-
potassium maintains the...
intracellular osmolality
-
normal potassium levels =
3.5 - 5.0 mEq/L
-
what is exchanged for H+ to buffer blood pH changes
Potassium
-
what stimulates the Na/K pump to move K into the liver and muscle cells
Insulin
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where is 90% of body's K excreted
the kidneys
-
when you think about issues with Na you should think....
- neurological issues
- water imbalances
-
when you think about issues with potassium what should you immediately think
-
if someones kidneys are not functioning appropriately what happens to potassium levels
they go up
-
if someone is on a lot of diuretics what happens to the potassium levels
they go down
-
Potassium is critical for what
- neuromuscular transmission of impulses
- all muscle contraction
- electrical activity and cardiac muscle contraction
- regulation of INTRACELLULAR osmolality
- acid base balance (H+ ion exchange)
- cell's electrical neutrality
-
what causes potassium to move from ECF to ICF
- Insulin
- Alkalosis
- Stress (beta adrenergic stimulation)
- tissue repair (rapid cell building)
-
Factors causing potassium to move from ICF to ECF
- Acidosis
- trauma to cells
- exercise
- Digoxin and beta blocking agents can impair K movement into cells
-
what can elevate serum K levels =
-
how much potassium does body need per day
40-60 mEq/day
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foods high in potassium
- oranges, bananas, cantaloupe, green leafy vegetables, avocados, dried fruit, bran cereal molasses, dry lentils, nuts, potatoes, lima beans
- SALT SUBSTITUTES
-
CELLS FIRE LESS EASILY WITH
HYPOKALEMIA
-
cells fire more easily with
hyperkalemia
-
things that can cause hypokalemia
- hyperaldosteronism
- Diuretics
- low magnesium levels
- alkalosis
- lack of potassium intake
-
hypokalemia S&S =
- SLOWS DOWN MUSCLE CONTRACTION
- dysrythmias
- cardiac arrest
- fatigue
- leg cramps
- parasthesis
- hyporeflexia
- costipation
- lethargy
- decreased bowel motility
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management of hypokalemia =
- oral replacement
- IV replacement
- Diet
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potassium should NEVER be administered by
IV push or IM
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IV PB potassium cannot be infused faster than
- 20 mEq/hr
- through a central line and if patient is on cardiac monitor
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high doses of potassium should be given through
central vein
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when potassium is administered through a peripheral vein you should do what
decrease rate to avoid irritating the vein and causing a burning sensation
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you should never give Potassium via
-
a decrease in urine volume to less than what would cause you to stop potassium and why
- 20-30mL/h for 2 consecutive hours
- because kidneys eliminate 90% of potassium
-
most common cause of hyperkalemia =
kidney failure
-
causes of hyperkalemia
- excess intake
- acidosis
- addison's disease
- renal disease
- hemolyzed sample
- potassium sparing diuretics
-
addison's disease =
- lack of hormones in the adrenal cortex
- DO NOT HAVE ALDOSTERONE
-
if you give pt PRBC what happens to K levels
K goes up because you are giving them CELLS and potassium is in CELLS
-
hyperkalemia S&S
- cardiac dysrhymias
- heart block
- irritability
- dyspnea
-
management of Hyperkalemia =
- limit intake
- Kayexalate
- administer insulin and dextrose (moves K into cells)
- IV calcium gluconate to prevent cardio toxicity
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why would you give IV calcium gluconate
to protect the heart from high potassium levels
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pseudohyperkalemia problems can be caused by
- hemolysis of blood sample
- clenched fist during blood draw
-
parasthesis =
tingling, prickling
-
hyperaldosterone levels K levels would
- decrease
- because aldosterone eliminates K
-
cell firing threshold goes up or down with hyperkalemia
threshold goes down so cell fires more rapidly
-
cell firing threshold goes up or down with hypokalemia
threshold goes up so cells fire less rapidly
-
Calcium is need for
- contraction
- conduction
- coagulation
-
where is Calcium mainly found
in the bones where it is stored
-
calcium is the guard that does not allow what into the cell
Na
-
inregards to calcium cells fire more rapidly with
- hypocalcemia
- because the cell doesn't have a lot of calcium to block sodium entering the cell
-
cells fire when
Na enters the cell and K leaves the cell
-
hypercalcemia is similar to
hypokalemia because cells fire less rapidly
-
normal serum calcium levels
- 8.6 -10.2 Mg/dl total calcium
- 4.6 - 5.3 mg/dl (ionized)`
-
functions of calcium =
- contraction
- conduction
- coagulation
- automaticity
- formation of teeth and bones
- hormone secretion and function of cell receptors
-
calcium is present in 3 forms
- 40% is bound to protein
- 50% is ionized (calcium that is free or unbound)
- 10% is bound to other substance
-
Calcitonin makes serum calcium levels go
- down
- calcitonin makes it go bone in
- it is secreted when calcium levels are high
-
calcium resorption =
calcium is released from the bone
-
PTH hormone makes serum levels of calcium
- go up
- PTH job is to make calcium levels go up
-
hypomagnesimia looks like
hypocalcemia
-
causes of hypocalcemia
- hyoparathyroidism
- decreased levels of magnesium
- decreased levels of vitamin D
- alcoholism
- blood transfusions (becasue citrate can bind up calcium)
-
S&S of hypocalcemia =
- tetany -
- tingling
- hyperreflexia
- trousseau's and Chvostek's sign
- cardiac dysrythmias
- increased bleeding
- laryngeal spasms
-
management of hypocalcemia =
- diet
- oral supplements
- IV calcium gluconate
-
trousseaus sign
- muscle spasms of hand when BP cuff on
- hypocalcemia
-
chvosteks sign
- tap on facial nerve results in ipsilateral facial muscle contraction
- hypocalcemia
-
hypercalcemia is serum level
greater than 10.2 mg/dL
-
if you have malignant done disease you will have
hypercalcemia
-
management of hypercalcemia =
- decrease calcium intake
- diuretics
- maintain hydration
- calcitonin
-
PTH hormone job
makes calcium levels go up
-
calcitonin job =
- makes calcium levels go down
- move calcium into bone
-
causes of hypercalcemia =
- malignant bone disease
- hyperparathyroidism
- vitamin D overdose
- immonilization
-
S&S of hypercalcemia =
- slows muscles down - anything attached to this ie muscle weaknes, decrease in reflexes
- polyuria
- thirst
- nephrolithiasis - kidney stones
-
biggest treatment for hypercalcemia =
hydrate hydrate hydrate because you pee off electrolytes with water
-
vitamin D causes
absorption of calcium in the gut
-
hypermagnesemia looks like
hypercalcemia
-
hypomagnesemia looks like
hypocalcemia
-
normal level of magnesium =
1.5 - 2.5 mEq/L
-
First line drug for women with eclampsia =
magnesium
-
what powers the sodium potassium pump =
Magnesium because it generates ATP
-
what is necessary for PTH function and bone function
Magnesium
-
what should you think when you see alcoholism
alcoholism
-
hypomagnesemia resembles
hypocalcemia
-
hypermagnesemia resembles
hypercalcemia
-
hypokalemia resembles
- hypercalcemia
- CHILLED OUT
-
-
management of hypomagnesemia
- diet magnesium salts
- Maalox or mylanta
- IV mag sulfate
-
serum levels in hypermagnesemia =
greater than 3.0
-
causes of hypermagnesemia =
- renal failure
- chronic use of antacids or laxatives
-
IV calcium gluconate given when
- hypermagnesemia
- hyperkalemia
-
management of hypermagnesemia =
- promote urinary excretion with fluid diuretics
- no Mg containing drugs
- IV calcium gluconate
-
primary anion in the ICF
phosphate
-
phosphate is essential for function of
muscle, RBC's, and nervous system
-
normal phosphate levels
2.7 - 4.5 mg/dL
-
phosphorous levels are often evaluated with what other levels
calcium
-
phosphate has a reciprocal relationship with
calcium
-
hyperPhosphatemia
- > 4.5
- looks like hypocalcemia
-
management of hyperphosphatemia
- adequate hydration
- correction of hypocalcemia
- phosphate binding agents
- calcium supplements
-
causes of hypophosphatemia =
- malnourishment
- alcohol withdraw
- parenteral nutrition
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