Chapter 10: Fluid and Electrolytes, NCLEX-Style Chapter Review Questions

Which is considered an isotonic solution? a. 0.9% normal saline b. Dextran in normal saline c. 3% NaCl d. 0.45% normal saline

a. 0.9% normal saline Rationale: An isotonic solution is 0.9% normal saline (NaCl). Dextran in normal saline is a colloid solution, 0.45% normal saline is a hypotonic solution, and 3% NaCl is a hypertonic solution.

The nurse is assessing a client for local complications of intravenous therapy. Which are local complications? Select all that apply. a. Hematoma b. Infection c. Extravasation d. Air embolism e. Phlebitis

a. Hematoma b. Infection c. Extravasation e. Phlebitis Rationale: Local complications of intravenous therapy include infiltration and extravasation, phlebitis, thrombophlebitis, hematoma, and clotting of the needle. Infections can be local or systemic. Systemic complications occur less frequently but are usually more serious than local complications and include circulatory overload, air embolism, and febrile reaction.

The nurse is assigned to care for a client with a serum phosphorus concentration of 5.0 mg/dL (1.61 mmol/L). The nurse anticipates that the client will also experience which electrolyte imbalance? a. Hypocalcemia b. Hypermagnesemia c. Hyperchloremia d. Hyponatremia

a. Hypocalcemia Rationale: The client is experiencing an elevated serum phosphorus concentration. Hyperphosphatemia is defined as a serum phosphorus that exceeds 4.5 mg/dL (1.45 mmol/L). Because of the reciprocal relationship between phosphorus and calcium, a high serum phosphorus concentration tends to cause a low serum calcium concentration.

The nurse is caring for a client undergoing alcohol withdrawal. Which serum laboratory value should the nurse monitor most closely? a. Magnesium b. Phosphorus c. Calcium d. Potassium

a. Magnesium Rationale: Chronic alcohol abuse is a major cause of symptomatic hypomagnesemia in the United States. The serum magnesium concentration should be measured at least every 2 or 3 days in clients undergoing alcohol withdrawal. The serum magnesium concentration may be normal at admission but may decrease as a result of metabolic changes, such as the intracellular shift of magnesium associated with intravenous glucose administration.

The nurse is caring for a client who was admitted with fluid volume excess (FVE). Which nursing assessments should the nurse include in the ongoing monitoring of the client? Select all that apply. a. Nutritional status and diet b. Strength testing for muscle wasting c. Skin assessment for edema and turgor d. Intake and output, urine volume, and color e. Blood pressure, heart rate, and rhythm

a. Nutritional status and diet c. Skin assessment for edema and turgor d. Intake and output, urine volume, and color e. Blood pressure, heart rate, and rhythm Rationale: To assess for FVE the nurse measures blood pressure, heart rate and rhythm, and breath sounds; inspects the skin to look for edema and turgor; and inspects neck veins. Intake and output, daily weight, urine volume and color, dyspnea, and thirst are assessments that will assist the nurse in identifying improvement or worsening of the fluid volume excess. In addition, the nurse will be able to identify potential fluid volume deficit from overtreatment of the fluid volume excess. Treatment of FVE typically involves dietary restriction of sodium.

Which condition leads to chronic respiratory acidosis in older adults? a. Erratic meal patterns b. Decreased renal function c. Thoracic skeletal change d. Overuse of sodium bicarbonate

c. Thoracic skeletal change Rationale: Poor respiratory exchange as the result of chronic lung disease, inactivity, or thoracic skeletal changes may lead to chronic respiratory acidosis. Decreased renal function in older adults can cause an inability to concentrate urine and is usually associated with fluid and electrolyte imbalance. A poor appetite, erratic meal patterns, inability to prepare nutritious meals, or financial circumstances may influence nutritional status, resulting in imbalances of electrolytes. Overuse of sodium bicarbonate may lead to metabolic alkalosis.

The nurse is caring for a client with severe diarrhea. The nurse recognizes that the client is at risk for developing which acid-base imbalance? a. Respiratory alkalosis b. Metabolic acidosis c. Metabolic alkalosis d. Respiratory acidosis

b. Metabolic acidosis Rationale: The client is at risk for developing metabolic acidosis. Metabolic acidosis is caused by diarrhea, lower intestinal fistulas, ureterostomies, and use of diuretics; early renal insufficiency; excessive administration of chloride; and the administration of parenteral nutrition without bicarbonate or bicarbonate-producing solutes (e.g., lactate).

Which is the preferred route of administration for potassium? a. Intramuscular b. Oral c. IV (intravenous) push d. Subcutaneous

b. Oral Rationale: When the client cannot ingest sufficient potassium by consuming foods that are high in potassium, administering oral potassium is ideal because oral potassium supplements are absorbed well. Administration by IV is done with extreme caution using an infusion pump, with the patient monitored by continuous ECG. To avoid replacing potassium too quickly, potassium is never administered by IV push or intramuscularly. Potassium is not administered subcutaneously.

The calcium concentration in the blood is regulated by which mechanism? a. Thyroid hormone (TH) b. Parathyroid hormone (PTH) c. Androgens d. Adrenal gland

b. Parathyroid hormone (PTH) Rationale: The serum calcium concentration is controlled by PTH and calcitonin. The thyroid hormone, adrenal gland, or androgens do not regulate the calcium concentration in the blood.

The nurse is analyzing the electrocardiographic (ECG) rhythm tracing of a client experiencing hypercalcemia. Which ECG change is typically associated with this electrolyte imbalance? a. Peaked T waves b. Prolonged PR intervals c. Elevated ST segments d. Prolonged QT intervals

b. Prolonged PR intervals Rationale: Cardiovascular changes associated with hypercalcemia may include a variety of dysrhythmias (e.g., heart blocks) and shortening of the QT interval and the ST segment. The PR interval is sometimes prolonged. The other changes are not associated with an elevated serum calcium concentration.

The nurse is caring for a client in the intensive care unit (ICU) following a near-drowning event in saltwater. The client is restless, lethargic, and demonstrating tremors. Additional assessment findings include swollen and dry tongue, flushed skin, and peripheral edema. The nurse anticipates that the client's serum sodium value would be a. 155 mEq/L (155 mmol/L) b. 125 mEq/L (125 mmol/L) c. 145 mEq/L (145 mmol/L) d. 135 mEq/L (135 mmol/L)

a. 155 mEq/L (155 mmol/L) Rationale: The client is experiencing signs and symptoms (S/S) of hypernatremia. Hypernatremia is a serum sodium concentration >145 mEq/L (>145 mmol/L). A cause of hypernatremia is near drowning in seawater (which contains a sodium concentration of approximately 500 mEq/L). S/S of hypernatremia include thirst, elevated body temperature, swollen and dry tongue and sticky mucous membranes, hallucinations, lethargy, restlessness, irritability, simple partial or tonic-clonic seizures, pulmonary edema, hyperreflexia, twitching, nausea, vomiting, anorexia, elevated pulse, and elevated blood pressure.

The nurse has been assigned to care for various clients. Which client is at the highest risk for a fluid and electrolyte imbalance? a. An 82-year-old client who receives all nutrition via tube feedings and whose medications include carvedilol and torsemide. b. A 45-year-old client who had a laparoscopic appendectomy 24 hours ago and is being advanced to a regular diet. c. A 66-year-old client who had an open cholecystectomy with a T-tube placed that is draining 125 mL of bile per shift. d. A 79-year-old client admitted with a diagnosis of pneumonia.

a. An 82-year-old client who receives all nutrition via tube feedings and whose medications include carvedilol and torsemide. Rationale: The 82-year-old client has three risk factors: advanced age, tube feedings, and diuretic usage (torsemide). This client has the highest risk for fluid and electrolyte imbalances. The 45-year-old client has the risk factor of surgery, the 79-year-old client has the risk factor of advanced age, and the 66-year-old client has the risk factors of age and the bile drain, but none of these are the client at the highest risk.

The nurse is caring for a client diagnosed with hyperchloremia. Which are signs and symptoms of hyperchloremia? Select all that apply. a. Tachypnea b. Hypotension c. Dehydration d. Lethargy e. Weakness

a. Tachypnea d. Lethargy e. Weakness Rationale: The signs and symptoms of hyperchloremia are the same as those of metabolic acidosis: hypervolemia and hypernatremia. Tachypnea; weakness; lethargy; deep, rapid respirations; diminished cognitive ability; and hypertension occur. If untreated, hyperchloremia can lead to a decrease in cardiac output, dysrhythmias, and coma. A high chloride concentration is accompanied by a high sodium concentration and fluid retention.

Which arterial blood gas (ABG) result would the nurse anticipate for a client with a 3-day history of vomiting? a. pH: 7.55, PaCO2: 60 mm Hg, HCO3-: 28 b. pH: 7.28, PaCO2: 25 mm Hg, HCO3: 15 c. pH: 7.45, PaCO2: 32 mm Hg, HCO3-: 21 d. pH: 7.34, PaCO2: 60 mm Hg, HCO3: 34

a. pH: 7.55, PaCO2: 60 mm Hg, HCO3-: 28 Rationale: The client's ABG would likely demonstrate metabolic alkalosis. Metabolic alkalosis is a clinical disturbance characterized by a high pH (decreased H+concentration) and a high plasma bicarbonate concentration. It can be produced by a gain of bicarbonate or a loss of H+. A common cause of metabolic alkalosis is vomiting or gastric suction with loss of hydrogen and chloride ions. The disorder also occurs in pyloric stenosis, where only gastric fluid is lost. The other results do not represent metabolic alkalosis.

When caring for a client who has risk factors for fluid and electrolyte imbalances, which assessment finding is the highest priority for the nurse to follow up? a. Mild confusion b. Irregular heart rate c. Blood pressure 96/53 mm Hg d. Weight loss of 4 lb

b. Irregular heart rate Rationale: Irregular heart rate may indicate a potentially life-threatening cardiac dysrhythmia. Potassium, magnesium, and calcium imbalances may cause dysrhythmias. Weight loss is a good indicator of the amount of fluid lost, confusion may occur with dehydration and hyponatremia, and blood pressure is slightly lower than normal (though not life threatening); in each case, following up on potential cardiac dysrhythmias is a higher priority.

The nurse is caring for a client diagnosed with bulimia. The client is being treated for a serum potassium concentration of 2.9 mEq/L (2.9 mmol/L). Which statement made by the client indicates the need for further teaching? a. "A good breakfast for me will include milk and a couple of bananas." b. "I can use laxatives and enemas but only once a week." c. "I will take a potassium supplement daily as prescribed." d. "I will be sure to buy frozen vegetables when I grocery shop."

b. "I can use laxatives and enemas but only once a week." Rationale: The client is experiencing hypokalemia, most likely due to the diagnosis of bulimia. Hypokalemia is defined as a serum potassium concentration <3.5 mEq/L (3.5 mmol/L), and usually indicates a deficit in total potassium stores. Clients diagnosed with bulimia frequently suffer increased potassium loss through self-induced vomiting and misuse of laxatives, diuretics, and enemas; thus, the client should avoid laxatives and enemas. Prevention measures may involve encouraging the client at risk to eat foods rich in potassium (when the diet allows), including fruit juices and bananas, melon, citrus fruits, fresh and frozen vegetables, lean meats, milk, and whole grains. If the hypokalemia is caused by abuse of laxatives or diuretics, client education may help alleviate the problem.

The nurse is instructing a client with recurrent hyperkalemia about following a potassium-restricted diet. Which statement by the client indicates the need for additional instruction? a. "Bananas have a lot of potassium in them; I'll stop buying them." b. "I will not salt my food; instead I'll use salt substitute." c. "I'll drink cranberry juice with my breakfast instead of coffee." d. "I need to check to see whether my cola beverage has potassium in it."

b. "I will not salt my food; instead I'll use salt substitute." Rationale: The client should avoid salt substitutes. The nurse must caution clients to use salt substitutes sparingly if they are taking other supplementary forms of potassium or potassium-conserving diuretics. Potassium-rich foods to be avoided include many fruits and vegetables, legumes, whole-grain breads, lean meat, milk, eggs, coffee, tea, and cocoa. Conversely, foods with minimal potassium content include butter, margarine, cranberry juice or sauce, ginger ale, gumdrops or jellybeans, hard candy, root beer, sugar, and honey. Labels of cola beverages must be checked carefully because some are high in potassium and some are not.

A client experiencing a severe anxiety attack and hyperventilating presents to the emergency department. The nurse would expect the client's pH value to be a. 7.3 b. 7.5 c. 7.35 d. 7.45

b. 7.5 Rationale: The patient is experiencing respiratory alkalosis. Respiratory alkalosis is a clinical condition in which the arterial pH is >7.45 and the PaCO2 is <38 mm Hg. Respiratory alkalosis is always caused by hyperventilation, which causes excessive "blowing off" of CO2 and, hence, a decrease in the plasma carbonic acid concentration. Causes include extreme anxiety, hypoxemia, early phase of salicylate intoxication, gram-negative bacteremia, and inappropriate ventilator settings.

Which could be a potential cause of respiratory acidosis? a. Diarrhea b. Hypoventilation c. Hyperventilation d. Vomiting

b. Hypoventilation Rationale: Respiratory acidosis is always due to inadequate excretion of CO2, with inadequate ventilation, resulting in elevated plasma CO concentration, which causes increased levels of carbonic acid. In addition to an elevated PaCO2, hypoventilation usually causes a decrease in PaO2.

Which condition might occur with respiratory acidosis? a. Decreased blood pressure b. Increased intracranial pressure c. Decreased pulse d. Mental alertness

b. Increased intracranial pressure Rationale: If respiratory acidosis is severe, intracranial pressure may increase, resulting in papilledema and dilated conjunctival blood vessels. Increased blood pressure, increased pulse, and decreased mental alertness occur with respiratory acidosis.

A client with cancer is being treated on the oncology unit for bilateral breast cancer. The client is undergoing chemotherapy. The nurse notes the client's serum calcium concentration is 12.3 mg/dL (3.08 mmol/L). Given this laboratory finding, the nurse should suspect that the a. client's diet is lacking in calcium-rich food products. b. malignancy is causing the electrolyte imbalance. c. client may be developing hyperaldosteronism. d. client has a history of alcohol abuse.

b. malignancy is causing the electrolyte imbalance. Rationale: The client's laboratory findings indicate hypercalcemia. Hypercalcemia is defined as a calcium concentration >10.2 mg/dL (>2.6 mmol/L).The most common causes of hypercalcemia are malignancies and hyperparathyroidism. Malignant tumors can produce hypercalcemia through a variety of mechanisms. The client's calcium level is elevated; there is no indication that the client's diet is lacking in calcium-rich food products. Hyperaldosteronism is not associated with a calcium imbalance. Alcohol abuse is associated with hypocalcemia.

When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis? a. HCO 21 mEq/L b. pH 7.48 c. O saturation 95% d. PaCO 36

b. pH 7.48 Rationale: Metabolic alkalosis is a clinical disturbance characterized by a high pH and high plasma bicarbonate concentration. The HCO value is below normal. The PaCO value and the oxygen saturation level are within a normal range.

Which is the most common cause of symptomatic hypomagnesemia? a. Burns b. Intravenous drug use c. Alcoholism d. Sedentary lifestyle

c. Alcoholism Rationale: Alcoholism is currently the most common cause of symptomatic hypomagnesemia. Intravenous drug use, sedentary lifestyle, and burns are not the most common causes of hypomagnesemia.

Which electrolyte is a major anion in body fluid? a. Calcium b. Potassium c. Chloride d. Sodium

c. Chloride Rationale: Chloride is a major anion found in extracellular fluid. Potassium, sodium, and calcium are cations.

A nurse is caring for a client with acute renal failure and hypernatremia. In this case, which action can be delegated to the nursing assistant? a. Assess the client's weight daily for trends. b. Monitor for signs and symptoms of dehydration. c. Provide oral care every 2-3 hours. d. Teach the client about increased fluid intake.

c. Provide oral care every 2-3 hours. Rationale: Providing oral care for the client every 2-3 hours is within the scope of practice of a nursing assistant. The other actions should be completed by the registered nurse.

The nurse is caring for a client with a serum sodium concentration of 113 mEq/L (113 mmol/L). The nurse should monitor the client for the development of which condition? a. Nausea b. Hallucinations c. Confusion d. Headache

c. Confusion Rationale: Normal serum concentration ranges from 135 to 145 mEq/L (135-145 mmol/L). Hyponatremia exists when the serum concentration decreases below 135 mEq/L (135 mmol/L). When the serum sodium concentration decreases to <115 mEq/L (<115 mmol/L), signs of increasing intracranial pressure, such as lethargy, confusion, muscle twitching, focal weakness, hemiparesis, papilledema, seizures, and death, may occur. General manifestations of hyponatremia include poor skin turgor, dry mucosa, headache, decreased saliva production, orthostatic fall in blood pressure, nausea, vomiting, and abdominal cramping. Neurologic changes, including altered mental status, status epilepticus, and coma, are probably related to cellular swelling and cerebral edema associated with hyponatremia. Hallucinations are associated with increased serum sodium concentrations.

A client with a magnesium concentration of 2.6 mEq/L (1.3 mmol/L) is being treated on a medical-surgical unit. Which treatment should the nurse anticipate will be used? a. Dialysis b. Oral magnesium oxide c. Intravenous furosemide d. Fluid restriction

c. Intravenous furosemide Rationale: The nurse should anticipate the administration of furosemide for the treatment of hypermagnesemia. Administration of loop diuretics (e.g., furosemide) and sodium chloride or lactated Ringer intravenous solution enhances magnesium excretion in clients with adequate renal function. Fluid restriction is contraindicated. The client should be encouraged to increase fluids to promote the excretion magnesium through the urine. Magnesium oxide is contraindicated because it would further elevate the client's serum magnesium concentration. In acute emergencies, when the magnesium concentration is severely elevated, hemodialysis with a magnesium-free dialysate can reduce the serum magnesium to a safe concentration within hours.

A client is being treated in the ICU 24 hours after having a radical neck dissection completed. The client's serum calcium concentration is 7.6 mg/dL (1.9 mmol/L). Which physical examination finding is consistent with this electrolyte imbalance? a. Slurred speech b. Negative Chvostek sign c. Presence of Trousseau sign d. Muscle weakness

c. Presence of Trousseau sign Rationale: After radical neck resection, a client is prone to developing hypocalcemia. Hypocalcemia is defined as a serum value <8.6 mg/dL (<2.15 mmol/L). Signs and symptoms of hypocalcemia include Chvostek sign, which consists of muscle twitching enervated by the facial nerve when the region that is about 2 cm anterior to the earlobe, just below the zygomatic arch, is tapped; and a positive Trousseau sign can be elicited by inflating a blood pressure cuff on the upper arm to about 20 mm Hg above systolic pressure; within 2 to 5 minutes, carpal spasm (an adducted thumb, flexed wrist and metacarpophalangeal joints, and extended interphalangeal joints with fingers together) will occur as ischemia of the ulnar nerve develops. Slurred speech and muscle weakness are signs of hypercalcemia.

The nurse is analyzing the arterial blood gas (ABG) results of a client diagnosed with severe pneumonia. Which of the following ABG results indicates respiratory acidosis? a. pH: 7.32, PaCO2: 40 mm Hg, HCO3-: 18 mEq/L b. pH: 7.40, PaCO2: 40 mm Hg, HCO3-: 24 mEq /L c. pH: 7.20, PaCO2: 65 mm Hg, HCO3-: 26 mEq/L d. pH: 7.50, PaCO2: 30 mm Hg, HCO3-: 24 mEq/L

c. pH: 7.20, PaCO2: 65 mm Hg, HCO3-: 26 mEq/L Rationale: Respiratory acidosis is a clinical disorder in which the pH is less than 7.35-7.40 and the PaCO2 is greater than 40-45 mm Hg and a compensatory increase in the plasma HCO3- occurs. Respiratory acidosis may be either acute or chronic.The ABG of pH: 7.32, PaCO2: 40 mm Hg, HCO3-: 18 mEq/L indicates metabolic acidosis.The ABGs of pH: 7.50, PaCO2: 30 mm Hg, and HCO3-: 24 mEq/L indicate respiratory alkalosis.The ABGs of pH 7.40, PaCO2: 40 mm Hg, and HCO3-: 24 mEq/L indicate a normal result/no imbalance.

At which serum sodium concentration might convulsions or coma occur? a. 140 mEq/L (140 mmol/L) b. 142 mEq/L (142 mmol/L) c. 145 mEq/L (145 mmol/L) d. 130 mEq/L (130 mmol/L)

d. 130 mEq/L (130 mmol/L) Rationale: Normal serum concentration level ranges from 135 to 145 mEq/L (135-145 mmol/L). When the level dips below 135 mEq/L (135 mmol/L), hyponatremia occurs. Manifestations of hyponatremia include mental confusion, muscular weakness, anorexia, restlessness, elevated body temperature, tachycardia, nausea, vomiting, and personality changes. Convulsions or coma can occur if the deficit is severe. Values of 140, 142, and 145 mEq/L (mmol/L) are within the normal range.

Which of the following measurable urine outputs indicates the client is maintaining adequate fluid intake and balance? a. A patient with a minimal urine output of 20 mL/hour b. A patient with a minimal urine output of 50 mL/hour c. A patient with a minimal urine output of 10 mL/hour d. A patient with a minimal urine output of 30 mL/hour

d. A patient with a minimal urine output of 30 mL/hour Rationale: A client with minimal urine output of 30 mL/hour provides the nurse with the information that the patient is maintaining proper fluid balance. Less then 30 mL/hour of urine output indicates dehydration and possible poor kidney function.

The nurse is caring for a patient with a metabolic acidosis (pH 7.25). Which of the following values is useful to the nurse in determining whether the cause of the acidosis is due to acid gain or to bicarbonate loss? a. Bicarbonate level b. PaCO2 c. Serum sodium level d. Anion gap

d. Anion gap Rationale: Metabolic acidosis is a common clinical disturbance characterized by a low pH (increased H+ concentration) and a low plasma bicarbonate concentration. It can be produced by a gain of hydrogen ion or a loss of bicarbonate. It can be divided clinically into two forms, according to the values of the serum anion gap: high anion gap acidosis and normal anion gap acidosis. A patient diagnosed with metabolic acidosis is determined to have normal anion gap metabolic acidosis if the anion gap is within this normal range. An anion gap greater than 16 mEq (16 mmol/L) (the normal value for an anion gap is 8-12 mEq/L (8-12 mmol/L) without potassium in the equation. If potassium is included in the equation, the normal value for the anion gap is 12-16 mEq/L (12-16 mmol/L) and suggests an excessive accumulation of unmeasured anions and would indicate high anion gap metabolic acidosis as the type. An anion gap occurs because not all electrolytes are measured. More anions are left unmeasured than cations. A low or negative anion gap may be attributed to hypoproteinemia. Disorders that cause a decreased or negative anion gap are less common compared to those related to an increased or high anion gap.

Which is an insensible mechanism of fluid loss? a. Nausea b. Urination c. Bowel elimination d. Breathing

d. Breathing Rationale: Insensible perspiration is a nonvisible form of water loss from the body. The lungs (breathing) eliminate water vapor creating an insensible loss.Losses from urination and bowel elimination are observable or sensible. Nausea does not result in fluid loss, however, if the client would develop emesis ( vomiting) this would be considered loss of body fluids and could be observed and measured.

The nurse is caring for a client with a serum potassium concentration of 6.0 mEq/L (6.0 mmol/L) and a fluid volume excess. The client is ordered to receive oral sodium polystyrene sulfonate and furosemide. What other order should the nurse anticipate giving? a. Change the lactated Ringer solution to 2.5% dextrose. b. Increase the rate of the intravenous lactated Ringer solution. c. Change the lactated Ringer solution to 3% saline. d. Discontinue the intravenous lactated Ringer solution.

d. Discontinue the intravenous lactated Ringer solution. Rationale: The lactated Ringer intravenous (IV) fluid is contributing to both the fluid volume excess and the hyperkalemia. In addition to the volume of IV fluids contributing to the fluid volume excess, lactated Ringer solution contains more sodium than daily requirements, and excess sodium worsens fluid volume excess. Lactated Ringer solution also contains potassium, which would worsen the hyperkalemia.

Oncotic pressure refers to the a. excretion of substances such as glucose through increased urine output. b. amount of pressure needed to stop the flow of water by osmosis. c. number of dissolved particles contained in a unit of fluid. d. osmotic pressure exerted by proteins.

d. osmotic pressure exerted by proteins. Rationale: Oncotic pressure is a pulling pressure exerted by proteins such as albumin. Osmolality refers to the number of dissolved particles contained in a unit of fluid. Osmotic diuresis occurs when urine output increases as a result of excretion of substances such as glucose. Osmotic pressure is the amount of pressure needed to stop the flow of water by osmosis.