Electrolyte Balance Flashcards
Sodium
Major
Extracellular cation
Sodium
Normal
135-145mEq/L
Sodium
Function
Muscle excitability
Regulates fluid balance
Sodium
Cellular control
Na-K pump
Sodium
Hormonal control
Aldosterone
Sodium
Aldosterone regulator
Rennin-angiotensin system
Hyponatremia
Causes
Renal failure
Hypervolemia
Fresh water
Hyponatremia
Result
Cell swelling
Hyponatremia
Manifestation
Generalized muscle weakness
Hypernatremia
Causes
Renal failure Hypovolemia Salt water Diabetes insipidus Aldosteronism
Hypernatremia
Result
Cell shrinkage
Hypernatremia
Manifestation
Hyper reflexes to seizures
Hypertension
Potassium
Normal
3.5-5.5 mEq/L
Potassium
Major
Intracellular cation
Potassium
Cellular control
Na-K pump
Potassium
Hormonal control
Aldosterone
Potassium
Function
Electrical conduction of heart
Hypokalemia
Causes
Hemodilution
Alkalosis
Acute alcoholism
Hypokalemia
Manifestations
Decrease cardiac output
Increase pulse
Motility ileus
Constipation
Hyperkalemia
Causes
Blood transfusion Decrease aldosterone (addisons disease) Cell destruction
Hyperkalemia
Manifestation
Numbness
Acidosis
Apathy
Diarrhea
ECG Changes
P wave hypo
Increase amplitude and width
ECG Changes
P wave hyper
Flat
ECG Changes
PR interva
Hypo
Prolonged
ECG Changes
PR interva
Hyper
Prolonged
ECG Changes
QRS interval
Hyper
Prolonged
ECG Changes
T wave
Hypo
Flattening/ inversion
ECG Changes
T wave
Hyper
Peak
Calcium
Normal
4-5.5 mEq/L or
8.5-10 mEq/L
Calcium
Absorption requirement
Vitamin D
Calcium
Metabolism regulator
Parathyroid hormone
Vitamin D
Calcium
Function
Muscle contraction
Blood clotting
Membrane stabilizer
Calcium
Calcitonin
Bone resorption inhibitor
Vitamin D inhibitor
Aid in calcium excretion
Hypocalcemia
Causes
Renal failure
Pancreatitis
Alkalosis
Hypocalcemia
Pathophysiology
Increase excitability of muscles
Bleeding disorders
Osteoporosis
Hypocalcemia
Manifestations
Positive trousseaus sign- carpopedal spasm
Positive chvosteks sign - facial muscle spasm
Hyperactive reflexes
Hypercalcemia
Causes
Hyperthyroidism
Excess parathyroid hormone
Cancer
Hypercalcemia
Manifestation
Homans sign Blood clots Kidney stones Muscle weakness Constipation Thirst Polyuria
Magnesium
Normal
1.5-2.5 mEq/L
Magnesium
Location
Intracellular
Magnesium
Function
Prevent overexcitability of muscles Inhibits acetylcholine Sedative Cofactor Bone and teeth production
Magnesium
Regulator
Aldosterone- increase Mg reabsorption in kidneys
Hypomagnesemia
Causes
Prolonged nasogastric suctioning
Excess calcium and vitamin D
Steroids
Hypoaldosteronism
Hypomagnesemia
Manifestation
Positive trousseaus sign Positive chvosteks sign Hyperactive reflex Tachycardia Hypertension
Hypermagnesemia
Causes
Antacids
Laxatives
Renal failure
Hypermagnesemia
Manifestations
Hypoactive reflex
Bradycardia
Hypotension
Respiratory depression