electrolytes Flashcards
Normal sodium levels
135-145
Minimum RDA of sodium
500 mg/day
Regulation of sodium
kidneys
GI
Skin
Hormonal regulation of sodium
Aldosterone increase retains sodium, and therefore water
Target organ of sodium
Brain
hyponatremia in high vs low blood volume
High blood volume dilutional hyponatremia
Low blood volume hypovolemic hyponatremia
Who should have a low salt diet, how much?
Hypertension and heart failure should have less than 1500 mg
Causes of hyponatremia
Not enough intake
Vomiting/ diarrhea
Excess sweating
Burns/ wounds
Increased ADH
Stress, pain trauma
SIADH
meds
symptoms of hyponatremia
Headache
Lethargy
Apathy
Confusion
Nausea/diarrhea
Fluid overload
Vomiting
Abdominal cramping
Muscle cramps and spasms
What serum sodium level has a mortality rate of over 50%
105
Causes of hypernatremia
Excessive intake
Decreased extracellular losses (increased water loss and hormones)
Decreased water intake
Hemoconcentration
Signs of hypernatremia
Dry mucous membranes
Restlessness
Decreases reflexes
Convulsions
Hyperactivity
Tachycardia
Hypertension
Hypernatremia with water retention
Edema
Weight Gain
Hypertension
Mental changes
Pulmonary edema
Most important electrolyte
Potassium
Normal potassium
3.5-5
How much potassium do adults need per day
50-100
Regulation of potassium (organ)
Kidneys
Foods rich in potassium
Bananas, orange juice, lentils, raisins
Target organ of potassium
Heart
Smooth electrical conduction to muscles
Symptoms of hypokalemia
cardiac arrythmias
tachycardia
Treatment of hypokalemia
Do not give rapid dose, it leads to cardiac arrest and excruciating pain in the skin and blood vessels
Must be diluted and only piggy back or PO
Causes of hyperkalemia
Excessive intake
massive crushing injuries
Inadequate renal losses
renal failure
addisons disease
potassium sparing diuretics
Signs of hyperkalemia
Dysrhythmias
Bradycardias
How does hyperkalemia affect ECGs
Wide QRS complex (above or equal to 0.12s)
Peaked and Pointy T
Treatment of severe hyperkalemia
Over 7
rapid treatment is needed to move potassium from ECF to ICF
Treatment of hyperkalemia
IV 50% dextrose with 10u of insulin
75meq of sodium bicarb
Lasix
Kalcinate
Kayexalate (excretion in feces)
If patient is in renal failure–> dialysis
Normal calcium (total and ionized)
total 8.5-10.5
ionized 4.5-5.6
Sources of calcium
Dairy products
Leafy greens
Hormonal regulation of calcium
Parathyroid hormone raises Ca by pulling it from bone
Calcitonin (produced by thyroid) powers serum Ca by storing it in the bones
Main function of calcium
bone development
Blood clotting
Smooth muscle contraction
Target organ of calcium
Skeletal muscles
Vit D and calcium
Vit D facilitates the absorption of Ca from GI tract into bloodstream
Plasma calcium and PTH
When calcium is low, PTH is stimulated. Vice versa
Calcium and phosphate
opposite relationship
What does calcitonin
Produced by the thyroid. Acts at bone and kidneys to remove Ca from circulation
Causes of hypocalcemia
inadequate vit D (impaired absorption, renal failure, liver disease)
Impaired ability to mobilize calcium from bind
Hypoparathyroidism
Abnormal calcium binding
Decreased serum albumin, pH, and acute pancreatitis
Symptoms of hypocalcemia
muscle spasms in face (trousseau)
Carpal spasm (chvosteks)
Laryngeal spasm
Tetany
Seizures
Key signs of hypocalcemia
Neuromuscular irritability
causes of hypercalcemia
Hyperparathyroidism
Cancer
Increased intestinal absorption
Excessive vit D and calcium
Milk-Alkali syndrome (burnetts) caused from increased calcium and antacids (calcium carb- tums)
Increased bone reabsorption (osteoclasts break down tissue and release Ca to blood)
Hyperthyroidism
Symptoms of hypercalcemia
Muscle flaccidity
Bone
Tenderness/ pain
Pathological fractures
High calcium in urine which increases susceptibility to renal calculi (stones)
Constipation
Hypertension
Normal phosphate levels
2.5-4.5
Symptoms of hypophosphatemia
Poor motor and nerve function
Symptoms of hypophosphatemia
Poor motor and nerve function
weakness
Slow GI tract
Low blood counts (low hemoglobin and hematocrit)
Causes of hypophosphatemia
most common is kidney failure
Excess intake (laxative)
chemo
Signs and symptoms of hyperphosphatemia
muscle cramps
twitching
tetany
Normal magnesium levels
2.2-3
Sources of magnesium
Nuts
Regulation of magnesium
Kidneys
Hormonal regulation of magnesium
Aldosterone increases and lowers it
target organ for magnesium
heart
Causes of hypomagnesmia
Prolonged diarrhea/ laxative abuse
Increased renal exertion of magnesium
Serious wounds requiring debridement (removal of damaged tissue)
Alcoholism
Malabsorption
Signs and symptoms of hypomagnesemia cardiac
Dysrhythmias
tachycardia
causes of hypermagnesemia
Low aldosterone
adrenal insufficency
most commonly causes by renal failute
excessive intake of antacids
signs of hypermagnesemia
Dysrhythmia
bradycardia
