcium = less phosphorus
causes of hypocalcemia
- inadequate intake
- calcium malabsorption
- inadequate parathyroid hormone
- vitamin D deficiency
signs and symptoms of hypocalcemia
- neuromuscular hyperactivity, spasms
- arrhythmias
- numbness and tingling
- seizures
- dyspnea
treating hypocalcemia
calcium carbonate antacid - lower phosphorus
vitamin D supplements
IV calcium gluconate - infusion pump
causes of hypercalcemia
- malignancies - bone metastases
- too much parathyroid hormone
- lithium and thiazide diuretics
signs and symptoms of hypercalcemia
- bone pain
- kidney stones
- abdominal pain, N/V, constipation
- anxiety, fatigue, psychosis, depression
- decreased deep tendon reflex
- cardiac arrhythmias
how does calcium affect bleeding?
hypocalcemia = bleeding risk
hypercalcemia = clotting risk
treating hypercalcemia
- treat malignancy
- restrict dietary intake
- loop diuretics
- IM calcitonin to encourage reabsorption
- dialysis
- sodium containing fluids
causes of hypomagnesemia
ETOH
malnutrition
diarrhea
DKA
loop and thiazide diuretics
signs and symptoms of hypomagnesemia
- muscle weakness and cramping
- disorientation, vertigo
- cardiac arrhythmias
- associated with hypokalemia and hypocalcemia
managing hypomagnesemia
- diet - green veg, PB, nuts, legumes
- oral magnesium salts
- magnesium sulfate IV
causes of hypermagnesemia
renal failure
tissue trauma: DKA, rhabdomyolysis
lithium
laxatives
opioids
anticholinergics
signs and symptoms of hypermagnesemia
- CNS and nerve depression - weakness, dizziness, confusion
- vasodilation and dysrhythmias = hypotension
- respiratory depression
- Lost DTR and paralysis = coma
- cardiac arrest
