Chapter 11: Electrolyte Balance and Imbalance EAQ Questions (Rationales)

Laboratory results for a patient with a large draining abdominal wound show a serum sodium decrease from 138 mEq/L to 131 mEq/L. What is the nurse's first action? A. Establish intravenous (IV) access. B. Assess for orthostatic hypotension. C. Assess the patient's respiratory status. D. Notify the provider of laboratory results.

C. Assess the patient's respiratory status. Rationale: Hyponatremia may present with neuromuscular changes including muscle weakness of the legs, arms, and respiratory muscles. The nurse should assess the respiratory effectiveness of a patient with hyponatremia as a priority. Obtaining assessment data is important when calling the provider in addition to reporting the laboratory result. Establishing IV access and assessing for orthostatic hypotension are important but are lower-priority interventions.

A patient reports painful muscle spasms in the lower legs at rest, a tingling sensation in the hands and lips, and abdominal cramping and diarrhea. The nurse reviews the patient's laboratory results for the presence of which disorder? A. Hypocalcemia B. Hypernatremia C. Hypermagnesemia D. Hypophosphatemia

A. Hypocalcemia Rationale: The primary symptoms of hypocalcemia are neuromuscular changes, specifically painful muscle cramps, and paresthesias that may spread to the face, progressing to tetany. Abdominal cramping and diarrhea may also occur. Muscle spasms in lower legs at rest, tingling sensation in the hands and lips, and abdominal cramping and diarrhea are not primary characteristics of hypernatremia, hypermagnesemia, or hypophosphatemia.

The health care provider writes orders for a patient who is admitted with a serum potassium (K) level of 6.9 mEq/L. What does the nurse implement first? A. Place the patient on a cardiac monitor. B. Administer sodium polystyrene sulfonate orally. C. Ensure that a potassium-restricted diet is ordered. D. Teach the patient about foods that are high in potassium.

A. Place the patient on a cardiac monitor. Rationale: Because hyperkalemia can lead to life-threatening bradycardia, the initial action should be to place the patient on a cardiac monitor. Administering a potassium-reducing medication, recommending a potassium-restricted diet, and teaching the patient about diet are appropriate but will not immediately decrease the serum potassium level and do not need to be implemented as quickly as monitoring cardiac rhythm.

Which drug therapy might be used to manage symptoms of hypocalcemia? A. Vitamin E B. Zinc sulfate C. Calcium chloride D. Potassium chloride

C. Calcium chloride Rationale: Calcium supplements are given to restore serum calcium levels. Potassium, zinc, and vitamin E are not indicated for the management of hypocalcemia.

Positive Trousseau's and Chvostek's signs are consistent with which electrolyte imbalance? A. Hypokalemia B. Hyperkalemia C. Hypocalcemia D. Hypercalcemia

C. Hypocalcemia Rationale: Trousseau's sign (palmar flexion) and Chvostek's sign (facial twitching) are consistent with acute hypocalcemia. These manifestations are caused by overstimulation of the nerves and muscles. Trousseau's and Chvostek's signs are not used to assess for potassium imbalances.

The nurse is reviewing serum electrolytes and blood chemistry for a newly admitted patient. Which result causes the greatest concern? A. Glucose: 97 mg/dL B. Sodium: 143 mEq/L C. Potassium: 5.9 mEq/L D. Magnesium: 2.1 mEq/L

C. Potassium: 5.9 mEq/L Rationale: A potassium value of 5.9 mEq/L is high, and the patient should be assessed further. A glucose value of 97 mg/dL, a magnesium value of 2.1 mEq/L, and a sodium value of 143 mEq/L are normal values.

An electrocardiogram (ECG) is ordered for a patient who was placed on intravenous (IV) fluids containing potassium. Which ECG finding is consistent with hyperkalemia? A. Absent T waves B. Elevated P waves C. Prolonged PR intervals D. Shortened QRS complexes

C. Prolonged PR intervals Rationale: When hyperkalemia is present, an individual may show absent P waves, tall T waves, prolonged PR intervals, and widened QRS complexes.

Which newly written prescription does the nurse administer first? A. Oral calcium supplements to a patient with severe osteoporosis B. Oral phosphorus supplements to a patient with acute hypophosphatemia C. Intravenous (IV) normal saline to a patient with a serum sodium of 132 mEq/L D. Oral potassium chloride (KCl) to a patient whose serum potassium is 3 mEq/L

D. Oral potassium chloride (KCl) to a patient whose serum potassium is 3 mEq/L Rationale: Because minor changes in serum potassium level can cause life-threatening dysrhythmias, the first priority should be to administer potassium supplements to the patient with hypokalemia. The electrolyte disturbance (sodium level of 132 and low phosphorus level) and the need for calcium in this patient are not immediately life-threatening.

A patient has a serum magnesium level of 1.2 mEq/L. Which instruction by the nurse is appropriate? A. "Notify me if you have diarrhea." B. "I will be giving you an intramuscular injection of magnesium sulfate." C. "Your urine may become darker and more concentrated in appearance." D. "I will be administering a phosphorus supplement in addition to the magnesium supplement."

A. "Notify me if you have diarrhea." Rationale: A serum magnesium level of 1.2 mEq/L represents mild hypomagnesemia (normal is 1.3-2.1 mEq/L) for which oral magnesium supplements are administered. Oral magnesium may lead to diarrhea; diarrhea contributes to magnesium loss. With severe hypomagnesemia, the IV route (instead of IM) is used because the IM route causes tissue damage and pain. Any medications containing phosphorus are contraindicated because they would contribute to associated hypocalcemia. Magnesium therapy does not affect the urine.

A patient with severe hypokalemia is prescribed parenteral administration of potassium. How does the nurse administer potassium to the patient? A. 1 mEq of potassium to 10 mL intravenous solution B. 10 mEq of potassium to 10 mL intravenous solution C. 1 mEq of potassium to 10 mL solution intramuscularly D. 10 mEq of potassium to 10 mL solution intramuscularly

A. 1 mEq of potassium to 10 mL intravenous solution Rationale: Potassium is given intravenously for severe hypokalemia, but only mixed in a solution. It is available in many concentrations. The risk of solute overload causing congested states with peripheral and pulmonary edema is directly proportional to the electrolyte concentrations of such solutions. Therefore 1 mEq of potassium to 10 mL of solution is the preferred dilution to prevent the risk associated with hyperkalemia. A concentration of 10 mEq of potassium to 10 mL of solution is too high and can cause tissue irritation. Potassium is a severe tissue irritant; it may cause necrosis and loss of function of the tissue, and so is never given as an intramuscular or subcutaneous injection.

When administering 20 mEq potassium chloride intravenously (IV), which is the priority intervention? A. Administer at a rate of 10 mEq/hr. B. Monitor respiratory rate and depth. C. Monitor for pain or burning at the IV infusion site. D. Place the patient on a heart monitor during administration.

A. Administer at a rate of 10 mEq/hr. Rationale: The maximum recommended infusion rate is 5 to 10 mEq/hr to avoid potentially lethal cardiac dysrhythmias. Monitoring for pain at the IV infusion site, assessing respiratory rate and depth, and placing the patient on a heart monitor are all appropriate options, but because a rapid rate of administration could have lethal effects, it has the greatest priority.

Which electrolyte imbalance does the nurse anticipate in association with a serum magnesium reading of 1.1 mEq/L? A. Calcium 7.8 mg/dL B. Sodium 149 mEq/L C. Potassium 5.7 mEq/L D. Phosphorus 2.6 mg/dL

A. Calcium 7.8 mg/dL Rationale: Hypocalcemia often occurs with hypomagnesemia. A calcium level of 7.8 mg/dL is low. A sodium level of 149 mEq/L is slightly elevated, but not related to the low magnesium level. A phosphorus level of 2.6 mg/dL is slightly low, but not related to hypomagnesemia. A potassium level of 5.7 is elevated, but not related to low magnesium levels.

The nurse manager of a medical-surgical unit is completing assignments for the day shift staff. The patient with which electrolyte laboratory value is assigned to the LPN/LVN? A. Calcium level of 9.5 mg/dL B. Sodium level of 120 mEq/L C. Potassium level of 6.0 mEq/L D. Magnesium level of 4.1 mEq/L

A. Calcium level of 9.5 mg/dL Rationale: Because a calcium level of 9.5 mg/dL is within normal limits, it is appropriate to assign this patient to an LPN/LVN. A magnesium level of 4.1 mEq/L, potassium level of 6.0 mEq/L, and a sodium level of 120 mEq/L are abnormalities in electrolytes that can cause serious complications and will require assessments and/or interventions by the RN.

Hyponatremia most affects the cells of which body systems? Select all that apply. A. Cerebral B. Endocrine C. Respiratory D. Cardiovascular E. Neuromuscular

A. Cerebral D. Cardiovascular E. Neuromuscular Rationale: The cells of the cerebral, cardiovascular, and neuromuscular systems are most affected by hyponatremia. The cells of the endocrine and respiratory systems are not as affected.

When treating a patient for hyponatremia, which type of drug must be altered to decrease sodium loss? A. Diuretics B. Biphosphates C. Corticosteroids D. Beta-adrenergic agonists

A. Diuretics Rationale: When treating a patient with hyponatremia, if the patient is already taking diuretics, his or her dosage must be adjusted because diuretics increase sodium loss. Biphosphates are used to prevent hypercalcemia. Corticosteroids can cause hypernatremia. Beta-adrenergic agonists can cause hypokalemia.

Which nursing interventions are consistent with safe administration of intravenous (IV) potassium to a patient with hypokalemia? Select all that apply. A. Evaluate the heart rate and regularity. B. Establish and evaluate the patency of a large vein. C. Obtain an IV controller device (pump). D. Plan to assess the respiratory rate and oxygen saturation every hour. E. Prepare to administer potassium IV push to reduce the risk of infiltration. F. Encourage the patient to ambulate independently to relieve muscle cramps.

A. Evaluate the heart rate and regularity. B. Establish and evaluate the patency of a large vein. C. Obtain an IV controller device (pump). D. Plan to assess the respiratory rate and oxygen saturation every hour. Rationale: Pulse irregularities (rapid to slow and irregular) may occur with changes in serum potassium levels and should be evaluated. To safely administer IV potassium, the nurse would ensure that the patient has IV access in a large vein if possible, obtain an IV pump to regulate the infusion rate at no greater than 10 mEq of potassium per hour, and evaluate the patient's respiratory status hourly during and immediately following infusion (as respiratory insufficiency is the major cause of death). Potassium should never be given IV push, as it will result in cardiac arrest. Patients with hypokalemia have skeletal muscle weakness, so fall precautions should be implemented, and the patient should have assistance with ambulation.

Laboratory results report a patient's serum potassium at 5.6 mEq/L. What does the nurse immediately assess in the patient? A. Heart rate B. Bowel sounds C. Feet for paresthesias D. Level of consciousness

A. Heart rate Rationale: Cardiovascular changes, specifically bradycardia; tall, peaked T waves; rhythm changes to complete heart block; asystole; and ventricular fibrillation are life-threatening consequences of elevated potassium. The provider or Rapid Response Team may need to be notified if changes in heart rate and rhythm are assessed. Paresthesias in the arms and feet and increased intestinal motility are lower-priority signs of elevated potassium. Level of consciousness would not be affected.

The primary health care provider prescribes intravenous administration of 100 mL of 20% glucose along with 20 units of insulin in a patient who is receiving furosemide therapy. What is the probable diagnosis of the patient? A. Hyperkalemia B. Hyperglycemia C. Hypernatremia D. Hypercalcemia

A. Hyperkalemia Rationale: Hyperkalemia is a condition where serum potassium levels are high. Potassium movement into the cells is enhanced by insulin. Intravenous administration of 100 mL 10% to 20% glucose with 10 to 20 units of regular insulin helps decrease serum potassium levels. Insulin increases the activity of sodium-potassium pumps, which decreases serum potassium levels temporarily by moving potassium from the extracellular fluid to the cells. This therapy is prescribed as an add-on therapy along with diuretics in a hyperkalemic patient. Conditions such as hyperglycemia, hypernatremia, and hypercalcemia cannot be managed with this insulin and glucose therapy.

A patient is admitted to the hospital with a heart rate of 166 beats/min, increased thirst, restlessness, and agitation. Which electrolyte imbalance does the nurse suspect? A. Hypernatremia B. Hypercalcemia C. Hypomagnesemia D. Hyperphosphatemia

A. Hypernatremia Rationale: These symptoms are indicative of hypernatremia. Clinical manifestations of hypomagnesemia are seen in the neuromuscular, central nervous, and intestinal systems. Hypercalcemia manifests with an altered level of consciousness that can range from confusion and lethargy to coma, and severe hypercalcemia depresses electrical conduction, slowing heart rate. Hyperphosphatemia causes few direct problems with body function (although hypocalcemia is usually also present).

A patient has a low serum potassium level and is ordered a dose of parenteral potassium chloride (KCl). How does a nurse safely administer KCl to the patient? A. Infuses 10 mEq over a 1-hour period B. Administers 5 mEq intramuscularly (IM) C. Pushes 5 mEq through a central access line D. Dilutes 200 mEq in 1 liter of normal saline and infuses at 100 mL/hr

A. Infuses 10 mEq over a 1-hour period Rationale: A dose of KCl 10 mEq given over 1 hour is appropriate for this patient. A dose of KCl 200 mEq in 1 liter of normal saline infused at 100 mL/hr is too concentrated and can cause injury. Potassium is a severe tissue irritant and is never given by the intramuscular or subcutaneous route. Because rapid infusion of potassium can cause cardiac arrest, potassium is not administered through central lines.

Which fruit will the nurse remove from the dietary tray of a patient with high potassium levels? A. Kiwi B. Berries C. Apricots Grapefruit

A. Kiwi Rationale: Kiwis are high in potassium, so the nurse will remove this food from the tray. However, berries, apricots, and grapefruits are low in potassium, so this patient does not need to avoid them.

When planning care for a patient with hypercalcemia, which intervention does the nurse consider? A. Monitor cardiac rhythm for changes. B. Limit activities to protect against injury. C. Assess oxygen saturation levels every 4 hours. D. Avoid invasive procedures due to increased bleeding tendency.

A. Monitor cardiac rhythm for changes. Rationale: Hypercalcemia increases the risk for cardiac dysrhythmias. It does not impair gas exchange, so oxygen saturation does not need to be routinely monitored. There is a greater tendency to clot, especially with slow venous perfusion, so invasive procedures do not need to be avoided and increased activity (not restriction) is recommended.

Which nursing action is recommended when providing care to a patient with hypokalemia? A. Question the continued administration of bumetanide. B. Administer prescribed oral potassium chloride before a meal or snack. C. Establish a peripheral IV, preferably in the hand, for administering IV potassium chloride. D. Obtain the prescribed vial of IV potassium chloride from the pharmacy and dilute before administration.

A. Question the continued administration of bumetanide. Rationale: Bumetanide is a loop diuretic, which contributes to potassium loss and should be questioned. The Joint Commission has mandated that all concentrated electrolytes be mixed by a pharmacist and that vials of KCl should not be available in patient care areas. A large vein with high blood flow should be accessed to avoid phlebitis; it is recommended that the hand be avoided. Oral potassium supplements should be given with or following a snack or meal to avoid nausea.

Which electrolyte excess results in irritability and severe cellular dehydration? A. Sodium B. Calcium C. Phosphorus D. Magnesium

A. Sodium Rationale: Hypernatremia occurs when serum sodium levels are very high; this condition causes excitable tissues to over-respond to stimuli. This leads to irritability and severe cellular dehydration. Hypercalcemia, an excess of calcium, decreases the sensitivity of excitable tissues to normal stimuli. Hyperphosphatemia (excess phosphorus) causes hypocalcemia. Hypermagnesemia (excess magnesium) causes hypotension, bradycardia, central nervous system changes, and neuromuscular changes.

Which electrolyte deficiency results in decreased depolarization in the excitable cells and increased cellular swelling? A. Sodium B. Calcium C. Potassium D. Magnesium

A. Sodium Rationale: Hyponatremia occurs when sodium levels are low; this condition causes decreased depolarization in excitable cells and increased cellular swelling. Low serum calcium levels lead to muscle cramping and cardiac arrhythmias. A potassium deficiency causes cardiac dysrhythmias. A decrease in the level of magnesium may cause increased nerve impulse transmission.

An older adult patient is admitted with dehydration. Which nursing assessment data identify that the patient is at risk for falling? A. Dry oral mucous membranes B. Orthostatic blood pressure changes C. Serum potassium level of 4.0 mEq/L D. Pulse rate of 72 beats/min and bounding

B. Orthostatic blood pressure changes Rationale: Blood pressure decreases when changing positions. The patient may not have sufficient blood flow to the brain, causing sensations of light-headedness and dizziness. This problem increases the risk for falling, especially in older adults. Assessment of oral mucous membranes and the pulse rate can detect symptoms of dehydration, but these are not the best ways to assess for a fall risk. Checking serum potassium does not assess for fall risk.

A hypertensive patient was brought to the emergency department with a heart rate of 115 beats per minute and an abnormal electrocardiogram showing a shortened QT interval. The laboratory findings of the patient show a serum calcium level of 11 mg/dL. What nursing interventions would help stabilize the patient? Select all that apply. A. Administering thiazide diuretics B. Administering high ceiling or loop diuretics C. Administering 0.9% normal saline intravenously D. Administering nonsteroidal, anti-inflammatory agents E. Administering lactated Ringer's solution intravenously

B. Administering high ceiling or loop diuretics C. Administering 0.9% normal saline intravenously Rationale: Hypercalcemia clinically manifests as serum calcium levels above 10.5 mg/dL. This condition can be managed by using loop diuretics such as furosemide, which promote the excretion of calcium. One cause of hypercalcemia is dehydration, which can be well managed by administering 0.9% normal saline intravenously. Thiazide diuretics do not promote the excretion of calcium and thus are not suitable treatments for hypercalcemia. Lactated Ringer's solution contains calcium; administering this solution does not help decrease the serum calcium levels. Administering nonsteroidal, anti-inflammatory agents prevents hypercalcemia by calcium resorption from the bone; however, it does not treat hypercalcemia.

A patient's morning laboratory results show a serum ionized calcium of 2.85 mmol/L. For what sign must the nurse assess? A. Tachypnea B. Blood clotting C. Muscle spasms D. Increased peristalsis

B. Blood clotting Rationale: Hypercalcemia allows blood clots to form more easily, especially in the lower legs and pelvic region. The nurse should assess for signs of blood clotting associated with the elevated serum calcium. Increased peristalsis and muscle spasms are associated with hypocalcemia. Tachycardia can occur initially with mild hypercalcemia, but bradycardia is associated with severe hypercalcemia.

When assessing the laboratory results of a patient who has hypomagnesemia, for which additional electrolyte imbalances should the nurse monitor? A. Hyperkalemia B. Hypocalcemia C. Hypernatremia D. Hypophosphatemia

B. Hypocalcemia Rationale: Hypocalcemia often occurs with hypomagnesemia, so the nurse would monitor for signs and symptoms of low calcium levels. Hypomagnesemia may increase potassium secretion in certain circumstances, leading the healthcare provider to be aware that replacement of magnesium is crucial before attempting to replace potassium if the patient is deficient in both. Hypernatremia and hypophosphatemia are not related to hypomagnesemia.

A patient who recently experienced an anterior neck injury reports frequent and painful muscle spasms in the calf during sleep. Which condition does the nurse suspect in the patient? A. Hypokalemia B. Hypocalcemia C. Hyponatremia D. Hypophosphatemia

B. Hypocalcemia Rationale: Patients with a history of anterior neck injury are at a high risk for hypocalcemia. Frequent painful muscle spasms in the calf or foot during rest or sleep (charley horses) indicate hypocalcemia. Hypokalemia, hyponatremia, and hypophosphatemia do not cause painful calf muscle spasms.

Which electrolyte imbalance should be anticipated and monitored in a patient with hyperphosphatemia? A. Hypokalemia B. Hypocalcemia C. Hypernatremia D. Hypermagnesemia

B. Hypocalcemia Rationale: Phosphorus and calcium have an inverse or reciprocal relationship. When one is increased, the other is usually decreased. Therefore a patient with hyperphosphatemia should be monitored for hypocalcemia. Hyperphosphatemia does not cause hypernatremia, hypokalemia, or hypermagnesemia.

A 77-year-old woman is brought to the emergency department by her family after she has had diarrhea for 3 days. The family tells the nurse that she has not been eating or drinking well, but that she has been taking her diuretics for congestive heart failure (CHF). Her laboratory results include a potassium level of 3.0 mEq/L. What does the nurse include in the patient's medication teaching? Select all that apply. A. Diuretics increase fluid retention. B. Laxatives can lead to fluid imbalance. C. It is important to weigh daily at the same time. D. Diuretics can lead to fluid and electrolyte imbalances. E. Daily weights are a poor indicator of fluid loss or gain.

B. Laxatives can lead to fluid imbalance. C. It is important to weigh daily at the same time. D. Diuretics can lead to fluid and electrolyte imbalances. Rationale: Diuretics decrease fluid retention and increase loss of fluids, thus can lead to fluid and electrolyte imbalances. Laxatives can also lead to fluid imbalance. Daily weight recording is a good indicator of fluid retention. Patients should be taught to weigh themselves at the same time, in the same clothing, and on the same scale.

The nurse is assessing a patient with hyponatremia. Which finding requires immediate action? A. Heightened acuity B. Muscular weakness C. Urine output of 35 mL/hr D. Diminished bowel sounds

B. Muscular weakness Rationale: Muscle weakness in patients with hyponatremia requires immediate action. If muscle weakness is present, immediately check respiratory effectiveness because ventilation is dependent on adequate strength of the respiratory muscles. Excessive bowel sounds, not diminished bowel sounds, are expected in the patient with hyponatremia, as well as mild confusion, not heightened acuity. A urine output of 35 mL/hr is normal (minimally) and does not require immediate action.

A patient is admitted to the nursing unit with a diagnosis of hypokalemia. Which assessment does the nurse complete first? A. Auscultating bowel sounds B. Obtaining a pulse oximetry reading C. Checking deep tendon reflexes (DTRs) D. Determining the level of consciousness (LOC)

B. Obtaining a pulse oximetry reading Rationale: Because hypokalemia may cause respiratory insufficiency and respiratory arrest, the patient's respiratory status should be assessed first. Bowel sounds, DTRs, and LOC may change in a patient with hypokalemia, but these changes are not immediately life-threatening.

Which foods will the nurse teach a patient with hyperkalemia to avoid? Select all that apply. A. Sugar B. Oranges C. Broccoli D. Cranberries E. Dairy products

B. Oranges C. Broccoli E. Dairy products Rationale: A patient with hyperkalemia has high levels of potassium, so the nurse should instruct the patient to avoid oranges, broccoli, and dairy products, which are all high in potassium. Sugar is low in potassium, so this patient does not necessarily need to avoid it in order to manage his or her hyperkalemia, but he or she should limit sugar consumption to healthy levels. Cranberries are low in potassium, so telling the patient to avoid cranberries is unnecessary.

A patient is admitted with hypokalemia and skeletal muscle weakness. Which assessment does the nurse perform first? A. Pulse B. Respirations C. Temperature D. Blood pressure

B. Respirations Rationale: Respiratory changes are likely because of weakness of the muscles needed for breathing. Skeletal muscle weakness results in shallow respirations. Thus respiratory status should be assessed first in any patient who might have hypokalemia. Blood pressure and pulse will be altered in this patient, but they are not the priority assessment. Temperature is not a priority assessment for the patient with hypokalemia.

What history and assessment findings may be associated with hypocalcemia in a 22-year-old man? Select all that apply. A. Absent bowel sounds B. Tingling around the mouth C. Awakening at night with muscle spasms in the calf D. Decreased deep tendon reflexes without paresthesia E. Recent blunt trauma to the throat during a football game

B. Tingling around the mouth C. Awakening at night with muscle spasms in the calf E. Recent blunt trauma to the throat during a football game Rationale: A history of anterior neck injury may be associated with hypocalcemia. Symptoms of hypocalcemia include "charley horses" in the calf during rest or sleep, and tingling in the lips. Hypocalcemia does not affect bowel sounds. Decreased deep tendon reflexes without paresthesia is a neuromuscular change in hypercalcemia.

The nurse is performing discharge dietary teaching for a patient with hyperkalemia. Which statement does the nurse include in the teaching? A. "You may use salt substitutes." B. "You don't need to restrict dairy products." C. "You may eat apples, strawberries, and peaches." D. "You may eat avocados, broccoli, and cantaloupe."

C. "You may eat apples, strawberries, and peaches." Rationale: The patient with hyperkalemia should be instructed to consume foods low in potassium such as apples, strawberries, and peaches. The patient should avoid foods high in potassium, which include avocados, broccoli, cantaloupe, and dairy products. Salt substitutes contain potassium.

A patient with hyperkalemia is being treated with drugs to improve the condition. Which potassium level indicates that therapy is effective? A. 7.6 mEq/L B. 5.6 mEq/L C. 4.6 mEq/L D. 2.6 mEq/L

C. 4.6 mEq/L Rationale: A potassium level of 4.6 mEq/L is a normal level, indicating that therapy was effective. Normal levels are 3.5 to 5.0 mEq/L. A potassium level of 2.6 mEq/L indicates hypokalemia. A potassium level of 5.6 mEq/L indicates hyperkalemia. A potassium level of 7.6 mEq/L indicates severe hyperkalemia.

Which patient is at greatest risk for hypernatremia? A. 30-year-old on a low-salt diet B. 42-year-old receiving hypotonic fluids C. 54-year old who is sweating profusely D. 17-year-old with a serum blood glucose of 189 mg/dL

C. 54-year old who is sweating profusely Rationale: Excessive sweating is a common cause of hypernatremia. Hyperglycemia, a low-salt diet, and hypotonic fluid administration are common causes of hyponatremia, not hypernatremia.

The nurse manager of the medical-surgical unit assigns which patient to the LPN/LVN? A. 44-year-old admitted with dehydration who has a heart rate of 126 B. 54-year-old just admitted with hyperkalemia who takes a potassium-sparing diuretic at home C. 64-year-old admitted yesterday with heart failure who still has dependent pedal edema D. 74-year-old who has just been admitted with severe nausea, vomiting, and diarrhea

C. 64-year-old admitted yesterday with heart failure who still has dependent pedal edema Rationale: Because the patient with heart failure is the most stable of the four patients, this patient is most appropriate to assign to the LPN/LVN. Dehydration, tachycardia, potassium overload, and gastrointestinal signs and symptoms in a patient indicate that he or she is unstable and should be cared for by RN staff members.

Which hormone regulates fluid and electrolyte balance by preventing water and sodium loss? A. Antidiuretic B. Thyrotropin C. Aldosterone D. Natriuretic peptide (NP)

C. Aldosterone Rationale: Aldosterone stimulates the nephrons to reabsorb sodium and water into the blood, preventing sodium and water loss. NP hormone levels are altered in response to increased blood volume and blood pressure. Antidiuretic hormone acts on the collecting ducts of the kidney to normalize the blood osmolarity. Thyrotropin is a thyroid-stimulating hormone that is released in response to low levels of the thyroid hormone.

A patient receiving insulin and glucose infusion therapy for hyperkalemia now has a serum potassium level of 3.6 mEq/L. What is the nurse's first action? A. Stop the infusion immediately. B. Continue the infusion at the prescribed rate. C. Assess the patient's heart rate, rhythm, and respiratory status. D. Slow the infusion and increase the frequency of vital sign assessment.

C. Assess the patient's heart rate, rhythm, and respiratory status. Rationale: The serum potassium is now at the low end of normal range (3.5-5.0 mEq/L). The nurse must first assess the patient's response to the infusion and subsequent change in serum potassium (notably a change in respiratory effectiveness and quality and regularity of the heart rate). Once assessment data are obtained, the nurse should contact the provider and the infusion may be stopped, but it does not have to occur immediately.

When caring for a patient with hyponatremia, which intervention does the nurse implement? A. 2-gram sodium diet B. Administration of Furosemide C. Intravenous administration of 0.45% normal saline D. Small-volume intravenous infusions of 3% normal saline

D. Small-volume intravenous infusions of 3% normal saline Rationale: 3% saline is hypertonic and is given in small volumes to replenish serum sodium. 0.45% saline is hypotonic and will further dilute serum sodium levels. Furosemide causes sodium loss in the kidneys and would further contribute to hyponatremia. A 2-gram sodium diet restricts sodium intake; the goal of nutritional therapy with hyponatremia is to increase sodium intake.

The nurse is caring for a patient who is receiving intravenous (IV) magnesium sulfate. Which assessment parameter is critical? A. 24-hour urine output B. Monitoring of serum calcium levels C. Hourly deep tendon reflexes (DTRs) D. Asking the patient about feeling depressed

C. Hourly deep tendon reflexes (DTRs) Rationale: The patient who is receiving IV magnesium sulfate should be assessed for signs of toxicity every hour by assessment of DTRs. Most patients who have fluid and electrolyte problems will be monitored for intake and output (I&O); this will not immediately generate data about problems with magnesium overdose. Low magnesium levels can cause psychological depression, but assessing this parameter as the levels are restored would not be a method by which to safely assess a safe dose or an overdose. Although administration of magnesium sulfate can cause a drop in calcium levels, this occurs over a period of time and would not be the best way to assess magnesium toxicity.

A patient's electrocardiogram (ECG) demonstrates a heart rate of 52 beats/minute and prolonged PR interval with widened QRS complex, and the patient is also hypotensive. Which laboratory results are consistent with these findings? A. Hypocalcemia, hyperkalemia, hypernatremia B. Hypokalemia, hypocalcemia, hypermagnesemia C. Hyperkalemia, hypercalcemia, hypermagnesemia D. Hypernatremia, hypercalcemia, hypophosphatemia

C. Hyperkalemia, hypercalcemia, hypermagnesemia Rationale: The cardiovascular changes noted on the ECG are consistent with elevated potassium (hyperkalemia), elevated calcium (hypercalcemia), and elevated magnesium (hypermagnesemia). This condition may progress to a life-threatening cardiac emergency. Although hypocalcemia can interfere with cardiac contractility, hypokalemia, hypernatremia, and hypophosphatemia do not.

Which are common symptoms of hypokalemia? Select all that apply. A. Paresthesia B. Bradycardia C. Shallow respirations D. Weak, thready pulse E. Musculoskeletal weakness

C. Shallow respirations D. Weak, thready pulse E. Musculoskeletal weakness Rationale: Common symptoms of hypokalemia include shallow respirations; weak, thready pulse; and musculoskeletal weakness. Paresthesia and bradycardia are symptoms of hyperkalemia.

The nurse is planning care for a patient with hypocalcemia. Which nursing action is appropriate to delegate to unlicensed assistive personnel (UAP)? A. Evaluating the patient's laboratory results B. Implementing seizure precautions for the patient C. Transferring the patient from the bed to a stretcher using a lift sheet D. Collaborating with the dietitian to provide calcium-rich foods for the patient

C. Transferring the patient from the bed to a stretcher using a lift sheet Rationale: Transferring patients is a nursing skill that is included in UAP education and scope of practice. Collaborating with the dietitian, evaluating the patient's laboratory results, and implementing seizure precautions all require broader education and scope of practice and should be done by licensed nursing personnel.

A 90-year-old patient with hypermagnesemia is seen in the emergency department (ED). The ED nurse prepares the patient for admission to which inpatient unit? A. Medical-surgical B. Dialysis/home care C. Geriatric/rehabilitation D. Telemetry/cardiac stepdown

D. Telemetry/cardiac stepdown Rationale: Because hypermagnesemia causes changes in the electrocardiogram that may result in cardiac arrest, the patient should be admitted to the telemetry/cardiac stepdown unit. Dialysis/home care units, geriatric/rehabilitation units, and medical-surgical units typically do not have cardiac monitoring capabilities.

The nurse is teaching proper nutrition to a patient who has been prescribed high-ceiling diuretic therapy. Which patient response indicates a need for further teaching? A. "I should eat fish a few times a week." B. "Eating meat will help with my potassium needs." C. "I should have fruits such as oranges and bananas every day." D. "I should eat more eggs and cereals to maintain a high potassium intake."

D. "I should eat more eggs and cereals to maintain a high potassium intake." Rationale: Eggs and cereal grains contain the least amount of natural potassium, so the statement that eating more eggs and cereals is needed to maintain a high potassium intake reflects a need for further patient teaching. Meats, fish, fruits, and some vegetables are highest in potassium. Diuretics that increase the kidney excretion of potassium can cause hypokalemia. The patient should be encouraged to eat foods high in potassium when taking high-ceiling diuretic agents to help compensate for potassium loss.

The nurse instructs an older adult patient to increase intake of dietary potassium when the patient is prescribed which classification of drugs? A. Beta blockers B. Corticosteroids C. Alpha antagonists D. High-ceiling (loop) diuretics

D. High-ceiling (loop) diuretics Rationale: High-ceiling (loop) diuretics are potassium-depleting drugs. The patient should increase intake of dietary potassium to compensate for this depletion. Alpha antagonists, beta blockers, and corticosteroids are not potassium-depleting drugs.

A patient with Crohn's disease reports numbness, tingling, and painful muscle contractions. After assessing the deep tendon reflexes of the patient, which intervention does the nurse perform next? A. Intravenous administration of sodium B. Intravenous administration of bicarbonate C. Intravenous administration of phosphorus D. Intravenous administration of magnesium sulfate

D. Intravenous administration of magnesium sulfate Rational: Patients with Crohn's disease are at a high risk for magnesium imbalance, mainly hypomagnesemia. A decrease in the levels of magnesium may cause increased nerve impulse transmission causing hyperactive deep tendon reflexes, numbness, tingling, and painful muscle contractions. This condition can be well treated by administering magnesium sulfate intravenously. Intravenous administration of sodium, bicarbonate, or phosphorous is not a suitable intervention.

Which laboratory value requires a priority response by the nurse to notify the primary health care provider? A. Sodium 133 mEq/L B. Calcium 9.0 mg/dL C. Potassium 5.0 mEq/L D. Magnesium 4.2 mEq/L

D. Magnesium 4.2 mEq/L Rationale: A magnesium level of 4.2 is markedly elevated (normal 1.3-2.1 mEq/L). Manifestations are not usually apparent until levels exceed 4 mEq/L. Patients with severe hypermagnesemia are in danger of cardiac arrest, so a level of 4.2 mEq/L requires prompt attention. A sodium level of 133 mEq/L is slightly low, but does not require immediate notification of the health care provider. A potassium level of 5.0 mEq/L is normal. A calcium level of 9.0 mg/dL is normal.

The nurse is reviewing lab values for a patient recently admitted to the medical-surgical unit. Which lab result is severely abnormal? A. Sodium, 137 mEq/L B. Chloride, 107 mEq/L C. Potassium, 3.5 mEq/L D. Magnesium, 6.2 mEq/L

D. Magnesium, 6.2 mEq/L Rationale: A magnesium level of 6.2 mEq/L is greatly elevated. Patients with severe hypermagnesemia are in grave danger of cardiac arrest. The normal magnesium level is 1.3 to 2.1 mEq/L. The sodium and potassium results are within normal limits. The chloride level is just slightly elevated, with the normal range being between 98 to 106 mEq/L.

A patient with mild hypokalemia caused by diuretic use is discharged home. The home health nurse delegates which of these interventions to the home health aide? A. Instruction on the proper use of drugs B. Education about potassium-rich foods C. Assessment of muscle tone and strength D. Measurement of the patient's urine output

D. Measurement of the patient's urine output Rationale: A home health aide may measure the patient's intake and output, which then would be reported to the RN. Assessment, education, and instruction are higher-level nursing actions that should be done by the RN.

Which written order does the nurse clarify with the provider when caring for a patient with a serum sodium level of 149 mEq/L? A. Weigh the patient daily. B. Monitor intake and output. C. Institute seizure precautions. D. Place the patient on nothing by mouth (NPO) status.

D. Place the patient on nothing by mouth (NPO) status. Rationale: Ensuring adequate water intake is an important nutritional therapy in the treatment of hypernatremia; the nurse should ask for clarification of the NPO order. The other orders are appropriate in the management of patients with hypernatremia.

What is the major cause of death in patients diagnosed with hypokalemia? A. Stroke B. Renal failure C. Cardiac arrest D. Respiratory insufficiency

D. Respiratory insufficiency Rationale: Respiratory changes may occur in patients with hypokalemia because of respiratory muscle weakness resulting in shallow respirations. The respiratory status of a patient with hypokalemia should be assessed at least every 2 hours because respiratory insufficiency is the major cause of death for these patients. A stroke is not a risk factor for hypokalemia. Hypokalemia does not cause renal failure; rather, hyperkalemia is caused by renal failure. Dysrhythmias may occur due to hypokalemia but are not the major cause of death in patients with hypokalemia.

A patient is brought to the emergency department with symptoms of diarrhea, chest discomfort, and paresthesia. The patient has a heart rate of 60 beats per minute. The electrocardiogram (ECG) of the patient shows missed P waves, tall T waves, prolonged PR intervals, and wide QRS complexes. Which laboratory finding would be consistent with the patient's condition? A. Serum sodium levels below 135 mEq/L B. Serum sodium levels above 145 mEq/L C. Serum potassium levels below 3.5 mEq/L D. Serum potassium levels above 5.0 mEq/L

D. Serum potassium levels above 5.0 mEq/L Rationales: Laboratory data confirms hyperkalemia if serum potassium levels are above 5.0 mEq/L. Hyperkalemia clinically manifests with cardiovascular changes such as bradycardia, hypotension, and ECG changes that include missed P waves, tall T waves, prolonged PR intervals, and wide QRS complexes. A neuromuscular change associated with hyperkalemia is numbness around the mouth, or paresthesia. Intestinal changes include frequent and watery bowel movements. Abnormalities in sodium levels are not associated with hyperkalemia. Hypokalemia is associated with serum potassium levels below 3.5 mEq/L, which do not show any such ECG changes.