Zusammenfassung der Ressource
Calcium (Ca++)
- Hypocalcemia
- Symptoms
- Positive Chvostek and Trousseau's signs.
- CV: heart rate high or low; weak thready pulse; Severe:
hypotension, prolonged ST and QT intervals
- NM: Paresthesias of hands and feet, muscle twitching, cramps, spasms; also
tingling lips, nose, ears. May signal onset of NM overstimulation and tetany.
- GI: Increased peristalsis, hyperactive bowel sounds, cramping, diarrhea
- SK: Osteoporosis, loss of height, curvatures; common with chronic hypocalcemia
- Medical Interventions
- Supplemental
Ca++: PO or IV
- Correction of
underlying cause
- AlOH and Vit D to increase absorption
- Mag Sulfate or
muscle relaxants
to decrease
nerve and muscle
responses.
- Labs
- Nursing Interventions
- Seizure Precautions: low bed, siderails up
- Nutrition therapy: a high-Ca++ for mild
hypocalcemia and chronic conditions
- Reduce Environmental Stimuli
- Emergency equipment on hand
(suctioning, ET tray, emergency drugs).
- Initiate/Maintain IV access.
- Monitor
frequently for
s/s of effective
treatment or
worsening
condition.
- Serum Value <9.0 mg/dL
- Etiology
- Actual Deficits =
reduction in total
body Ca++.
- Ex: Inadequate intake
of Ca++ or Vit D,
malabsorption
(Celiac, Crohn's),
ESRD, Diarrhea,
Steatorrhea, wound
drainage - esp. GI
- Relative Deficits = total
body Ca++ is normal, serum
Ca++ is low.
- Ex: Hyperproteinemia,
alkalosis, citrate, Ca++
chelators, penicillamine,
acute pancreatitis,
hyperphosphatemia,
immobility, parathyroid
removal/destruction.
- Hypercalcemia
- Symptoms
- CV: First increases HR and BP; Severe hypercalcemia depresses HR; dysrhythmias; increased and unnecessary
clot formation, shown by s/s of impaired blood flow to tissues (cap refills, temperature inequality, color changes).
- NM: Severe muscle weakness, decreased deep tendon reflexes, altered LOC, psychiatric problems.
- GI: Decreased peristalsis, constipation, anorexia, N/V, hypoactive/absent bowel sounds, abdominal
distention.
- Medical Interventions
- D/C Ca++ or Vit D
containing drugs.
- Fluid Volume Replacement
(IV NS to increase
excretion of Ca++).
- Labs
- Change from thiazide diuretics to those that increase excretion of Ca++.
- Ca++ chelators or binders, phosphorus, calcitonin, biphosphonates, aspirin, NSAIDs.
- CARDIAC
MONITORING!
- Dialysis for severe and
life-threatenting hypercalcemia,
usually hemodialysis or blood
ultrafiltration.
- Nursing Interventions
- CARDIAC
MONITORING!
- Watch for changes in HR and Rhythm, and
changes in T waves and QT interval.
- Monitor frequently,
compare with baseline.
- Cardiac
changes are
most life
threatening!
- Frequent assessment of NM status
- Assess LOC, DTR's,
skeletal muscle strength.
- Assess for slowed
or impaired blood
flow (calf circ, cap
refills, pallor,
temperature
changes), esp. in
BLE, pelvic region.
- Monitor frequently for s/s of
effective treatment or worsening
condition.
- Serum Value >10.5 mg/dL
- Etiology:
- Actual Excess: increase in total body Ca++.
- Ex: Excess
intake of Ca++
or Vit D, Kidney
failure, use of
Thiazide
diuretics.
- Relative Excess: total body
Ca++ is normal, serum Ca++
is high.
- Ex: Hyperparathyroidism;
malignancies (esp of lung,
breast, and bone); indirect
resorption; hyperthyroidism;
immobility; use of
glucocorticoids; dehydration
(hemoconcentration).
- Normal Range (Free/Unbound Ca++ in blood): 9.0-10.5 mg/dL
- Any change in Ca++ can have major effects on
function because of the relatively low serum levels
- Importance in the Body
- Functions are closely r/t P and Mg
- Enters the body through dietary intake (esp. dairy!) and
absorption is facilitated by Vit D.
- Dairy products, tofu, leafy greens, and almonds are high in calcium.
- Absorbed in the intestinal tract, stored in the bones, and regulated
by PTH (parathyroid hormone) and TCT (thyrocalcitonin).
- PTH increases serum levels by releasing free Ca++ from bone
storage, stimulating Vit D activation to increase intestinal
absorption, inhibiting kidney excretion and stimulating kidney
reabsorption of Ca++.
- PTH is inhibited when Ca++ is high in the blood, and TCT is
excreted by the thyroid. TCT inhibits bone resorption, inhibits
Vit D assisted intestinal uptake, and increases the kidney
excretion of Ca++.
- Excitable membrane stabilizer, regulates the depolarization
and generation of AP's in the CNS and PNS.
- Low serum levels make excitable
membranes MORE excitable because
they increase the movement of Na+
across the membranes.
- High serum levels make excitable membranes LESS
excitable, requiring MORE stimuli.Usually this affects
the heart, skeletal muscles, and intestinal smooth
muscles initially and predominantly, but affects all systems.
- Maintains bone strength,
activates enzymes,facilitates
skeletal and cardiac muscle
contraction.
- Controls impulse
transmission in the
CNS and PNS.
- Remember Ca++
channels from Phys?
- Utilized by many
of enzymes
involved in blood
clotting
- Ignaviticus, D., & Workman, M. L. (2013). Medical-surgical nursing: Patient-centered collaborative
care. (7th ed., pp. 187-191). St. Louis, Missouri: Elsevier-Saunders.
- AH 1 F&E Presentation
- Barb, Jenny, Tandi
- 05/13/2013