calcium Flashcards
calcium - cation or anion?
One of body’s most abundant ions (major ECF cation)
Primarily combined with phosphorus to form mineral salts of bone & teeth
Exerts sedative effect on (milk before bedtime calms my nerves)
(drink milk before bedtime) nerve cells
Functions to develop cardiac action potential and contraction of muscle
what regulates Ca? and what does it activate? (Ca goes from bones to ECF, to kidney for reabsoption)
Parathyroid Hormone
- Released from parathyroid gland
- Promotes transfer of Ca from bones to ECF
- Activates vitamin D
- Promotes Kidney reabsorption
vitamin D is a major source of
calcium through oral intake of foods rich in Ca++
calcitonin - what is it and where is it produced? (mom needs to tone her thyroid)
- Hormone produced by thyroid gland.
hypocalcemia causes - (when the albino is low, the milk is low)
Due to reduction of total body Ca++ or due to % of Ca++ that is ionized (look at albumin levels; low albumin is most common cause)
Increased Ca++ loss
Altered intestinal absorption
Altered regulation
Increased phosphorus or decreased Mg levels
hypocalcemia - Clinical Manifestations (low ca makes me french)
Related to diminished function of
neuromuscular, cardiac and renal systems
Numbness, tingling of hands, muscle spasms,
+ Truosseau (20 mm above systolic and cramping of fingers) , +Chvosteks sign (twitching of cheek - Ch for cheek), increased DTRs (deep tendon reflex)
Muscle cramps, can progress to tetany
Cardiac Arrhythmias
hypocalcemia - what numbers on blood test (Selene without Ca) and what number is serum albumin?
Diagnostic Tests
Serum Ca++ less than 8.5
Look at serum albumin less than 3.5
Xray findings may show osteoporosis, bone cavitation
hypocalcemia signs and monitor what? (everyone else is doing it)
Monitor for signs of hypocalcemia - altered sensorium, assess orientation. call light within reach, etc. deep tendon reflexex, apical heart rate for arrythemias.
hypercalcemia typically develops when there is an…(Ca moves from what to what)
increased movement of calcium from bone to ECF (hyperparathyroid, matestis of bone)
Shift of Ca++ from Bone to ECF
Increased Intake & Absorption
Decreased Ca++ Excretion
hypercalcemia clinical manifestions (too much ca makes me weak)
Many effects related to excess Ca++ in cells, which causes a decrease in cell membrane excitability. Especially in skeletal and heart muscle and nervous system:
Weakness, decreased or absent DTRs
Bone pain
Constipation
Potential for renal calculi (flank pain, abdominal pain)
Dysrythmias
hypercalcemia - labs (not 10 exactly)
Total serum Ca++ > 10.5mg/dL (also look at albumin level)
hypercalcemia - monitor for what? (buffy drinking milk)
Monitor for altered sensorium
Provide safe environment (fall risk)
hypercalcemia from taking what meds?
tums, maalox
Ca is necessary for…
blood clotting process
where is Ca located? and where is most of it?
Less than 1% of Ca++ is located in ECF & ICF compartments (of which approx 40% is bound to albumin)
99% located in bone
what has an inverse relationship with Ca?
Phosphorus & calcium have inverse relationship.
- Vitamin D is required to promote absorption of calcium via the
GI tract
You need a functioning GI tract. won’t work if you have - diarrhea, chrones, CF, malabsoportion.
sources of vitamin D
food and produced via the skin with exposure to sunlight. Sun is the best source.
Parathyroid antagonist is…
calcitonin
calcitonin inhibits…and what can the nasal spray do?
bone resorption. Enhances excretion of Ca by kidneys
- Decreases Calcium levels
it blocks bone reabsorption. calcitonin nasal spray can prevent bone fractures, keep Ca in the bones.
hypocalcemia - IV Ca precautions - what you know about calcium and blood
Administer po calcium and Vit D supplement as ordered
May need phosphorus binding antacids ex. tums or phoslow.
Encourage foods rich in Ca++/low in PO-4 (look at foods posted on canvas)
Administer IV calcium as ordered (use caution) go slowly, dilute properly, monitor output! should be on cardiac monitor.
Seizure precautions
Observe for bleeding or bruising (Ca promotes clotting)
symptoms of hypercalcemia don’t usually occur until levels reach…
Sx usually absent unless concentration is >11mg/dL
what happens to PTH with hypercalcemia? And x-rays?
PTH increased with hyperparathyroidism
Xray findings show osteoporosis, bone cavitation
hypercalcemia - how often to monitor symptoms? (too much milk every hour on the hour)
Monitor for worsening hypercalcemia (weakness, DTR hourly, HR and rhythm)
hypercalcemia - if taking digoxin, (can you dig, too much milk and mag)
Monitor for signs of digoxin toxicity if taking digoxin (causes dig toxicity)
hypercalcemia - what meds to administer? (hulu loop - 3 in the hulu loop)
Administer saline and loop diuretics (lasix (furosamide) as prescribed
Avoid Vitamin D preparations
Low Ca++ diet, avoid Ca++ containing meds
loop for calcium, phosphorus and potassium
hypercalcemia and kidneys…
Monitor renal fx
Monitor for kidney stones. last resort dialysis.
Ca normal values
Normal value is 4.3 –
5.3 mEq/L (ionized Ca++) or 8.5 – 10 mg/dL (total Ca++) Serum value is
usually total Ca++
high calcium causes body to
relax, low calcium more excitable
calcium has an inverse relationship with
phosphorus
opposite of pth
calcitonin
mg required for
parathyroid hormone.
hyperphosphatemia causes what to happen with calcium?
hypocalcemia
calcium - reasons regulation is altered
damage to the parathyroid gland - ppl who have had thyroid removed are at risk for hypocalcemia bc the parathyroid can be damaged. also hypoparathyroidism
low albumin a cause of
low calcium ionization
low calcium GI can be caused by
vitamin D absorption
calcium, mag, and potassium..(maggie milk and potatoes in the race)
run in same direction
if someone has neck surgery, always check for
hypocalcemia = could be damage to parathyroid gland
IV calcium = what precaution?
seizure precaution if signs of tetany
hydrothiazide dirutics promote what? (thia can only hold onto to milk, everyone else runs)
the retention of ca so could cause hypercalcemia
hypercalcemia symptoms usually not present until you reach what level? (hyper after 11)
11 mg/dl
low calcium and mag vs. low phosphorus
low cal and mag increases muscle twitches, low mag relaxes.
