5.2: Electrolytes
By the end of this section, you should be able to:
- 5.2.1 Define electrolytes.
- 5.2.2 Discuss the functions of major electrolytes.
- 5.2.3 Describe clinical manifestations related to common electrolyte imbalances.
- 5.2.4 Identify characteristics of treatment for common electrolyte imbalances.
- 5.2.5 Explain the indications, actions, adverse reactions, contraindications, and interactions of electrolyte therapy.
- 5.2.6 Describe the nursing implications related to treatment of electrolyte imbalances.
- 5.2.7 Explain the client education related to treatment of electrolyte imbalances.
Electrolytes are minerals that carry electrical charges and play vital roles in maintaining fluid homeostasis and regulating various physiological functions. When there are imbalances in electrolytes, it can lead to a range of symptoms and health issues that can significantly impact an individual’s health and well-being. Therefore, it is important to maintain proper electrolyte balance through a healthy diet, hydration, and medical care.
Electrolytes
Electrolytes are found in ICF and ECF compartments. They are responsible for many functions including regulating nerves, muscle function, and fluid balance within the body and helping to maintain a healthy pH level. In the next few sections, you will learn about potassium, sodium, calcium, phosphorus, magnesium, and chloride.
Potassium
Potassium (K) is an essential cation primarily found inside cells. The normal intracellular concentration of potassium ions in the body is approximately 140 mEq/L; the normal extracellular concentration is around 4 mEq/L. Therapeutic serum potassium levels are 3.6 to 5.4 mEq/L (Shrimanker & Bhattarai, 2023).
Potassium moves into and out of the cells via the sodium-potassium-ATPase pump (also known as the Na + K + ATPase pump) (see Figure 5.4), which uses energy from ATP hydrolysis to transport sodium ions out of cells and potassium ions into cells against their concentration gradients. The pump is vital for maintaining the concentration gradient of sodium and potassium ions across the cell membrane (Shrimanker & Bhattarai, 2023).
The levels of potassium in the body are influenced by acid–base imbalances. Acidotic conditions can lead to the movement of potassium out of cells, whereas alkalotic conditions can promote movement of potassium into cells. There is an inverse relationship between sodium and potassium reabsorption in the kidneys. Additionally, the hormone aldosterone plays a role in regulating potassium excretion (Shrimanker & Bhattarai, 2023).
Potassium is necessary for transmission and conduction of nerve impulses and for contraction of skeletal, cardiac, and smooth muscles. It is essential for normal renal function and glycolysis , the process of converting glucose into energy. Potassium also promotes glycogen storage in hepatic cells and regulates osmolality of cellular fluids (Dalga et al., 2023; Shrimanker & Bhattarai, 2023).
Hyperkalemia
Hyperkalemia is a condition where the level of potassium in the blood is higher than normal (usually above 5.5 mEq/L) (Shrimanker & Bhattarai, 2023). Common causes include excessive potassium intake, impaired kidney function that decreases its excretion, or a shift from intracellular to extracellular spaces.
Manifestations of hyperkalemia include muscle weakness, fatigue, palpitations, tachycardia, paresthesia, nausea, diarrhea, and confusion. Electrocardiogram (ECG, EKG) changes such as peaked T waves, flattened P waves, and prolonged QRS durations may be seen. In severe cases, hyperkalemia can cause cardiac arrest (Shrimanker & Bhattarai, 2023).
Treatment for hyperkalemia includes removing excess potassium from the body through dialysis, administering drugs that shift potassium from the extracellular fluid into the cells, administering potassium-binding drugs that help bind to potassium and excrete it from the body, and treating the underlying cause. Common underlying causes of hyperkalemia include kidney failure and diabetes (Shrimanker & Bhattarai, 2023).
Nursing implications include restricting potassium in the diet. The health care provider may order administration of sodium bicarbonate (which elevates the pH level and moves potassium back into cells, thereby lowering the serum potassium levels), insulin and glucose (insulin helps to move potassium back into the cells by promoting the uptake of glucose and potassium), and/or sodium polystyrene sulfonate (which exchanges sodium ions for potassium ions in the colon, leading to removal of excess potassium through the stool). Monitoring potassium levels and reporting significant changes to the health care provider is key in ensuring appropriate potassium balance within the body (Shrimanker & Bhattarai, 2023).
Clients should avoid food high in potassium (such as bananas, potatoes, and spinach), avoid salt substitutes (as these are high in potassium), take drugs as prescribed, and seek medical attention if they develop manifestations of hyperkalemia, such as palpitations, tachycardia, and muscle weakness.
Hypokalemia
Hypokalemia is a condition where the level of potassium in the blood is lower than normal (less than 3.6 mEq/L). Hypokalemia can be caused by excessive loss of potassium through the kidneys, increased loss of potassium in the digestive tract (through vomiting or diarrhea), insufficient potassium intake, redistribution of potassium from extracellular fluid into cells (by insulin therapy, alkalosis, or drugs), or by a magnesium deficiency (magnesium is necessary for the proper function of channels that regulate potassium transport in cells) (Shrimanker & Bhattarai, 2023).
Manifestations of hypokalemia include fatigue, muscle weakness, muscle cramps, constipation, and irregular heartbeat. EKG changes may be present with T wave inversion, widespread ST depression, and prominent U waves (Shrimanker & Bhattarai, 2023).
Treatment for hypokalemia includes administering potassium supplements orally or intravenously, treating the underlying cause, and monitoring for complications such as low blood pressure. Common underlying causes of hypokalemia include diarrhea, diuretic use, excessive laxative use, excessive sweating, and diabetic ketoacidosis. Adverse reactions with potassium supplements include nausea, vomiting, abdominal pain, and diarrhea. Potassium supplements should be used cautiously with ARBs, ACE inhibitors, and potassium-sparing diuretics such as spironolactone.
Nursing implications include monitoring potassium levels, assessing for manifestations of hypokalemia, and administering potassium supplements as prescribed by the health care provider. Clients should eat a diet containing potassium-rich foods (such as bananas, lentils, and dried fruits). Clients should avoid excessive use of laxatives or diuretics and report symptoms of hypokalemia, such as muscle weakness and constipation, to their health care provider.
Safety Alert
Potassium and IV Bolus or Push
Never push or bolus potassium intravenously. Rapid administration of potassium via intravenous bolus or push can result in cardiac dysrhythmias and client death. Intravenous potassium solutions are often premixed (diluted in 100–1000 mL of normal saline or lactated Ringer’s solutions) to decrease the risk of errors.
Clinical Tip
Potassium Administration and IV Site Assessment
Monitor the client’s IV site closely when administering potassium intravenously for infiltration because potassium solutions can cause extravasation and tissue necrosis if they infiltrate into subcutaneous tissues. Discontinue the IV fluids immediately if this occurs and notify the health care provider. Maximum potassium concentration is 40 mEq/L with a maximum peripheral infusion rate of 20 mEq/hour (Sur & Mohiuddin, 2022).
Sodium
Sodium (Na) is predominantly an extracellular cation, meaning it is found primarily outside of the cells in the extracellular fluid. The normal concentration of sodium in the body is approximately 135–145 mEq/L (which is the same as the therapeutic range for serum sodium levels), whereas the normal intracellular concentration is around 10 mEq/L (Shrimanker & Bhattarai, 2023).
The sodium-potassium-ATPase pump is vital for maintaining the concentration gradient of sodium and potassium ions across the cell membrane. As you may recall, the pump uses energy to move sodium out of cells and potassium into cells against their concentration gradients in order to maintain sodium–potassium balance (Shrimanker & Bhattarai, 2023).
Sodium has many functions within the body. It is the primary determinant of the osmolality and volume of extracellular fluids. It is involved in the transmission of nerve impulses throughout the body, including the brain and nervous system. Sodium is important for proper muscle contraction and relaxation. Potassium and sodium work together to regulate blood pressure by maintaining the proper fluid balance. Sodium helps to maintain the pH balance of the blood. Additionally, sodium is necessary for the absorption of certain nutrients such as glucose and amino acids in the small intestine (Shrimanker & Bhattarai, 2023; Veniamakis et al., 2022).
Hypernatremia
Hypernatremia is a condition in which the sodium levels in the blood are higher than normal (above 145 mEq/L). As sodium levels rise, hypertonicity occurs, and water shifts out of the ICF space into the ECF. This can be caused by dehydration, excessive salt intake, deficient water intake, or kidney problems (Shrimanker & Bhattarai, 2023).
Manifestations of hypernatremia include thirst, dry mucous membranes, flushed dry skin, elevated body temperature, muscle twitching, seizure, and coma. Treatment for hypernatremia involves correcting the underlying cause and restoring fluid and electrolyte balance. Intravenous fluids and drugs to lower sodium levels may be administered gradually.
Nursing implications include monitoring intake and output as well as electrolyte levels. IV fluids and drugs such as diuretics are administered as needed.
Client Teaching Guidelines
The client with hypernatremia should:
- Avoid foods high in sodium, avoid using salt when cooking, and refrain from adding extra salt to foods at the table.
- Read food labels and over-the-counter (OTC) drug labels to avoid excessive sodium intake.
- Report manifestations of hypernatremia, such as thirst and muscle twitching, to their health care provider.
Hyponatremia
Hyponatremia is a condition in which sodium levels are lower than normal (less than 135 mEq/L). As sodium levels decrease, hypotonicity occurs, and water shifts from the ECF into the ICF. This can be caused by conditions such as kidney disease, heart failure, or excessive fluid intake (Shrimanker & Bhattarai, 2023). Manifestations of hyponatremia include muscle weakness, decreased deep tendon reflexes, headache, lethargy, confusion, weak or thready pulse, decreased blood pressure, seizures, and coma.
Treatment for hyponatremia includes correcting the underlying cause and restoring fluid and electrolyte balance. Oral sodium replacement or intravenous fluids may be necessary to restore homeostasis. Adverse reactions include hypertension and fluid volume excess. Sodium replacement supplements should be used cautiously in clients with advanced renal disorders or heart failure.
Nursing implications include monitoring intake and output of sodium and electrolyte levels, administering oral sodium replacements or intravenous solutions as ordered by the health care provider, and client education on fluid intake.
Client Teaching Guidelines
The client with hyponatremia should:
- Limit fluid intake to maintain proper fluid and electrolyte balance.
- Report manifestations or changes in symptoms such as headache and lethargy to the health care provider.
Calcium
Calcium (Ca) is the fifth most abundant mineral in the body and is present in both intracellular and extracellular fluid compartments. In the ECF, calcium is present in ionized and protein-bound forms; in ICF, calcium is primarily bound to proteins and organelles. The therapeutic range for serum calcium levels is 8.8–10.4 mg/dL (Drake & Gupta, 2022; Shrimanker & Bhattarai, 2023).
Calcium is necessary for the formation and maintenance of bones and teeth. It is also important for proper muscle function, including contraction and relaxation. Calcium is involved in the transmission of nerve impulses and is necessary for the release of certain hormones and enzymes. Additionally, calcium is involved in the clotting of blood and helps to regulate heart rhythm (Shrimanker & Bhattarai, 2032). Calcium has an inverse relationship with phosphorus and a synergistic relationship with magnesium. The parathyroid hormone from the parathyroid gland and calcitonin from the thyroid gland regulate calcium levels. The absorption of calcium requires activated vitamin D.
Hypercalcemia
Hypercalcemia is a condition in which serum calcium levels are higher than normal (greater than 10.4 mg/dL). Hypercalcemia can be a result of hyperparathyroidism, malignancy, hypophosphatasia, and thiazide diuretic use (Drake & Gupta, 2022; Sadiq et al., 2022; Shrimanker & Bhattarai, 2023).
Manifestations of hypercalcemia include nausea, vomiting, loss of appetite, excessive thirst or urination, constipation, abdominal pain, bone pain, diminished deep tendon reflexes, confusion, kidney stones, muscle weakness or twitching, and an irregular heartbeat.
Treatment for hypercalcemia includes identifying and treating the underlying cause, such as hyperparathyroidism or certain cancers. Treatment options include drugs to decrease calcium levels, such as loop diuretics, bisphosphonates, or calcitonin, or IV fluids to help flush excess calcium from the body.
Nursing implications include close monitoring of calcium levels and vital signs, administering drugs as prescribed by the health care provider, and monitoring for complications such as kidney stones, renal impairment, and cardiac arrhythmias.
Client Teaching Guidelines
The client with hypercalcemia should:
- Avoid overuse of calcium-containing antacids.
- Report symptoms, such as bone pain or changes in urination, to the health care provider.
Hypocalcemia
Hypocalcemia is a condition in which serum calcium levels are lower than normal (lower than 8.8 mg/dL) (Drake & Gupta, 2022). Hypocalcemia can result from calcium loss from bone, pathologic fractures due to calcium loss, hypoparathyroidism, hyperphosphatemia, diarrhea, alcoholism, vitamin D deficiency, and malnutrition. Manifestations of hypocalcemia include paresthesia, muscle cramps or spasms, weakness, fatigue, difficulty swallowing or speaking, confusion, osteoporosis, irritability, seizures, and dysrhythmias (Shrimanker & Bhattarai, 2023).
Treatment for hypocalcemia includes identifying and treating the underlying cause, such as vitamin D deficiency. Treatment options may include calcium and vitamin D supplements, drugs to improve calcium absorption, or intravenous calcium if levels are severely low. Adverse reactions include constipation, severe diarrhea, and abdominal pain. Calcium supplements should be used cautiously with levothyroxine, tetracycline antibiotics, and quinolone antibiotics because they can decrease their absorption.
Nursing implications include administering oral or intravenous calcium supplements, administering vitamin D supplements, assessing renal and cardiac functioning, and monitoring the IV site for infiltration and extravasation.
Client Teaching Guidelines
The client with hypocalcemia should:
- Maintain a balanced diet with calcium - rich foods, such as dairy products enriched with vitamin D, sardines, salmon, winter squash, and edamame.
Clinical Tip
Calcium Supplements and Iron Administration
Avoid administering oral iron supplements within 1 to 2 hours of oral calcium supplements and dairy products because calcium may interfere with the absorption of iron and reduce its effectiveness (Piskin et al., 2022).
Phosphorous
Phosphorous (P) is the second most abundant element in the body and is a major anion in intracellular fluid. The majority of the body’s phosphorus is found in phosphate; it is important to note that the terms phosphate and phosphorus are used interchangeably. Phosphorus is needed to help bones and teeth maintain their structure, for RNA and DNA synthesis, for cell signaling, and for pH balance in the body. The therapeutic range for serum phosphorus level is 3.4–4.5 mEq/L (Shrimanker & Bhattarai, 2023).
Hyperphosphatemia
Hyperphosphatemia is a condition where the body’s phosphorus level is greater than the therapeutic range (above 4.5 mEq/L). Causes of hyperphosphatemia include chronic kidney disease, hypoparathyroidism, excess phosphorus intake, and certain drugs (Goyal & Jialal, 2022; Shrimanker & Bhattarai, 2023).
Manifestations of hyperphosphatemia include muscle spasms, hyperreflexia, nausea, diarrhea, and abdominal cramps. Treatment for hyperphosphatemia involves addressing the underlying cause and may involve restricting dietary intake of phosphorus, administering phosphate-binding drugs, and in severe cases, dialysis.
Nursing implications include monitoring serum phosphate levels, assessing manifestations, and educating the client regarding dietary intake.
Client Teaching Guidelines
The client with hyperphosphatemia should:
- Report symptoms such as abdominal pain and tetany to the health care provider.
- Avoid foods high in phosphorus, such as whole grains and nuts.
Hypophosphatemia
Hypophosphatemia is a condition where the body’s phosphorus level is lower than the therapeutic range (below 2.5 mEq/L). Causes include malnutrition, alcoholism, hyperparathyroidism, and certain drugs, such as diuretics. Manifestations include muscle weakness, altered mental status, bone pain, paresthesia, and dysphagia (Sharma et al., 2022; Shrimanker & Bhattarai, 2023).
Treatment for hypophosphatemia depends on the underlying cause and may involve oral or intravenous phosphorus supplementation and adjusting drugs or drug dosages. Adverse effects of phosphorus supplements include kidney stones, headache, dizziness, and seizures. Phosphorus supplements should be used cautiously in clients at risk for kidney stones or who have kidney failure.
Nursing implications include monitoring phosphate levels, assessing manifestations for worsening symptoms, and monitoring for adverse effects of phosphorus supplements, which include bone pain, muscle cramps, confusion, tachycardia, or swelling in hands, legs, or feet.
Client Teaching Guidelines
The client with hypophosphatemia should:
- Report symptoms such as bone pain and tremors to the health care provider.
- Maintain a well-balanced diet with foods high in phosphorus, such as whole grain cereals, nuts, and dairy products.
- Drink a full glass of water every hour to reduce the risk of kidney stone development.
Magnesium
Magnesium (Mg) is a mineral that is essential for many physiological processes, including energy production, protein synthesis, muscle and nerve function, and bone health. It is found in both ICF and ECF. The therapeutic range for serum magnesium is 1.46–2.68 mEq/L (Shrimanker & Bhattarai, 2023). Magnesium assists in the release of parathyroid hormone (PTH). Magnesium and potassium have an interdependent relationship; when potassium levels decrease, so do magnesium levels, and vice versa.
Hypermagnesemia
Hypermagnesemia refers to high levels of magnesium in the blood (greater than 2.68 mEq/L). It can be caused by kidney dysfunction, excessive use of magnesium-containing antacids or laxatives, excessive magnesium supplement use, or use of certain medications, such as proton pump inhibitors and lithium-based psychotropic drugs (Cascella & Vaqar, 2023; Shrimanker & Bhattarai, 2023).
Manifestations of hypermagnesemia include weakness, lethargy, confusion, low blood pressure, and in severe cases, cardiac arrest. Treatment of hypermagnesemia consists of removing the cause of excess magnesium, administering drugs such as calcium gluconate to reduce magnesium in the body, and symptom management.
Nursing implications include close monitoring of electrolyte levels and timely reporting of any changes in client symptoms or laboratory values to the health care provider.
Client Teaching Guidelines
The client with hypermagnesemia should:
- Use magnesium or magnesium-containing supplements or drugs carefully.
- Promptly report any symptoms that may indicate hypermagnesemia, such as weakness and low blood pressure, to the health care provider.
Hypomagnesemia
Hypomagnesemia refers to low levels of magnesium in the blood (less than 1.46 mEq/L). It can be caused by a variety of factors including malnutrition, alcoholism, gastrointestinal disorders, and drugs such as diuretics. Manifestations include generalized weakness, tremors, cramps, arrhythmias, and seizures (Gragossian et al., 2022; Shrimanker & Bhattarai, 2023).
Treatment for hypomagnesemia involves oral or intravenous magnesium supplementation and addressing the underlying cause. Adverse reactions to magnesium supplements include nausea, abdominal cramping, diarrhea, hypotension, flushing of skin, and urinary retention. Magnesium supplements should be used cautiously in clients with diabetes, digestive disorders, and heart or kidney disorders.
Nursing implications involve careful monitoring of magnesium levels, identifying clients at risk for development of hypomagnesemia, and monitoring and reporting changes in symptoms and laboratory values to the health care provider.
Client Teaching Guidelines
The client with hypomagnesemia should:
- Take magnesium supplements with meals to prevent gastrointestinal upset and diarrhea.
- Eat foods rich in magnesium, such as avocado, broccoli, spinach, and lentils.
Clinical Tip
Magnesium and Folic Acid, Fiber, and Iron Supplements
Avoid administering magnesium within 2 hours of folic acid, fiber, and iron supplements because magnesium may interfere with the absorption of these drugs and reduce their effectiveness (National Health Service, 2023).
Chloride
Chloride (Cl) is an anion found primarily in the ECF and is essential in maintaining fluid balance and helping to regulate the pH of bodily fluids. Chloride ions are important for the formation of hydrochloric acid in the stomach, which is necessary for the digestion of food. Additionally, chloride ions work together with other electrolytes, such as sodium and potassium, to maintain proper electrical balance and conduct nerve impulses throughout the body. The therapeutic range for chloride is 98–106 mEq/L (Fishman, 2023; Shrimanker & Bhattarai, 2023).
Hyperchloremia
Hyperchloremia is a condition where there is an excess amount of chloride in the blood (greater than 106 mEq/L). It may be caused by various conditions such as dehydration, metabolic acidosis, and kidney disease and by certain drugs, such as chemotherapy (Shrimanker & Bhattarai, 2023).
Manifestations of hyperchloremia include weakness, confusion, lethargy, and tachypnea (rapid breathing). Treatment involves addressing the underlying cause in addition to fluid and electrolyte replacement.
Nursing implications include monitoring fluid and electrolyte balance, intake, and output; administering drugs such as diuretics as ordered; and maintaining the client on a low-sodium diet.
Client Teaching Guidelines
The client with hyperchloremia should:
- Avoid foods high in salt because chloride binds readily to sodium.
- Monitor their fluid intake and report symptoms of hyperchloremia, such as tachypnea and lethargy, to the health care provider.
Hypochloremia
Hypochloremia is a condition where there is a low amount of chloride in the blood (less than 98 mEq/L). It may be caused by diarrhea, vomiting, kidney disease, or metabolic alkalosis. Manifestations include weakness, fatigue, trouble breathing, and dizziness (Fishman, 2023; Shrimanker & Bhattarai, 2023).
Treatment is focused on treating the underlying cause, replacing fluids and electrolytes, and adjusting drugs or drug dosages. Adverse effects include fever and fluid volume excess. Fluid replacement with chloride-containing solutions should be administered cautiously in clients with heart failure and kidney disorders.
Nursing implications include monitoring intake and output, administering fluids and electrolytes per health care provider orders, and monitoring for signs of fluid volume excess, such as shortness of breath, crackles, and peripheral edema, from overtreatment.
Client Teaching Guidelines
The client with hypochloremia should:
- Maintain a balanced diet that includes sources of sodium.
- Report symptoms of hypochloremia, such as tremors and low blood pressure, to the health care provider.