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Calcium (Ca++)

Hypocalcemia
1. Symptoms
  1. Positive Chvostek and Trousseau's signs.
  2. CV: heart rate high or low; weak thready pulse; Severe: hypotension, prolonged ST and QT intervals
  3. NM: Paresthesias of hands and feet, muscle twitching, cramps, spasms; also tingling lips, nose, ears. May signal onset of NM overstimulation and tetany.
  4. GI: Increased peristalsis, hyperactive bowel sounds, cramping, diarrhea
  5. SK: Osteoporosis, loss of height, curvatures; common with chronic hypocalcemia
2. Medical Interventions
  1. Supplemental Ca++: PO or IV
  2. Correction of underlying cause
  3. AlOH and Vit D to increase absorption
  4. Mag Sulfate or muscle relaxants to decrease nerve and muscle responses.
  5. Labs
3. Nursing Interventions
  1. Seizure Precautions: low bed, siderails up
  2. Nutrition therapy: a high-Ca++ for mild hypocalcemia and chronic conditions
  3. Reduce Environmental Stimuli
  4. Emergency equipment on hand (suctioning, ET tray, emergency drugs).
  5. Initiate/Maintain IV access.
  6. Monitor frequently for s/s of effective treatment or worsening condition.
4. Serum Value <9.0 mg/dL
5. Etiology
  1. Actual Deficits = reduction in total body Ca++.
    1. Ex: Inadequate intake of Ca++ or Vit D, malabsorption (Celiac, Crohn's), ESRD, Diarrhea, Steatorrhea, wound drainage - esp. GI
  2. Relative Deficits = total body Ca++ is normal, serum Ca++ is low.
    1. Ex: Hyperproteinemia, alkalosis, citrate, Ca++ chelators, penicillamine, acute pancreatitis, hyperphosphatemia, immobility, parathyroid removal/destruction.
Hypercalcemia
1. Symptoms
  1. 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).
  2. NM: Severe muscle weakness, decreased deep tendon reflexes, altered LOC, psychiatric problems.
  3. GI: Decreased peristalsis, constipation, anorexia, N/V, hypoactive/absent bowel sounds, abdominal distention.
2. Medical Interventions
  1. D/C Ca++ or Vit D containing drugs.
  2. Fluid Volume Replacement (IV NS to increase excretion of Ca++).
    1. Labs
  3. Change from thiazide diuretics to those that increase excretion of Ca++.
  4. Ca++ chelators or binders, phosphorus, calcitonin, biphosphonates, aspirin, NSAIDs.
  5. CARDIAC MONITORING!
  6. Dialysis for severe and life-threatenting hypercalcemia, usually hemodialysis or blood ultrafiltration.
3. Nursing Interventions
  1. CARDIAC MONITORING!
    1. Watch for changes in HR and Rhythm, and changes in T waves and QT interval.
    2. Monitor frequently, compare with baseline.
    3. Cardiac changes are most life threatening!
  2. Frequent assessment of NM status
    1. Assess LOC, DTR's, skeletal muscle strength.
  3. Assess for slowed or impaired blood flow (calf circ, cap refills, pallor, temperature changes), esp. in BLE, pelvic region.
  4. Monitor frequently for s/s of effective treatment or worsening condition.
4. Serum Value >10.5 mg/dL
5. Etiology:
  1. Actual Excess: increase in total body Ca++.
    1. Ex: Excess intake of Ca++ or Vit D, Kidney failure, use of Thiazide diuretics.
  2. Relative Excess: total body Ca++ is normal, serum Ca++ is high.
    1. 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
1. Any change in Ca++ can have major effects on function because of the relatively low serum levels
Importance in the Body
1. Functions are closely r/t P and Mg
2. Enters the body through dietary intake (esp. dairy!) and absorption is facilitated by Vit D.
  1. Dairy products, tofu, leafy greens, and almonds are high in calcium.
3. Absorbed in the intestinal tract, stored in the bones, and regulated by PTH (parathyroid hormone) and TCT (thyrocalcitonin).
  1. 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++.
  2. 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++.
4. Excitable membrane stabilizer, regulates the depolarization and generation of AP's in the CNS and PNS.
  1. Low serum levels make excitable membranes MORE excitable because they increase the movement of Na+ across the membranes.
  2. 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.
  3. Maintains bone strength, activates enzymes,facilitates skeletal and cardiac muscle contraction.
  4. Controls impulse transmission in the CNS and PNS.
  5. Remember Ca++ channels from Phys?
5. 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
1. Barb, Jenny, Tandi
2. 05/13/2013

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Calcium (Ca++)

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	Created by teej984 almost 11 years ago