6-C II. Managing Electrolyte Imbalances

Question 1

sodium

0. 9% NaCl (isotonic or normal saline)
1. 45% NaCl (hypotonic saline)

3% NaCl (hypertonic)

Answer 1

Action: the major extracellular cation; important in cell membrane function and action potential, osmotic pressure, acid-base balance, and extracellular fluid volume; controls fluid movement

Uses: hyponatremia, provide osmotic pressure, fluid volume expander, maintain electroneutrality

Serum Na+ level 145 mEq/L
Thirst, elevated temperature, dry mucous membranes, oliguria, hyperreflexia; infants exhibit depressed fontanelles and irritability

assess and monitor fluid status, edema, weight, neurologic status

client teaching:
read food labels for sodium content
daily weight

Question 2

potassium

potassium chloride

Answer 2

Action: the major intracellular ion; maintains intracellular fluid volume and action potential of cell membranes; maintenance of myocardial contractility

Uses: hypokalemia, concurrent diuretic therapy, ventricular dysrhythmias

Adverse effects
life-threatening: hyperkalemia, arrhythmias, GI obstruction, bleed, and ulcer/perforation

most common: nausea, vomiting, flatulence, abdominal pain/discomfort, diarrhea, hyperkalemia

Contraindications: hyperkalemia, delayed GI transit, esophageal stricture, GI obstruction, renal failure

establish baseline data and monitor serum potassium, renal function tests

Serum K+ level 5 mEq/L
Client may experience irregular heartbeat; nausea; bradycardia; EKG changes include peaked T wave and depressed P wave, wide QRS complex

assess and monitor urine output, ECG

use large bore needle to draw blood specimen to prevent hemolysis

administration
never administer by IV push
stop infusion with client complaints
rapid infusion may cause cardiac standstill
slowly infuse through central line or large vein

client teaching
take with full glass of water
do not crush or chew tablets
need for follow-up care and testing

AVOID over-the-counter drugs and salt substitutes
foods containing potassium include raw salmon, avocado, raisins, banana, spinach, tomatoes

Question 3

calcium

calcium chloride and calcium gluconate, calcium citrate

calcium carbonate

Answer 3

Action: neuromuscular function, bone strength and density, enzyme activation, blood clotting

Uses: osteoporosis, hypocalcemia, hypersecretory (HCl) state, hyperphosphatemia, hypoparathyroidism, life-threatening arrhythmias, adjunct treatment for hypermagnesemia, calcium channel blocker overdose, prevention of postmenopausal osteoporosis

Adverse effects
life-threatening: hypercalcemia, nephrolithiasis, arrhythmias, syncope, extravasation necrosis

most common: hypercalciuria, hypomagnesemia, constipation, nausea

Contraindications
hypercalcemia, hypophosphatemia
ventricular fibrillation, digitalis toxicity

establish baseline data and monitor serum calcium, magnesium, phosphorous, and albumin

Serum calcium level 10.2 mg/dL
Constipation, anorexia, nausea, abdominal pain, muscle twitches and weakness, dementia, irritability

assess and monitor bone density, orientation, headache, blood pressure, ECG

provide adequate vitamin D
seizure precautions for hypocalcemia

administration
infuse slowly in large vein, stop infusion with client complaints of burning, prevent extravasation
PO: give 1 1/2 to 2 hours after meals, avoid giving with enteric-coated tablets
prevent constipation with fluid, fiber, and exercise

client teaching
do not change antacids
limit vitamin D intake to 400 units daily
establish regular bowel habits with fluids, fiber, and exercise

Question 4

magnesium

magnesium sulfate

Answer 4

Action: skeletal muscle contraction, energy production, carbohydrate metabolism activation of B-complex vitamins, protein synthesis

Uses: prevention and treatment of hypomagnesemia, pregnancy induced hypertension, malabsorption syndromes

Adverse effects
life-threatening: cardiovascular collapse, respiratory paralysis, hypothermia, depressed cardiac function, pulmonary edema

other:

depressed reflexes, hypotension, flushing, drowsiness

depressed cardiac function, diaphoresis, hypocalcemia, hypophosphatemia, hyperkalemia

Contraindications: myocardial damage, heart block, diabetic coma

Nursing interventions - see also previous page about calcium

establish baseline data and monitor serum magnesium, potassium, calcium, renal function studies

Serum magnesium level 2.1 mEq/L
Uncommon -Usually associated with increased intake; prolonged PR interval and widened QRS; hyporeflexia, hypotension, respiratory depression and cardiac arrest

client teaching: foods rich in magnesium include tuna, avocado, spinach, rolled oats, yogurt

assess and monitor ECG, deep tendon reflexes, blood pressure; respiratory rate

IV administration

slow IV push

use infusion control device for continuous infusion; stop for sudden hypotension, somnolence, or hyporeflexia

Question 5

phosphorus

Answer 5

vitamin B-complex activation, energy production, cell division; carbohydrate, protein, and fat metabolism, acid-base balance

Uses: hyperparathyroidism, osteomalacia, cirrhosis, hypokalemia, excess IV glucose, respiratory alkalosis

Contraindications: renal failure

Nursing interventions

establish baseline data and monitor serum phosphorus

Serum phosphorus level 4.1 mg/dL
Usually asymptomatic; similar to hypocalcemia

client teaching: foods rich in phosphorus include whole wheat and bran mixes, cottage cheese or cheddar, corn, broccoli, sunflower seeds, garlic, legumes and nuts