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2012-02-15 14:31:10

Electrolyte info and imbalances
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  1. Sodium
    • Major electrolyte in ECF
    • Values: 135 - 145 mEq/L
    • Effects: Neurological
    • Regulated by: ADH, thirst, renin-angiotensin-aldosterone system
    • Function: muscle contraction, transmission of nerve impulses, acid-base balance, active & passive transport
    • SIADH: Syndrome of Inappropriate Secretion of ADH
  2. Hyponatremia
    • Serum sodium less than 135 mEq/L
    • Causes: adrenal insufficiency, water intoxication (renal failure, diabetes, ptocin), SIADH, and losses by vomiting, diarrhea, sweating, and diuretics
    • Manifestations: poor skin turgor, dry mucosa, headache, decreased salivation, decreased BP, nausea, abdominal cramping, and neurologic changes
    • Medical management: water restriction and sodium replacement, if SIADH H2O restriction 1st because Na would cause increase H2O retention
    • Nursing management: assessment and prevention, monitoring of dietary sodium and fluid intake, identification and monitoring of at-risk patients and the effects of medications (diuretics and lithium)
  3. Hypernatremia
    • Serum sodium greater than 145mEq/L
    • Causes: excess water loss, excess sodium administration, diabetes insipidus, heat stroke, and hypertonic IV solutions
    • Manifestations: thirst; elevated temperature; dry, swollen tongue; sticky mucosa; neurologic symptoms; restlessness; and weakness
    • â—¦Thirst may be impaired in the elderly or ill
    • Medical management: hypotonic electrolyte solution or D5W (Isotonic solution but in body acts as a hypertonic solution)
    • Nursing management: assessment and prevention, assess for over-the-counter (OTC) sources of sodium, offer and encourage fluids to meet patient needs, and provide sufficient water with tube feedings
  4. Potassium
    • Major electrolyte in ICF
    • Values: 3.5-5.0 mEq/L
    • Effects: Cardiac
    • Regulated by: sodium-potassium pump, renal function, aldosterone
    • Function: cell metabolism, nerve impulse transmission, funtioning of cardiac, lung, and muscle tissues, and acid-base balance
  5. Hypokalemia
    • Below-normal serum potassium (<3.5 mEq/L) may occur with normal potassium levels in alkalosis due to shift of serum potassium into cells
    • Causes: GI losses, medications, alterations of acid–base balance, hyperaldosteronism, and poor dietary intake
    • Manifestations: fatigue, anorexia, nausea, vomiting, dysrhythmias, muscle weakness, cramps, paresthesias, glucose intolerance, decreased muscle strength, and deep tendon reflexes (DTRs)
    • Medical management: increased dietary potassium, potassium replacement, and IV for severe deficit
    • Nursing management: assessment (severe hypokalemia is life-threatening), monitoring of electrocardiogram (ECG), arterial blood gases (ABGs), and dietary potassium, and providing nursing care related to IV potassium administration (know output when admin; 20-40 mEq/L in 1000mL), pt. at risk for falls
  6. Hyperkalemia
    • Serum potassium greater than 5.0 mEq/L
    • Causes: usually treatment-related, impaired renal function, hypoaldosteronism, tissue trauma, and acidosis; Hemolysis of blood specimen or drawing of blood above IV site may result in false laboratory result; Salt substitutes and medications may contain K+; Potassium-sparing diuretics: should not be used in patients with renal dysfunction
    • Manifestations: cardiac changes and dyrhythmias, muscle weakness with potential respiratory impairment, paresthesias, anxiety, and GI manifestations
    • Medical management: monitor ECG, cation exchange resin (Kayexalate), IV sodium bicarbonate, IV calcium gluconate, regular insulin (causes K+ to shift into ICF from ECF quickly - temp fix) and hypertonic dextrose IV, and b-2 agonists; limit dietary potassium; and perform dialysis
    • Nursing management: assess serum potassium levels, mix well IVs containing K+, monitor medication effects, and initiate dietary potassium restriction and dietary teaching for patients at risk
  7. Calcium
    • Value: 8.6-10.2 mg/dL
    • Function: Muscle contraction and relaxation
    • Regulated by: PTH and calcitonin
  8. Hypocalcemia
    • Serum level less than 8.5 mg/dL must be considered in conjunction with serum albumin level
    • Causes: hypoparathyroidism, malabsorption, pancreatitis, alkalosis, massive transfusion of citrated blood, renal failure, medications, other
    • Manifestations: tetany, circumoral numbness, paresthesias, hyperactive DTRs, Trousseau’s sign (spasm of hand/forearm), Chovstek's sign (facial spasm), seizures, respiratory symptoms of dyspnea and laryngospasm, abnormal clotting, and anxiety
    • Medical management: IV of calcium gluconate; calcium and vitamin D supplements; diet
    • Nursing management: assessment as severe hypocalcemia is life-threatening, weight-bearing exercises to decrease bone calcium loss, patient teaching related to diet and medications, and nursing care related to IV calcium administration, monitor for digoxin toxicity
  9. Hypercalcemia
    • Serum level above 10.5 mg/dL
    • Causes: malignancy and hyperparathyroidism, bone loss related to immobility
    • Manifestations: muscle weakness, incoordination, anorexia, constipation, nausea and vomiting, abdominal and bone pain, polyuria, thirst, ECG changes, and dysrhythmias
    • Medical management: treat underlying cause, administer fluids, furosemide, phosphates, calcitonin, and biphosphonates Nursing management: assessment as hypercalcemic crisis has high mortality, encourage ambulation, fluids of 3 to 4 L/d, provide fluids containing sodium unless contraindicated and fiber for constipation, and ensure safety
  10. Magnesium
    • Value: 1.8-2.7 mg/dL
    • Location: most abundant in the ICF after K+
    • Effects: Muscles
    • Function: neuromuscular
  11. Hypomagnesemia
    • Serum level less than 1.8 mg/dL; evaluate in conjunction with serum albumin
    • Causes: alcoholism, GI losses, enteral or parenteral feeding deficient in magnesium, medications, rapid administration of citrated blood; contributing causes include diabetic ketoacidosis, sepsis, burns, and hypothermia
    • Manifestations: neuromuscular irritability, muscle weakness, tremors, athetoid movements, ECG changes and dysrhythmias, and alterations in mood and level of consciousness, can lead to seizures
    • Medical management: diet, oral magnesium, and magnesium sulfate IV (if respers <12 don't give)
    • Nursing management: assessment, ensure safety, assess DTRs, patient teaching related to diet, medications, alcohol use, and nursing care related to IV magnesium sulfate
    • Hypomagnesemia is often accompanied by hypocalcemia
    • Monitor and treat potential hypocalcemia
    • Dysphagia is common in magnesium-depleted patients; assess ability to swallow with water before administering food or medications
  12. Hypermagnesemia
    • Decreased Muscular Response
    • Serum level more than 2.7 mg/dL
    • Causes: renal failure, diabetic ketoacidosis, and excessive administration of magnesium Manifestations: flushing, lowered BP, nausea, vomiting, hypoactive reflexes, drowsiness, muscle weakness, depressed respirations, ECG changes, and dysrhythmias
    • Medical management: IV calcium gluconate, loop diuretics, IV NS of RL, hemodialysis
    • Nursing management: assessment, avoid administering medications containing magnesium, and provide patient teaching regarding magnesium-containing OTC medications, monitor urine output
  13. Phosphorus
    • Value: 2.5-4.5 mg/dL
    • Where: primarily ICF
    • Inverse Relationship with Calcium
  14. Hypophosphatemia
    • Serum level below 2.5 mg/dL
    • Causes: alcoholism, refeeding of patients after starvation, pain, heat stroke, respiratory alkalosis, hyperventilation, diabetic ketoacidosis, hepatic encephalopathy, major burns, hyperparathyroidism, low magnesium, low potassium, diarrhea, vitamin D deficiency, and diuretic and antacid use
    • Manifestations: neurologic symptoms, confusion, muscle weakness, tissue hypoxia, muscle and bone pain, and increased susceptibility to infection
    • Medical management: oral or IV phosphorus replacement
    • Nursing management: assessment, encourage foods high in phosphorus, and gradually introduce calories for malnourished patients receiving parenteral nutrition
  15. Hyperphosphatemia
    • Serum level above 4.5 mg/dL
    • Causes: renal failure, excess phosphorus, excess vitamin D, acidosis, hypoparathyroidism, and chemotherapy
    • Manifestations: few symptoms, soft-tissue calcifications, symptoms occur due to associated hypocalcemia
    • Medical management: treat underlying disorder; use vitamin D preparations, calcium-binding antacids, phosphate-binding gels or antacids, loop diuretics, NS IV, and dialysis
    • Nursing management: assessment, avoid high-phosphorus foods, and provide patient teaching related to diet, phosphate-containing substances, and signs of hypocalcemia
  16. Chloride
    • Value: 97-107 mEq/L
    • Where: ECF
    • Inverse Relationship with Bicarbonate
    • Function: acid-base balance, buffer in exchange of O2/CO2 in RBCs
  17. Hypochloremia
    • Serum level less than 96 mEq/L
    • Causes: Addison’s disease, reduced chloride intake, GI loss, diabetic ketoacidosis, excessive sweating, fever, burns, medications, and metabolic alkalosis Loss of chloride occurs with loss of other electrolytes, potassium, and sodium
    • Manifestations: agitation, irritability, weakness, hyperexcitability of muscles, dysrhythmias, seizures, and coma
    • Medical management: replace chloride—IV, NS, or 0.45% NS
    • Nursing management: assessment, avoid free water, encourage high-chloride foods, and provide patient teaching related to high-chloride foods
  18. Hyperchloremia
    • Serum level more than 108 mEq/L
    • Causes: excess sodium chloride infusions with water loss, head injury, hypernatremia, dehydration, severe diarrhea, respiratory alkalosis, metabolic acidosis, hyperparathyroidism, and medications
    • Manifestations: tachypnea, lethargy, weakness, rapid, deep respirations, hypertension, and cognitive changes
    • Normal serum anion gap
    • Medical management: restore electrolyte and fluid balance, LR, sodium bicarbonate, and diuretics
    • Nursing management: assessment, provide patient teaching related to diet and hydration
  19. Electrolyte Values
    • Sodium: 135-145 mEq/L
    • Potassium: 3.5-5.0 mEq/L
    • Calcium: 8.6-10.2 mg/dL
    • Magnesium: 1.8-2.7 mg/dL
    • Phosphorus: 2.5-4.5 mg/dL
    • Chloride: 97-107 mEq/L