Electrolytes and Body Fluid

• Electrolytes are minerals in the body that separate into electrically charged particles when in solution.
• Some electrolytes are positively charged, and others are negatively charged.
• Electrolytes regulate water distribution, govern acid-base balance, move nutrients and waste in and out of cells, and transmit nerve impulses/muscle contraction.
• Electrolytes are vital for nearly every cellular reaction and function.

Cations

• Negatively charged.
• Sodium.
• Potassium.
• Calcium.
• Magnesium.

Anions

• Positively charged.
• Chloride: Normal value 95-106 mEq/L which maintains osmolality.
• Bicarbonate: Normal value 22-26 mEq/L and a buffer regulated by the kidneys. Phosphate which is involved in ADP and ATP.

Major electrolytes outside the cell (ECF)

• Sodium and chloride are major electrolytes outside the cell.
• Other electrolytes on the outside of the cell include calcium and bicarbonate.

Major electrolytes inside the cell (ICF)

• Potassium, phosphorus, and magnesium.

Electrolyte protocol standing orders

• Hospitals utilize electrolyte protocol standing orders.
• Labs should be checked before calling a Health Care Provider for abnormal labs.
• A Basic Metabolic Panel (BMP) or Comprehensive Metabolic Panel (CMP) will measure electrolytes.

Common causes of electrolyte imbalance

• Vomiting.
• Diarrhea.
• Dehydration.
• Medications.
• Endocrine disorders.
• Kidney diseases.

Imbalances

• Hyper or plasma excess occurs when electrolyte intake > output/shift from cells or bone into ECF.
• Hypo or plasma deficit occurs when electrolyte intake < output/shift from ECF into cells or bone.

Sodium (extracellular cation 135-145 mEq/L)

• Affects neurological function.

Hyponatremia

• Below 135 mEq/L.
• Critical value below 120 mEq/L causes cerebral edema, and below 110 mEq/L can cause death.
• Pathophysiology: Most abundant cation in ECF, maintains ECF osmolality, essential for nerve impulse transmission, maintains blood volume, renal retention/excretion, and regulates pH balance.
• Causes: GI losses like vomiting and NG suction, excess diuretics, burns, water intoxication, kidney diseases, CHF, and SIADH.
• Signs/Symptoms: Headache, altered level of consciousness (LOC), fatigue, lower muscle strength, seizures, tachycardia, polydipsia, low BP, high BP, and/or bounding pulse.

Two Types of Hyponatremia

• Hypovolemic is dry from loss of water and sodium.
• Hypervolemic is fluid overload with an increase in water greater than sodium.
• Treatments: Administer NS 0.9% or 3% Hypertonic Saline in severe cases, high sodium foods, water restriction, and diuretics.
• Nursing Interventions: Monitor electrolytes and vital signs, neurological responses, fluids/Intake and output, daily weights, implement seizure precautions, and ensure IV access and monitor airway.

Hypernatremia

• Above 145 mEq/L.
• Critical value above 160 mEq/L.
• Pathophysiology: Most abundant cation in ECF, maintains ECF osmolality, essential for nerve impulse transmission, maintains blood volume, renal retention/excretion, and regulates pH balance.
• Causes: Dehydration, excess salt intake, fever, diabetes, and/or diabetes insipidus.
• Signs/Symptoms: Dry mucus membranes and swollen tongue, low urinary output, high hematocrit, agitation, restlessness, flushed/red skin, edema, shortness of breath (SOB), hypertension, polydipsia, and seizures.

Two Types of Hypernatremia

• Hypovolemic is dry hemoconcentrated.
• Sodium Gain: Fluid drawn into blood vessels causing hypervolemia.
• Treatments: Replace fluids, administer diuretics, and restrict foods high in sodium.
• Nursing Interventions: Monitor electrolytes, vital signs, and mental status, monitor weight/Intake and output, ensure IV access, and monitor for seizures.

Potassium (intracellular cation, measured extracellularly 3.5-5.0 mEq/L)

• Affects heart rhythm.

Hypokalemia

• Below 3.5 mEq/L.
• Critical value below 3 mEq/L.
• Pathophysiology: Action potential in cells, muscles, neurons, assists in controlling cardiac rate and rhythm, kidney exchanges of NA+ and K+ (Pump), and acid/base buffer.
• Causes: Inadequate intake, renal loss from loop diuretics, severe diarrhea, ETOH abuse, and alkalosis.
• Signs/Symptoms: Weakness, flaccid lower DTRs, leg cramping, U waves and PVCs on ECG, heart palpitations, less bowel sounds (BS), and constipation.
• Clinical Note Slowing down the gut and potassium should never be pushed straight, it should be diluted.

Treatments for Hypokalemia

• Foods high in K+, oral or parenteral K+, Pedialyte, sports drinks, and/or K+ sparing diuretics.
• Nursing Interventions: Monitor electrolytes per protocol, vital signs, and cardiac rhythm via telemetry or ECG.
• Dilute K+ in IV, could burn them. IV or PO.

Hyperkalemia

• Above 5.0 mEq/L.
• Critical value above 6.0 mEq/L.
• Pathophysiology: Action potential in cells, muscles, neurons, assists in controlling cardiac rate and rhythm, kidney exchanges of NA+ and K+ (Pump). Causes: Dehydration, K+ sparing diuretics, renal failure, acidosis, tissue damage-burns, salt substitutes, and old age increased risk.
• Signs/Symptoms: Heart conduction abnormalities, muscle twitching, higher DTRs, hyperactive BS, diarrhea, and cardiac arrest.
• Clinical Note Avoid if patient with acidosis. Treatments: Kayexalate oral or enema, Insulin & D50 to move K+ into cell and prevent hypoglycemia, sodium bicarbonate, diuretics but don't give K+ sparing, and lastly dialysis.
• Nursing Interventions: Monitor electrolytes, vital signs, and ECG, and monitor neurological responses; stop any infusion of IV K+.

Potassium Intake

• Daily intake of potassium is necessary to prevent hypokalemia.
• Foods High in Potassium: Fruits (avocado, apricots, bananas, citrus (oranges) and prune juice), vegetables (potato (highest), beans, broccoli, and spinach, carrots and vegetable juice), also found in all meats, poultry & fish, and salmon.

Potassium Administration

• By mouth with a pill or liquid: The liquid must be diluted followed by a glass of water and given with food while remaining upright for 30 minutes to avoid esophagitis.
• Parenteral routes requires dilution in NS, to monitor IV site and infusion carefully because infiltration can cause tissue necrosis, to administer with an IV pump, with IV infusion rates of 10 to 20 mEq/hr and never exceed 40 mEq/L via central line access.

Potassium Patient Education

• Elderly patients are at risk for hyper/hypokalemia with multiple medications and should be taught the signs/symptoms.
• Do not crush slow-release K+ supplements as this can trigger quick release of this electrolyte.
• Discuss foods high in potassium if taking a K+ depletion diuretic, e.g. Lasix or Bumex.
• Avoid salt substitutes if patient prone to high K+ levels because the main ingredient is potassium.
• May need periodic lab testing to evaluate K+.

Calcium (most abundant ion in body, but only small amount in serum, 9.0-10.5 mEq/L)

• Controls and maintains contractions.

Hypocalcemia

• Below 9.0 mEq/L.
• Critical value below 7.
• Pathophysiology: Necessary for almost all vital processes, muscle contraction, and clotting factors, and stored in bones/teeth.
• Causes: Thyroid/parathyroid diseases, renal failure decreasing phosphate excretion, low albumin levels, or diet low in Ca+.
• Signs/Symptoms: Tetany, twitching, brittle nails, numbness/tingling around mouth, Chvostek's sign being face twitching when touched, Trousseau's sign from tightening BP cuff makes hand move, cardiac changes, and diarrhea. Clinical Note Calcium likes to follow albumin. Treatments: Diet (dark leafy greens, dairy), calcium replacement, thiazide diuretics, and phosphorus binding antacids.
• Nursing Interventions: Monitor electrolytes per protocol, vital signs, and cardiac rhythm (dysrhythmias), monitor neuromuscular function for tetany, seizures, and/or muscle spasms, and place on fall precautions.

Hypercalcemia

• Above 10.5
• Critical value: >12
• Pathophysiology: Necessary for almost all vital processes, muscle contraction, and clotting factors, and stored in bones/teeth.
• Causes: Prolonged immobilization, dehydration, hyperparathyroidism, cancer, and excess antacid intake.
• Signs/Symptoms: Anorexia, N/V and constipation, decreased LOC, personality changes, kidney stones, death, and pathological fx. Causes: prolonged immobilization, dehydration, hyperparathyroidism, cancer or excess antacid intake. Treatments: Hydration, loop diuretics, and hold foods high in Ca+.
• Nursing Interventions: Monitor electrolytes per protocol, vital signs, and cardiac rhythm (dysrhythmias), monitor for N/V, place on fall precautions, and move patient carefully with a draw sheet. Clinical Note Low albumin can cause this.

Magnesium (intracellular, small amount in serum 1.3-2.1 mEq/L)

• Helps relax muscles.
• Hypomagnesemia
• Below 1.3 mEq/L.
• Critical value below 1.2
• Pathophysiology: Carbohydrate metabolism, neurotransmission, and regulates muscle contraction to relax after contraction.
• Causes: Malnutrition, alcoholism, diarrhea, and vomiting. Signs/Symptoms: Muscular tremors, hyperactive DTRs, confusion, dysrhythmias, positive Chvostek and Trousseau, hypertension, and tachycardia. Treatments: Treat underlying cause and give magnesium replacement or dietary mag with spinach, avocado, fish, grains, nuts, and legumes.
• Nursing Interventions: Monitor electrolytes and vital signs, cardiac rhythm dysrhythmias and monitor for tachycardia, hypertension, tremors, tetany, and/or muscle weakness.

Hypermagnesemia

• Above 2.1 mEq/L.
• Critical value above 4.9 mEq/L.
• Pathophysiology: Carbohydrate metabolism, neurochemicals, and muscle excitation.
• Nursing Interventions: Monitor vital signs for bradycardia and hypotension including possible muscle weakness.
• Treatments: Rehydration, diuretics, and calcium gluconate for severe cardiac changes.
• Causes: Renal failure, excess intake, and dehydration.
• Signs/Symptoms: Hypoactive deep tendon reflexes, hypotension/bradycardia, generalized weakness, and lethargy.